Mokhtar Arami - Profile on Academia.edu (original) (raw)

Papers by Mokhtar Arami

Sampling and Analysis of Aerosols in the Black Sea Atmosphere

Black Sea Oceanography, 1991

Application of response surface methodology for dye removal from aqueous solution by activated carbon prepared from pomegranate residual

... M. Rajasimman a , Corresponding Author Contact Information , E-mail The Corresponding Author ... more ... M. Rajasimman a , Corresponding Author Contact Information , E-mail The Corresponding Author and P. Karthic b. a Department of Chemical Engineering, Annamalai University, Annamalai Nagar-608002, Tamil Nadu, India. ...

Optimization of electrocoagulation process for removal of an azo dye using response surface methodology and investigation on the occurrence of destructive side reactions

Chemical Engineering and Processing: Process Intensification, 2013

ABSTRACT The optimization and modeling of the electrocoagulation process which conducted by means... more ABSTRACT The optimization and modeling of the electrocoagulation process which conducted by means of iron (EC-Fe) and aluminum (EC-Al) anodes, in the removal of C.I. Reactive Red 43 were performed through the response surface methodology (RSM). Moreover, the occurrence of possible destructive reactions during both EC-Fe and EC-Al processes was investigated using UV–Vis spectrometry, total organic carbon (TOC) and GC–MS analyses. The electrocoagulation experiments were carried out in a monopolar batch reactor using two anodes and two cathodes in parallel connections. Current density, time, pH and chloride concentration were considered as input variables for RSM. The analysis of variance revealed a high coefficient of determination (REC-Fe2=0.981 and REC-Al2=0.934) between experimental removal efficiency and predicted one by RSM developed models. The optimum conditions proposed by RSM to reach the maximum RR43 removal through the EC-Fe were different from the ones proposed for the EC-Al. At the optimum conditions, the removal efficiency of dye was more than 99% for both processes, whereas 90.58% and 98.37% of initial TOC concentration decreased during EC-Fe and EC-Al processes, respectively. The analyses results confirmed that beside sweep flocculation mechanism, known as the main removal mechanism, the degradation of dye was occurred during EC-Fe as a minor pathway.

Environmental Engineering and Management Journal, 2012

The aim of this study is to employ the response surface methodology (RSM) for optimizing three op... more The aim of this study is to employ the response surface methodology (RSM) for optimizing three operating variables of adsorption process for the removal of reactive blue 19 (RB19) dye using wood waste (WW) of Mazandaran wood and paper industries (MWPI). For the maximum dye removal efficiency (100%), optimum conditions were obtained at initial pH of 1.72, adsorbent dose of 13.36 g/L and initial dye concentration of 65.91 mg/L with RSM program. Under these experimental conditions, the dye removal efficiency and q (the amount of removed dye per unit mass of adsorbent) were observed 96.38% and 4.75 mg/g, respectively which confirms close to RSM results. According to the ANOVA results, the model presents high R2value of 99.3% for RB19 dye removal using wood waste. For the real textile wastewater containing RB 19 dye, the dye removal efficiency and q were obtained 87.73% and 32.78 mg/g, respectively. The maximum desorption efficiency of the dye loaded adsorbent was obtained 58.69% using alkaline solution (pH of 12.4) under the optimum conditions of RSM results.

Journal of Polymer Research, 2016

Mixed matrix concept using cellulose nanosheets (CNs) and polyethersulfone was employed to fabric... more Mixed matrix concept using cellulose nanosheets (CNs) and polyethersulfone was employed to fabricate hierarchical porous membrane with potential application for efficient dye/salt mixture fractionation. To this end, CNs was extracted by acid hydrolysis of alpha cellulose and incorporated in polyethersulfone casting solutions at four concentration levels. After that, membranes were manufactured by typical nonsolvent induced phase separation method. Effect of CNs incorporation on thermodynamic stability and phase separation behavior of polymer solution was investigated by construction of phase diagram. In addition, the obtained flat-sheet membranes characteristics including surface morphology, cross-section structure, thermal decomposition, porosity, pore size and pure water flux, were investigated. CNs filled membranes were also evaluated for fractionation of direct dye/NaCl binary mixture. Results reveal that, two stages of phase separation process are observed in CNs filled solution, in which the early stage can initiate with lower water content. This leads to fabrication of more porous membranes with longer finger-like cavities which were confirmed by FESEM analysis of the membranes. Results of TGA reveal that, two weight loss steps forms during decomposition process of CNs filled membranes. It was also observed that addition of 1.5 wt.% CNs into polymer solution increases water permeability from 20 to 90 L/m 2 h. Application of 1.5 wt.% CNs filled membranes for fractionation of binary mixture containing direct red 23 (1 g/l) and NaCl (40 g/l) revealed that dye rejection and salt penetration percentages of obtained membranes are 98 % and 97 % respectively. Results confirm the potential of CNs filled membrane as a novel and promising approach for highly efficient fractionation of salt/dye mixtures, owning to its fabrication simplicity and perfect structural features. Keywords Cellulose nanosheets. Mixed matrix membrane. Thermodynamic stability. Dye/salt mixture fractionation Highlights •PES/CNs mixed matrix membranes were prepared. •CNs can induce two-stage phase separation during the nonsolvent induced phase separation process. •CNs filled membranes have more porous skin layer and longer fingerlike cavities than unfilled case. •Addition of CNs greatly improves water permeability of membranes. •Dye/salt aqueous mixture can be efficiently fractionated by CNs filled membranes.

Water Practice and Technology, 2011

The aim of this study is to examine the effect of operational parameters on fluoride removal usin... more The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electro...

Using wood waste of of mazandaran wood and the paper industry as adsorbent for reactive blue 19 removal

Dye removal using final sludge of mazandaran wood and the paper industry and its ash

Paper: REMOVAL OF CI ACID BLUE 292 USING POLYALUMINUM CHLORIDE

Paper: PREPARATION OF NANOFILTRATION MEMBRANES VIA UV PHOTO-GRAFTING TECHNIQUE FOR SEPARATION OF ACID DYES AT DIFFERENT PH VALUES

Preparation of nanofiltration membranes via uv photografting technique for separation of acid dyes at different ph values

J. Color Sci. …, 2009

Page 1. *Corresponding author: arami@aut.ac.ir available online @ www.jcst.icrc.ac.ir @ /2) 1387 ... more Page 1. *Corresponding author: arami@aut.ac.ir available online @ www.jcst.icrc.ac.ir @ /2) 1387 (< 247 237 > @ @ > @ pH > 1< 2* < @ 3 @> < 4 1 < < < > < 4413 - 15784 2 < < < > < 4413 - 15784 3 < > > < < 51167 - 87317 4 < < < < < 654 - 16765 ...

JOURNAL OF COLOR SCIENCE …, 2008

This study aims to investigate the performance of polyaluminum chloride (PAC) as a coagulant to r... more This study aims to investigate the performance of polyaluminum chloride (PAC) as a coagulant to remove Acid blue 292 (AB292), which is used widely in textile industry in Iran. The effect of pH, coagulant dosage, kaolinite (as a natural coagulant aid), and initial dye ...

Water Science and Technology, 2011

Chitosan was selected as a natural coagulating agent for the removal of acid dyes (Acid Blue 292;... more Chitosan was selected as a natural coagulating agent for the removal of acid dyes (Acid Blue 292; AB292, and Acid Red 398; AR398) from dye-containing solutions. The study was organised in two phases. In phase 1, chitosan was used alone as a natural coagulant for the removal of the dyes. For this purpose, the effect of different parameters including pH, chitosan dosage and initial dye concentration on the dye removal efficiency was examined. In phase 2 of the study, the application of chitosan as a natural coagulant aid in conjunction with polyaluminium chloride (PAC) was assessed. According to the results of phase 1, the best removal efficiencies occurred in an acidic pH range (less than 6) for both of the dyes. Also, excellent dye removal results (about 90%) were achieved with relatively low dosages of chitosan (30–35 mg L−1 for AB292 and 50–60 mg L−1 for AR398). However, the initial concentration of the dyes severely influenced the coagulation performance of chitosan, which can co...

A comparison study on Acid Red 119 dye removal using two different types of waterworks sludge

Water Science and Technology, 2010

This study aims to compare the performance of two waterworks sludge samples, ferric chloride slud... more This study aims to compare the performance of two waterworks sludge samples, ferric chloride sludge (FCS) and polyaluminium chloride sludge (PACS), as coagulants to remove Acid Red 119 (AR119) dye from aqueous solution. A series of batch experiments were performed to investigate the effect of initial pH, coagulant dosage and initial dye concentration on coagulation/flocculation process efficiency. Results showed that the dye removal was strongly pH-dependent and followed the same trend for both coagulants, increasing steadily with decreasing initial pH in the range of 3–12. With the increase of coagulant dosage, the dye removal efficiency increased and no re-stabilization phenomenon was observed. However, the coagulant dosage needed for the maximum dye removal efficiency was much lower for FCS (150 mg dried sludge/L) in compare with PACS (5.5 g dried sludge/L). It seems that both charge neutralization and sweep flocculation mechanisms were involved in removal of AR119 using FCS and ...

Wastewaters containing dyes are qualitatively dangerous and toxic. Researchers have, therefore, c... more Wastewaters containing dyes are qualitatively dangerous and toxic. Researchers have, therefore, concentrated on simple and efficient methods for their treatment. The present study investigates the preparation of adsorbents from waste materials and evaluation of their performance in removing dyes from aqueous solutions. For this purpose, activated carbon is prepared from pomegranate residuals by phosphoric acid (37%) activation and used to remove the reactive blue 19 from aqueous solutions. Furthermore, the activated carbon thus obtained is characterized in terms of its morphological and textural properties, and the effects of such operation parameters as contact time, initial pH, adsorbent dose, and initial dye concentration on dye removal efficiency are evaluated. Results indicate the high surface area (SBET) of the pomegranate-based activated carbon (572.53 m2/g) and its maximum dye removal efficiency (98.16%) for a contact time of 5 minutes, at an initial pH of 11 with 3.5 gr/L of the adsorbent in an aqueous solution with an initial dye concentration of 300 mg/L. Finally, adsorption isotherm studies (Langmuir, Freundlich, and Temkin) and kinetic studies (the pseudo first-order, pseudo-secondorder, Elovich and intraparticle diffusion kinetic models) are performed to show that the adsorption process follows a Langmuir isotherm equation (R2=0.955) and the pseudo-second order kinetic model (R2=0.997).

This note revisits the literature evaluating the thermodynamic parameters of adsorption equilibri... more This note revisits the literature evaluating the thermodynamic parameters of adsorption equilibrium uptakes of heavy metals and dyes from water and wastewater streams using low-cost adsorbents derived from agricultural waste, industrial wastes, inorganic particulates, or some natural products. We highlighted the possible flaws in some adsorption studies when their thermodynamic parameters were assessed, since compensation effects during enthalpy and entropy evaluation were possibly overlooked.

Environmental Engineering and Management Journal

In this study, response surface methodology (RSM) method was applied based on a five-level and fo... more In this study, response surface methodology (RSM) method was applied based on a five-level and four-variable central composite design. The optimization of the C.I. Direct Red 81 (DR81) removal by the combination of electrocoagulation (EC) and UV processes was also performed. The effect of initial pH, reaction time, current density and initial dye concentration on the dye removal was investigated to obtain the optimal experimental conditions. The optimal conditions with the dye removal of 95% were found to be at initial pH of 3.78, reaction time of 6.44 min, current density of 62 A/m 2 and initial dye concentration of 111.5 mg/L. The experimental value for dye removal (94.36%) was in a satisfactory agreement with the predicted value. The kinetic of dye removal was investigated at various initial pH and high correlation coefficients (R 2 > 0.95) indicated that the DR81 removal has followed second order kinetic model. The results showed that UV irradiation has enhanced the EC performance and COD removal efficiency. The results also indicate that the proposed combined method has a high efficiency and RSM experimental design is a proper method for modeling the removal processing of DR81.

Environmental Engineering and Management Journal

The paper compares the electrocoagulation performance during the removal of Acid Brown 14, Acid Y... more The paper compares the electrocoagulation performance during the removal of Acid Brown 14, Acid Yellow 17, Acid Blue 113 and Acid Black 172 dyes from aqueous solutions. For this purpose, pH changes and effectiveness of main parameters including initial dye concentrations and current densities for the selected dyes were examined. In addition, effluent turbidity, energy consumption and amounts of released aluminum were also investigated. The present work shows that Acid Yellow 17 removal efficiencies were less than 30% in contrast with more than 90% for Acid Brown 14, Acid Blue 113 and Acid Black 172 at the end of experiments. The dye removal efficiencies, within first time interval (5 min) and at the best elimination conditions (initial dye concentration=100 mg/L and current density=250 A/m 2) were measured 12.47%, 85.67%, 95.07% and 99.52% for Acid Yellow 17, Acid Black 172, Acid Brown 14 and Acid Blue 113, respectively.

Environmental Engineering and Management Journal

In this research, response surface methodology (RSM) was applied to model the effect of main oper... more In this research, response surface methodology (RSM) was applied to model the effect of main operational variables including initial pH, initial phosphate concentration, current density and reaction time on phosphate removal by electrocoagulation. It was found that the decrease of initial pH and initial phosphate concentration, and the increase of current density and reaction time are beneficial for improving phosphate removal efficiency. According to the ANOVA (analysis of variance) results, the model presented high R 2 value of 96.9% for phosphate removal efficiency which indicates that the accuracy of the polynomial model is acceptable. According to Minitab output, the initial pH of 3, initial phosphate concentration of 400mg/l, current density of 0.0166A/cm 2 and reaction time of 11.72 min obtained as optimum experimental parameter. Phosphate removal efficiency of 85.8% was observed in the experiment at optimum conditions, which was close to the model predicted result of 90%. It can be concluded that RSM is a powerful tool for evaluation and optimization of electrocoagulation process for phosphate removal.

Antimicrobial and Dyeing studies of treated cotton fabrics by prepared Chitosan-PAMAM Dendrimer/Ag Nano-emulsion

Fibers and Polymers, 2015

Sampling and Analysis of Aerosols in the Black Sea Atmosphere

Black Sea Oceanography, 1991

Application of response surface methodology for dye removal from aqueous solution by activated carbon prepared from pomegranate residual

... M. Rajasimman a , Corresponding Author Contact Information , E-mail The Corresponding Author ... more ... M. Rajasimman a , Corresponding Author Contact Information , E-mail The Corresponding Author and P. Karthic b. a Department of Chemical Engineering, Annamalai University, Annamalai Nagar-608002, Tamil Nadu, India. ...

Optimization of electrocoagulation process for removal of an azo dye using response surface methodology and investigation on the occurrence of destructive side reactions

Chemical Engineering and Processing: Process Intensification, 2013

ABSTRACT The optimization and modeling of the electrocoagulation process which conducted by means... more ABSTRACT The optimization and modeling of the electrocoagulation process which conducted by means of iron (EC-Fe) and aluminum (EC-Al) anodes, in the removal of C.I. Reactive Red 43 were performed through the response surface methodology (RSM). Moreover, the occurrence of possible destructive reactions during both EC-Fe and EC-Al processes was investigated using UV–Vis spectrometry, total organic carbon (TOC) and GC–MS analyses. The electrocoagulation experiments were carried out in a monopolar batch reactor using two anodes and two cathodes in parallel connections. Current density, time, pH and chloride concentration were considered as input variables for RSM. The analysis of variance revealed a high coefficient of determination (REC-Fe2=0.981 and REC-Al2=0.934) between experimental removal efficiency and predicted one by RSM developed models. The optimum conditions proposed by RSM to reach the maximum RR43 removal through the EC-Fe were different from the ones proposed for the EC-Al. At the optimum conditions, the removal efficiency of dye was more than 99% for both processes, whereas 90.58% and 98.37% of initial TOC concentration decreased during EC-Fe and EC-Al processes, respectively. The analyses results confirmed that beside sweep flocculation mechanism, known as the main removal mechanism, the degradation of dye was occurred during EC-Fe as a minor pathway.

Environmental Engineering and Management Journal, 2012

The aim of this study is to employ the response surface methodology (RSM) for optimizing three op... more The aim of this study is to employ the response surface methodology (RSM) for optimizing three operating variables of adsorption process for the removal of reactive blue 19 (RB19) dye using wood waste (WW) of Mazandaran wood and paper industries (MWPI). For the maximum dye removal efficiency (100%), optimum conditions were obtained at initial pH of 1.72, adsorbent dose of 13.36 g/L and initial dye concentration of 65.91 mg/L with RSM program. Under these experimental conditions, the dye removal efficiency and q (the amount of removed dye per unit mass of adsorbent) were observed 96.38% and 4.75 mg/g, respectively which confirms close to RSM results. According to the ANOVA results, the model presents high R2value of 99.3% for RB19 dye removal using wood waste. For the real textile wastewater containing RB 19 dye, the dye removal efficiency and q were obtained 87.73% and 32.78 mg/g, respectively. The maximum desorption efficiency of the dye loaded adsorbent was obtained 58.69% using alkaline solution (pH of 12.4) under the optimum conditions of RSM results.

Journal of Polymer Research, 2016

Mixed matrix concept using cellulose nanosheets (CNs) and polyethersulfone was employed to fabric... more Mixed matrix concept using cellulose nanosheets (CNs) and polyethersulfone was employed to fabricate hierarchical porous membrane with potential application for efficient dye/salt mixture fractionation. To this end, CNs was extracted by acid hydrolysis of alpha cellulose and incorporated in polyethersulfone casting solutions at four concentration levels. After that, membranes were manufactured by typical nonsolvent induced phase separation method. Effect of CNs incorporation on thermodynamic stability and phase separation behavior of polymer solution was investigated by construction of phase diagram. In addition, the obtained flat-sheet membranes characteristics including surface morphology, cross-section structure, thermal decomposition, porosity, pore size and pure water flux, were investigated. CNs filled membranes were also evaluated for fractionation of direct dye/NaCl binary mixture. Results reveal that, two stages of phase separation process are observed in CNs filled solution, in which the early stage can initiate with lower water content. This leads to fabrication of more porous membranes with longer finger-like cavities which were confirmed by FESEM analysis of the membranes. Results of TGA reveal that, two weight loss steps forms during decomposition process of CNs filled membranes. It was also observed that addition of 1.5 wt.% CNs into polymer solution increases water permeability from 20 to 90 L/m 2 h. Application of 1.5 wt.% CNs filled membranes for fractionation of binary mixture containing direct red 23 (1 g/l) and NaCl (40 g/l) revealed that dye rejection and salt penetration percentages of obtained membranes are 98 % and 97 % respectively. Results confirm the potential of CNs filled membrane as a novel and promising approach for highly efficient fractionation of salt/dye mixtures, owning to its fabrication simplicity and perfect structural features. Keywords Cellulose nanosheets. Mixed matrix membrane. Thermodynamic stability. Dye/salt mixture fractionation Highlights •PES/CNs mixed matrix membranes were prepared. •CNs can induce two-stage phase separation during the nonsolvent induced phase separation process. •CNs filled membranes have more porous skin layer and longer fingerlike cavities than unfilled case. •Addition of CNs greatly improves water permeability of membranes. •Dye/salt aqueous mixture can be efficiently fractionated by CNs filled membranes.

Water Practice and Technology, 2011

The aim of this study is to examine the effect of operational parameters on fluoride removal usin... more The aim of this study is to examine the effect of operational parameters on fluoride removal using electrocoagulation method. For this purpose, various operational parameters including initial pH, initial fluoride concentration, applied current, reaction time, electrode connection mode, anode material, electrolyte salt, electrolyte concentration, number of electrodes and interelectrode distance were investigated. The highest defluoridation efficiency achieved at initial pH 6. In the case of initial fluoride concentration, maximum removal efficiency (98.5%) obtained at concentration of 25mg/l. The increase of applied current and reaction time improved defluoridation efficiency up to 99%. The difference of fluoride removal efficiencies between monopolar and bipolar series and monopolar parallel were significant, especially at reaction time of 5 min. When aluminum used as anode material, higher removal efficiency (98.5%) achieved compared to that of iron anode (67.7%). The best electro...

Using wood waste of of mazandaran wood and the paper industry as adsorbent for reactive blue 19 removal

Dye removal using final sludge of mazandaran wood and the paper industry and its ash

Paper: REMOVAL OF CI ACID BLUE 292 USING POLYALUMINUM CHLORIDE

Paper: PREPARATION OF NANOFILTRATION MEMBRANES VIA UV PHOTO-GRAFTING TECHNIQUE FOR SEPARATION OF ACID DYES AT DIFFERENT PH VALUES

Preparation of nanofiltration membranes via uv photografting technique for separation of acid dyes at different ph values

J. Color Sci. …, 2009

Page 1. *Corresponding author: arami@aut.ac.ir available online @ www.jcst.icrc.ac.ir @ /2) 1387 ... more Page 1. *Corresponding author: arami@aut.ac.ir available online @ www.jcst.icrc.ac.ir @ /2) 1387 (< 247 237 > @ @ > @ pH > 1< 2* < @ 3 @> < 4 1 < < < > < 4413 - 15784 2 < < < > < 4413 - 15784 3 < > > < < 51167 - 87317 4 < < < < < 654 - 16765 ...

JOURNAL OF COLOR SCIENCE …, 2008

This study aims to investigate the performance of polyaluminum chloride (PAC) as a coagulant to r... more This study aims to investigate the performance of polyaluminum chloride (PAC) as a coagulant to remove Acid blue 292 (AB292), which is used widely in textile industry in Iran. The effect of pH, coagulant dosage, kaolinite (as a natural coagulant aid), and initial dye ...

Water Science and Technology, 2011

Chitosan was selected as a natural coagulating agent for the removal of acid dyes (Acid Blue 292;... more Chitosan was selected as a natural coagulating agent for the removal of acid dyes (Acid Blue 292; AB292, and Acid Red 398; AR398) from dye-containing solutions. The study was organised in two phases. In phase 1, chitosan was used alone as a natural coagulant for the removal of the dyes. For this purpose, the effect of different parameters including pH, chitosan dosage and initial dye concentration on the dye removal efficiency was examined. In phase 2 of the study, the application of chitosan as a natural coagulant aid in conjunction with polyaluminium chloride (PAC) was assessed. According to the results of phase 1, the best removal efficiencies occurred in an acidic pH range (less than 6) for both of the dyes. Also, excellent dye removal results (about 90%) were achieved with relatively low dosages of chitosan (30–35 mg L−1 for AB292 and 50–60 mg L−1 for AR398). However, the initial concentration of the dyes severely influenced the coagulation performance of chitosan, which can co...

A comparison study on Acid Red 119 dye removal using two different types of waterworks sludge

Water Science and Technology, 2010

This study aims to compare the performance of two waterworks sludge samples, ferric chloride slud... more This study aims to compare the performance of two waterworks sludge samples, ferric chloride sludge (FCS) and polyaluminium chloride sludge (PACS), as coagulants to remove Acid Red 119 (AR119) dye from aqueous solution. A series of batch experiments were performed to investigate the effect of initial pH, coagulant dosage and initial dye concentration on coagulation/flocculation process efficiency. Results showed that the dye removal was strongly pH-dependent and followed the same trend for both coagulants, increasing steadily with decreasing initial pH in the range of 3–12. With the increase of coagulant dosage, the dye removal efficiency increased and no re-stabilization phenomenon was observed. However, the coagulant dosage needed for the maximum dye removal efficiency was much lower for FCS (150 mg dried sludge/L) in compare with PACS (5.5 g dried sludge/L). It seems that both charge neutralization and sweep flocculation mechanisms were involved in removal of AR119 using FCS and ...

Wastewaters containing dyes are qualitatively dangerous and toxic. Researchers have, therefore, c... more Wastewaters containing dyes are qualitatively dangerous and toxic. Researchers have, therefore, concentrated on simple and efficient methods for their treatment. The present study investigates the preparation of adsorbents from waste materials and evaluation of their performance in removing dyes from aqueous solutions. For this purpose, activated carbon is prepared from pomegranate residuals by phosphoric acid (37%) activation and used to remove the reactive blue 19 from aqueous solutions. Furthermore, the activated carbon thus obtained is characterized in terms of its morphological and textural properties, and the effects of such operation parameters as contact time, initial pH, adsorbent dose, and initial dye concentration on dye removal efficiency are evaluated. Results indicate the high surface area (SBET) of the pomegranate-based activated carbon (572.53 m2/g) and its maximum dye removal efficiency (98.16%) for a contact time of 5 minutes, at an initial pH of 11 with 3.5 gr/L of the adsorbent in an aqueous solution with an initial dye concentration of 300 mg/L. Finally, adsorption isotherm studies (Langmuir, Freundlich, and Temkin) and kinetic studies (the pseudo first-order, pseudo-secondorder, Elovich and intraparticle diffusion kinetic models) are performed to show that the adsorption process follows a Langmuir isotherm equation (R2=0.955) and the pseudo-second order kinetic model (R2=0.997).

This note revisits the literature evaluating the thermodynamic parameters of adsorption equilibri... more This note revisits the literature evaluating the thermodynamic parameters of adsorption equilibrium uptakes of heavy metals and dyes from water and wastewater streams using low-cost adsorbents derived from agricultural waste, industrial wastes, inorganic particulates, or some natural products. We highlighted the possible flaws in some adsorption studies when their thermodynamic parameters were assessed, since compensation effects during enthalpy and entropy evaluation were possibly overlooked.

Environmental Engineering and Management Journal

In this study, response surface methodology (RSM) method was applied based on a five-level and fo... more In this study, response surface methodology (RSM) method was applied based on a five-level and four-variable central composite design. The optimization of the C.I. Direct Red 81 (DR81) removal by the combination of electrocoagulation (EC) and UV processes was also performed. The effect of initial pH, reaction time, current density and initial dye concentration on the dye removal was investigated to obtain the optimal experimental conditions. The optimal conditions with the dye removal of 95% were found to be at initial pH of 3.78, reaction time of 6.44 min, current density of 62 A/m 2 and initial dye concentration of 111.5 mg/L. The experimental value for dye removal (94.36%) was in a satisfactory agreement with the predicted value. The kinetic of dye removal was investigated at various initial pH and high correlation coefficients (R 2 > 0.95) indicated that the DR81 removal has followed second order kinetic model. The results showed that UV irradiation has enhanced the EC performance and COD removal efficiency. The results also indicate that the proposed combined method has a high efficiency and RSM experimental design is a proper method for modeling the removal processing of DR81.

Environmental Engineering and Management Journal

The paper compares the electrocoagulation performance during the removal of Acid Brown 14, Acid Y... more The paper compares the electrocoagulation performance during the removal of Acid Brown 14, Acid Yellow 17, Acid Blue 113 and Acid Black 172 dyes from aqueous solutions. For this purpose, pH changes and effectiveness of main parameters including initial dye concentrations and current densities for the selected dyes were examined. In addition, effluent turbidity, energy consumption and amounts of released aluminum were also investigated. The present work shows that Acid Yellow 17 removal efficiencies were less than 30% in contrast with more than 90% for Acid Brown 14, Acid Blue 113 and Acid Black 172 at the end of experiments. The dye removal efficiencies, within first time interval (5 min) and at the best elimination conditions (initial dye concentration=100 mg/L and current density=250 A/m 2) were measured 12.47%, 85.67%, 95.07% and 99.52% for Acid Yellow 17, Acid Black 172, Acid Brown 14 and Acid Blue 113, respectively.

Environmental Engineering and Management Journal

In this research, response surface methodology (RSM) was applied to model the effect of main oper... more In this research, response surface methodology (RSM) was applied to model the effect of main operational variables including initial pH, initial phosphate concentration, current density and reaction time on phosphate removal by electrocoagulation. It was found that the decrease of initial pH and initial phosphate concentration, and the increase of current density and reaction time are beneficial for improving phosphate removal efficiency. According to the ANOVA (analysis of variance) results, the model presented high R 2 value of 96.9% for phosphate removal efficiency which indicates that the accuracy of the polynomial model is acceptable. According to Minitab output, the initial pH of 3, initial phosphate concentration of 400mg/l, current density of 0.0166A/cm 2 and reaction time of 11.72 min obtained as optimum experimental parameter. Phosphate removal efficiency of 85.8% was observed in the experiment at optimum conditions, which was close to the model predicted result of 90%. It can be concluded that RSM is a powerful tool for evaluation and optimization of electrocoagulation process for phosphate removal.

Antimicrobial and Dyeing studies of treated cotton fabrics by prepared Chitosan-PAMAM Dendrimer/Ag Nano-emulsion

Fibers and Polymers, 2015