Pb2+ and Cd2+ in leachate were adsorbed on clay-solidified grouting curtain for waste landfills with equilibrium experiment. The cation exchange capacity was determined with ammonium acetate. And the concentration of ...Pb2+ and Cd2+ in leachate were adsorbed on clay-solidified grouting curtain for waste landfills with equilibrium experiment. The cation exchange capacity was determined with ammonium acetate. And the concentration of heavy metal cations in leachate was determined with atomic absorption spectrophotometer. Their equilibrium isotherms were measured, and the experimental isotherm data were analyzed by using Freundlich and Langmuir models. The results show that the adsorption capacities of the heavy metal cations are closely related to the compositions of clay-solidified grouting curtain, and the maximum adsorption appears at the ratio of cement to clay of 2∶4 in the experimental conditions. At their maximum adsorption and pH 5.0, the adsorption capacities of Pb 2+ and Cd 2+ are 16.19mg/g and 1.21mg/g. The competitive adsorption coefficients indicate that the adsorption of clay-solidified grouting curtain for Pb2+ is stronger than that for Cd 2+ . The adsorption process conforms to Freundlich’s model with related coefficient higher than 0.996.展开更多
Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed...Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed biomass in ethylene glycol system with sulfuric acid as catalyst for the precursors of polyurethane compounds was studied.The results show that giant reed biomass from metal-contaminated soil is potentially liquefied and significantly affected by solvent/solid ratio,liquefaction temperature and liquefaction time （P〈0.05）.The liquefaction rate of biomass in acidified ethylene glycol system can reach 85.2% with optimized conditions of 60 min,170 ℃,3% sulfuric acid and solvent/biomass ratio of 5：1.The hydroxyl value of liquefied products is of 481 mg KOH/g while reactive hydroxyl groups of them are abundant,which is promised as potential precursors for polyurethane compounds.The solvent liquefaction is a potential method to dispose the metal-contaminated biomass,however,the containing-metal liquefied products should be studied deeply in order to get the suitable precursors in future.展开更多
Nowadays,a certain amount of landfills in China were constructed without horizontal liner system.The research conducted focuses mainly on the contaminants from landfill leachate migrating in the aquifer of a fractured...Nowadays,a certain amount of landfills in China were constructed without horizontal liner system.The research conducted focuses mainly on the contaminants from landfill leachate migrating in the aquifer of a fractured granite area,and pollution predictions for groundwater were made by establishing numerical model with Visual Modflow combining field investigation like geological surveys,drilling,geophysical explorations,hydrogeological experiments,water quality analysis.The transportation of the chloride ion from landfill in the aquifer was simulated in the model with time frames of 2 555,3 650,5 475 and7 300 d.The model shows that from 2 555 d to 7 300 d starting from 2003,the chloride ion migrated from 900 m to 1 300 m,respectively,along the groundwater flow.The results indicate that as leachate plume migrated in the aquifer,the concentration of the pollutants can be up to 19.74 to 251.76 times that of background value.The research proves that the leachate poses a threat to the local water body and offers a reference towards groundwater pollution prevention for fractured granite landfill sites.展开更多
基金Project (200065) supported by University Key Teacher Foundation of the Ministry of Education of China
文摘Pb2+ and Cd2+ in leachate were adsorbed on clay-solidified grouting curtain for waste landfills with equilibrium experiment. The cation exchange capacity was determined with ammonium acetate. And the concentration of heavy metal cations in leachate was determined with atomic absorption spectrophotometer. Their equilibrium isotherms were measured, and the experimental isotherm data were analyzed by using Freundlich and Langmuir models. The results show that the adsorption capacities of the heavy metal cations are closely related to the compositions of clay-solidified grouting curtain, and the maximum adsorption appears at the ratio of cement to clay of 2∶4 in the experimental conditions. At their maximum adsorption and pH 5.0, the adsorption capacities of Pb 2+ and Cd 2+ are 16.19mg/g and 1.21mg/g. The competitive adsorption coefficients indicate that the adsorption of clay-solidified grouting curtain for Pb2+ is stronger than that for Cd 2+ . The adsorption process conforms to Freundlich’s model with related coefficient higher than 0.996.
基金Project(41271330)supported by the National Natural Science Foundation of ChinaProject(2012BAC09B04)supported by the National Key Technology Research and Development Program of the Ministry of Science and Technology of ChinaProject(2012FJ1010)supported by the Science and Technology Major Program of Hunan Province,China
文摘Giant reed is a suitable pioneer plant for metal-contaminated soil phytoremediation,however,it is imperative to dispose the metal-contaminated biomass after harvesting.The liquefaction of metal-contaminated giant reed biomass in ethylene glycol system with sulfuric acid as catalyst for the precursors of polyurethane compounds was studied.The results show that giant reed biomass from metal-contaminated soil is potentially liquefied and significantly affected by solvent/solid ratio,liquefaction temperature and liquefaction time （P〈0.05）.The liquefaction rate of biomass in acidified ethylene glycol system can reach 85.2% with optimized conditions of 60 min,170 ℃,3% sulfuric acid and solvent/biomass ratio of 5：1.The hydroxyl value of liquefied products is of 481 mg KOH/g while reactive hydroxyl groups of them are abundant,which is promised as potential precursors for polyurethane compounds.The solvent liquefaction is a potential method to dispose the metal-contaminated biomass,however,the containing-metal liquefied products should be studied deeply in order to get the suitable precursors in future.
基金Project(12JJ305)supported by the Education Department of Hunan Province,China
文摘Nowadays,a certain amount of landfills in China were constructed without horizontal liner system.The research conducted focuses mainly on the contaminants from landfill leachate migrating in the aquifer of a fractured granite area,and pollution predictions for groundwater were made by establishing numerical model with Visual Modflow combining field investigation like geological surveys,drilling,geophysical explorations,hydrogeological experiments,water quality analysis.The transportation of the chloride ion from landfill in the aquifer was simulated in the model with time frames of 2 555,3 650,5 475 and7 300 d.The model shows that from 2 555 d to 7 300 d starting from 2003,the chloride ion migrated from 900 m to 1 300 m,respectively,along the groundwater flow.The results indicate that as leachate plume migrated in the aquifer,the concentration of the pollutants can be up to 19.74 to 251.76 times that of background value.The research proves that the leachate poses a threat to the local water body and offers a reference towards groundwater pollution prevention for fractured granite landfill sites.
