The use of new food grade polysaccharides (mucilage) obtained from Hibiscus esculentus and Trigonella foenum graceum,commonly called Okra and Fenugreek,respectively,as flocculants was described.These polysaccharides w...The use of new food grade polysaccharides (mucilage) obtained from Hibiscus esculentus and Trigonella foenum graceum,commonly called Okra and Fenugreek,respectively,as flocculants was described.These polysaccharides were used for removal of solids (suspended solids (SS) and total dissolved solids (TDS)) and dyes from real textile effluents and aqueous solutions of different class of synthetic dyes.Influences of varying polysaccharide concentration,contact time and pH on removal of pollutant from the textile...展开更多
The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent.The clay characteriz...The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent.The clay characterization shows that the used clay is a rich-smectite clay.The response surface methodology(RSM)technique based on Box-Behnken design(BBD)was used to optimize the process.At optimum conditions which are initial pH solution of 8.24,effluent flow rate of 0.5 L·min^(-1),voltage of 70 V,and added suspension of clay flow rate of 100 ml·min^(-1) the achieved color,chemical oxygen demand(COD)and total suspended solid(TSS)removal efficiencies were respectively 96.87%,89.77%and 84.46%with0.75 USD·m^(-3) as total cost.The additional laboratory experiments at optimum conditions agree with the predicted results,which confirm the accuracy and the capability of RSM to predict results in the defined space.Finally the designed process could be a good eco-friendly alternative to treat and reuse wastewater in industrial process with reasonable cost.展开更多
Physicochemical properties and metal contents of five dye-based textile effluents collected in summer and winter season, 201<span style="font-family:Verdana;"><span style="font-family:Verdana;&...Physicochemical properties and metal contents of five dye-based textile effluents collected in summer and winter season, 201<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">6</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> from Savar, Dhaka, Bangladesh were within the recommended acceptable limit. The average value of all physicochemical parameters was found high in summer season except turbidity. A total of 94 heavy metal resistant bacteria (46 gram positive & 48 gram negative) were isolated from textile effluent sample</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and among them 17 isolates were multi metal resistant. Highest tolerance level of the isolates was shown at 10 mM concentration against Pb. All the heavy metal resistant bacterial isolates were presumably grouped into 14 genera according to mor</span><span style="font-family:Verdana;">phological and biochemical assay. Three isolates designated WFB3c</span><span style="font-family:Verdana;"> (65.41%),</span><span style="font-family:Verdana;"> WFB4g (62%) and SFB5c (60.07%) were found to potentially degrade dye as </span><span style="font-family:Verdana;">well as tolerate heavy metal</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. Three potential dye decolorizer isolates were</span></span></span><span><span><span style="font-family:;" "=""> <span><span style="font-family:Verdana;">screened out and most potential one (WFB3c) was identified as </span><i><span style="font-family:Verdana;">Proteus</span></i></span><span style="font-family:Verdana;"> <i>mirabilis</i> </span><span style="font-family:Verdana;">according to</span><span> </span><span style="font-family:Verdana;">the 16S rRNA identification.</span><span> </span><span style="font-family:Verdana;">The isolated bacterial strain </span><i><span style="font-family:Verdana;">Proteus</span></i><span style="font-family:Verdana;"> <i>mirabilis</i></span><span style="font-family:Verdana;"> would be a potential candidate for microbes based treatment to decolorize dye from textile effluents.</span></span></span></span>展开更多
A selfmade positively charged nanofiltration (NF) membrane was used to treat textile dye effluent to generate water for reuse, and the factors affecting nanofiltration process such as operating pressure, feed flow a...A selfmade positively charged nanofiltration (NF) membrane was used to treat textile dye effluent to generate water for reuse, and the factors affecting nanofiltration process such as operating pressure, feed flow and membrane cleaning were investigated. With an applied pressure of 1.0 MPa and a feed flow of 40 L/h, this NF membrane has a removal of 93.3% for CODor and a reduction of approximately 51.0% in TDS, salinity and conductivity achieving the chroma removal of 100%. The permeate obtained through this membrane is suitable for recycling. Moreover, the membrane could be reused after being cleaned with 1% NaOH solution.展开更多
This study investigated the removal of dissolved organic matter(DOM) from real dyeing bio-treatment effluents(DBEs) with the use of a novel magnetic anion exchange resin(NDMP).DOMs in two typical DBEs were fract...This study investigated the removal of dissolved organic matter(DOM) from real dyeing bio-treatment effluents(DBEs) with the use of a novel magnetic anion exchange resin(NDMP).DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight(MW)(〈3 kDa) DOM fractions constituted a major portion(〉50%) of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254absorbance(SUVA254),and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon(DOC) removal via NDMP treatment was performed by comparing it with that of particle active carbon(PAC). Results indicated that the removal of DOC from DBEs via NDMP was 60%,whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC,NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants,with selected concentrations of 10% NaCl(m/m)/1%NaOH(m/m),could improve desorption efficiency.展开更多
文摘The use of new food grade polysaccharides (mucilage) obtained from Hibiscus esculentus and Trigonella foenum graceum,commonly called Okra and Fenugreek,respectively,as flocculants was described.These polysaccharides were used for removal of solids (suspended solids (SS) and total dissolved solids (TDS)) and dyes from real textile effluents and aqueous solutions of different class of synthetic dyes.Influences of varying polysaccharide concentration,contact time and pH on removal of pollutant from the textile...
文摘The aims of this study is to design and optimize the functioning of a full continuous combined process based on electrocoagulaion-adsorption on crude Tunisian clay to treat a real textile effluent.The clay characterization shows that the used clay is a rich-smectite clay.The response surface methodology(RSM)technique based on Box-Behnken design(BBD)was used to optimize the process.At optimum conditions which are initial pH solution of 8.24,effluent flow rate of 0.5 L·min^(-1),voltage of 70 V,and added suspension of clay flow rate of 100 ml·min^(-1) the achieved color,chemical oxygen demand(COD)and total suspended solid(TSS)removal efficiencies were respectively 96.87%,89.77%and 84.46%with0.75 USD·m^(-3) as total cost.The additional laboratory experiments at optimum conditions agree with the predicted results,which confirm the accuracy and the capability of RSM to predict results in the defined space.Finally the designed process could be a good eco-friendly alternative to treat and reuse wastewater in industrial process with reasonable cost.
文摘Physicochemical properties and metal contents of five dye-based textile effluents collected in summer and winter season, 201<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">6</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> from Savar, Dhaka, Bangladesh were within the recommended acceptable limit. The average value of all physicochemical parameters was found high in summer season except turbidity. A total of 94 heavy metal resistant bacteria (46 gram positive & 48 gram negative) were isolated from textile effluent sample</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> and among them 17 isolates were multi metal resistant. Highest tolerance level of the isolates was shown at 10 mM concentration against Pb. All the heavy metal resistant bacterial isolates were presumably grouped into 14 genera according to mor</span><span style="font-family:Verdana;">phological and biochemical assay. Three isolates designated WFB3c</span><span style="font-family:Verdana;"> (65.41%),</span><span style="font-family:Verdana;"> WFB4g (62%) and SFB5c (60.07%) were found to potentially degrade dye as </span><span style="font-family:Verdana;">well as tolerate heavy metal</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. Three potential dye decolorizer isolates were</span></span></span><span><span><span style="font-family:;" "=""> <span><span style="font-family:Verdana;">screened out and most potential one (WFB3c) was identified as </span><i><span style="font-family:Verdana;">Proteus</span></i></span><span style="font-family:Verdana;"> <i>mirabilis</i> </span><span style="font-family:Verdana;">according to</span><span> </span><span style="font-family:Verdana;">the 16S rRNA identification.</span><span> </span><span style="font-family:Verdana;">The isolated bacterial strain </span><i><span style="font-family:Verdana;">Proteus</span></i><span style="font-family:Verdana;"> <i>mirabilis</i></span><span style="font-family:Verdana;"> would be a potential candidate for microbes based treatment to decolorize dye from textile effluents.</span></span></span></span>
基金Funded by the Major State Basic Research Development Program of China (973 Program)( No.2003CB615706)
文摘A selfmade positively charged nanofiltration (NF) membrane was used to treat textile dye effluent to generate water for reuse, and the factors affecting nanofiltration process such as operating pressure, feed flow and membrane cleaning were investigated. With an applied pressure of 1.0 MPa and a feed flow of 40 L/h, this NF membrane has a removal of 93.3% for CODor and a reduction of approximately 51.0% in TDS, salinity and conductivity achieving the chroma removal of 100%. The permeate obtained through this membrane is suitable for recycling. Moreover, the membrane could be reused after being cleaned with 1% NaOH solution.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University (Nos.51208249,51290282)Natural Science Foundation of China (Nos.51178215,51308283)+1 种基金the Jiangsu Nature Science Fund,China (Nos.BK2010006,BK2011032)the Joint Innovation Project for Production-Study-Research in Jiangsu Province,China (No.BY2013061)
文摘This study investigated the removal of dissolved organic matter(DOM) from real dyeing bio-treatment effluents(DBEs) with the use of a novel magnetic anion exchange resin(NDMP).DOMs in two typical DBEs were fractionized using DAX-8/XAD-4 resin and ultrafiltration membranes. The hydrophilic fractions and the low molecular weight(MW)(〈3 kDa) DOM fractions constituted a major portion(〉50%) of DOMs for the two effluents. The hydrophilic and low MW fractions of both effluents were the greatest contributors of specific UV254absorbance(SUVA254),and the SUVA254 of DOM fractions decreased with hydrophobicity and MW. Two DBEs exhibited acute and chronic biotoxicities. Both acute and chronic toxicities of DOM fractions increased linearly with the increase of SUVA254 value. Kinetics of dissolved organic carbon(DOC) removal via NDMP treatment was performed by comparing it with that of particle active carbon(PAC). Results indicated that the removal of DOC from DBEs via NDMP was 60%,whereas DOC removals by PAC were lower than 15%. Acidic organics could be significantly removed with the use of NDMP. DOM with large MW in DBE could be removed significantly by using the same means. Removal efficiency of NDMP for DOM decreased with the decrease of MW. Compared with PAC,NDMP could significantly reduce the acute and chronic bio-toxicities of DBEs. NaCl/NaOH mixture regenerants,with selected concentrations of 10% NaCl(m/m)/1%NaOH(m/m),could improve desorption efficiency.