Gao J.,Academy of Environmental science |
Luo Q.,Academy of Environmental science |
Luo Q.,State Environmental Protection Engineering Center |
Zhang C.,Academy of Environmental science |
And 2 more authors.
Chemical Engineering Journal | Year: 2013
A bench-scale study was conducted to enhance the electrokinetic (EK) processes in the sludge remediation with an improved catholyte circulation system (improved EK-C). Three layers of replaceable anion exchange resin were set in the system to prevent cadmium ions migrated into liquids from re-entering the sludge. Results indicate that the improved EK-C treatment was more stable and efficiently prevented Cd ions to re-enter the sludge which is necessary for providing better assurance and had positive effects on Cd removal, especially in a long period of EK process. Removal efficiency of Cd has increased 60%. The current and electroosmosis rates of improved EK-C increased rapidly. The pH in sludge and the cathode reservoir were between 7.1 and 8.7. Sequential extraction analysis reveals that the reducible and oxidizable Cd had higher removal efficiencies after improved EK-C. The increased potential availability indicates that the attached Cd was desorbed and transformed to a more readily migratory form (exchangeable), which was the reason of Cd removal enhancement. © 2013.
Yang S.,Academy of Environmental science |
Fu Q.,China National Environmental Monitoring Center |
Teng M.,China National Environmental Monitoring Center |
Yang J.,China National Environmental Monitoring Center
Archives of Environmental Protection | Year: 2015
Polybrominated diphenyl ethers (PBDEs) levels in environmental media have increased over the last 20-25 years in the world. In aquatic environments PBDEs were found to be accumulated along food chain and Endocrine disruptors toxicity. In this study PBDEs were investigated in sediment and fish tissues from Lake Chaohu in central eastern China. There were 10 PBDEs congeners detected out of all 41 PBDEs. BDE-47 was of the highest with 5.17 ng/g in sediment and 58.47 ng/g in fish. PBDEs were evenly distributed across the surface sediment in the whole lake. It implied that the main source of PBDEs may not be an inflow river like Nanfei. Tissue distribution patterns of PBDEs in four fish species were in the order of BDE-47 > BDE-99 > BDE-100 > BDE-66 > BDE-138 > BDE-183 > BDE-154 > BDE-153. Octa- and deca-BDEs were below the detection limit. The concentrations of all PBDE congeners were higher in gills, livers, and kidneys than those in muscles and adipose tissue. Furthermore, PBDEs in different tissues had some different distribution patterns with fish size. Those discrepancies appeared to be correlated with the PBDEs pollution fluxes varying with the change of the year and their metabolism divergences in fish tissues. © Copyright by Polish Academy of Sciences and Institute of Environmental Engineering of the Polish Academy of Sciences 2015.