The synthesis,characterization,and its response to metal ions of a novel thiourea N,N＇-diethoxycarbonyl-A＂,iV″＇-（1,2- ethylidene） dithiourea was reported.The results show that this dithiourea with new structure ...The synthesis,characterization,and its response to metal ions of a novel thiourea N,N＇-diethoxycarbonyl-A＂,iV″＇-（1,2- ethylidene） dithiourea was reported.The results show that this dithiourea with new structure can react with Cu^（2＋） and Ni^（2＋） separately,and has a best selectivity to Fe^（3＋） ions.Bench-scale flotation tests were also carried out,verifying it has higher copper flotation recovery and better selectivity to sulfide ores containing Cu compared with universal collectors.展开更多
The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2＋and Zn2＋in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was...The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2＋and Zn2＋in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients（above 0.99 for both metal ions） and insignificant lack of fit（p = 0.0838 and 0.0782 for Pb2＋and Zn2＋, respectively）. Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation（between –NH2,-CN and metal ions） and ion-exchange（between –COOH and metal ions）. The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions.展开更多
基金the financial supports from National High-Tech Research and Development Plan of China(No. 2007AA06Z122)National Basic Research Program of China(No.2007CB613602)National Natural Science Foundation of China(Nos.51074183 and 50604016)
文摘The synthesis,characterization,and its response to metal ions of a novel thiourea N,N＇-diethoxycarbonyl-A＂,iV″＇-（1,2- ethylidene） dithiourea was reported.The results show that this dithiourea with new structure can react with Cu^（2＋） and Ni^（2＋） separately,and has a best selectivity to Fe^（3＋） ions.Bench-scale flotation tests were also carried out,verifying it has higher copper flotation recovery and better selectivity to sulfide ores containing Cu compared with universal collectors.
基金the support provided by China Scholarship Council, Sheng Yun-Fei College Students Scientific and Technological Innovation Fundthe National Science & Technology Pillar Program (No. 2013BAD21B03)
文摘The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2＋and Zn2＋in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients（above 0.99 for both metal ions） and insignificant lack of fit（p = 0.0838 and 0.0782 for Pb2＋and Zn2＋, respectively）. Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation（between –NH2,-CN and metal ions） and ion-exchange（between –COOH and metal ions）. The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions.
