The purpose of this research is to investigate the potential of pre-treatment with phosphoric acid(PA) and monobasic calcium phosphate(MCP) for the stabilization of heavy metals in sludge and its bottom ash.The tanner...The purpose of this research is to investigate the potential of pre-treatment with phosphoric acid(PA) and monobasic calcium phosphate(MCP) for the stabilization of heavy metals in sludge and its bottom ash.The tannery sludge samples were collected in Wenzhou,China and heavily contaminated with heavy metals,such as Pb,Cr and so on.The samples were pre-treated with PA or MCP.Then XRD and TCLP tests were adopted as the evaluating methods to characterize the Pb,Cr,Cu,Zn and Cd immobilization in the pre-treated sludge and its bottom ash.The results showed that this treatment effectively immobilized Pb and Cd in the sludge,lightly stabilized the metal Cu,and adversely,enhanced the leachability of Zn.After incineration at 900℃,Pb and Cr in the bottom ash of pre-treated sludge were significantly stabilized due to the formation of their highly thermostable phosphates and pyromorphite-like minerals during the incineration process.However,an increase of Cu and Zn solubility was observed which might be attributable to the acidification of sludge due to the addition of PA or MCP.展开更多
Severe operational problems of sediment deposition have frequently occurred in stormwater sewer systems in Shanghai city due to the flat topography of the area and serious illicit connections. To control sewer sedimen...Severe operational problems of sediment deposition have frequently occurred in stormwater sewer systems in Shanghai city due to the flat topography of the area and serious illicit connections. To control sewer sediment and its subsequential problems,optimized operation plans were proposed and an innovative performance assessment method was developed. Simula-tion results demonstrated that,through changing the way of pump operation and installing necessary actuators in the system,the optimized operations,especially batch intermittent intercept plan,effectively improved the flow velocity in the entire system in dry-weather condition. In conclusion,the optimized operation is an innovative idea for improving the performance and solving the problem of sediment deposition in the sewer system in Shanghai,China.展开更多
基金Project (No. 50908070) supported by the National Nature Science Foundation of China
文摘The purpose of this research is to investigate the potential of pre-treatment with phosphoric acid(PA) and monobasic calcium phosphate(MCP) for the stabilization of heavy metals in sludge and its bottom ash.The tannery sludge samples were collected in Wenzhou,China and heavily contaminated with heavy metals,such as Pb,Cr and so on.The samples were pre-treated with PA or MCP.Then XRD and TCLP tests were adopted as the evaluating methods to characterize the Pb,Cr,Cu,Zn and Cd immobilization in the pre-treated sludge and its bottom ash.The results showed that this treatment effectively immobilized Pb and Cd in the sludge,lightly stabilized the metal Cu,and adversely,enhanced the leachability of Zn.After incineration at 900℃,Pb and Cr in the bottom ash of pre-treated sludge were significantly stabilized due to the formation of their highly thermostable phosphates and pyromorphite-like minerals during the incineration process.However,an increase of Cu and Zn solubility was observed which might be attributable to the acidification of sludge due to the addition of PA or MCP.
基金Project (No. 2008ZX07317-001) supported by the Special Grand National Science-Technology Project for Water Pollution Control and Treatment, China
文摘Severe operational problems of sediment deposition have frequently occurred in stormwater sewer systems in Shanghai city due to the flat topography of the area and serious illicit connections. To control sewer sediment and its subsequential problems,optimized operation plans were proposed and an innovative performance assessment method was developed. Simula-tion results demonstrated that,through changing the way of pump operation and installing necessary actuators in the system,the optimized operations,especially batch intermittent intercept plan,effectively improved the flow velocity in the entire system in dry-weather condition. In conclusion,the optimized operation is an innovative idea for improving the performance and solving the problem of sediment deposition in the sewer system in Shanghai,China.
