In order to amend the superficial performance of palygorskite and improve its application, the natural palygorskite(NP) was treated in the dipping and ionic exchanging experiments using 6mol/L hydrochloric acid treatm...In order to amend the superficial performance of palygorskite and improve its application, the natural palygorskite(NP) was treated in the dipping and ionic exchanging experiments using 6mol/L hydrochloric acid treatment. The performance and pore structure of the treated palygorskite(TP) were investigated by means of microscope analyses, FT-IR, XRF, BET-SSA and full hole distribution analytical techniques. The results show that the hydrochloric acid treatment can make the gracile and aggregating compact crystal bundles inside palygorskite clay broken and dispersed, the roughness of microcrystalline surface increases, which not only can dissolve or remove dolomite but vary the superficial performance of palygorskite to some degree. The specific surface area and pore volume increase a lot, while the mean pore size decreases. The pore structure of TP changes remarkably compared with that of NP after 6mol/L hydrochloric acid treatment, and the relevant physicochemical performance can be improved.展开更多
A combined system consisting of hydrolysis acidification, denitrification and nitrification reactors was used to remove carbon and nitrogen from the nylon - 6 production wastewater, which was characterized by good bio...A combined system consisting of hydrolysis acidification, denitrification and nitrification reactors was used to remove carbon and nitrogen from the nylon - 6 production wastewater, which was characterized by good biodegradability and high nitrogen concentration. The influences of Chemical Oxygen Demand （COD） in the influent, recirculation ratio, Hydraulic Residence Time （HRT） and Dissolved Oxygen （DO） concentration on the system performances were investigated. From results it could be seen that good performances have been achieved during the overall experiments periods, and COD, Total Nitrogen （TN）, NH^＋ -N and Suspended Solids （SS） in the effluent were 53, 16, 2 and 24 mg· L^-1, respectively, which has satisfied the first standard of wastewater discharge established by Environmental Protection Agency （EPA） of China. Furthermore, results showed that operation factors, viz. COD in the influent, recirculation ratio, HRT and DO concentration, all had important influences on the system performances.展开更多
Water hyacinth is a raw material for long-term sustainable production of cellulosics ethanol. In this study, the acid pretreatment and enzymatic hydrolysis were used to evaluate to produce more sugar, to be fermented ...Water hyacinth is a raw material for long-term sustainable production of cellulosics ethanol. In this study, the acid pretreatment and enzymatic hydrolysis were used to evaluate to produce more sugar, to be fermented to ethanol. Separated hydrolysis and fermentation （SHF） studies were carried out to produce ethanol from water hyacinth leaves. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions. The optimum pretreatment conditions included T = 135 ℃, t = 30 min, and sulfuric acid concentration = 0.1 M. The residue was enzymatically hydrolyzed using the mixture of enzymes cellulase, xylanase and pectinase. The maximum enzymatic saccharification of cellulosic material （76.8%） was achieved. SHF by mono-culture of Saccharomyces cerevisiae KM1195 achieved the highest yields of ethanol. Furthermore, ethanol production was accomplished with the co-culture ofS. cerevisiae TISTR5048 and Candida tropicalis TISTR5045 which produced the highest increase in ethanol Yield. In this case, the ethanol concentration of 3.42 （g/L）, percentage of the theoretical ethanol yield of 99.9%, the ethanol yield of 0.27 g/g and the productivity of 0.22 g/L/h were obtained. This suggested that mild acid pretreatment and co-cultureare promising methods to improve enzymatic hydrolysis and ethanol production from water hyacinth.展开更多
An environmentally benign biodegradable chelant,polyepoxysuccinic acid(PESA),was used to separate heavy metals from sewage sludge from the Shanghai Taopu Wastewater Treatment Plant,China,based on chemical extraction t...An environmentally benign biodegradable chelant,polyepoxysuccinic acid(PESA),was used to separate heavy metals from sewage sludge from the Shanghai Taopu Wastewater Treatment Plant,China,based on chemical extraction technology.The extraction of chromium(Cr) from sewage sludge with an aqueous solution of PESA was studied under various conditions.It was found that the extraction of Cr using PESA was more efficient than that using ethylenediaminetetraacetic acid(EDTA) and S,S-ethylenediaminedisuccinic acid(EDDS) under similar conditions.PESA was capable of extracting Cr from the sewage sludge,and the extraction efficiency was obviously dependent on both the pH and the concentration of the chelating reagent.The extraction efficiency decreased gradually with increasing pH,and the dependence on pH decreased as the concentration of PESA increased.The extraction efficiency reached 58% under conditions of pH = 4 and a ratio of PESA to total heavy metals of 10:1.The extraction efficiency was maintained above 40% within the pH range from 1 to 7 at the high ratio of PESA to total heavy metals of 10:1.Comparing the contents of heavy metals in the sewage sludge before and after the extraction,it was found that the extracted Cr came mainly from the reducible and oxidizable fractions.展开更多
基金Project(10200202002) supported by the National Tobacco Monopolistic Bureau of China project(40473006) supportedby the National Natural Science Foundation of China project(2006KJ010A) supported by the Natural Science Key Research Foundation ofAnhui Province
文摘In order to amend the superficial performance of palygorskite and improve its application, the natural palygorskite(NP) was treated in the dipping and ionic exchanging experiments using 6mol/L hydrochloric acid treatment. The performance and pore structure of the treated palygorskite(TP) were investigated by means of microscope analyses, FT-IR, XRF, BET-SSA and full hole distribution analytical techniques. The results show that the hydrochloric acid treatment can make the gracile and aggregating compact crystal bundles inside palygorskite clay broken and dispersed, the roughness of microcrystalline surface increases, which not only can dissolve or remove dolomite but vary the superficial performance of palygorskite to some degree. The specific surface area and pore volume increase a lot, while the mean pore size decreases. The pore structure of TP changes remarkably compared with that of NP after 6mol/L hydrochloric acid treatment, and the relevant physicochemical performance can be improved.
基金Shanghai Science and Technology Committee(No.042312045)Shanghai Post-doctor Fund
文摘A combined system consisting of hydrolysis acidification, denitrification and nitrification reactors was used to remove carbon and nitrogen from the nylon - 6 production wastewater, which was characterized by good biodegradability and high nitrogen concentration. The influences of Chemical Oxygen Demand （COD） in the influent, recirculation ratio, Hydraulic Residence Time （HRT） and Dissolved Oxygen （DO） concentration on the system performances were investigated. From results it could be seen that good performances have been achieved during the overall experiments periods, and COD, Total Nitrogen （TN）, NH^＋ -N and Suspended Solids （SS） in the effluent were 53, 16, 2 and 24 mg· L^-1, respectively, which has satisfied the first standard of wastewater discharge established by Environmental Protection Agency （EPA） of China. Furthermore, results showed that operation factors, viz. COD in the influent, recirculation ratio, HRT and DO concentration, all had important influences on the system performances.
文摘Water hyacinth is a raw material for long-term sustainable production of cellulosics ethanol. In this study, the acid pretreatment and enzymatic hydrolysis were used to evaluate to produce more sugar, to be fermented to ethanol. Separated hydrolysis and fermentation （SHF） studies were carried out to produce ethanol from water hyacinth leaves. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions. The optimum pretreatment conditions included T = 135 ℃, t = 30 min, and sulfuric acid concentration = 0.1 M. The residue was enzymatically hydrolyzed using the mixture of enzymes cellulase, xylanase and pectinase. The maximum enzymatic saccharification of cellulosic material （76.8%） was achieved. SHF by mono-culture of Saccharomyces cerevisiae KM1195 achieved the highest yields of ethanol. Furthermore, ethanol production was accomplished with the co-culture ofS. cerevisiae TISTR5048 and Candida tropicalis TISTR5045 which produced the highest increase in ethanol Yield. In this case, the ethanol concentration of 3.42 （g/L）, percentage of the theoretical ethanol yield of 99.9%, the ethanol yield of 0.27 g/g and the productivity of 0.22 g/L/h were obtained. This suggested that mild acid pretreatment and co-cultureare promising methods to improve enzymatic hydrolysis and ethanol production from water hyacinth.
基金Supported by the State Key Laboratory of Pollution Control and Resource Reuse Foundation,China (No. PCRRF09004)the Natural Science Foundation of the Education Department of Fujian Province of China (Nos. JK2011055 and HX200805)
文摘An environmentally benign biodegradable chelant,polyepoxysuccinic acid(PESA),was used to separate heavy metals from sewage sludge from the Shanghai Taopu Wastewater Treatment Plant,China,based on chemical extraction technology.The extraction of chromium(Cr) from sewage sludge with an aqueous solution of PESA was studied under various conditions.It was found that the extraction of Cr using PESA was more efficient than that using ethylenediaminetetraacetic acid(EDTA) and S,S-ethylenediaminedisuccinic acid(EDDS) under similar conditions.PESA was capable of extracting Cr from the sewage sludge,and the extraction efficiency was obviously dependent on both the pH and the concentration of the chelating reagent.The extraction efficiency decreased gradually with increasing pH,and the dependence on pH decreased as the concentration of PESA increased.The extraction efficiency reached 58% under conditions of pH = 4 and a ratio of PESA to total heavy metals of 10:1.The extraction efficiency was maintained above 40% within the pH range from 1 to 7 at the high ratio of PESA to total heavy metals of 10:1.Comparing the contents of heavy metals in the sewage sludge before and after the extraction,it was found that the extracted Cr came mainly from the reducible and oxidizable fractions.
