Iranian Journal of Environmental Health Science & Engineering, 2012
Colored effluents are one of the important environment pollution sources since they contain unuse... more Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r 2 >0.99) and Langmuir (r 2 >0.99) isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r 2 >0.99) and intra-particle diffusion (r 2 >0.98) models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively.
Journal of the Taiwan Institute of Chemical Engineers, 2014
ABSTRACT The sorption potential of natural (NP) and surface modified pumice using MgCl2 (MGMP) as... more ABSTRACT The sorption potential of natural (NP) and surface modified pumice using MgCl2 (MGMP) as an abundant and low cost geo-material for the removal of Cr(VI) ion was investigated. The influence of contact time, solution pH, initial metal concentration, amount of absorbents and solution temperature was studied. Natural and modified adsorbents were characterized by means of XRD, XRF, SEM and FTIR technologies. Maximum sorption was observed at pH 1 and 100 mg/L metal concentration. Equilibrium data were accurately fitted onto Langmuir, Freundlich and Temkin isotherms, showing the heterogeneous nature of the adsorbents; maximum sorption capacity according to the Langmuir isotherm were 87.72 mg/g and 105.43 mg/g for NP and MGMP, respectively, showing a high sorption potential if compared to adsorbents used for Cr(VI) removal. Intra-particle model demonstrated that film diffusion was the rate-limiting step instead of intra-particle diffusion, as confirmed from the analysis of pseudo-second order rate constants, showing an absence of limitation due to pore diffusion. Relevance of pumice was confirmed since high regeneration yields were obtained, 94.3% in acidic conditions (1 M HCl) for spent non-modified pumice and 91.3% in alkaline conditions (4 M NaOH) for spent modified pumice.
ABSTRACT The objective of this study was to investigate the potential of natural and acid-modifie... more ABSTRACT The objective of this study was to investigate the potential of natural and acid-modified pumice as an adsorbent in phosphorous removal from aqueous solution. Various experimental parameters such as initial phosphorous concentration, adsorbent dosage, contact time, and pH were investigated. The most common isotherms and the kinetic adsorption models were used for survey of phosphorous adsorption mechanism. Results indicated that pH plays a significant role in the adsorption of phosphorous. The adsorption capacity increased with increase in contact time and initial phosphorous concentration and after 30 and 45 min, reached equilibrium for modified and natural pumice, respectively. Maximum adsorption of phosphorous (9.74 mg/g) was obtained in the pH ranging from 5 to 7, pumice dosage of 2 g/L, and contact time of 30 min using the modified pumice. Further increase of adsorbent dosage over 2 g/L didn’t have significant effect on the phosphorous adsorption. The experimental results showed that absorption process and equilibrium data were well fitted using the pseudo-second-order kinetic model (R2 > 0.99) and Langmuir No 2 isotherm (R2 > 0.99). The foreign anions such as Cl−, NO3−, SO42−, and HCO3− didn’t have noticeable effects on the phosphorous adsorption. In general, the adsorption capacity of acid-modified pumice in the same conditions is more than natural pumice (55–60%). As general conclusion; modified pumice can be used successfully as low-cost and effective absorbent for phosphorous removal from aqueous solution.
Desalination and Water Treatment - DESALIN WATER TREAT, 2012
The textile industry induces one of the main environmental pollution, mainly due to the dyes cont... more The textile industry induces one of the main environmental pollution, mainly due to the dyes containing in its effluents. There is therefore a need for their treatment prior to discharge to the environment. The removal efficiency of Acid Red 18 and Acid Red 14 dyes by zero-valent iron were investigated in this study. The effect of some parameters such as pH (3–11), contact time (15–120 min), initial dye concentration (25–100 mg l−1) and initial concentration of iron powder (0.5–2 g l−1) were examined. The results showed that dye removal efficiency increased with increasing contact time and initial concentration of iron powder on the one hand, and decreased for increasing pH and initial dye concentration on the other hand. Experimental data were rather accurately fitted onto both first-order and second-order kinetic models, even if the first-order kinetic model led to higher correlation coefficients. Comparison of the kinetic rate constants showed a low impact of the initial dye concentration and that an acidic pH of 3 was optimal for the removal of Acid Red 14 and Acid Red 18.
ABSTRACT In this study, the removal of Cr (III) from tanning effluents by Aspergillus niger isola... more ABSTRACT In this study, the removal of Cr (III) from tanning effluents by Aspergillus niger isolated from tanning environment was investigated in a bioreactor. Various experimental parameters such as initial Cr (III) concentration, pH, nutrients addition, air volume, inoculum size, contact time and temperature were investigated. The selected fungus exhibited a maximum tolerance to Cr (III) of 500 mg/L for 0.12% inoculum size. Optimal culture conditions for fungal growth and Cr (III) removal efficiency were observed to be pH 5.1, 30 °C, 32 h contact time and 4 v/v aeration rate. In addition, the effect of some nitrogen nutrients was investigated. Among used nutrients, di-hydrogen ammonium phosphate (4 g/L) was found to be the more efficient compound on chromium removal efficiency and fungal growth. In addition, sodium nitrite showed a reverse effect on growth. Without any nutrients addition, Cr (III) removal efficiency and biomass were found to be 88% and 2.12 g/L, respectively; while in presence of additional nitrogen these parameters increased up to 96% and 5.03 g/L, respectively. These results appeared especially promising showing on the one hand the efficiency of the considered microorganism, A. niger, and on the other hand the relevance of the culture configuration, airlift reactor. Experimental equilibrium data were accurately fitted onto pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, even if the highest correlation coefficient was found for the pseudo-second kinetic order model. Contrarily the results of intra-particle diffusion kinetic model revealed that intra-particle diffusion was not the rate-controlling step.
Removal of Cr (III) was investigated using Phanerochaete chrysosporium-isolated living microorgan... more Removal of Cr (III) was investigated using Phanerochaete chrysosporium-isolated living microorganism; pH, contact time, temperature and nutrients addition were examined. It was found that P. chrysosporium can tolerate up to 600 mg/L chromium solution. The optimal growth conditions of the biosorbent were found to be 35˚C, 26 h contact time and pH = 5. In addition, a complex nitrogen substrate, yeast powder, was shown to be most efficient than a synthetic one, like di-hydrogen ammonium phosphate. High chromium removal (98%) was observed in these optimal growth conditions. Experimental data were found to follow a Langmuir isotherm model (r 2 > 0.99). Maximum sorption capacity for the present biosorbent was 213 mg/g according to the Langmuir isotherm model, namely significantly higher than the values reported in the literature, even for activated carbon. The fitting of experimental data onto kinetic models showed the relevance of the pseudo-second-order model (r 2 > 0.99) for Cr (III) sorption by P. chrysosporium. In addition, a real effluent was obtained from tanning factory and was treated to examine process feasibility on real effluents.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Journal of the Taiwan Institute of Chemical Engineers, 2014
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Journal of the Taiwan Institute of Chemical Engineers, 2012
... Mohammad Noori Sepehr a , Mansur Zarrabi a , Corresponding Author Contact Information , E-mai... more ... Mohammad Noori Sepehr a , Mansur Zarrabi a , Corresponding Author Contact Information , E-mail The Corresponding Author , Abdeltif Amrane b. a, Department of Environmental Health Engineering, Faculty of Health, Alborze University of Medical Science, Karaj, Iran. ...
Journal of the Taiwan Institute of Chemical Engineers, 2014
ABSTRACT A comprehensive study involving the use of Mg/Al layered double-hydroxide nanosheets (nL... more ABSTRACT A comprehensive study involving the use of Mg/Al layered double-hydroxide nanosheets (nLDHs) was conducted for the first time in simultaneous adsorption of sulfate and hardness agents from real drinking water. The prepared adsorbent was in nano size and synthesized by only hydrolysis of urea without any addition of alkali and in the presence of hydrogen peroxide. High concentrations of hardness and sulfate agents were used for the first time to evaluate the efficiency of the prepared adsorbent for both synthetic solution and real water sample. According to scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy, the synthesized adsorbent exhibited hexagonal plates with widths of 500 to 1500 nm and thicknesses of 30 to 100 nm. A multi-response optimization-based modeling and factor analysis were also performed for assessing the optimal conditions for several responses obtained within the framework of the present adsorption process. The optimum values of the three test variables were computed as pH0 = 5.57, TC = 119.9 min and C0 = 10 g/L by using a multi-objective optimization algorithm, and the corresponding removal efficiency values were found to be 65.1% and 69.2% for hardness and sulfate, respectively.
Journal of Environmental Health Science and Engineering, 2013
Increase of impervious surfaces in urban area followed with increases in runoff volume and peak f... more Increase of impervious surfaces in urban area followed with increases in runoff volume and peak flow, leads to increase in urban storm water pollution. The polluted runoff has many adverse impacts on human life and environment. For that reason, the aim of this study was to investigate the efficiency of nano iron oxide coated sand with and without magnetic field in treatment of urban runoff. In present work, synthetic urban runoff was treated in continuous separate columns system which was filled with nano iron oxide coated sand with and without magnetic field. Several experimental parameters such as heavy metals, turbidity, pH, nitrate and phosphate were controlled for investigate of system efficiency. The prepared column materials were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDXA) instruments. SEM and EDXA analyses proved that the sand has been coated with nano iron oxide (Fe 3 O 4 ) successfully. The results of SEM and EDXA instruments well demonstrate the formation of nano iron oxide (Fe 3 O 4 ) on sand particle. Removal efficiency without magnetic field for turbidity; Pb, Zn, Cd and PO 4 were observed to be 90.8%, 73.3%, 75.8%, 85.6% and 67.5%, respectively. When magnetic field was applied, the removal efficiency for turbidity, Pb, Zn, Cd and PO 4 was increased to 95.7%, 89.5%, 79.9%, 91.5% and 75.6% respectively. In addition, it was observed that coated sand and magnetic field was not able to remove NO 3 ions. Statistical analyses of data indicated that there was a significant difference between removals of pollutants in two tested columns. Results of this study well demonstrate the efficiency of nanosized iron oxide-coated sand in treatment of urban runoff quality; upon 75% of pollutants could be removed. In addition, in the case of magnetic field system efficiency can be improved significantly. Cite this article as: Khiadani (Hajian) et al.: Urban runoff treatment using nano-sized iron oxide coated sand with and without magnetic field applying.
Journal of Environmental Health Science and Engineering, 2013
The aim of this study was to investigate the performance of a two-stage fluidized bed reactor (FB... more The aim of this study was to investigate the performance of a two-stage fluidized bed reactor (FBR) system for the post-treatment of secondary wastewater treatment plant effluents (Shahrak Gharb, Tehran, Iran). The proposed treatment scheme was evaluated using pilot-scale reactors (106-L of capacity) filled with PVC as the fluidized bed (first stage) and gravel for the filtration purpose (second stage). Aluminum sulfate (30 mg/L) and chlorine (1 mg/L) were used for the coagulation and disinfection of the effluent, respectively. To monitor the performance of the FBR system, variation of several parameters (biochemical oxygen demand (BOD 5 ), chemical oxygen demand (COD), turbidity, total phosphorous, total coliform and fecal coliform) were monitored in the effluent wastewater samples. The results showed that the proposed system could effectively reduce BOD 5 and COD below 1.95 and 4.06 mg/L, respectively. Turbidity of the effluent could be achieved below 0.75 NTU, which was lower than those reported for the disinfection purpose. The total phosphorus was reduced to 0.52 mg/L, which was near the present phosphorous standard for the prevention of eutrophication process. Depending on both microorganism concentration and applied surface loading rates (5-10 m/h), about 35 to 75% and 67 to 97% of coliform were removed without and with the chlorine addition, respectively. Findings of this study clearly confirmed the efficiency of the FBR system for the post-treatment of the secondary wastewater treatment plant effluents without any solid problem during the chlorination.
Lightweight Expanded Clay Aggregate (LECA) modified with an aqueous solution of magnesium chlorid... more Lightweight Expanded Clay Aggregate (LECA) modified with an aqueous solution of magnesium chloride MgCl 2 and hydrogen peroxide H 2 O 2 was used to remove Cr(VI) from aqueous solutions. The adsorption properties of the used adsorbents were investigated through batch studies, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), X-ray Fluorescence Spectroscopy (XRF), and Fourier Transform Infrared (FTIR) spectroscopy. The effect created by magnesium chloride on the modification of the LECA surface was greater than that of hydrogen peroxide solution and showed a substantial increase in the specific surface area which has a value of 76.12 m 2 /g for magnesium chloride modified LECA while the values of 53.72 m 2 /g, and 11.53 m 2 /g were found for hydrogen peroxide modified LECA and natural LECA, respectively. The extent of surface modification with enhanced porosity in modified LECA was apparent from the recorded SEM patterns. XRD and FTIR studies of themodified LECA surface did not show any structural distortion. The adsorption kinetics was found to follow the modified Freundlich kinetic model and the equilibrium data fitted the Sips and Dubinin-Radushkevich equations better than other models. Maximum sorption capacities were found to be 198.39, 218.29 and 236.24 mg/g for natural LECA, surface modified LECA with H 2 O 2 and surface modified LECA with MgCl 2 , respectively. Adsorbents were found to have only a weak effect on conductivity and turbidity of aqueous solutions. Spent natural and surface modified LECA with MgCl 2 was best regenerated with HCl solution, while LECA surface modified with H 2 O 2 was best regenerated with HNO 3 concentrated solution. Thermal method showed a lower regeneration percentage for all spent adsorbents.
ABSTRACT Natural and Mg2+ modified pumice were used for the removal of phosphorous. The adsorbent... more ABSTRACT Natural and Mg2+ modified pumice were used for the removal of phosphorous. The adsorbents were characterized using XRF, XRD, SEM and FTIR instrumental techniques. In the optimal conditions, namely at equilibrium time (30 min), for a phosphorus concentration of 15 mg/L and pH 6, 69 and 97% phosphorus removals were achieved using 10 g/L of natural and modified pumice adsorbents, respectively. Maximum adsorption capacities were 11.88 and 17.71 mg/g by natural and modified pumice, respectively. Pseudo-second order kinetic model was the most relevant to describe the kinetic of phosphorus adsorption. External mass transfer coefficient decreased for increasing phosphorous concentration and film diffusion was found to be the rate-controlling step. Only a very low dissolution of the adsorbent was observed, leading to a low increase in conductivity and turbidity. Removal efficiency decreased for increasing ionic strength. It also decreased in the presence of competing ions; however modified pumice remained effective, since 67% of phosphorus was removed, versus only 17% for the natural pumice. The efficiency of the modified pumice was confirmed during the regeneration tests, since 96% regeneration yield was obtained after 510 min experiment, while only 22% was observed for the raw pumice.
Natural and alkaline modified pumice stones were used for the adsorption of water hardening catio... more Natural and alkaline modified pumice stones were used for the adsorption of water hardening cations, Ca 2+ and Mg 2+ . The adsorbents were characterized using XRF, XRD, SEM and FTIR instrumental techniques. At equilibrium time and for 150 mg/L of a given cation, removal efficiencies were 83% and 94% for calcium and 48% and 73% for magnesium for raw and modified pumices, respectively. The optimal pH for raw and modified pumices were found to be 6.0, leading to the removal of 79 and 96% of calcium and 51 and 93% of magnesium by 10 g/L of raw and modified pumice adsorbents, respectively. Maximum adsorption capacities were 57.27 and 62.34 mg/g for Ca 2+ and 44.53 and 56.11 mg/g for Mg 2+ on the raw and modified pumices, respectively. Ca 2+ and Mg 2+ adsorption capacities of the pumice adsorbents decreased in the presence of competing cations. Less than 300 min were needed to achieve 99 and 92% desorption of the adsorbed Ca 2+ and 100 and 89% of the adsorbed Mg 2+ from the natural and modified pumices, respectively. After treating synthetic water solution simulating an actual water stream with the alkali-modified pumice, total hardness of the treated sample met the required standard for drinking water, namely below 300 mg/L of CaCO 3 (297.5 mg/L). The studied pumice adsorbents, and especially the treated pumice, can be therefore considered as promising low cost adsorbents, suitable for the removal of hardness ions from drinking water.
Iranian Journal of Environmental Health Science & Engineering, 2012
Colored effluents are one of the important environment pollution sources since they contain unuse... more Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal of AR14 and AR18 followed Freundlich (r 2 >0.99) and Langmuir (r 2 >0.99) isotherm models. Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r 2 >0.99) and intra-particle diffusion (r 2 >0.98) models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer. Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89% regeneration for AR14 and AR18, respectively.
Journal of the Taiwan Institute of Chemical Engineers, 2014
ABSTRACT The sorption potential of natural (NP) and surface modified pumice using MgCl2 (MGMP) as... more ABSTRACT The sorption potential of natural (NP) and surface modified pumice using MgCl2 (MGMP) as an abundant and low cost geo-material for the removal of Cr(VI) ion was investigated. The influence of contact time, solution pH, initial metal concentration, amount of absorbents and solution temperature was studied. Natural and modified adsorbents were characterized by means of XRD, XRF, SEM and FTIR technologies. Maximum sorption was observed at pH 1 and 100 mg/L metal concentration. Equilibrium data were accurately fitted onto Langmuir, Freundlich and Temkin isotherms, showing the heterogeneous nature of the adsorbents; maximum sorption capacity according to the Langmuir isotherm were 87.72 mg/g and 105.43 mg/g for NP and MGMP, respectively, showing a high sorption potential if compared to adsorbents used for Cr(VI) removal. Intra-particle model demonstrated that film diffusion was the rate-limiting step instead of intra-particle diffusion, as confirmed from the analysis of pseudo-second order rate constants, showing an absence of limitation due to pore diffusion. Relevance of pumice was confirmed since high regeneration yields were obtained, 94.3% in acidic conditions (1 M HCl) for spent non-modified pumice and 91.3% in alkaline conditions (4 M NaOH) for spent modified pumice.
ABSTRACT The objective of this study was to investigate the potential of natural and acid-modifie... more ABSTRACT The objective of this study was to investigate the potential of natural and acid-modified pumice as an adsorbent in phosphorous removal from aqueous solution. Various experimental parameters such as initial phosphorous concentration, adsorbent dosage, contact time, and pH were investigated. The most common isotherms and the kinetic adsorption models were used for survey of phosphorous adsorption mechanism. Results indicated that pH plays a significant role in the adsorption of phosphorous. The adsorption capacity increased with increase in contact time and initial phosphorous concentration and after 30 and 45 min, reached equilibrium for modified and natural pumice, respectively. Maximum adsorption of phosphorous (9.74 mg/g) was obtained in the pH ranging from 5 to 7, pumice dosage of 2 g/L, and contact time of 30 min using the modified pumice. Further increase of adsorbent dosage over 2 g/L didn’t have significant effect on the phosphorous adsorption. The experimental results showed that absorption process and equilibrium data were well fitted using the pseudo-second-order kinetic model (R2 > 0.99) and Langmuir No 2 isotherm (R2 > 0.99). The foreign anions such as Cl−, NO3−, SO42−, and HCO3− didn’t have noticeable effects on the phosphorous adsorption. In general, the adsorption capacity of acid-modified pumice in the same conditions is more than natural pumice (55–60%). As general conclusion; modified pumice can be used successfully as low-cost and effective absorbent for phosphorous removal from aqueous solution.
Desalination and Water Treatment - DESALIN WATER TREAT, 2012
The textile industry induces one of the main environmental pollution, mainly due to the dyes cont... more The textile industry induces one of the main environmental pollution, mainly due to the dyes containing in its effluents. There is therefore a need for their treatment prior to discharge to the environment. The removal efficiency of Acid Red 18 and Acid Red 14 dyes by zero-valent iron were investigated in this study. The effect of some parameters such as pH (3–11), contact time (15–120 min), initial dye concentration (25–100 mg l−1) and initial concentration of iron powder (0.5–2 g l−1) were examined. The results showed that dye removal efficiency increased with increasing contact time and initial concentration of iron powder on the one hand, and decreased for increasing pH and initial dye concentration on the other hand. Experimental data were rather accurately fitted onto both first-order and second-order kinetic models, even if the first-order kinetic model led to higher correlation coefficients. Comparison of the kinetic rate constants showed a low impact of the initial dye concentration and that an acidic pH of 3 was optimal for the removal of Acid Red 14 and Acid Red 18.
ABSTRACT In this study, the removal of Cr (III) from tanning effluents by Aspergillus niger isola... more ABSTRACT In this study, the removal of Cr (III) from tanning effluents by Aspergillus niger isolated from tanning environment was investigated in a bioreactor. Various experimental parameters such as initial Cr (III) concentration, pH, nutrients addition, air volume, inoculum size, contact time and temperature were investigated. The selected fungus exhibited a maximum tolerance to Cr (III) of 500 mg/L for 0.12% inoculum size. Optimal culture conditions for fungal growth and Cr (III) removal efficiency were observed to be pH 5.1, 30 °C, 32 h contact time and 4 v/v aeration rate. In addition, the effect of some nitrogen nutrients was investigated. Among used nutrients, di-hydrogen ammonium phosphate (4 g/L) was found to be the more efficient compound on chromium removal efficiency and fungal growth. In addition, sodium nitrite showed a reverse effect on growth. Without any nutrients addition, Cr (III) removal efficiency and biomass were found to be 88% and 2.12 g/L, respectively; while in presence of additional nitrogen these parameters increased up to 96% and 5.03 g/L, respectively. These results appeared especially promising showing on the one hand the efficiency of the considered microorganism, A. niger, and on the other hand the relevance of the culture configuration, airlift reactor. Experimental equilibrium data were accurately fitted onto pseudo-first order, pseudo-second order and intra-particle diffusion kinetic models, even if the highest correlation coefficient was found for the pseudo-second kinetic order model. Contrarily the results of intra-particle diffusion kinetic model revealed that intra-particle diffusion was not the rate-controlling step.
Removal of Cr (III) was investigated using Phanerochaete chrysosporium-isolated living microorgan... more Removal of Cr (III) was investigated using Phanerochaete chrysosporium-isolated living microorganism; pH, contact time, temperature and nutrients addition were examined. It was found that P. chrysosporium can tolerate up to 600 mg/L chromium solution. The optimal growth conditions of the biosorbent were found to be 35˚C, 26 h contact time and pH = 5. In addition, a complex nitrogen substrate, yeast powder, was shown to be most efficient than a synthetic one, like di-hydrogen ammonium phosphate. High chromium removal (98%) was observed in these optimal growth conditions. Experimental data were found to follow a Langmuir isotherm model (r 2 > 0.99). Maximum sorption capacity for the present biosorbent was 213 mg/g according to the Langmuir isotherm model, namely significantly higher than the values reported in the literature, even for activated carbon. The fitting of experimental data onto kinetic models showed the relevance of the pseudo-second-order model (r 2 > 0.99) for Cr (III) sorption by P. chrysosporium. In addition, a real effluent was obtained from tanning factory and was treated to examine process feasibility on real effluents.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Journal of the Taiwan Institute of Chemical Engineers, 2014
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
Journal of the Taiwan Institute of Chemical Engineers, 2012
... Mohammad Noori Sepehr a , Mansur Zarrabi a , Corresponding Author Contact Information , E-mai... more ... Mohammad Noori Sepehr a , Mansur Zarrabi a , Corresponding Author Contact Information , E-mail The Corresponding Author , Abdeltif Amrane b. a, Department of Environmental Health Engineering, Faculty of Health, Alborze University of Medical Science, Karaj, Iran. ...
Journal of the Taiwan Institute of Chemical Engineers, 2014
ABSTRACT A comprehensive study involving the use of Mg/Al layered double-hydroxide nanosheets (nL... more ABSTRACT A comprehensive study involving the use of Mg/Al layered double-hydroxide nanosheets (nLDHs) was conducted for the first time in simultaneous adsorption of sulfate and hardness agents from real drinking water. The prepared adsorbent was in nano size and synthesized by only hydrolysis of urea without any addition of alkali and in the presence of hydrogen peroxide. High concentrations of hardness and sulfate agents were used for the first time to evaluate the efficiency of the prepared adsorbent for both synthetic solution and real water sample. According to scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy, the synthesized adsorbent exhibited hexagonal plates with widths of 500 to 1500 nm and thicknesses of 30 to 100 nm. A multi-response optimization-based modeling and factor analysis were also performed for assessing the optimal conditions for several responses obtained within the framework of the present adsorption process. The optimum values of the three test variables were computed as pH0 = 5.57, TC = 119.9 min and C0 = 10 g/L by using a multi-objective optimization algorithm, and the corresponding removal efficiency values were found to be 65.1% and 69.2% for hardness and sulfate, respectively.
Journal of Environmental Health Science and Engineering, 2013
Increase of impervious surfaces in urban area followed with increases in runoff volume and peak f... more Increase of impervious surfaces in urban area followed with increases in runoff volume and peak flow, leads to increase in urban storm water pollution. The polluted runoff has many adverse impacts on human life and environment. For that reason, the aim of this study was to investigate the efficiency of nano iron oxide coated sand with and without magnetic field in treatment of urban runoff. In present work, synthetic urban runoff was treated in continuous separate columns system which was filled with nano iron oxide coated sand with and without magnetic field. Several experimental parameters such as heavy metals, turbidity, pH, nitrate and phosphate were controlled for investigate of system efficiency. The prepared column materials were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis (EDXA) instruments. SEM and EDXA analyses proved that the sand has been coated with nano iron oxide (Fe 3 O 4 ) successfully. The results of SEM and EDXA instruments well demonstrate the formation of nano iron oxide (Fe 3 O 4 ) on sand particle. Removal efficiency without magnetic field for turbidity; Pb, Zn, Cd and PO 4 were observed to be 90.8%, 73.3%, 75.8%, 85.6% and 67.5%, respectively. When magnetic field was applied, the removal efficiency for turbidity, Pb, Zn, Cd and PO 4 was increased to 95.7%, 89.5%, 79.9%, 91.5% and 75.6% respectively. In addition, it was observed that coated sand and magnetic field was not able to remove NO 3 ions. Statistical analyses of data indicated that there was a significant difference between removals of pollutants in two tested columns. Results of this study well demonstrate the efficiency of nanosized iron oxide-coated sand in treatment of urban runoff quality; upon 75% of pollutants could be removed. In addition, in the case of magnetic field system efficiency can be improved significantly. Cite this article as: Khiadani (Hajian) et al.: Urban runoff treatment using nano-sized iron oxide coated sand with and without magnetic field applying.
Journal of Environmental Health Science and Engineering, 2013
The aim of this study was to investigate the performance of a two-stage fluidized bed reactor (FB... more The aim of this study was to investigate the performance of a two-stage fluidized bed reactor (FBR) system for the post-treatment of secondary wastewater treatment plant effluents (Shahrak Gharb, Tehran, Iran). The proposed treatment scheme was evaluated using pilot-scale reactors (106-L of capacity) filled with PVC as the fluidized bed (first stage) and gravel for the filtration purpose (second stage). Aluminum sulfate (30 mg/L) and chlorine (1 mg/L) were used for the coagulation and disinfection of the effluent, respectively. To monitor the performance of the FBR system, variation of several parameters (biochemical oxygen demand (BOD 5 ), chemical oxygen demand (COD), turbidity, total phosphorous, total coliform and fecal coliform) were monitored in the effluent wastewater samples. The results showed that the proposed system could effectively reduce BOD 5 and COD below 1.95 and 4.06 mg/L, respectively. Turbidity of the effluent could be achieved below 0.75 NTU, which was lower than those reported for the disinfection purpose. The total phosphorus was reduced to 0.52 mg/L, which was near the present phosphorous standard for the prevention of eutrophication process. Depending on both microorganism concentration and applied surface loading rates (5-10 m/h), about 35 to 75% and 67 to 97% of coliform were removed without and with the chlorine addition, respectively. Findings of this study clearly confirmed the efficiency of the FBR system for the post-treatment of the secondary wastewater treatment plant effluents without any solid problem during the chlorination.
Lightweight Expanded Clay Aggregate (LECA) modified with an aqueous solution of magnesium chlorid... more Lightweight Expanded Clay Aggregate (LECA) modified with an aqueous solution of magnesium chloride MgCl 2 and hydrogen peroxide H 2 O 2 was used to remove Cr(VI) from aqueous solutions. The adsorption properties of the used adsorbents were investigated through batch studies, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), X-ray Fluorescence Spectroscopy (XRF), and Fourier Transform Infrared (FTIR) spectroscopy. The effect created by magnesium chloride on the modification of the LECA surface was greater than that of hydrogen peroxide solution and showed a substantial increase in the specific surface area which has a value of 76.12 m 2 /g for magnesium chloride modified LECA while the values of 53.72 m 2 /g, and 11.53 m 2 /g were found for hydrogen peroxide modified LECA and natural LECA, respectively. The extent of surface modification with enhanced porosity in modified LECA was apparent from the recorded SEM patterns. XRD and FTIR studies of themodified LECA surface did not show any structural distortion. The adsorption kinetics was found to follow the modified Freundlich kinetic model and the equilibrium data fitted the Sips and Dubinin-Radushkevich equations better than other models. Maximum sorption capacities were found to be 198.39, 218.29 and 236.24 mg/g for natural LECA, surface modified LECA with H 2 O 2 and surface modified LECA with MgCl 2 , respectively. Adsorbents were found to have only a weak effect on conductivity and turbidity of aqueous solutions. Spent natural and surface modified LECA with MgCl 2 was best regenerated with HCl solution, while LECA surface modified with H 2 O 2 was best regenerated with HNO 3 concentrated solution. Thermal method showed a lower regeneration percentage for all spent adsorbents.
ABSTRACT Natural and Mg2+ modified pumice were used for the removal of phosphorous. The adsorbent... more ABSTRACT Natural and Mg2+ modified pumice were used for the removal of phosphorous. The adsorbents were characterized using XRF, XRD, SEM and FTIR instrumental techniques. In the optimal conditions, namely at equilibrium time (30 min), for a phosphorus concentration of 15 mg/L and pH 6, 69 and 97% phosphorus removals were achieved using 10 g/L of natural and modified pumice adsorbents, respectively. Maximum adsorption capacities were 11.88 and 17.71 mg/g by natural and modified pumice, respectively. Pseudo-second order kinetic model was the most relevant to describe the kinetic of phosphorus adsorption. External mass transfer coefficient decreased for increasing phosphorous concentration and film diffusion was found to be the rate-controlling step. Only a very low dissolution of the adsorbent was observed, leading to a low increase in conductivity and turbidity. Removal efficiency decreased for increasing ionic strength. It also decreased in the presence of competing ions; however modified pumice remained effective, since 67% of phosphorus was removed, versus only 17% for the natural pumice. The efficiency of the modified pumice was confirmed during the regeneration tests, since 96% regeneration yield was obtained after 510 min experiment, while only 22% was observed for the raw pumice.
Natural and alkaline modified pumice stones were used for the adsorption of water hardening catio... more Natural and alkaline modified pumice stones were used for the adsorption of water hardening cations, Ca 2+ and Mg 2+ . The adsorbents were characterized using XRF, XRD, SEM and FTIR instrumental techniques. At equilibrium time and for 150 mg/L of a given cation, removal efficiencies were 83% and 94% for calcium and 48% and 73% for magnesium for raw and modified pumices, respectively. The optimal pH for raw and modified pumices were found to be 6.0, leading to the removal of 79 and 96% of calcium and 51 and 93% of magnesium by 10 g/L of raw and modified pumice adsorbents, respectively. Maximum adsorption capacities were 57.27 and 62.34 mg/g for Ca 2+ and 44.53 and 56.11 mg/g for Mg 2+ on the raw and modified pumices, respectively. Ca 2+ and Mg 2+ adsorption capacities of the pumice adsorbents decreased in the presence of competing cations. Less than 300 min were needed to achieve 99 and 92% desorption of the adsorbed Ca 2+ and 100 and 89% of the adsorbed Mg 2+ from the natural and modified pumices, respectively. After treating synthetic water solution simulating an actual water stream with the alkali-modified pumice, total hardness of the treated sample met the required standard for drinking water, namely below 300 mg/L of CaCO 3 (297.5 mg/L). The studied pumice adsorbents, and especially the treated pumice, can be therefore considered as promising low cost adsorbents, suitable for the removal of hardness ions from drinking water.
Uploads
Papers by mansur zarrabi