The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on acti...The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.展开更多
A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferr...A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferrous metallic ore flotation was evaluated. The results show that the two stages of domestication can improve microbial degradation ability. The BAC reactor obtains a chemical oxygen demand(COD) reduction rate of 82.5% for ethyl xanthate and its effluent COD concentration lowers to below 20 mg/L. The kinetics equation of the BAC reactor proves that the activated carbon layers at the height of 0 mm to 70 mm play a key role in the removal of flotation reagents. Ultraviolet spectral analysis indicates that most of the ethyl xanthate are degraded by microorganisms after advanced treatment by the BAC reactor.展开更多
In order to improve the efficiency of bioleaching heavy metal from the contaminated soil using Penicillium chrysogenum(P.chrysogenum),experiment was conducted to evaluate the influence of heavy metal stress on P.chrys...In order to improve the efficiency of bioleaching heavy metal from the contaminated soil using Penicillium chrysogenum(P.chrysogenum),experiment was conducted to evaluate the influence of heavy metal stress on P.chrysogenum during bioleaching.The morphology and physiology of P.chrysogenum were observed.Assuming that the heavy metals are all leached out from the experiment soil,heavy metals are added into the agar medium by simulating the heavy metal content in the soil.It is concluded that the survivable heavy metal contaminated soil mass range for P.chrysogenum is 2.5-5.0 g.As for biomass determination,the contaminated soil is added into the liquid medium directly.The soil mass that P.chrysogenum can be survivable is in the range of 2.5-8.75 g.In this mass range,the biomass of P.chrysogenum is bigger than that of the control sample.10 g soil mass is the threshold of the growth of P.chrysogenum.102.2 mg/L gluconic acid,156.4 mg/L oxalic acid,191.6 mg/L pyruvic acid,0.02 mg/L citric acid,0.03 mg/L malic acid and 70.6 mg/L succinic acid are determined after 15 d bioleaching.The mycelium is broken into fragments,and heavy metals are adsorbed on the cell wall or transported into the cytoplasm during bioleaching.The GOD activity declines from 1.08 U/mL to 0.2 U/mL under 400 mg/L of multi-metal stress.The influence of Pb on GOD activity is bigger than that of Cr and Cd,and the GOD activity is not influenced apparently by Mn,Zn and Cu.展开更多
基金Project(5227010679)supported by the National Natural Science Foundation of China。
文摘The process of preparing anodic oxide film containing active sites and electroless nickel plating on highly active rare earth magnesium alloy was developed.The formation mechanism of electroless nickel plating on active anodic oxide film and the structure and properties of the composite coating were studied by several surface and electrochemical techniques.The results showed that Ag nanograins with an average size of 10 nm were embedded into the anodic oxide film with pores of 0.1−2μm.Ag nanoparticles provided a catalytic site for the deposition of Ni-B alloy,and the Ni crystal nucleus was first grown in horizontal mode and then in cylindrical mode.The corrosion potential of the composite coating increased by 1.37 V and the corrosion current reduced two orders of magnitude due to the subsequent deposition of Ni-P alloy.The high corrosion resistance was attributed to the misaligning of these micro defects in the three different layers and the amorphous structure of the Ni-P alloy in the outer layer.These findings provide a new idea for electroless nickel plating on anodic oxide film.
基金Project(201209013)supported by Special Fund for Environmental Scientific Research in the Public Interest,China
文摘A laboratory scale up-flow biological activated carbon(BAC) reactor was constructed for the advanced treatment of synthetic flotation wastewater. Biodegradation of a common collector(i.e., ethyl xanthate) for non-ferrous metallic ore flotation was evaluated. The results show that the two stages of domestication can improve microbial degradation ability. The BAC reactor obtains a chemical oxygen demand(COD) reduction rate of 82.5% for ethyl xanthate and its effluent COD concentration lowers to below 20 mg/L. The kinetics equation of the BAC reactor proves that the activated carbon layers at the height of 0 mm to 70 mm play a key role in the removal of flotation reagents. Ultraviolet spectral analysis indicates that most of the ethyl xanthate are degraded by microorganisms after advanced treatment by the BAC reactor.
基金Project(50925417)supported by the National Natural Science Foundation of China for Distinguished Young ScholarsProject(51074191)supported by the National Natural Science Foundation of ChinaProject(2012BAC09B04)supported by the National Key Technology Research and Development Program of China
文摘In order to improve the efficiency of bioleaching heavy metal from the contaminated soil using Penicillium chrysogenum(P.chrysogenum),experiment was conducted to evaluate the influence of heavy metal stress on P.chrysogenum during bioleaching.The morphology and physiology of P.chrysogenum were observed.Assuming that the heavy metals are all leached out from the experiment soil,heavy metals are added into the agar medium by simulating the heavy metal content in the soil.It is concluded that the survivable heavy metal contaminated soil mass range for P.chrysogenum is 2.5-5.0 g.As for biomass determination,the contaminated soil is added into the liquid medium directly.The soil mass that P.chrysogenum can be survivable is in the range of 2.5-8.75 g.In this mass range,the biomass of P.chrysogenum is bigger than that of the control sample.10 g soil mass is the threshold of the growth of P.chrysogenum.102.2 mg/L gluconic acid,156.4 mg/L oxalic acid,191.6 mg/L pyruvic acid,0.02 mg/L citric acid,0.03 mg/L malic acid and 70.6 mg/L succinic acid are determined after 15 d bioleaching.The mycelium is broken into fragments,and heavy metals are adsorbed on the cell wall or transported into the cytoplasm during bioleaching.The GOD activity declines from 1.08 U/mL to 0.2 U/mL under 400 mg/L of multi-metal stress.The influence of Pb on GOD activity is bigger than that of Cr and Cd,and the GOD activity is not influenced apparently by Mn,Zn and Cu.
