In this study,a series of CuMgAl layered double oxides(CuMgAl-LDOs)were obtained via calcination of CuMgAl layered double hydroxides(CuMgAl-LDHs)synthesised via a co-precipitation method.The results show that CuMgAl-L...In this study,a series of CuMgAl layered double oxides(CuMgAl-LDOs)were obtained via calcination of CuMgAl layered double hydroxides(CuMgAl-LDHs)synthesised via a co-precipitation method.The results show that CuMgAl-LDO can be prepared using an optimal Cu:Mg:Al molar ratio of 3:3:2,NaOH:Na_(2)CO_(3)molar ratio of 2:1,and calcination temperature of 600°C.CuMgAl-LDO is a characteristic of mesoporous material with a lamellar structure and large specific surface area.The removal efficiency of sulfameter(SMD)based on CuMgAl-LDO/persulfate(PS)can reach>98%over a wide range of initial SMD concentrations(5–20 mg L^(-1)).The best removal efficiency of99.49%was achieved within 120 min using 10 mg L^(-1)SMD,0.3 g L^(-1)CuMgAl-LDO,and 0.7 mmol L^(-1)PS.Kinetic analysis showed that the degradation of SMD was in accordance with a quasi-first-order kinetic model.The stability of the CuMgAl-LDO catalyst was verified by the high SMD removal efficiency(>97%within 120 min)observed after five recycling tests and low copper ion leaching concentration(0.89 mg L^(-1)),which is below drinking water quality standard of 1.3 mg L^(-1)permittable in the U.S.Radical scavenging experiments suggest that SO_(4)^(-)is the primary active species participating in the CuMgAl-LDO/PS system.Moreover,our mechanistic investigations based on the radical scavenging tests and X-ray photoelectron spectroscopy(XPS)results indicate that Cu^((II))-Cu^((III))-Cu^((II))circulation is responsible for activating PS in the degradation of SMD and the degradation pathway for SMD was deduced.Accordingly,the results presented in this work demonstrate that CuMgAl-LDO may be an efficient and stable catalyst for the activation of PS during the degradation of organic pollutants.展开更多
Heat-integrated water network synthesis(HIWNS)has received considerable attention for the advantages of reducing water and energy consumptions.HIWNS is effective in water and energy sustainability.Mixed integer non-li...Heat-integrated water network synthesis(HIWNS)has received considerable attention for the advantages of reducing water and energy consumptions.HIWNS is effective in water and energy sustainability.Mixed integer non-linear programming(MINLP)is usually applied in HIWNS.In this work,a novel nonlinear programming(NLP)was proposed for HIWNS by considering wastewater reuse and wastewater regeneration reuse.Integer variables are changed to non-linear equation by the methods for identifying stream roles and denoting the existence of process matches.The model is tested by examples with single and multiple regeneration unit problems.The testing results showed that the NLP is an alternative method for HIWNS with wastewater reuse and regeneration reuse.展开更多
基金financially supported by the National Natural Science Foundation of China[No:21676203]Tianjin Universities“Youth Innovation Talent Training Program”
文摘In this study,a series of CuMgAl layered double oxides(CuMgAl-LDOs)were obtained via calcination of CuMgAl layered double hydroxides(CuMgAl-LDHs)synthesised via a co-precipitation method.The results show that CuMgAl-LDO can be prepared using an optimal Cu:Mg:Al molar ratio of 3:3:2,NaOH:Na_(2)CO_(3)molar ratio of 2:1,and calcination temperature of 600°C.CuMgAl-LDO is a characteristic of mesoporous material with a lamellar structure and large specific surface area.The removal efficiency of sulfameter(SMD)based on CuMgAl-LDO/persulfate(PS)can reach>98%over a wide range of initial SMD concentrations(5–20 mg L^(-1)).The best removal efficiency of99.49%was achieved within 120 min using 10 mg L^(-1)SMD,0.3 g L^(-1)CuMgAl-LDO,and 0.7 mmol L^(-1)PS.Kinetic analysis showed that the degradation of SMD was in accordance with a quasi-first-order kinetic model.The stability of the CuMgAl-LDO catalyst was verified by the high SMD removal efficiency(>97%within 120 min)observed after five recycling tests and low copper ion leaching concentration(0.89 mg L^(-1)),which is below drinking water quality standard of 1.3 mg L^(-1)permittable in the U.S.Radical scavenging experiments suggest that SO_(4)^(-)is the primary active species participating in the CuMgAl-LDO/PS system.Moreover,our mechanistic investigations based on the radical scavenging tests and X-ray photoelectron spectroscopy(XPS)results indicate that Cu^((II))-Cu^((III))-Cu^((II))circulation is responsible for activating PS in the degradation of SMD and the degradation pathway for SMD was deduced.Accordingly,the results presented in this work demonstrate that CuMgAl-LDO may be an efficient and stable catalyst for the activation of PS during the degradation of organic pollutants.
基金financially supported by the Major Science and Technology Project of Xinjiang Bingtuan(2017AA007/02)。
文摘Heat-integrated water network synthesis(HIWNS)has received considerable attention for the advantages of reducing water and energy consumptions.HIWNS is effective in water and energy sustainability.Mixed integer non-linear programming(MINLP)is usually applied in HIWNS.In this work,a novel nonlinear programming(NLP)was proposed for HIWNS by considering wastewater reuse and wastewater regeneration reuse.Integer variables are changed to non-linear equation by the methods for identifying stream roles and denoting the existence of process matches.The model is tested by examples with single and multiple regeneration unit problems.The testing results showed that the NLP is an alternative method for HIWNS with wastewater reuse and regeneration reuse.
