Title: Evaluation of volcanic pumice stone as media in fixed bed sequence batch reactor for atrazine removal from aquatic environments

Author(s):Derakhshan, Zahra; Ehrampoush, Mohammad Hassan; Mahvi, Amir Hossein; Faramarzian, Mohammad; Mokhtari, Mehdi ; Mazloomi, Seyed Mohammad

Article

Abstract: Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a component of S-triazine. Its characteristics make it a pollutant of ecosystems and a probable human carcinogen. The present study evaluated volcanic pumice stone as a suitable media for biological growth and biofilm development in a fixed-bed sequencing batch reactor (FBSBR) for atrazine removal from aquatic environments. The FBSBR was fed with synthetic wastewater containing sucrose and atrazine at four hydraulic retention times to assess biodegradation of atrazine by a microbial consortium for removal from aquatic environments. The maximum efficiency for atrazine and soluble chemical oxygen demand removal were 97.9% and 98.9%, respectively. The results of this research showed that the Stover-Kincannon model was a very good fit (R-2 > 99%) for loading atrazine onto the FBSBR. Increasing the initial concentration of atrazine increased the removal efficiency. There was no significant inhibition of the mixed aerobic microbial consortia by the atrazine. Atrazine degradation depended on its initial concentration in the wastewater and the amount of atrazine in the influent. Although this system shows good potential for atrazine removal from aqueous environments, that remaining in the effluent does not yet meet international standards. Further research is required to make this system effective for removal of atrazine from the environment.

Title: Modeling of adsorption kinetic and equilibrium isotherms of naproxen onto functionalized nano-clay composite adsorbent

Author(s): Rafati, L; Ehrampoush, MH; Rafati, AA; Mokhtari, M; Mahvi, AH 

Article

Abstract: In this research, nano-clay was firstly modified with p-cyclodextrin and polymerized by polyvinylpyrrolidone (PVP) to provide more surfaces for higher adsorption. The adsorption process as batch study was investigated under the experimental conditions affecting some parameters such as pH, contact time, concentration of naproxen and the amount of adsorbent for adsorption efficiency. Then, the adsorption kinetic and equilibrium isotherms were also studied. The results showed that the adsorption was influenced by some factors such as initial concentration of naproxen, the amount of adsorbent and solutions pH. The optimum values of adsorbent dosage, contact time, initial naproxen concentration and pH were evaluated as 1 g, 120 min, 10 mg/l and 6, respectively. Also, the maximum efficiency of adsorption was achieved 92.2%. The equilibrium constant was studied with 9 more common isotherm models, and among them, all isotherm models could well describe the adsorption of naproxen on the modified nano-composite except Langmuir and Tempkin models that show large deviation from experimental data. This was confirmed by investigating the results of error function analysis. Moreover, it was indicated that the adsorption follows Elovich kinetic model. Based on the obtained results, it can be stated that the adsorption method using the modified nano-composite is an efficient, facile and reliable method for the removal of naproxen from aqueous solutions.

Title: Fluoride in Drinking Water in 31 Provinces of Iran

Author(s): KheradPisheh, Z; Ehrampoush, MH; Montazeri, A; Mirzaei, M; Mokhtari, M ; Mahvi, AH

Article

Abstract: During operation of most water treatment plants, spent filter backwash water (SFBW) is generated, which accounts about 2-10% of the total plant production. By increasing world population and water shortage in many countries, SFBW can be used as a permanent water source until the water treatment plant is working. This data article reports the practical method being used for water reuse from SFBW through different method including pre-sedimentation, coagulation and flocculation, second clarification, ultra filtration (UF) and returned settled SFBW to the beginning of water treatment plant (WTP). Also, two coagulants of polyaluminum ferric chloride (PAFCI) and ferric chloride (FeCl3) were investigated with respect to their performance on treated SFBW quality. Samples were collected from Isfahans WTP in Iran during spring and summer season. The acquired data indicated that drinkable water can be produced form SFBW by applying hybrid coagulation-UF process (especially when PAFCI used as coagulant).

Title: HEAVY METALS IN RECYCLED PASTRY PACKAGES AND PASTRIES

Author(s): Mohammadpour, I; Ahmadkhaniha, R; Jeddi, MZ; Rastkari, N

Article

Abstract: The safe use of recycled paper and board material for food packaging applications is a major area of investigations. Therefore, the aim of current study was to evaluate the amount of heavy metals in recycled paper pastry packages and measurement of migration over the time into pastries. In this study, the presence of heavy metals in common confectionery packaging and effects of storage time and kind of pastry on the migration are investigated. The results of the study indicate that harmful metals such as Pb are detected at high concentrations in most of the recycled boxes that are used for pastry packaging, and heavy metals could migrate from the recycled packages into food during usage. It seems that the procedure of preparing recycled paperboard for food packaging should be reconsidered.

Title: Adsorption of phosphorus from aqueous solution by cubic zeolitic imidazolate framework-8: Modeling, mechanical agitation versus sonication

Author(s): Shams, M; Dehghani, MH; Nabizadeh, R; Mesdaghinia, A; Alimohammadi, M; Najafpoor, AA

Article

Abstract: Cubic zeolitic imidazolate framework-8 (ZIF-8), a new class of hybrid adsorbent, was synthesized and investigated for phosphorus (P) removal from aqueous solution. A prediction model for P adsorption was developed by performing the experiments according to central composite design. The adsorption model showed that P adsorption is associated directly with time and ZIF-8 dosage and indirectly with initial P concentration. The removal also increased with decrease in pH until reaching the critical pH of about 2.6. The efficiency of P removal under mechanically stirred increased with agitation speed from 100 to 300 rpm. In contrast to high ultrasonic frequency (130 kHz), sonication under 35 kHz provides excellent dispersive mixing and shortened the equilibrium time. Study of coexisting ions showed that P adsorption hindered considerably in the presence of carbonate. Equilibrium studies indicated that P adsorbed onto ZIF-8 in monolayer and the adsorbent has definite localized sites that are energetically identical. The maximum Langmuir sorption capacity of ZIF-8 for P was 38.22 mg/g in the present study. Analysis of experimental data also revealed that the chemosorption is the rate limiting step in P adsorption by ZIF-8.In conclusion, the present report suggest zif-8 as an efficient and fast removal sorbent for P from aqueous solutions.

Title: Rapid removal of noxious nickel (II) using novel gamma-alumina nanoparticles and multiwalled carbon nanotubes: Kinetic and isotherm studies

Author(s): Agarwal, S; Tyagi, I ; Gupta, VK; Dehghani, MH; Jaafari, J; Balarak, D; Asif, M

Article

Abstract: Novel gamma-alumina nanoparticles and MWCNTs were synthesized for the rapid removal of the noxious nickel (II) from the solvent phase. Hence this study investigated the ability of nano-sized particle in Ni (II) adsorption. The influential parameters including contact time (min), adsorbent dosage (g/L), pH and the initial concentration of Ni (II) were investigated and optimized using the batch adsorption study. The adsorption equilibrium and kinetic data were well fitted and found to be in good agreement with Langmuir and pseudo-second order kinetic model respectively and the maximum Ni (II) percentage removal using MWCNTs and novel gamma-alumina nanoparticle was 87.65% and 99.41%, respectively under optimum conditions. The maximum removal of Ni (II) was observed at pH = 10. Upon experimentation, it was observed on increasing the adsorbent dosage and initial concentration the amount of Ni (II) removal efficiency also increased. Finally, it can be concluded that the synthesized nanoparticles can be applied as the best adsorbent to remove the Ni (II) from aqueous solution. (C) 2016 Elsevier B.V. All rights reserved.

Title: The effect of aeration on advanced coagulation, flotation and advanced oxidation processes for color removal from waste water

Author(s): Dehghani, MH; Karimi, B; Rajaei, MS 

Article

Abstract: A colored effluent entry into the environment gives rise to disruption of the environment and the production of hazardous and toxic byproducts. In order to improve the color removal of methyl orange and methylene blue, a flotation method with poly-aluminum chloride (PAC), granular ferric hydroxide (GFA), alum, ferrous sulfate and also simultaneous application of an advanced oxidation method UV/TiO2/H2O2 was used. A reactor with a useful volume,of 6 L and an inlet flow of 100 mL/min along with two UV-C (15 W) lamps were applied as a flotation tank. The effect of concentration of PAC, GFA coagulants, alum, and ferrous sulfate in 0.5, 1, 1.5, and 2 mg/L concentrations, TiO2 in 0.5-2 g/L concentrations, and also H2O2 in 150-400 mL concentrations on the flotation process were put into account. Alum was obtained in the concentration of 1.5 mg/L with an efficiency of 84.6% and also in concentrations of 0.5, 1, and 2 mg/L with efficiencies of 66%, 82%, and 75%. In a flow of 150 mL/min, the color removal efficiency was obtained between 54 and 86.5% and in pH 10; the most removal efficiency was (89%). In the best condition, the removal efficiency of methyl orange (MO) and methylene blue (MB) in AOP/flotation process in pH 10, the alum concentration of 5 mg/L, air flow of 100 mL/min, TiO2 concentration of 1 g/L, H2O2 concentration of 200 mL were obtained 96-98% and 90-95%, respectively. Results of the present study indicate the effect of flotation method well with coagulants in combination with advanced oxidation methods on removing and reducing the concentration Of soluble compounds in water like a color.

Title: Investigating the toxicity of acid dyes from textile effluent under UV/ZnO process using Daphnia magna

Author(s): Dehghani, MH; Mahdavi, P; Tyagi, I; Agarwal, S; Gupta, VK

Article

Abstract: Some of textile wastewater dyes and their raw materials are carcinogenic for humans due to production of toxic aromatic amines. The toxicity measurement of the textile wastewater was analyzed using zinc oxide nanoparticles under ultraviolet irradiation process (UV/ZnO) and Daphnia magna bioassay was performed. D. magna has been evaluated as indicator to test effluent toxicity in dyes effluent. The impact of effective parameters such as zinc oxide nanoparticles load, pH, and exposure time were well investigated and optimized. It was found that increase in toxicity during the process is possibly due to the production of intermediate toxic compounds, presence of excessive hydrogen peroxide in the solution, presence of excessive ZnO in the solution, or ZnO toxicity or presence of excessive hydrogen peroxide in wastewater and consequent death of D. magna. Obtained experimental results revealed that toxicity increases during the nanophotocatalytic process.

Title: Evaluation of corrosion and scaling tendency indices in water distribution system: a case study of Torbat Heydariye, Iran

Author(s): Mirzabeygi, M; Naji, M ; Yousefi, N; Shams, M; Biglari, H; Mahvi, AH 

Article

Abstract: ACorrosion and scaling tendency of water is an etiology of economic and health concerns in the water supply systems. The aim of this study was to investigate the water stability in Torbat Heydariye drinking water distribution system. This cross-sectional study was done with cluster sampling schemes and 90 samples were collected by simple random sampling from 15 clusters. All samples were taken from water distribution network during 2014. Also, the water stability was determined using Langelier saturation index (LSI), Ryznar Stability index (RSI), Puckorius scaling index (PSI), Larson-Skold index (LS), and Aggressiveness index (AI). Physical and chemical analysis showed that the mean of pH, total dissolve solid, electrical conductivity, chloride concentration, sulfate, temperature, bicarbonate, total alkalinity, calcium hardness were 7.75, 896mg/L, 1,254Moh/cm, 203mg/L, 201mg/L, 22.7 degrees C, 251mg/L, 209mg/L as CaCO3, 111.6mg/L as CaCO3, respectively. The results illustrated that the average values of LSI, RSI, PSI, LS, and AI was 0.02 (+/- 0.125), 7.71 (+/- 0.2), 12.04 (+/- 0.125), 7.55 (+/- 0.3), and 1.7 (+/- 0.456), respectively. Moreover, According to LSI, RSI, PSI, LS, and AI, corrosion tendency in the water network was 40, 100, 93.3, 94, and 33.3%, respectively. The severity of corrosion in different regions of Torbat Heydariye was displayed using Geographic Information System.

Title: Preparation, characterization, and application of activated carbon from low-cost material for the adsorption of tetracycline antibiotic from aqueous solutions

Author(s): Takdastan, A; Mahvi, AH; Lima, EC; Shirmardi, M; Babaei, AA; Goudarzi, G; Neisi, A; Farsani, MH; Vosoughi, M

Article

Abstract: In this study, a new zinc chloride (ZnCl2) impregnated activated carbon (Zn-AC) was prepared from oak charcoals as low-cost material and used as adsorbent for tetracycline (TC) adsorption. The Zn-AC was characterized using field emission-scanning electron microscope, powder X-ray diffraction, and CHNS-O analyses. Specific surface area of the adsorbent was also measured using the Brunauer, Emmett and Teller (BET) isotherm model. The TC adsorption onto the Zn-AC was investigated as a function of solution pH, adsorbent dosage, and inorganic cations (Li+, K+, Mg2+, Ca2+, Ni2+, and Fe3+) and anions (HCO3-, NO3- and SO42-) that could interfere in the adsorption of TC. The adsorbate solution pH had no considerable effect on TC adsorption. The adsorption of TC onto the adsorbent was relatively fast and reached the equilibrium after about 120 min. The results showed that all studied cations and anions decreased TC adsorption onto the Zn-AC, but this decrease in TC adsorption was strongly significant for Fe3+ and Ni2+ ions. The general order kinetic model and the Redlich-Peterson isotherm model provided the best fit to the experimental data. The maximum amount of TC adsorbed onto the Zn-AC (Q(max)) is 282.06 mg g(-1), indicating this adsorbent is a good adsorbent for the removal of TC from aqueous solutions.

Title: Removal of Reactive Red 198 from aqueous solution by combined method multi-walled carbon nanotubes and zero-valent iron: Equilibrium, kinetics, and thermodynamic

Author(s): Pourfadakari, S; Yousefi, N ; Mahvi, AH

Article

Abstract: Dyes often include toxic, carcinogenic compounds and are harmful to humans health. Therefore, removal of dyes from textile industry wastewater is essential. The present study aimed to evaluate the efficiency of the combination of zero valent iron (ZVI) powder and multi-walled carbon nanotubes (MWCNTs) in the removal of Reactive Red 198 (RR198) dye from aqueous solution. This applied research was performed in a batch system in the laboratory scale. This study investigated the effect of various factors influencing dye removal, including contact time, pH, adsorbent dose, iron powder dose, initial dye concentration, and temperature. The equilibrium adsorption data were analyzed using three common adsorption models: Langmuir, Freundlich and Temkin. Besides, kinetic and thermodynamic parameters were used to establish the adsorption mechanism. The results showed, in pH = 3, contact time = 100 min, ZVI dose = 5000 mg center dot L-1, and MWCNTs dose = 600 mg center dot L-1 in 100mg center dot L-1 dye concentration, the adsorption efficiency increased to 99.16%. Also, adsorption kinetics was best described by the pseudo-second-ordermodel. Equilibriumdata fitted wellwith the Freundlich isotherm (R-2= 0.99). The negative values of Delta G(0) and the positive value of Delta H-0 (91.76) indicate that the RR198 adsorption process is spontaneous and endothermic. According to the results, the combination of MWCNTs and ZVI was highly efficient in the removal of azo dyes. (C) 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.

Title: Sulphate removal from aqueous solutions by granular ferric hydroxide

Author(s): Shams, M ; Qasemi, M; Afsharnia, M; Mahvi, AH 

Article

Abstract: Sulphate is an important ion occurring in both natural waters and industrial effluents. Granular ferric hydroxide (GFH), a poorly crystallized -FeOOH, was used to remove sulphate in a series of batch experiments. Sulphate removal increased with increase in GFH dose and more than 50% of the adsorption happened within the first 15 min of agitation. In addition, sulphate adsorption was influenced by pH and the optimum pH range was 2-7. Adsorption also increased by increasing temperature from 15 to 55 degrees C, indicated the endothermic nature of the process. Among the co-existing anions, phosphate and bicarbonate strongly inhibited the sulphate removal. The kinetics of the process follows the pseudo-second-order with a high correlation coefficient value (R-2>0.99). Equilibrium tests also showed that the sulphate removal by GFH fitted well with the Freundlich model, which indicated the multilayer adsorption of sulphate and heterogeneous distribution of adsorption sites on GFH surface.

Title: The assessment of health impacts and external costs of natural gas-fired power plant of Qom

Author(s): Fard, RF; Naddafi, K; Yunesian, M; Nodehi, RN; Dehghani, MH; Hassanvand, MS

 Article

Abstract: The external health damage costs of the combined cycle natural gas-fired power plant of Qom were investigated via the simplified impact pathway approach. Emitted particulate matter (PM10) and gaseous pollutants (NO (x) , CO, and SO2) from the power plant stack were measured The health effects and related costs were estimated by QUERI model from AirPacts according to the emissions, source and stack parameters, pollutant depletion velocities, exposure-response functions, local and regional population density, and detailed meteorological data. The results showed that the main health effect was assigned to the nitrate as restricted activity days (RAD) with 25,240 days/year. For all pollutants, the maximum health damage costs were related to the long-term mortality (49 %), restricted activity days (27 %), and chronic bronchitis (21 %). The annual health damage costs were approximately 4.76 million US$, with the cost being 0.096 US per kWh of generating electricity. Although the health damage costs of gas-fired power plant were lower than those of other heavy fuels, it seems essential to consider the health and environmental damages and focus on the emission control strategies, particularly in site selection for the new power plants and expanding the current ones.

Title: FLUORIDE LEVEL IN THE BREAST MILK IN KOOHBANAN, A CITY WITH ENDEMIC DENTAL FLUOROSIS

Author(s): Poureslami, H ; Khazaeli, P; Mahvi, AH; Poureslami, K ; Poureslami, P; Haghani, J; Aghaei, M 

Article

Abstract: Dental fluorosis is a major health issue in Koohbanan, a city in Kerman province, Iran, and the aim of this study was to determine the amount of fluoride ion (F) in womens breast milk. Sixty-two mothers who breast-fed their infants participated in the study and were separated in two groups according to whether or not they had dental fluorosis. Two mL of the breast milk from each mother was sent to a laboratory in standard conditions and the amount of F measured with a special fluoride ion electrode. The data were analyzed with independent t-test using the SPSS version 20. The mean amount of F in the breast milk of mothers without dental fluorosis was 0.006 ppm while in the mothers with dental fluorosis it was markedly elevated at 0.550 ppm (p< 0.001). The high level of F in the breast milk of mothers with dental fluorosis, is a concern as it may be a risk factor for their children also developing dental fluorosis.

Title: INVESTIGATION OF THE FLUORIDE CONTENT OF EDIBLE SALT AND THE FLUORIDE INTAKE FROM EDIBLE SALT CONSUMPTION IN IRAN

Author(s): Yousefian, F; Hosseini, SS ; Mahvi, AH

Article

Abstract: In order to estimate the fluoride ion (F) content of edible salt and the F intake from edible salt consumption in Iran, the F content was measured in 37 brands of edible salt consumed in Iran. The F analysis was made by the standard SPADNS method using a Spectrophotometer DR/5000s (HACH Company, USA). The mean F level of the edible salt was 0.0424 +/- 0.012 mg F/g of salt, with a range of 0.020-0.066 mg F/g salt. Based on an estimated mean salt intake in Iran of 9.9 +/- 2.9 g/day/person, the mean daily F intake from edible salt was calculated to be 0.420 mg F/day, range 0.212-0.696 mg F/day. After considering the daily salt intake and the levels of F in the drinking water in three provinces in Iran, Gilan, Mazandaran, and Ilam, the total daily intake of F from edible salt and drinking water for adults in these provinces was found to have a range of 0.96-1.21 mg F/day.

Title: EFFECT OF ER:YAG LASER ON SODIUM FLUORIDE VARNISH UPTAKE BY PRIMARY TOOTH ENAMEL: AN IN-VITRO STUDY

Author(s): Jahanimoghadam, F; Poureslami, H ; Shamsaddin, H; Horri, A; Khazaeli, P; Mahvi, AH

Article

Abstract: This in vitro study evaluated the effect of Er:YAG laser irradiation on the fluoride ion (F) uptake of primary enamel. It is believed that Er: YAG laser irradiation on the dental structure can lead to a more F uptake and a more acid-resistant surface. Ninety enamel samples obtained from 90 primary canines were ground and randomly divided into six groups (n=15): group 1 (G1): no treatment (negative control); G2: F varnish #1; G3: F varnish #2; G4: Er: YAG laser (2 Hz, 80-90 mJ, 60 s/cm(2), handpiece RO2, beam diameter at the focal area 300 mu m); G5: F varnish #1 + Er: YAG laser, and G6: F varnish #2 + Er: YAG laser. After the surface treatment, the samples were submitted to an acid challenge consisting of daily immersion for 5 days in demineralizing and remineralizing solutions for 3 and 21 hr per day, respectively. The F concentrations were then calculated with a potentiometer. Chi-squared and variance analysis with post hoc Tukey tests were used for the statistical analyses (p<0.05). There were statistical differences between G1 and G4 when compared with G2, G3, and G6 (p< 0.05). G2, G3, G5, and G6 exhibited a higher F uptake compared with G4 and the non-irradiated samples (G1). The findings revealed that Er: YAG lasers can be a suitable tool for enhancing primary enamel resistance to acids.

Title: Removal of cyanobacterial and algal cells from water by ultrasonic waves - A review

Author(s): Dehghani, MH

Article

Abstract: The importance of cyanobacteria and algae cells in water is attributed to the diverse effects they have on an aquatic environment. The decomposition of certain compounds from live and dead algae gives water a taste and smell. It is proposed in this study that ultrasonic waves may provide on environmentally friendly method to inhibit the growth rate of cyanobacteria and algae in water. The aim of this study was to review ultrasonication for the removal of cyanobacterial and algal cells and cyanotoxins from water. In this article, effects of the operational parameters of exposure time, frequency, intensity, power level and these parameters influence on cyanobacterial and algal bloom (removal percentage, content of chlorophyll a etc.) are reviewed.

Title: The study of non-linear kinetics and adsorption isotherm models for Acid Red 18 from aqueous solutions by magnetite nanoparticles and magnetite nanoparticles modified by sodium alginate

Author(s): Berizi, Z; Hashemi, SY; Hadi, M; Azari, A; Mahvi, AH

Article

Abstract: Azo dyes are widely used in various industries. These substances produce toxic byproducts in aquatic environments in addition to their mutagenic and carcinogenic potential effects. In this study, the effect of magnetite nanoparticles and magnetite nanoparticles modified by sodium alginate in batch systems and nonlinear kinetic and adsorption isotherm models were investigated. Magnetite nanoparticles were synthesized by chemical co-precipitation method and then modified and used as adsorbent to adsorb Acid Red 18. After determining the optimum pH and adsorbent dose, non-equilibrium models for kinetic adsorption were tested with concentrations (25-100 mg/L) and at eight different periods of time (1-15 min) and the pseudo-first-order and pseudo-second-order non-linear models were used to describe the results. For adsorption isotherm, a contact time of 120 min was studied in different concentrations (25-100 mg/L) and the residual concentration of Acid Red 18 was obtained. The results are described by non-linear Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The optimum amounts of pH for magnetite nanoparticles and for modified ones were 3 and 5, respectively, the efficiencies were 0.75 and 0.2 g/L, respectively. According to the results sodium alginate has a high performance in adsorption of Acid Red 18. Adjusted correlation coefficients and chi-square test showed that Freundlich isotherm and then Langmuir isotherm can well describe the experimental results. In Freundlich, the value of (Kf) was 3.231 (L/g) for magnetite nanoparticles and 21.615 (L/g) for modified adsorbent. In Langmuir, the value of (qm) was 16.259 (mg/g) for magnetite nanoparticles and 73.464 (mg/g) for modified adsorbent. Comparing the Langmuir maximum calculated adsorption capacity indicated that modified adsorbent can adsorb the pollutants 6.5 times more than the other one.

Title: Investigating the residual aluminum elimination from conventional and enhanced coagulation by phosphate compounds in wastewater treatment process

Author(s): Agarwal, S; Tyagi, I; Gupta, VK; Dehghani, MH; Ghanbari, R

Article

Abstract: Aluminum salts are important chemical materials which are extensively used next to in water treatment processes. High concentration of Al in drinking water may produce health problems. Post coagulant addition of phosphate compounds could reduce the concentrations of residual metals without the need of installing new unit processes in existing water treatment plants. Concentrations of residual metals in conventional coagulation were different in various pHs and minimum and maximum concentrations of Al were in pHs of 6.5 and 5.5. Maximum removal of Al took place in pH = 5.5 with 037 mg/l reduction. Maximum and minimum concentrations of residual phosphate were detected at pHs of 8.5 and 5.5 respectively. In natural pH concentrations of Al in enhanced coagulation had been increased versus coagulant dose increase (from 0.21 mg/l to 035 mg/l). Maximum removal of Al took place by alum dosage of 20 mg/l which reduce the concentration from 0.28 mg/l to 0.07 mg/l. Residual Al concentration in enhanced coagulation at pH of 5.5 increased from 0.55 mg/l to 2.4 mg/l with the increase of coagulant dosages from 10 to 50 mg/l. Maximum removal of residual Al happened in coagulant dosage of 50 mg/l. Temperature increases permanently increased the concentrations of soluble metals and consequently removal efficiency.

Title: Degradation of azinphos-methyl and chlorpyrifos from aqueous solutions by ultrasound treatment

Author(s): Agarwal, S; Tyagi, I; Gupta, VK; Dehghani, MH; Bagheri, A; Yetilmezsoy, K ;Amrane, A ; Heibati, B; Rodriguez-Couto, S 

Article

Abstract: Azinphos-methyl and chlorpyrifos are the organophosphorous pesticides which pose serious threats to the environment including their detrimental effect on humans and, therefore, their removal from the environment is a must. Hence, in the present paper the ultrasound technique was applied to remove the above-mentioned hazardous compounds. For this, the effect of influential parameters such as pH, initial pesticide concentration, frequency, electric power and treatment time on the ultrasound degradation of azinphos-methyl and chlorpyrifos was well investigated and elucidated. The results obtained showed that azinphos-methyl and chlorpyrifos were effectively and rapidly degraded by the ultrasound technique. Thus, the operating optimal conditions (initial pH 9, initial pesticide concentration 1 mg/L, frequency 130 kHz, electric power 500 Wand treatment time 20 min) lead to a degradation of 78.50% for azinphos-methyl and of 98.96% for chlorpyrifos with in 20 min of contact time. Two multiple regression-based equations were derived to describe the degradation process of the pesticides by the ultrasound treatment. The result of this study showed that the-polynomial equations satisfactorily described the behavior of the present process for various operating conditions.

Title: Application of low purity horseradish peroxidase enzyme to removal of oil from oily wastewater

Author(s): Gholami-Borujeni, F; Nejatzadeh-Barandozi, F; Mahvi, AH

Article

Abstract: Application of low purity horseradish peroxidase (HRP) extracted from horseradish root for oil removal from oily wastewater was studied. Factors, such as oil concentration; contact time; HRP dose; H2O2 concentration; pH; temperature; Fe2+ ion concentration; and effect of emulsifier (Tween 80), were studied. Results indicate optimum HRP concentration for 20, 60, and 120mg/L oil were 2U/mL and pH 7.5. Removal efficacy of oil increased with an increase in H2O2 concentration at first, and reached maximum of 58.33% at H2O2 concentration of 4mM, and then decreased. Temperature has significantly effect on oil removal. Presence of Fe2+ ion in mixture solution has no effect on enzymatic treatment. Results of this study were found to be independent of enzyme purity and therefore, it was possible to utilize crude enzyme preparation instead of purified one. Experimental data of initial reaction rates were fitted using analytical equation proposed by Michaelis-Menten.

Title: Equilibrium and Kinetic Studies of Trihalomethanes Adsorption onto Multi-walled Carbon Nanotubes

Author(s): Dehghani, MH; Mohammadi, M; Mohammadi, MA ; Mahvi, AH; Yetilmezsoy, K; Bhatnagar, A; Heibati, B; McKay, G 

Article

Abstract: In the present study, multi-walled carbon nanotubes (MWCNTs) have been used for the rapid removal of four trihalomethanes (THMs) from aqueous solutions. The adsorption capacity of THMs onto MWCNTs was reasonably constant in the pH range of 5-7 but decreased as the pH exceeded 7. Four equilibrium isotherm models, namely, Langmuir, Freundlich, Temkin, and Sips, were applied to determine the best-fit equilibrium expressions. The results showed that all four experimental adsorption isotherms were best correlated by using the Sips model. The maximum adsorption capacities for the CHCl3, CHCl2Br, CHClBr2, and CHBr3 were found to be 10.98, 6.85, 6.57, and 5.95 mg/g, respectively. The rate of adsorption followed the pseudo-second-order kinetic model. Furthermore, four nonlinear regression-based equations were also derived to model THM adsorption from aqueous solutions by MWCNTs. The modeling results clearly indicated that the empirical formulations satisfactorily described the behavior of the present adsorption process for CHCl3 (R-2 = 0.949), CHCl2Br (R-2 = 0.945), CHClBr2 (R-2 = 0.936), and CHBr3 (R-2 = 0.919). The overall results confirmed that MWCNTs could be a promising adsorbent material for THMs removal from aqueous solutions.

Title: Adsorptive removal of endocrine disrupting bisphenol A from aqueous solution using chitosan

Author(s): Dehghani, MH; Ghadermazi, M; Bhatnagar, A; Sadighara, P; Jahed-Khaniki, G; Heibati, B; McKay, G 

Article

Abstract: Bisphenol-A (BPA) is an important industrial chemical generally introduced into the environment through the wastes of factories producing, for example, paper, plastics and plastic products-making industries. Consequently, factory effluents and sewage containing BPA are sources of contamination in the aquatic environments. The objective of this research is to study the efficiency of BPA removal from aqueous solutions using two chitosans, (1) synthesized chitosan; a waste derived adsorbent from waste seafood shell and which was synthesized in our laboratory and (2) commercial chitosan a chitosan sample obtained commercially. The effects of process parameters such as solution pH, adsorbent dose, contact time, and initial concentration of BPA have been examined and compared. The results obtained from this study indicated that the efficiency of removal declines with increased contaminant concentration and decreased adsorbent dose. The optimal pH for maximum adsorption for both chitosan adsorbents was 5. The adsorption data were fitted into six isotherm models namely Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Redlich-Peterson and Sips and the isotherm parameters were determined. Furthermore, the kinetics of the process were correlated by three kinetic models, namely, the pseudo-first-order, pseudo-second-order and intra-particle diffusion models. The kinetic experiments revealed that both chitosan adsorbents follow the pseudo-second-order kinetic model. The isotherm studies demonstrated that both adsorbents follow the Langmuir model. Based on the results, chitosan, synthesized (SC) and commercial (CC), is an efficient, novel and inexpensive alternative for the removal of BPA from aqueous solution.

Title: Removal of atrazine as an organic micro-pollutant from aqueous solutions: a comparative study

Author(s): Shirmardi, M; Alavi, N; Lima, EC ; Takdastan, A; Mahvi, AH; Babaei, AA

Article

Abstract: In the present study, different adsorbents were prepared: activated carbon (AC), MgO and ZnO nanoparticles, and the composite of AC/MgO/ZnO. The AC was prepared from oak charcoals, as low-cost and abundantly available materials in Iran, by chemical activation. MgO and ZnO nanoparticles were synthesized using a sol gel method. The adsorbents were characterized using Powder X-ray diffraction (XRD), Field Emission-Scanning Electron Microscope (FESEM), and Energy Dispersive X-ray Spectroscopy (EDS). Then, the adsorption behavior of the adsorbents was tested for the removal of atrazine (ATZ) herbicide as a model of organic micro-pollutant. The average crystallite size of MgO and ZnO nanoparticles was calculated from their XRD data using the Scherrer equation. The results showed that the MgO and ZnO nanoparticles had a size in nano scale, which was supported by FESEM images. The experimental data showed that the pH of solution had no considerable effect on the adsorption of ATZ herbicide. The experimental data obtained for the AC and AC/MgO/ZnO composite were fitted to nonlinear pseudo first-order, pseudo-second order, and general order kinetic models. The general order kinetic model provided the best fit to experimental data compared with the other models. The adsorption isotherm data of these two adsorbents at different temperatures fitted well to the Langmuir and Liu models, but followed the Liu isotherm model most precisely, based on the lowest SD value provided by this model. The results of this study indicate that the chemically prepared AC has excellent adsorptive capacity and can be used as an effective adsorbent for the removal of ATZ from aqueous solutions. However, MgO and ZnO nanoparticles exhibited low adsorptive capacity for ATZ and could not be suitable adsorbents for the removal of this pollutant. (C) 2016 Institution of Chemical Engineers.

Title: Comparison of Moringa stenopetala seed extract as a clean coagulant with Alum and Moringa stenopetala-Alum hybrid coagulant to remove direct dye from Textile Wastewater

Author(s): Dalvand, A; Gholibegloo, E; Ganjali, MR ; Golchinpoor, N; Khazaei, M; Kamani, H; Hosseini, SS; Mahvi, AH

Article

Abstract: In this study, the efficiency of Moringa stenopetala seed extract was compared with alum and M. stenopetala-alum hybrid coagulant to remove Direct Red 23 azo dye from textile wastewater. The effects of parameters such as pH, coagulant dose, type of salt used for the extraction of coagulant and initial dye concentration on dye removal efficiency were investigated. Moreover, the existing functional groups on the structure of M. stenopetala coagulant (MSC) were determined by Fourier transform infrared spectroscopy, and the morphology of sludge produced by MSC, alum, and hybrid coagulant was characterized by scanning electron microscopy. Ninhydrin test was also used to determine the quantity of primary amines in the MSC and Moringa oleifera coagulant (MOC). According to the results, with increasing the coagulant dose and decreasing the initial dye concentration, dye removal efficiency has increased. The maximum dye removal of 98.5, 98.2, and 98.3 % were obtained by using 240, 120, and 80 mg/L MSC, alum and hybrid coagulant at pH 7, respectively. The results also showed MSC was much more effective than MOC for dye removal. The volume of sludge produced by MSC was one fourth and half of those produced by alum and hybrid coagulant, respectively. Based on the results, hybrid coagulant was the most efficient coagulant for direct dye removal from colored wastewater.

Title: One-Pot synthesis, characterization and adsorption studies of amine-functionalized magnetite nanoparticles for removal of Cr (VI) and Ni (II) ions from aqueous solution: kinetic, isotherm and thermodynamic studies

Author(s): Baghani, AN; Mahvi, AH; Gholami, M ; Rastkari, N; Delikhoon, M

 Article

Abstract: Background: Discharge of heavy metals such as hexavalent chromium (Cr (VI)) and nickel (Ni (II)) into aquatic ecosystems is a matter of concern in wastewater treatment due to their harmful effects on humans. In this paper, removal of Cr (VI) and Ni (II) ions from aqueous solution was investigated using an amino-functionalized magnetic Nano-adsorbent (Fe3O4-NH2).
Methods: An amino-functionalized magnetic Nano-adsorbent (Fe3O4-NH2) was synthesized by compositing Fe3O4 with 1, 6-hexanediamine for removal of Cr (VI) and Ni (II) ions from aqueous solution. The adsorbent was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM), powder X-Ray Diffraction (XRD), and Vibrating Sample Magnetometry (VSM). Also, the effects of various operational parameters were studied.
Results: According to our finding, Fe3O4-NH2 could be simply separated from aqueous solution with an external magnetic field at 30 s. The experimental data for the adsorption of Cr (VI) and Ni (II) ions revealed that the process followed the Langmuir isotherm and the maximum adsorption capacity was 232.51 mg g(-1) for Cr (VI) at pH = 3 and 222.12 mg g(-1) and for Ni(II) at pH = 6 at 298 degrees K. Besides, the kinetic data indicated that the results fitted with the pseudo-second-order model (R-2: 0.9871 and 0.9947 % for Cr (VI) and Ni (II), respectively. The results of thermodynamic study indicated that: standard free energy changes (Delta G degrees), standard enthalpy change (Delta H degrees), and standard entropy change (Delta S degrees) were respectively -3.28, 137.1, and 26.91 kJ mol(-1) for Cr (VI) and -6.8433, 116.7, and 31.02 kJ mol(-1) for Ni (II). The adsorption/desorption cycles of Fe3O4-NH2 indicated that it could be used for five times.
Conclusions: The selected metals sorption was achieved mainly via electrostatic attraction and coordination interactions. In fact, Fe3O4-NH2 could be removed more than 96 % for both Cr (VI) and Ni (II) ions from aqueous solution and actual wastewater.

Title: Investigating the removal of linear alkyl benzene sulfonate from aqueous solution by ultraviolet irradiation and hydrogen peroxide process

Author(s): Ghaderpoori, M; Dehghani, MH

Article

Abstract: This study investigated the efficiency of ultraviolet radiation and hydrogen peroxide for the removal of linear alkylbenzene sulfonate (LAS) from aqueous solutions. Methylene blue active substances assay and spectrophotometry were used to determine the amount of anionic and residual surfactants. The effect of H2O2 concentration, initial concentration of surfactant, pH, and length of UV radiation were examined. The potential for use of UV/H2O2 to degrade LAS was analyzed statistically using multiple linear regression analysis. The results showed that after 20min of contact time, ultraviolet radiation alone removed 38.44% of the LAS. The use of hydrogen peroxide alone for 10, 20, and 30min showed no effect on the removal of LAS. The removal rates for the combination UV/H2O2 at 10, 20, and 30min were 86.2, 90, and 96.5%, respectively. The results of this study showed that the use of ultraviolet radiation and hydrogen peroxide individually for degradation of anionic surfactant was not effective, but the combination of UV/H2O2 was effective for the removal of anionic detergents.

Title: Optimization of the enzymatic elimination of flumequine by laccase-mediated system using response surface methodology

Author(s): Ashrafi, SD (Ashrafi, S. D.)^{[ 1 ]} ; Nasseri, S ; Alimohammadi, M; Mahvi, AH; Faramarzi, MA

Article

Abstract: Response surface methodology (RSM) was applied to optimize the removal of flumequine (FLU) from aqueous solution by laccase from Trametes versicolor. Box-Behnken design (BBD) with four variables namely pH, temperature, FLU initial concentration, and 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) concentration was used to optimize these factors. The results showed that the predicted values for FLU removal were close to the experimental values, and the R-2 (0.9967) indicated that the regression was able to give a good prediction of response for the FLU removal process in the studied range. Optimization of the factors levels was carried out in two approaches. At first, all factors were set in the studied range. The selected optimal conditions for the maximum removal of FLU (98.27%) were predicted as: temperature of 39.64 degrees C, pH of 4.06, FLU initial concentration of 90.74mgL(-1), and ABTS concentration of 1.35mM. Then, the optimization was carried out by minimizing the amount of ABTS, maximizing the FLU initial concentration, and maximizing the removal efficiency. The recommended optimum conditions are: temperature of 39.19 degrees C, pH value of 4.32, FLU initial concentration of 125mgL(-1), and ABTS concentration of 0.28mM with the percentage FLU removal of 77.76%.

Title: ISOTHERM AND KINETIC STUDIES ON FLUORIDE BIOSORPTION FROM AQUEOUS SOLUTION BY USING CUTTLEBONE OBTAINED FROM THE PERSIAN GULF

Author(s): Keshtkar, M; Dobaradaran, S; Nabipour, I; Mahvi, AH; Ghasemi, FF; Ahmadi, Z; Heydari, M

Article

Abstract: Biosorption is considered to be one of the favored treatment technologies for fluoride ion (F) removal from aqueous solutions. The aim of this study was to determine the efficiency of cuttlebone (cuttlefish bone) obtained from the Persian Gulf in the removal of F from aqueous solutions. The biosorption experiments were studied in batch systems at room temperature. The effects of experimental parameters biosorbent dose, contact time, pH, and initial F concentration were studied. The highest removal biosorption was observed at 100 g/ L of biosorbent, at 120 min contact time and an initial F concentration at 12 mg/L (88.52%). The Langmuir model fitted better than the Frendlich model and showed a homogeneous biosorption surface with the possibility of a monolayer biosorption of F by the biosorbent. The biosorption kinetic was controlled by the pseudo-second order and pore diffusion models. The results showed that cuttlebone can be used as an environmentally friendly, cheap, and effective biosorbent of F from aqueous solutions, particularly in the coastal areas of the Persian Gulf with high-F levels in the drinking water.

Title: FLUORIDE CONTENT OF POPULAR PERSIAN HERBAL DISTILLATES

Author(s): Soleimani, F; Dobaradaran, S; Mahvi, AH; Karbasdehi, VN; Keshtkar, M; Esmaili, A 

Article

Abstract: The fluoride ion (F) concentration levels of the 20 most popular herbal distillates sold in Iran were determined. The mean F content of the samples was 50 mu g/L with a range of not detectable-340 mu g/L. The estimated maximum daily, weekly, and monthly intakes of F were 34, 238, and 1020 mu g/day respectively. The results of this study showed that the low concentration levels of F found in Persian herbal distillates should not normally significantly increase the F intake of consumers.

Title: EFFECT OF BREWING TIME AND WATER HARDNESS ON FLUORIDE RELEASE FROM DIFFERENT IRANIAN TEAS

Author(s): Maleki, A; Abulmohammadi, P; Teymouri, P; Zandi, S; Daraei, H; Mahvi, AH; Shahsawari, S

Article

Abstract: The present study aimed to investigate the fluoride concentration in tea leaves of different types of commonly used Iranian tea and the influence of brewing time and water hardness on fluoride release during their infusion. The concentrations of fluoride, phosphate, sulfate, nitrate, and chloride were measured, after 3 to 120 min brewing time, in 100 tea samples, including white, green, oolong, and black teas. The daily fluoride intake was also assessed. The fluoride concentration was measured with the ion chromatography method. The results showed that the minimum and maximum concentrations of fluoride in the tea liquor, after 15 min infusion, were 1.46 and 2.9 mg/L in teas made with oolong tea leaf and green tea leaf, respectively. Fluoride release from the tea leaves into the infusion increased significantly with increased brewing time (p<0.05). Fluoride release, after a 15-min brewing time, ranged from 43.7% for green tea bag to 73.5% for black tea leaf. Fluoride extraction was less in hard water.

Title: FLUORIDE REMOVAL FROM AQUEOUS SOLUTIONS BY CUPRICOXIDE NANOPARTICLES

Author(s): Bazrafshan, E; Balarak, D; Panahi, AH; Kamani, H; Mahvi, AH

Article

Abstract: Excess fluoride ion (F) in drinking water causes harmful effects such as dental and skeletal fluorosis. Hence, its concentration in drinking water must not exceed a certain range. This study investigated the removal of F from aqueous solutions with CuO nanoparticles using a range of experimental approaches, including pH, adsorbent dose, contact times, and initial F concentration. The equilibrium adsorption data were analyzed using the Langmuir and Freundlich adsorption models. The maximum uptake value of F was 3152 mg/g at pH 5 during 40 min with 0.005 g/L nanoparticles of CuO and an initial F concentration of 5 mg/L. The fluoride adsorption equilibrium over the adsorbent was well described by the Freundlich model. The findings of this study showed that CuO nanoparticles are quite effective for F removal from aqueous environments. Thermodynamic analyses showed that the adsorption of F onto CuO nanoparticles was endothermic and spontaneous.

Title: Optimization and modeling of process variables for adsorption of Basic Blue 41 on NaOH-modified rice husk using response surface methodology

Author(s): Ashrafi, SD; Kamani, H; Arezomand, HS; Yousefi, N; Mahvi, AH

Abstract: The aim of this study was to optimize the conditions of the Basic Blue 41 (BB41) adsorption on NaOH-modified rice husk (NaOH-RH) using response surface methodology based on Box-Behnken design. The three-level factors considered were pH (4, 7, and 10), initial concentration of BB41 (50, 75, and 100mgL(-1)), and adsorbent dose (0.025, 0.0875, and 0.15gL(-1)). Statistical analysis of result has shown that the predicted values for BB41 adsorption were close to the experimental values and were in a good agreement, on the other hand, the F-value (40.48), p-value (0.0004), and R-2 (0.9865) indicated that the regression is able to give a good prediction of response for the adsorption process in the range studied. According to the results, when the response was set in maximize and all the three factors were set in a range, the optimized values for BB41 adsorption were predicted as follows: pH value of 8.47, and BB41 initial concentration of 67.9mgL(-1) and adsorbent dose of 0.12gL(-1) for removal efficiency of 97.65%.

Title: Assessment and selection of the best treatment alternative for infectious waste by modified Sustainability Assessment of Technologies methodology

Author(s): Rafiee, A; Yaghmaeian, K; Hoseini, M; Parmy, S; Mahvi, A; Yunesian, M; Khaefi, M; Nabizadeh, R

Article

Abstract: Background: Improper treatment of infectious waste can cause numerous adverse environmental and health effects such as transmission of diseases through health personnel and other susceptible groups, who come in contact with such wastes. On the other hand, selection of appropriate treatment alternatives in infectious waste management has become a challenging task for public health authorities especially in developing countries. The objective of this paper is to select the best infectious waste treatment alternative by the modified Sustainability Assessment of Technologies (SAT) methodology, developed by the International Environmental Technology Center of the United Nations Environment Program (IETC-UNEP).
Methods: SAT methodology consists of three main components, including screening, scoping and detailed assessment. In screening, different infectious waste treatment alternatives undergo screening using the finalized environmental and technical criteria. Short-listed treatment options from the previous step, then go through the comprehensive scoping and detailed assessment (2nd and 3rd components) which is more qualitative and quantitative in nature. An empirical case in Tehran, the largest city in Iran, is provided to illustrate the potential of the proposed methodology.
Results: According to the final score, "Hydroclave", was the most suitable infectious treatment technology. The ranking order of the treatment alternatives were "Autoclave with a shredder", "Autoclave", "Central Incineration" and "chemical treatment" on the basis of technical, economical, social and environmental aspects and their related criteria.
Conclusions: According to the results it could be concluded that the top ranking technologies basically have higher scores in all the aspects. Hence it is easier to arrive at a decision for the final technology selection based on the principles of sustainability.

Title: A novel and inexpensive method for producing activated carbon from waste polyethylene terephthalate bottles and using it to remove methylene blue dye from aqueous solution

Author(s): Djahed, B; Shahsavani, E; Naji, FK; Mahvi, AH

 Article

Abstract: The current study aims to present a novel and inexpensive method for producing activated carbon using waste polyethylene terephthalate (PET) bottles in order to remove methylene blue (MB) dye from aqueous solution. Here, a novel method for producing activated carbon is developed by utilizing KOH and combining the carbonation and activation processes. Besides, the inert gases are not used in the production process. In order to determine the characteristics of the produced activated carbon texture, N-2 gas adsorption at 77K and scanning electron microscope are used. The adsorption isotherms of MB have been studied using Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin models. The specific surface area and the total volume of the generated activated carbon pores are 353.307m(2)/g and 0.288cc/g, respectively. In addition, q(max) for adsorption of MB dye is obtained as 404.089mg/g. Obtained results show that the Langmuir isotherm model has the best fitness. The values of R-2, the sum of squares of the errors percentage, and chi(2) for this model are measured as 0.996, 3.878, and 0.109, respectively. The present study shows that PET bottles are appropriate precursors for producing activated carbon. Besides, the present proposed method is effective and inexpensive.

Title: Textile wastewater treatment by application of combined chemical coagulation, electrocoagulation, and adsorption processes

Author(s): Bazrafshan, E; Alipour, MR; Mahvi, AH

Article

Abstract: The aim of this work was to study the feasibility of treating real textile wastewater by combined chemical coagulation (using poly aluminum chloride (PAC) as coagulant), electrocoagulation (using aluminum electrodes), and adsorption process (using pistachio nut shell ash) to achieve the required standards. The influence of the critical operating variables such as coagulant dose, electrical potential, reaction time, and adsorbent dose on the removal efficiencies of major pollutants was determined. The results of this study were showed that removal of pollutants increased with increasing doses of PAC and applied voltage. The chemical coagulation process showed 40% of chemical oxygen demand (COD), 34% of biochemical oxygen demand (BOD5), 23.7% TSS, and 44.5% of dye removal efficiency, even though using relatively low PAC concentration (30mg/L). COD, BOD5, and dye removals of 93.1, 88.8, and 98.6% were achieved by electrocoagulation process (applied voltage 60V). In addition, COD, BOD5, and dye removals of 98, 94.2, and 99.9% were achieved by overall combined process (chemical coagulation, electrocoagulation, and adsorption processes). The experiments demonstrated the effectiveness of combined processes for the treatment of real textile wastewaters. Consequently, combined processes are inferred to be superior to these processes alone for the removal of both organic and inorganic compounds from textile wastewater.

Title: Concentration of heavy metals in surface water and sediments of ChahNimeh water reservoir in Sistan and Baluchestan province, Iran

Author(s): Bazrafshan, E; Mostafapour, FK; Esmaelnejad, M; Ebrahimzadeh, GR; Mahvi, AH

Article

Abstract: Heavy metals, which may result from chemical leaching of bedrock, water drainage, and runoff from banks, the discharge of urban industrial and rural agricultural wastewaters, are widely present in water and sediments. Metal concentrations in aquatic ecosystems are usually monitored by determining their concentrations in water and sediment samples. The main purpose of this study was to examine the levels of eight heavy metals (Cr, Cd, Cu, Mn, Fe, Pb, Zn, and Ni) in surface water and sediments in the Chah Nimeh reservoir. Seven sampling sites were predefined in different locations of the reservoir. The concentrations of heavy metals were measured in the surface water and sediments of Chah Nimeh reservoir. A preliminary study of heavy metals in the surface water and sediments was determined. The obtained results showed that, in general, the heavy metal concentrations in water and sediments did not exceed WHO guidelines (except Cd). The concentrations of heavy metals in sediments were found to be considerably higher than those obtained in reservoir water. Generally, heavy metal concentrations of the sediments were found to decrease in the sequence of Fe>Mn>Zn>Ni>Pb>Cr>Cd>Cu. The findings of this study indicated a general absence of serious pollution in the Chah Nimeh reservoir.

Title: Modeling of Reactive Blue 19 azo dye removal from colored textile wastewater using L-arginine-functionalized Fe3O4 nanoparticles: Optimization, reusability, kinetic and equilibrium studies

Author(s): Dalvand, A; Nabizadeh, R; Ganjali, MR; Khoobi, M; Nazmara, S; Mahvi, AH

Article

Abstract: This study aimed to investigate the removal of Reactive Blue 19 from colored wastewater using Fe3O4 magnetic nanoparticles modified with L-arginine (Fe3O4@L-arginine). In order to investigate the effect of independent variables on dye removal and determining the optimum condition, the Box-Behnken Design (BBD) under Response Surface Methodology (RSM) was employed. Fe3O4@L-arginine nanoparticles were synthesized and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and vibrating sample magnetometer. Applying Fe3O4@L-arginine nanoparticles for dye removal showed that; by increasing adsorbent dose and decreasing pH, dye concentration, and ionic strength dye removal has been increased. In the optimum condition, Fe3O4@L-arginine nanoparticles were able to remove dye as high as 96.34% at an initial dye concentration of 50 mg/L, adsorbent dose of 0.74 g/L, and pH 3. The findings indicated that dye removal followed pseudo-second-order kinetic (R-2=0.999) and Freundlich isotherm (R-2=0.989). Based on the obtained results, as an efficient and reusable adsorbent, Fe3O4@L-arginine nanoparticles can be successfully applied for dye removal from colored wastewater.

Title: Adsorptive removal of fluoride from aqueous solution using single- and multi-walled carbon nanotubes

Author(s): Dehghani, MH; Haghighat, GA; Yetilmezsoy, K; McKay, G; Heibati, B; Tyagi, I; Agarwal, S; Gupta, VK 

Article

Abstract: In the present study, defluoridation study of liquid phase with the help of multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) were well investigated and elucidated. The impact of different experimental conditions such as solution pH, initial fluoride concentration, adsorbent dose, and contact time was well studied and optimized for the maximum fluoride removal from water. The experimental data were fitted by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherm models and the related equilibrium constants were calculated. The results of the isotherm studies showed that fluoride removal by both adsorbents followed the Freundlich isotherm model. Kinetic studies were conducted and the results demonstrated that the experimental data were fitted well with the pseudo-second order kinetic model. Furthermore, two multiple regression-based equations were also derived to model the removal of fluoride from aqueous solutions by the carbon nanotubes. This study demonstrated that the polynomial equations satisfactorily described the behavior of the pres

Title: High-performance removal of toxic phenol by single-walled and multi-walled carbon nanotubes: Kinetics, adsorption, mechanism and optimization studies

Author(s): Dehghani, MH; Mostofi, M; Alimohammadi, M; McKay, G; Yetilmezsoy, K; Albadarin, AB; Heibati, B; AlGhouti, M; Mubarak, NM; Sahu, JN

 Article

Abstract: The adsorption capabilities of two nano-sized adsorbents: multi-walled carbon nanotubes (MWCNTs) and single-walled carbon nanotubes (SWCNTs) were investigated for the removal of toxic phenol. The maximum adsorption capacities of MWCNTs and SWCNTs were determined as 64.60 and 50.51 mg/g, respectively. Adsorption kinetics followed the pseudo-second order model for both adsorbents. The optimum conditions using SWCNT5 and MWCNTs were pH 6.57 and 4.65, phenol concentration 50 and 50 mg/L, dose 1.97 and 2 g/L and contact time 36 and 56 min, respectively. The results indicated that MWCNTs and SWCNT5 were proven as high-performance adsorbents for toxic phenol removal from wastewater. (C) 2015 The Korean Society of Industrial and Engineering Chemistry.

Title: Nitrogen and phosphorous removal from aerated lagoon effluent using horizontal roughing filter (HRF)

Author(s): Khazaei, M; Nabizadeh, R; Mahvi, AH; Izanloo, H; Tadi, RA; Gharagazloo, F

 Article

Abstract: Traditionally, aerated lagoons are not reliable wastewater treatment systems to eliminate nutrient contents of municipal wastewater. This study aimed to enhance the aerated lagoon effluent quality by applying a simple filtration system. Removal of nitrogen and phosphorous from aerated lagoon effluent using horizontal roughing filter (HRF) was investigated. Also, the 1/3-2/3 theory was applied to predict the TSS concentration of HRF effluent. An experimental setup of HRF was used to receive the continuous effluent from wastewater treatment plant. HRF was operated at three consecutive filtration rates, including 0.5, 1 and 1.5m(3)m(-2)h(-1). At the first filtration rate (0.5m(3)m(-2)h(-1)), the removal efficiencies of total Kjeldahl nitrogen, total phosphorous, TSS, and COD were reported 50, 54, 63, and 68%, respectively. Decreasing the removal efficiency was occurred during raising the filtration rate (p<0.05). Applying the 1/3-2/3 theory revealed the significant correlation between predicted and measured TSS values. The capacity of HRF to retain nitrogen, phosphorous, and COD during the filtration runs was 24.3, 10.1, and 435.4gm(-3)d(-1), respectively. HRF can be applied as an appropriate alternative for tertiary treatment of the aerated lagoon effluent.

Title: Removal of chromium(VI) from aqueous solution using treated waste newspaper as a low-cost adsorbent: Kinetic modeling and isotherm studies

Author(s): Dehghani, MH; Sanaei, D; Ali, I; Bhatnagar, A

Article

Abstract: In the present study, treated waste newspaper (TWNP) was used to remove chromium(VI) from aqueous solution using batch experiments. The adsorption parameters optimized were: initial Cr(VI) concentration (5, 20, 50 mg/l), contact time (60 min.), adsorbent dose (3.0 g/L), and solution pH (3.0). The experimental data fitted well to Langmuir isotherm (R-2 = 0.98; maximum adsorption capacity 59.88 mg/g.) and pseudo-second-order kinetic model. The rate constant k(2) varied from 0.0019 to 0.0068 at initial Cr (VI) concentration from 5 to 20 mg/L. It was observed that adsorption of Cr(VI) was pH dependent. The percentage removal of Cr(VI) was 59.88 mg/g (64% at pH 3). The results of the present study suggest that TWNP may be used as a low-cost adsorbent for the removal of chromium (VI) from aqueous solutions.

Title: Sodium Dodecyl Sulfate Modified-Zeolite as a Promising Adsorbent for the Removal of Natural Organic Matter From Aqueous Environments

Author(s): Mahvi, AH; Vosoughi, M; Mohammadi, MJ; Asadi, A; Hashemzadeh, B; Zahedi, A; Pourfadakar, S

Article

Abstract: Background: High concentrations of natural organic matter (NOM) may cause the production of harmful compounds in treated drinking water. Surfactant-modified zeolites (SMZs) with various loadings of sodium dodecyl sulfate (SDS) have been used as adsorbents to remove NOM from aqueous solution. SMZ has presented higher NOM adsorption more efficiency than natural zeolite. NOM affects the quality of drinking water in several points.
Objectives: The purpose this study was to investigate the SDS-modified isotherm of natural Iranian zeolite obtained from Semnan mines, for the removal of NOM from aqueous solution.
Materials and Methods: The adsorption of NOM onto SDS-modified zeolite as a function of contact time, initial NOM concentrations, adsorbent dose and solution pH was investigated. The isotherm experiments were carried out with fixing the adsorbent dose and varying the initial concentration of NOM.
Results: The results indicated that SDS-modified zeolite showed greatly enhanced adsorption capacity. Findings revealed that the Langmuir isotherm best described the NOM adsorption on the adsorbent. The adsorption isotherm was well fitted to the Langmuir model. The maximum adsorption capacity of SMZ with surfactant bilayer coverage for NOM was 111 mg/g at 25 degrees C and pH = 5.
Conclusions: The findings of this study showed that the modification of natural zeolites can achieve higher adsorption capacity for organics. In addition, based on the results, natural zeolite being modified with SDS as a cationic surfactant had good efficiency for the adsorption of NOM.

Title: Assessment of bed sediment metal contamination in the Shadegan and Hawr Al Azim wetlands, Iran

Author(s): Nasirian, H; Irvine, KN; Sadeghi, SMT; Mahvi, AH; Nazmara, S 

Article

Abstract: The Shadegan and Hawr Al Azim wetlands are important natural resources in southwestern Iran, yet relatively little work has been done to assess ecosystem health of the wetlands. Bed sediment from both wetlands was sampled in individual months between October, 2011 and December, 2012 and analyzed for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, and Zn using inductively coupled plasma optical emission spectrometry (ICP-OES). The metals data were evaluated using a combination of sediment quality guidelines from the Ontario Ministry of Energy and Environment (MOEE, Canada), enrichment factors (EFs), and a geoaccumulation index (I-geo) approach. The sediments exceeded MOEE Lowest Effect Levels (LELs) consistently for Cr and Cu and a small proportion of samples (5 %) for Hg. Levels of As, Cd, Fe, Pb, and Zn did not exceed LELs and none of the samples exceeded the Severe Effect Levels (SELs). In addition to the sediment guidelines, both the EF and I-geo calculations suggested levels of Mn and Fe were severely enriched, while the EF indicated Cd was slightly enriched. Metal levels in the Shadegan wetland exhibited both spatial and seasonal trends. Metal levels were greater near input areas from agricultural, urban, and industrial discharges and runoff as compared to the more remote and quiescent central part of the wetland. Except for Fe, the metal levels were greater in the wet season as compared to the dry season, perhaps due to greater stormwater runoff and sediment loads. This study provides baseline data which can be used to support development of appropriate contaminant source management strategies to help ensure conservation of these valuable wetland resources.

Title: Assessment of tetracycline contamination in surface and groundwater resources proximal to animal farming houses in Tehran, Iran

Author(s): Javid, A; Mesdaghinia, A; Nasseri, S; Mahvi, AH; Alimohammadi, M; Gharibi, H

Article

Abstract: Background: Antibiotics have been increasingly used for veterinary and medical purposes. The overuse of these compounds for these purposes can pollute the environment, water resources in particular. Tetracycline, among other forms of antibiotics, is one of the most applied antibiotic in aquaculture and veterinary medicine. The present study aimed to tack the traces of tetracycline in the effluents of municipal and hospital wastewater treatment plants, surface and groundwater resources and finally the drinking water provided from these water resources.
Methods: The samples were taken from Fasha-Foyeh Dam, wells located at Varamin Plain, and Yaftabad; and also, wastewater samples were collected from the wastewater treatment plant effluents of Emam Khomeini Hospital and a municipal wastewater treatment plant which its effluent is being released to the surface water of the area covered in this work. 24 samples were collected in total during July 2012 to December 2012. The prepared samples were analyzed using high-performance liquid chromatography.
Results: Based on the results, mean tetracycline levels in surface and ground water at nearby of animal farms was found to vary from 5.4 to 8.1 ng L-1. Furthermore, the maximum TC concentration of 9.3 ng L-1 was found to be at Yaft-Abad sampling station. Although tetracycline traces could not be detected in any investigated Hospital WWTP effluents, it was tracked in MWWTP effluent samples, in the concentration range of 280 to 540 ng L-1.
Conclusion: The results showed that the concentration of TC in water resource near the animal farms is higher than the other sampling stations. This is related to the usage of antibiotic for animals. In fact, it caused the contamination of water resources and could contribute to radical changes in the ecology of these regions.

Title: Spatial and temporal variability of fluoride concentrations in groundwater resources of Larestan and Gerash regions in Iran from 2003 to 2010

Author(s): Amini, H Haghighat, GA; Yunesian, M; Nabizadeh, R; Mahvi, AH; Dehghani, MH; Davani, R; Aminian, AR; Shamsipour, M; Hassanzadeh, N; Faramarzi, H; Mesdaghinia, A 

Article

Abstract: There is discrepancy about intervals of fluoride monitoring in groundwater resources by Iranian authorities. Spatial and temporal variability of fluoride in groundwater resources of Larestan and Gerash regions in Iran were analyzed from 2003 to 2010 using a geospatial information system and the Mann-Kendall trend test. The mean concentrations of fluoride for the 8-year period in the eight cities and 31 villages were 1.6 and 2.0 mg/l, respectively; the maximum values were 2.4 and 3.8 mg/l, respectively. Spatial, temporal, and spatiotemporal variability of fluoride in overall groundwater resources were relatively constant over the years. However, results of the Mann-Kendall trend test revealed a monotonic trend in the time series of one city and 11 villages for the 8-year period. Specifically, one city and three villages showed positive significant Kendalls Tau values, suggesting an upward trend in fluoride concentrations over the 8-year period. In contrast, seven villages displayed negative significant Kendalls Tau values, arguing for a downward trend in fluoride concentrations over the years. From 2003 to 2010, approximately 52 % of the Larestan and Gerash areas have had fluoride concentrations above the maximum permissible Iranian drinking water standard fluoride level (1.4 mg/l), and about 116,000 people were exposed to such excess amounts. Therefore, our study supports for a close monitoring of fluoride concentrations from health authorities in monthly intervals, especially in villages and cities that showed positive trend in fluoride concentrations. Moreover, we recommend simultaneous implementation of cost-effective protective measures or interventions until a standard fluoride level is achieved.

Title: Sonocatalytic degradation of humic acid by N-doped TiO2 nano-particle in aqueous solution

Author(s): Kamani, H; Nasseri, S; Khoobi, M; Nodehi, RN; Mahvi, AH

Article

Abstract: Background: Un-doped and N-doped TiO2 nano-particles with different nitrogen contents were successfully synthesized by a simple sol-gel method, and were characterized by X-ray diffraction, field emission scanning electron microscopy, Energy dispersive X-ray analysis and UV-visible diffuse reflectance spectra techniques. Then enhancement of sonocatalytic degradation of humic acid by un-doped and N-doped TiO2 nano-particles in aqueous environment was investigated. The effects of various parameters such as initial concentration of humic acid, N-doping, and the degradation kinetics were investigated.
Results: The results of characterization techniques affirmed that the synthesis of un-doped and N-doped TiO2 nano-particles was successful. Degradation of humic acid by using different nano-particles obeyed the first-order kinetic. Among various nano-particles, N-doped TiO2 with molar doping ratio of 6 % and band gap of 2.92 eV, exhibited the highest sonocatalytic degradation with an apparent-first-order rate constant of 1.56 x 10(-2) min(-1).
Conclusions: The high degradation rate was associated with the lower band gap energy and well-formed anatase phase. The addition of nano-catalysts could enhance the degradation efficiency of humic acid as well as N-doped TiO2 with a molar ratio of 6 N/Ti was found the best nano-catalyst among the investigated catalysts. The sonocatalytic degradation with nitrogen doped semiconductors could be a suitable oxidation process for removal of refractory pollutants such as humic acid from aqueous solution.

Title: Reduction of noxious Cr(VI) ion to Cr(III) ion in aqueous solutions using H2O2 and UV/H2O2 systems

Author(s): Dehghani, MH; Heibati, B; Asadi, A; Tyagi, I; Agarwal, S; Gupta, VK

Article

Abstract: Conversion of the toxic Cr(VI) to the less toxic Cr(III) in aqueous solutions by chemical and photochemical reduction was carried out using H2O2 and UV radiation. The whole mechanism was well elucidated and investigated using potassium dichromate (K2Cr2O7) as a standard model compound. The effects of potential factors affecting the reduction efficiency were well studied and optimized, the optimized parameters such as concentration of H2O2 (from 0.5 to 1.5 M), pH (from 5 to 9), irradiation time (0 to 140 min) and reaction time (0 to 120 min). Initial concentration of Cr(VI) in the solution was varied from 0.1 to 15 mg/L plays a significant role in the mechanism involves for the reduction of noxious Cr(VI) to less toxic Cr(III). (C) 2015 The Korean Society of Industrial and Engineering Chemistry.

Title: Response surface modeling of lead (II) removal by graphene oxide-Fe3O4 nanocomposite using central composite design

Author(s): Khazaei, M; Nasseri, S; Ganjali, MR; Khoobi, M; Nabizadeh, R; Mahvi, AH; Nazmara, S; Gholibegloo, E

Article

Abstract: Background: Magnetic graphene oxide (Fe3O4@SiO2-GO) nanocomposite was fabricated through a facile process and its application as an excellent adsorbent for lead (II) removal was also demonstrated by applying response surface methodology (RSM).
Methods: Fe3O4@SiO2-GO nanocomposite was synthesized and characterized properly. The effects of four independent variables, initial pH of solution (3.5-8.5), nanocomposite dosage (1-60 mg L-1), contact time (2-30 min), and initial lead (II) ion concentration (0.5-5 mg L-1) on the lead (II) removal efficiency were investigated and the process was optimized using RSM. Using central composite design (CCD), 44 experiments were carried out and the process response was modeled using a quadratic equation as function of the variables.
Results: The optimum values of the variables were found to be 6.9, 30.5 mg L-1, 16 min, and 2.49 mg L-1 for pH, adsorbent dosage, contact time, and lead (II) initial concentration, respectively. The amount of adsorbed lead (II) after 16 min was recorded as high as 505.81 mg g(-1) for 90 mg L-1 initial lead (II) ion concentration. The Sips isotherm was found to provide a good fit with the adsorption data (K-S = 256 L mg(-1), n(S) = 0.57, q(m) = 598.4 mg g(-1), and R-2 = 0.984). The mean free energy E-ads was 9.901 kJ/mol which confirmed the chemisorption mechanism. The kinetic study determined an appropriate compliance of experimental data with the double exponential kinetic model (R-2 = 0.982).
Conclusions: Quadratic and reduced models were examined to correlate the variables with the removal efficiency of Fe3O4@SiO2-GO. According to the analysis of variance, the most influential factors were identified as pH and contact time. At the optimum condition, the adsorption yield was achieved up to nearly 100 %.

Title: Performance evaluation of montmorillonite and modified montmorillonite by polyethyleneimine in removing arsenic from water resources

Author(s): Nadali, A; Khoobi, M; Nabizadeh, R; Naseri, S; Mahvi, AH

Article

Abstract: Arsenic, known as a pollutant, mostly found in ground water resources, has become a major problem in the most of underdeveloped and developing countries around the world. More than 140 million of people around the world, especially those who reside in South America and south-east of Asia, are gravely at risk of being exposed to arsenic pollution. In this study, the performance of montmorillonite (MMT) and modified montmorillonite by polyethyleneimine (MMT@PEI) in removing arsenic from water resources was evaluated and compared with each other. Response surface methodology used as experimental procedures and interaction of four variables, namely, detention time, pH, initial arsenic concentration, and the adsorbent concentration on the arsenic ion removal were conducted. It is noteworthy that all chemical experiments conducted in this study are in accordance with Standard Methods for Water and Wastewater Experiments. Also, XRD analysis was performed to determine the characteristics of the adsorbent. Based on the results, maximum percentage of fluoride removal efficiencies by applying montmorillonite (R-2=0.95) and modified montmorillonite (R-2=0.97) were 45 and 96%, respectively.

Title: Remediation of Fuel Oil Contaminated Soils by Activated Persulfate in the Presence of MnO2

Author(s): Mazloomi, S; Nasseri, S; Nabizadeh, R; Yaghmaeian, K; Alimohammadi, M; Nazmara, S; Mahvi, AH 

Article

Abstract: In this study, batch system experiments were carried out for evaluating the capability of persulfate (PS) to re mediate fuel oil contaminated soils. Remediation was performed by spiking soil samples with fuel oil and then treating the mixture with sodium PS. Different controlling factors including pH (3, 6, and 9), PS concentrations (50-500 mmol/1), metal activators (ferrous sulfate, magnetite, and MnO2), and temperature (25, 40, and 60 degrees C) were considered. Results proved that PS oxidation is effective in fuel oil degradation. The best PS : Fe2+ molar ratios were reported 400 : 2 and 250 : 1 for silty clay and loamy sand soil samples, respectively. Lower pH was more of interest in removal of fuel oil by PS oxidation. MnO2 improved fuel oil degradation when used together with metal activators. The results showed that when MnO2 was used together with ferrous sulfate and magnetite at acidic condition (pH = 3), the removal efficiencies were the best. Increasing temperature from 25 to 60 degrees C improved the fuel oil degradation in the PS oxidation batch system. The results showed that activating PS by using ferrous sulfate along with MnO2 at acidic condition in 60 degrees C could increase fuel oil degradation near to 58% in silty clay soil samples, while the degradation rate for loamy sand soil samples in similar conditions was 62%.

Title: Application of nanofilter in removal of phosphate, fluoride and nitrite from groundwater

Author(s): Yousefi, N; Fatehizedeh, A; Ghadiri, K; Mirzaei, N; Ashrafi, SD; Mahvi, AH 

Article

Abstract: At present, nanofiltration (NF) technologies find the ever greater use in the water industry, particularly, drinking water supplies. The concentrations of most anions in the groundwater sources are much higher than surface water and in some cases are higher than drinking water standards. In this regard, the aim of this study was to investigate the possibility of application of nanofilters in removing phosphate, fluoride, and nitrite from aqueous solutions. In this research, the effect of different factors including initial concentrations of nitrate, phosphate, and fluoride along with the flow rate were investigated. The results showed that with an increase in the initial concentrations of phosphate, fluoride, and nitrite, along with an increase in flow rate, the removal efficiencies decreased. The maximum removal efficiencies for phosphate, fluoride, and nitrite were 98, 82, and 87%, respectively. According to the findings, NF membrane could be recommended for removing nitrates, fluoride, and phosphate from aqueous solutions.

Title: DEGRADATION OF PHENANTHRENE AND PYRENE USING GENETICALLY ENGINEERED DIOXYGENASE PRODUCING Pseudomonas putida IN SOIL

Author(s): Mardani, G; Mahvi, AH; Hashemzadeh-Chaleshtori, M; Nasseri, S; Dehghani, MH; Ghasemi-Dehkordi, P

Article

Abstract: Bioremediation use to promote degradation and/or removal of contaminants into nonhazardous or less-hazardous substances from the environment using microbial metabolic ability. Pseudomonas spp. is one of saprotrophic soil bacterium and can be used for biodegradation of polycyclic aromatic hydrocarbons (PAHs) but this activity in most species is weak. Phenanthrene and pyrene could associate with a risk of human cancer development in exposed individuals. The aim of the present study was application of genetically engineered P. putida that produce dioxygenase for degradation of phenanthrene and pyrene in spiked soil using high-performance liquid chromatography (HPLC) method. The nahH gene that encoded catechol 2,3-dioxygenase (C23O) was cloned into pUC18 and pUC18-nahH recombinant vector was generated and transformed into wild P. putida, successfully. The genetically modified and wild types of P. putida were inoculated in soil and pilot plan was prepared. Finally, degradation of phenanthrene and pyrene by this bacterium in spiked soil were evaluated using HPLC measurement technique. The results were showed elimination of these PAH compounds in spiked soil by engineered P. putida comparing to dishes containing natural soil with normal microbial flora and inoculated autoclaved soil by wild type of P. putida were statistically significant (p< 0.05). Although adding N and P chemical nutrients on degradation ability of phenanthrene and pyrene by engineered P. putida in soil were not statistically significant (p> 0.05) but it was few impact on this process (more than 2%). Additional and verification tests including catalase, oxidase and PCR on isolated bacteria from spiked soil were indicated that engineered P. putida was alive and functional as well as it can affect on phenanthrene and pyrene degradation via nahH gene producing. These findings indicated that genetically engineered P. putida generated in this work via producing C23O enzyme can useful and practical for biodegradation of phenanthrene and pyrene as well as petroleum compounds in polluted

Title: Application of response surface methodology for modeling and optimization of trichloroacetic acid and turbidity removal using potassium ferrate(VI)

Author(s): Aslani, H; Nabizadeh, R; Nasseri, S; Mesdaghinia, A; Alimohammadi, M; Mahvi, AH; Rastkari, N; Nazmara, S

Article

Abstract: Coagulation/flocculation and oxidation are two of the main processes in treating colloidal and organic substances. Potassium ferrate(VI), a multipurpose chemical, is used in water treatment plants as coagulant and oxidant. In this study, ferrate(VI) was evaluated for the degradation of trichloroacetic acid and turbidity removal in synthetic water. The effects of five independent variables, initial pH of solution (3-9), ferrate(VI) dosage (1-10mg L-1), contact time (5-60min), trichloroacetic acid concentration (100-1,000g L-1), and initial turbidity (1-10 NTU) were investigated and the process was optimized by means of response surface methodology. Trichloroacetic acid and turbidity removal efficiencies were considered as the process responses. The highest efficiency achieved for trichloroacetic acid removal was 24%, while for turbidity the maximum removal efficiency was in the range 85-95%. The optimum conditions for initial turbidity, pH, and ferrate dosage were 8.89 NTU, 3, and 4.26mg L-1 as Fe, respectively. Experimentally obtained 89% turbidity removal in the optimum condition confirmed the results predicted by the model. Therefore, it can be concluded that ferrate(VI) can be effectively used in colloidal substances removal, while it is not successful enough in trichloroacetic acid decomposition.

Title: Geochemical study of groundwater conditions with special emphasis on fluoride concentration, Iran

Author(s): Biglari, H; Chavoshani, A; Javan, N; Mahvi, AH

Article

Abstract: The quality of groundwater at any point below the surface shows the combined effects of many processes in the groundwater flow path. Factors of chemical reactions such as precipitation, weathering, dissolution, ion exchange, and various biological processes commonly happen below the surface, influencing fluoride concentrations in groundwater. Due to the fluoride effects on human health and the fact that few studies have been conducted on the factors affecting low fluoride amounts, these factors were investigated in Sistan and Baluchestan province, Iran. Water samples from 270 open dug wells, located in nine cities, were collected within 10years (from 2004 to 2014). They were analyzed for major ions according to the standard methods. In this study, parameters such as pH, specific electrical conductivity, temperature, total dissolved solids, sulfate, nitrate, fluoride, total alkalinity, total hardness, carbonate, bicarbonate, magnesium, calcium, sodium, and potassium were analyzed. It was revealed that the soil was saline with natural pH. The fluoride amount in groundwater was deeply influenced by the composite of granitic, NaF, and CaF2 rocks for a prolonged period. The wells showed many changes of fluoride concentration from 0.125 to 1.71mg/l and fluoride decreased toward the Southeast. Na+, Ca+, Cl-, and along with F showed a positive correlation; however, plots in comparison with F showed a negative correlation. Obtained results from this study indicate that the hydrological condition of groundwater is also an important factor controlling the amount of fluoride in groundwater.

Title: The optimization study of direct red 81 and methylene blue adsorption on NaOH-modified rice husk

Author(s): Ashrafi, SD; Kamani, H; Mahvi, AH

Article

Abstract: The objectives of this investigation are to obtain optimal adsorption conditions for direct red 81 (DR81) and methylene blue (MB) from aqueous solution on NaOH-modified rice husk (NaOH-RH) using response surface methodology (RSM). A Box-Behnken design (BBD) statistical experimental design was used to investigate the adsorption of DR81 and MB on NaOH-RH. For DR81, pH(4-7), initial concentration of dye (25-125mg/l), adsorbent dose (2-6g/l) and for MB pH(7-10), initial concentration of dye (25-125mg/l) and adsorbent dose (0.25-0.75g/l) were selected as independent variables. The results showed that the predicted values for both dye adsorptions were close to the experimental values and were in a good agreement, on the other hand, the R-2 values for DR81 (R-2=0.9685) and MB (R-2=0.9832) indicated that the regression is able to give a good predict of response for the adsorption process in the range studied. From the BBD predictions, the optimal conditions in the adsorption process for removing 54.04% of DR81 were found to be 25mg/l initial dye concentration and 6g/l adsorbent dose at pH4. Also, removing 97.66% of MB was found to be 25mg/l initial dye concentration and 0.595g/l adsorbent dosage at pH8.89.

Title: Experimental design and response surface modeling for optimization of fluoroquinolone removal from aqueous solution by NaOH-modified rice husk

Author(s): Ashrafi, SD; Kamani, H; Jaafari, J; Mahvi, AH

Article

Abstract: The aim of this study is to obtain optimal adsorption conditions for enrofloxacin (ENR) as a fluoroquinolone antibiotic onto NaOH-modified rice husk using response surface methodology (RSM). On the basis of a four variable Box-Behnken design (BBD), RSM was used to determine the effect of adsorbent dose (0.25, 0.5, and 0.75gL(-1)), pH (5, 7, and 9), ENR initial concentration (25, 75, and 125mgL(-1)), and temperature (15, 30, and 45 degrees C) on adsorption efficiency. By applying the quadratic regression analysis, among the main parameters, the removal efficiency was significantly affected by all the four variables. The results showed that the predicted values for ENR adsorption were close to the experimental values and were in good agreement. In addition, the R-2 value (R-2=0.9705) indicates that the regression is able to give a good predict of response for the adsorption process in the studied range. From the BBD predictions, the optimal conditions for 92.25% ENR removal were found to be 0.69gL(-1) of adsorbent dose, pH 5.11, and initial concentration of ENR 25.02mgL(-1), at temperature 36.43 degrees C.

Title: APPLICATION OF ADSORPTION PROCESS FOR PHENOLIC COMPOUNDS REMOVAL FROM AQUEOUS ENVIRONMENTS: A SYSTEMATIC REVIEW

Author(s): Bazrafshan, E; Amirian, P; Mahvi, AH; Ansari-Moghaddam, A

Article

Abstract: Wastewater from various types of industries such as synthetic resins, plywood industries, paper and pulp, gas and coke oven plants, paints, coal gas, tanning, textile, plastic, rubber, pharmaceutical, petroleum and mine discharges, contain different types of phenols. Phenolic compounds are toxic substances and some are known or suspected carcinogens. Therefore it is important to remove phenol and phenolic compounds from contaminated industrial aqueous streams before discharged into any water bodies. Adsorption of phenol and its derivatives from aqueous solution by activated carbon is one of the most investigated of all liquid phase applications of carbon adsorbents. Several adsorbents have been used for treatment of wastewater and removal of phenolic compounds. Literature contains various adsorption processes and adsorbents such as pistachio nut shell ash, Moringa peregrina tree shell ash, agricultural fibers, red mud, low cost clay, olive mill waste, natural zeolites, rubber seed coat, peat, fly ash, bentonite and. which have been used for the removal of phenol and its derivatives. Any of chemical, biological and physical treatment processes has its own advantages and disadvantages. It is worth mentioning that economic aspects of these processes are important, for example biosorption were found to be effective methods with scope for further research in this field in terms of cost effectiveness and regeneration. At present study various adsorbents used by the authors of this article and other researchers for phenol and its derivatives from aqueous environments have been reported and summarized. Additionally, more research is needed to find the practical utility of low-cost adsorbents on commercial scale.

Title: Removal of Bisphenol A from aqueous solutions using ultrasonic waves and hydrogen peroxide

Author(s): Nikfar, E; Dehghani, MH; Mahvi, AH; Rastkari, N; Asif, M; Tyagi, I; Agarwal, S; Gupta, VK

Article

Abstract: Efficiency of technologies using ultrasonic waves superimposed with hydrogen peroxide for the removal of Bisphenol A (BPA) from the aqueous solution was well studied and investigated. BPA is a non-biodegradable antioxidant, which was highly resistant to the biological and chemical breakdown; the non-biodegradability of the dye made it noxious and hazardous material for the both aquatic flora as well as fauna. Tests were done at two levels i.e. ultrasonic power 300 and 500 W; frequencies of 35 and 130 kHz respectively and at the optimum pH levels of 3, 7 and 11. Hydrogen peroxide levels were tested at concentrations of 5, 15 and 30 mg/l. Obtained results demonstrated that the efficiency of BPA breakdown using a process combining ultrasonic waves assisted by hydrogen peroxide was more effective than separately applied processes. The highest rate of decomposition was achieved at the frequency of 130 kHz and 500 W assisted by 30 mg/l H2O2 at pH level 11. The removal efficiency of BPA in natural samples decreased compared to efficiency in synthetic samples.

Title: Characterization and source identification of trace elements in airborne particulates at urban and suburban atmospheres of Tabriz, Iran

Author(s): Gholampour, A; Nabizadeh, R; Hassanvand, MS; Taghipour, H; Rafee, M; Alizadeh, Z; Faridi, S; Mahvi, AH

 Article

Abstract: Concentration of particulate matter (PM10 and total suspended particulate (TSP)) and their elemental constituents were measured to identify the major sources of elements in urban and industrial suburban sites in Tabriz, Iran, from September 2012 to June 2013. TSP and PM10 samples were collected using high-volume samplers. Concentrations of 31 elements in aerosols and crustal soil were determined by ICPMS. The most abundant detected metals in the urban sampling sites were Al (217.5-4019.9 ng m(-3)), Fe (272.5-7658.0 ng m(-3)), Pt (4.7-1994.4 ng m(-3)), and P (13.6-2054.8 ng m(-3)( for TSP and Al (217.6-3687.3 ng m(-3)), Fe (197.1-3724.9 ng m(-3)), Pt (65.9-2054.5 ng m(-3)), and P (11.0-756.6 ng m(-3)( for PM10. In the suburban sampling site, the most abundant detected metals were Al (2083.0-9664.0 ng m(-3)), Fe (360.0-7221.5 ng m(-3)), P (229.4-870.5 ng m(-3)), and Ti (137.3-849.7 ng m(-3)) for TSP and Al (218.5-4179.6 ng m(-3)), Fe (106.3-2005.1 ng m(-3)), P (251.9-908.4 ng m(-3)), and Ba (10.6-584.9 ng m(-3)) for PM10. For the crustal soil, the most abundant detected elements included Al (60,088-60,694 ppm), Fe (19,886-20,474 ppm), Ti (894-3481 ppm), and Si (365-4246 ppm). Key emission sources were identified, and the concentrations contributed from individual sources were estimated. Enrichment factor (EF) explaining a preponderance of the variance in the data was applied to the datasets. EF calculations revealed that non-crustal trace elements were more enriched in the urban than suburban sampling sites. Results of the factor analysis on the elements showed that emissions from road traffic (involving oil and fuel combustions by vehicles, platinum group elements from vehicle exhaust, and resuspension of particulate matter from polluted soil) and construction dust from nearby construction sites and electricity generation plant were the major contributors of anthropogenic metals at ambient atmosphere in Tabriz. Results of this study elucidated the need for developing pollution control strategy, especially vehicle exhaust control, and creating green spaces around the city.

Title: Statistical modeling and optimization of the phosphorus biosorption by modified Lemna minor from aqueous solution using response surface methodology (RSM)

Author(s): Naghipour, D; Taghavi, K; Jaafari, J; Mahdavi, Y; Ghozikali, MG; Ameri, R; Jamshidi, A; Mahvi, AH

Article

Abstract: Response surface methodology involving Box-Behnken design was used to evaluate the effects of three operating variables: pH, initial concentration of phosphorus, and adsorbent dosage on biosorption of phosphorus by modified Lemna minor by lab-scale batch study. Analysis of variance (ANOVA) showed pH, initial phosphorus concentration, interaction of phosphorus and adsorbent dose and the second-order effect of pH have values of Prob.>F less than 0.0500 indicating that model terms are significant for the biosorption of phosphorus. Optimum operational conditions for maximizing phosphorus biosorption were achieved at pH 4.8, initial phosphorus concentration of 19mg/L and adsorbent dosage of 5.15g/L. Under optimal value of parameters, high biosorption (89.2%) was obtained for phosphorus. Langmuir with 0.99 consistencies fitted better than Temkin, or Freundlich models. The maximum adsorption capacity of phosphorus was determined as 3.6mg/g. Pseudo-second-order kinetic model exhibited the highest correlation with data. Results suggest that the modified L. minor has potential for biosorption as a low-cost and effective absorbent for phosphorus removal from aqueous solution.

Title: Daily Fluoride Intake from Iranian Green Tea: Evaluation of Various Flavorings on Fluoride Release

Author(s): Maleki, A; Daraei, H; Mohammadi, E; Zandi, S; Teymouri, P; Mahvi, AH; Gharibi, F 

 Article

Abstract: With increased awareness of the health benefits of the compounds in green tea, especially polyphenols, its consumption is rising. The main purpose of this study is to determine the effect of different additives on the released fluoride into tea liquor and also daily fluoride intake. The concentrations of fluoride, nitrate, sulfate, and chloride were measured in 15 different flavored green teas (Refah-Lahijan). The fluoride and other anion concentrations were measured by ion chromatography method. The data were analyzed with Statistical Package for the Social Sciences version 16.0. The results showed that the minimum and maximum concentrations of fluoride in the green tea infusions were 0.162 mg/L (cinnamon-flavored green tea) and 3.29 mg/L (bagged peach-flavored green tea), respectively. The mean concentration of fluoride in the green tea leaves was 52 mg/kg, and approximately 89% of the fluoride was released from the green tea leaves into the infusions after brewing. The fluoride concentrations varied significantly among the examined green teas (P < 0.05). However, the additives had no significant effect on the fluoride release into the infusions (P > 0.05). Finally, drinking of the studied green teas cannot make a significant contribution to the daily dietary intake of F for consumers.

Title: KINETIC, ISOTHERMS AND THERMODYNAMIC MODELING FOR ADSORPTION OF ACID BLUE 92 (AB92) FROM AQUEOUS SOLUTION BY MODIFIED AZOLLA FILICOLOIDES

Author(s): Balarak, D; Mandavi, Y; Bazrafshan, E; Mahvi, AH 

Article

Abstract: Dyes are the important contaminants of the environment. The dyes are often toxic, carcinogenic and mutagenic and can lead to allergies and skin problems. Therefore, it is necessary to treat the colorfull effluents before discharging into the environment. The aim of this research was to evaluate the Azolla filicoloides ability in removal of AB92 dye from aqueous solution. The Azolla biomass was dried in the sunlight and then it was crushed and sieved to particle sizes in range of 1-2 mm. After that, it was treated with 0.1M HCl for a period of 5h. The residues concentration of AB92dye was measured by spectrophotometer in lambda max of 571 nm. The effect of pH, contact time, initial AB92 dye concentration, biosorbent dosage, kinetic and isotherm models of AB92 adsorption were investigated. The pH value of 3, contact time of 90 min, adsorbent dosage of 7 g/L and dye concentration of 10 mg/L were determined as optimum conditions for the adsorption process. The maximum Acid Blue 92 dye removal efficiency by modified Azolla filicoloides was 99% which it obtained in optimum conditions. The equilibrium data is best fitted on Langmuir isotherm and the adsorption kinetic model follows pseudo-second model. Thermodynamic parameters showed that biosorption of Acid Blue 92 was spontaneous and endothermic. This study showed that Azolla could be used as an efficient sorbent for the removal of dyes from aqueous solution.