title: Bioassay directed identification of toxicants in sludge and related reused materials from industrial wastewater treatment plants in the Yangtze River Delta.
abstract: Industrialized development of the Yangtze River Delta, China, has resulted in larger amounts of wastes, including sludges from treatment of these wastes. Methods to manage and dispose, including reuse were urgently needed. Sludge and reused products were collected from two largest factories, KEYUAN and HENGJIA where treated sludges were turned into bricks or sludge cake to be placed in landfills, respectively. Metals and organic compounds were quantified in sludges and leachates assessed by use of toxicity characterized leaching procedure (TCLP) while acute toxicity was determined by Daphnia magna. Nine metals were detected in all raw sludges with concentrations of Cr and Ni exceeding Chinese standards. For sludge leachate, concentrations of metals were all less than Chinese standards, which changed little after being made into cake by HENGJIA, but were significantly less after being made into brick by KEYUAN. Toxicity units (TU) for all samples are greater than 1.0 indicating that they are potentially toxic to aquatic organisms. TUs changed little after being made into filter cake, but were 10-fold less after being made into bricks. Cr and Ni contributed most to the total toxicity followed by Zn and Cu. Making of sludges into K-brick 1 resulted in better inactivation of contaminants, which resulted in less toxic potencies. So that is the recommended method for handling of industrial sludges. To further assure their safe reuse, additional research on identification of key toxicants and potential hazards, based on additional endpoints, by combining bio-tests and chemical analysis should be done for reused sludges.
authors: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, People's Republic of China; Key Laboratory of Environmental Engineering, Jiangsu Provincial Academy of Environmental Science, Nanjing 210036, People's Republic of China.
authors: Binbin
authors: B
authors: Fang
authors: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.
authors: Jing
authors: J
authors: Guo
authors: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, People's Republic of China.
authors: Fuxing
authors: F
authors: Li
authors: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China; Department of Veterinary Biomedical Sciences and Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Biological Sciences, University of Hong Kong, Hong Kong Special Administrative Region.
authors: John P
authors: JP
authors: Giesy
authors: Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, People's Republic of China. Electronic address: wanglj@mail.njust.edu.cn.
authors: Lianjun
authors: L
authors: Wang
authors: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address: njushiwei@nju.edu.cn.
authors: Wei
authors: W
authors: Shi
mesh_terms: D000818:Animals; D001681:Biological Assay; D002681:China; D002857:Chromium / Q000032:analysis; D003300:Copper / Q000032:analysis; D003621:Daphnia / Q000187:drug effects; D015386:Hazardous Substances / Q000032:analysis*; D020128:Inhibitory Concentration 50; D019216:Metals, Heavy / Q000032:analysis*; D009532:Nickel / Q000032:analysis; D009930:Organic Chemicals; D045483:Rivers; D012722:Sewage / Q000737:chemistry*; D055549:Volatile Organic Compounds / Q000032:analysis; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis; D015032:Zinc / Q000032:analysis
chemical_list: D002857:Chromium; D003300:Copper; D015386:Hazardous Substances; D019216:Metals, Heavy; D009532:Nickel; D009930:Organic Chemicals; D012722:Sewage; D055549:Volatile Organic Compounds; D062065:Wastewater; D014874:Water Pollutants, Chemical; D015032:Zinc
keywords: Leaching test; Metals; Sewage; The Yangtze River Delta; Toxicity; Treatment