The concentration and chemical speciation of heavy metals including REEs （rare earth elements）, Th （thorium） and U （uranium） in domestic sludge and electroplating sludge were investigated, and those of the domes...The concentration and chemical speciation of heavy metals including REEs （rare earth elements）, Th （thorium） and U （uranium） in domestic sludge and electroplating sludge were investigated, and those of the domestic sludge were compared with those of natural soil. Removal of heavy metals in electroplating sludge was studied with bio-surfactants （saponin and sophorolipid） by batch and column experiments. The results suggested that heavy metals have greater concentrations and exist as more relatively unstable fraction in sludge than those in Natural soil. Nonionic saponin is more efficient than sophorolipid for the removal of heavy metals from the electroplating sludge, and mainly reacts with carbonate state （i.e., F3） and Fe-Mn oxide state （i.e., F5） fractions. The recovery efficiency of heavy metals in leachates from the electroplate sludge was attained 88%-97%. Saponin can be reused and be a promising and cost-effective material for the removal of heavy metals in sludge.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
文摘The concentration and chemical speciation of heavy metals including REEs （rare earth elements）, Th （thorium） and U （uranium） in domestic sludge and electroplating sludge were investigated, and those of the domestic sludge were compared with those of natural soil. Removal of heavy metals in electroplating sludge was studied with bio-surfactants （saponin and sophorolipid） by batch and column experiments. The results suggested that heavy metals have greater concentrations and exist as more relatively unstable fraction in sludge than those in Natural soil. Nonionic saponin is more efficient than sophorolipid for the removal of heavy metals from the electroplating sludge, and mainly reacts with carbonate state （i.e., F3） and Fe-Mn oxide state （i.e., F5） fractions. The recovery efficiency of heavy metals in leachates from the electroplate sludge was attained 88%-97%. Saponin can be reused and be a promising and cost-effective material for the removal of heavy metals in sludge.
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.
