Active iron catalysts with 5A molecular sieve as the carrier were prepared firstly, and then were used in the treatment of ammonia nitrogen in landfill leachate pretreated by MBR by using CWPO, finally the effects of ...Active iron catalysts with 5A molecular sieve as the carrier were prepared firstly, and then were used in the treatment of ammonia nitrogen in landfill leachate pretreated by MBR by using CWPO, finally the effects of preparation process of catalysts, assistants and reaction conditions on the removal rate of ammonia nitrogen were analyzed. The results show that the preparation process of catalysts and assistants had great effects on catalytic activity; when steeping fluid concentration was 2 mol/L and 0.01 mol/L cerium nitrate was used as an assistant, Fe-Ce/5A catalyst roasted for 3 h at 400 ~C had a good catalytic effect. As 10 g of Fe-Ce/5A catalyst was added to water sample, and landfill leachate pretreated by MBR reacted with 15 ml of H2 02 for 30 min at 60 ~C, the removal rate of ammonia nitrogen was up to 90.8%, that is, ammonia nitrogen concentra- tion decreased from 253 to 23 mg/L, reaching the national emission standard. Besides, the kinetic analysis of ammonia nitrogen removal reveals that the removal reaction of ammonia nitrogen conformed with pseudo first order kinetic equation. Thus, it is feasible to use this method to deeply treat landfill leachate pretreated by MBR.展开更多
This study analyzes the design and operation of multi-level governance system for the smooth delivery of infrastructure mega-projects with high institutional complexity caused by market transition. From an institution...This study analyzes the design and operation of multi-level governance system for the smooth delivery of infrastructure mega-projects with high institutional complexity caused by market transition. From an institutional perspective, this study scrutinizes the structure,elements, and dynamics of the governance system of infrastructure mega-projects and then proposes an integrative framework based on the inductive case study of the Hong Kong-Zhuhai-Macao Bridge mega-project. Multiple evidences of archives, field studies, and interviews related to the case project are triangulated to further analyze the institutional effects, specifically those with government logics and market structures, on the design and operation of the three-level governance system. Results reveal that the co-evolution between governments and markets in China has shaped the vertical levels of the mega-project governance system and has further affected their evolution and operation across various stages of project development. This study contributes to the rapidly emerging research on complex system governance by proposing a systematic model of three-level mega-project governance to enhance the timely delivery of infrastructure megaprojects within budget.展开更多
基金Supported by the Project of Agricultural Key Programs for Science and Technology Development of Ningbo (2011C11006)Key Spark Program Project of Science and Technology Ministry (2012GA7010011)the Science and Technology Plan Project of Ningbo City,Zhejiang Province
文摘Active iron catalysts with 5A molecular sieve as the carrier were prepared firstly, and then were used in the treatment of ammonia nitrogen in landfill leachate pretreated by MBR by using CWPO, finally the effects of preparation process of catalysts, assistants and reaction conditions on the removal rate of ammonia nitrogen were analyzed. The results show that the preparation process of catalysts and assistants had great effects on catalytic activity; when steeping fluid concentration was 2 mol/L and 0.01 mol/L cerium nitrate was used as an assistant, Fe-Ce/5A catalyst roasted for 3 h at 400 ~C had a good catalytic effect. As 10 g of Fe-Ce/5A catalyst was added to water sample, and landfill leachate pretreated by MBR reacted with 15 ml of H2 02 for 30 min at 60 ~C, the removal rate of ammonia nitrogen was up to 90.8%, that is, ammonia nitrogen concentra- tion decreased from 253 to 23 mg/L, reaching the national emission standard. Besides, the kinetic analysis of ammonia nitrogen removal reveals that the removal reaction of ammonia nitrogen conformed with pseudo first order kinetic equation. Thus, it is feasible to use this method to deeply treat landfill leachate pretreated by MBR.
基金funded by the National Natural Science Foundation of China(Grant Nos.71501142,71390523/71390520 and 71471136)Shanghai Pujiang Program(Grant No.17PJC101)
文摘This study analyzes the design and operation of multi-level governance system for the smooth delivery of infrastructure mega-projects with high institutional complexity caused by market transition. From an institutional perspective, this study scrutinizes the structure,elements, and dynamics of the governance system of infrastructure mega-projects and then proposes an integrative framework based on the inductive case study of the Hong Kong-Zhuhai-Macao Bridge mega-project. Multiple evidences of archives, field studies, and interviews related to the case project are triangulated to further analyze the institutional effects, specifically those with government logics and market structures, on the design and operation of the three-level governance system. Results reveal that the co-evolution between governments and markets in China has shaped the vertical levels of the mega-project governance system and has further affected their evolution and operation across various stages of project development. This study contributes to the rapidly emerging research on complex system governance by proposing a systematic model of three-level mega-project governance to enhance the timely delivery of infrastructure megaprojects within budget.
