Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake...Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake of heavy metal ions. In this study, biosorbents derived from the biomass of a group of marine macroalgae were used for the removal and recovery of heavy metal ions from aqueous solutions. Results indicated that the biosorbents have high uptake capacities and affinities for a number of heavy metal ions. The uptake capacities of the biosorbents were in the range of 1.0 to 1.5mmol·g-1 for divalent heavy metal ions. The kinetics of the uptake process was fast and the process can be used in both batch and fixed-bed operations. It appears that the biosorption process by using biosorbents from marine macroalgae can be an efficient and cost effective technology for the treatment of heavy metal containing wastewater.展开更多
The effects of the coagulation-flocculation process using polyaluminium chloride (PAC) and its aids on the removal of organics and nutrient in the combined sewage from Shanghai Zhuyuan First Municipal Wastewater Treat...The effects of the coagulation-flocculation process using polyaluminium chloride (PAC) and its aids on the removal of organics and nutrient in the combined sewage from Shanghai Zhuyuan First Municipal Wastewater Treatment Plant are studied. The coagulant aids include cationic polyacrylamide (PAM), polyvinyl alcohol (PVA), activated silica (AS) and a kind of polyelectrolyte called AN prepared by the authors. The coagulating solution was added to the glass jar holding 1 L wastewater and stirred to a uniform mixture which was stilled to let the supernatant turn out. The supernatant was analyzed to see the removal efficiencies of suspended solid (SS), chemical oxygen demand (COD), soluble chemical oxygen demand (S-COD), total phosphorus (TP) and orthophosphate (PO4 -P). It is found that PAC is efficient in reducing those five matters, PAM, PVA and 3? AN each faciliates the reduction of TP, SS, COD and S-COD and has little contribution to the removal of ammonia nitrigen and orthophosphate, and AS is noneffective at all. The coagulation-flocculation process with PAC has demonstrated applicable to the treatment of combined sewage in Shanghai, and it involves mainly the sweep coagulation mechanism and maybe some more complicated mechanism as well.展开更多
The process of adsorption of metal ions by immobilized marine algae with the existence of clay was investigated. It can be noted from the results that, after mixing with clay, the adsorption rate increases rapidly wit...The process of adsorption of metal ions by immobilized marine algae with the existence of clay was investigated. It can be noted from the results that, after mixing with clay, the adsorption rate increases rapidly with the increasing amount of the marine algae. When pH=5, the best ratio between the clay and the marine algae is 1:4 for Pb2+. The result of in situ handling of the waste water containing heavy metals shows that the average adsorption rates of heavy metal irons Cu2+, Cd2+, Pb2+ and Ni2+ are all over 70 %.展开更多
基金Supported in part by the Australian Research Council (Small Grant Scheme) and a Royal Thai Government Scholarship.
文摘Heavy metal pollution from industrial wastewater is a worldwide environmental issue. Biosorption of heavy metals by using biosorbents derived from various types of biomass has been shown to be effective for the uptake of heavy metal ions. In this study, biosorbents derived from the biomass of a group of marine macroalgae were used for the removal and recovery of heavy metal ions from aqueous solutions. Results indicated that the biosorbents have high uptake capacities and affinities for a number of heavy metal ions. The uptake capacities of the biosorbents were in the range of 1.0 to 1.5mmol·g-1 for divalent heavy metal ions. The kinetics of the uptake process was fast and the process can be used in both batch and fixed-bed operations. It appears that the biosorption process by using biosorbents from marine macroalgae can be an efficient and cost effective technology for the treatment of heavy metal containing wastewater.
文摘The effects of the coagulation-flocculation process using polyaluminium chloride (PAC) and its aids on the removal of organics and nutrient in the combined sewage from Shanghai Zhuyuan First Municipal Wastewater Treatment Plant are studied. The coagulant aids include cationic polyacrylamide (PAM), polyvinyl alcohol (PVA), activated silica (AS) and a kind of polyelectrolyte called AN prepared by the authors. The coagulating solution was added to the glass jar holding 1 L wastewater and stirred to a uniform mixture which was stilled to let the supernatant turn out. The supernatant was analyzed to see the removal efficiencies of suspended solid (SS), chemical oxygen demand (COD), soluble chemical oxygen demand (S-COD), total phosphorus (TP) and orthophosphate (PO4 -P). It is found that PAC is efficient in reducing those five matters, PAM, PVA and 3? AN each faciliates the reduction of TP, SS, COD and S-COD and has little contribution to the removal of ammonia nitrigen and orthophosphate, and AS is noneffective at all. The coagulation-flocculation process with PAC has demonstrated applicable to the treatment of combined sewage in Shanghai, and it involves mainly the sweep coagulation mechanism and maybe some more complicated mechanism as well.
文摘The process of adsorption of metal ions by immobilized marine algae with the existence of clay was investigated. It can be noted from the results that, after mixing with clay, the adsorption rate increases rapidly with the increasing amount of the marine algae. When pH=5, the best ratio between the clay and the marine algae is 1:4 for Pb2+. The result of in situ handling of the waste water containing heavy metals shows that the average adsorption rates of heavy metal irons Cu2+, Cd2+, Pb2+ and Ni2+ are all over 70 %.
