Study On The Optimizing Schemes For The Hazardous Waste Treatment And Disposal In Chongqing Urban Area

At present, the environmental problem caused by the hazardous wastes has become one of the greatest concerns of the whole world. In China, the treatment, disposal and management of the hazardous wastes are not enough to match the rising amount of the hazardous wastes. So it is very necessary to study on the optimizing schemes for the hazardous waste treatment and disposal.In this paper, the information of the hazardous waste in Chongqing urban area was detailedly investigated, which related to 22 county towns, 29 industries and 303 enterprises, and the amount of the hazardous waste was predicted up to 15 years later. Considering the category and component of these hazardous waste and taking numbers of treatment and disposal methods in international and domestic for reference, the optimizing schemes of treatment and disposal for hazardous waste Chongqing urban area were suggested.The investigating result showed that the amount of hazardous waste in Chongqing urban area was 29.8×104 t/a, in which 26.88×10~4 t/a had been disposed and 3.06×10~4 t/a not disposed. In detail, 2475 t/a high toxicity waste, 1651 t/a wasted liquid of acid and alkali and 7839 t/a waste containing heavy metal needed to treated and disposed in Chongqing urban area now, besides 1465 t/a waste that could land-fill directly and 17168 t/a that could be reused. It was predicted that the amount would be up to 79×10~4 t/a 15 years later, and 8.1×10~4 t/a need to be disposed.Based on the study on many schemes, incineration disposal and sanitary landfill were selected as ultimate disposal for the undisposed hazardous waste in Chongqing urban area. Meantime, the corresponding treatment for the different waste was carried on before the disposal. In incineration disposal, the turning kiln and the semi-drying scrubber and bag hose precipitation for smoke decontaminating was suggested. In sanitary landfill, the scheme by partitioned space allocation and by stages was appropriate in Chongqing urban area, and those needed to solidify before landfill should be solidified by cement. In addition, the project avoiding leakage and the design closing over for the landfill field were taken into account. Finally, the secondary pollution caused during the process of treatment and disposal for the hazardous waste was analyzed, and the optimizing scheme for prevention and treatment was put forward.