活性污泥与施泥土壤中二英污染水平的研究

研究了北京市大兴污泥堆肥厂不同处理阶段的活性污泥和周边的施泥农田土壤中PCDD/Fs污染水平,并与周边背景土壤进行比较.不同处理阶段活性污泥的PCDD/Fs浓度水平为3118.31～3617.36pg/g,毒性当量(TEQ,下同)为26.19～35.81pg/g,在世界范围处于中等偏下水平.施泥农田土壤和背景土壤中PCDD/Fs总浓度水平分别为55.05～72.07pg/g、8.69～18.06pg/g,毒性当量分别为1.20～2.64pg/g、0.28～0.39pg/g,污泥农用导致施泥农田土壤中PCDD/Fs及其各异构体的浓度含量均有提高,浓度总量增高因子在3.0～8.3之间,施泥农田土壤中PCDD/Fs的浓度与施泥比率呈正相关性.施泥农田土壤与施用的活性污泥中PCDD/Fs的17种异构体浓度分布模式十分相似,而与背景土壤中PCDD/Fs各异构体浓度分布模式差异较大,由此说明,活性污泥是施泥农田土壤中PCDD/Fs的主要来源.本研究探讨了施用活性污泥对农田土壤中PCDD/Fs污染水平的影响,揭示了施泥农田土壤中PCDD/Fs的污染来源和污染模式.

Research of PCDD/Fs Pollution Level in Activated Sludge and Sludge Amended Soils

The pollution level of PCDD/Fs of activated sludge in the different processing stages on Beijing Daxing Sludge Composting Plant and pollution level in the neighboring sludge amended soils were studied, and the pollution level was compared with the surrounding background soils. The concentration levels of PCDD/Fs of activated sludge samples in the different treatment stages were 3118.31-3617.36 pg/g, and the TEQ was 26.19-35.81 pg/g, which ranked in middle and lower level in worldwide studies. The concentration of PCDD/Fs of sludge amended soils and background soil samples were 55.05-72.07 pg/g, 8.69-18.06 pg/g respectively, and the TEQ were 1.20-2.64 pg/g, 0.28-0.39 pg/g. The agriculture application of sewage sludge increased the concentration level of PCDD/Fs and their isomers in sludge amended soils, and the total quantity increase ratio was 3.0-8.3. The concentration of PCDD/Fs in sewage sludge amended soils displayed positive correlation with application rates. The concentration distribution pattern of 17 kinds isomers of PCDD/Fs in sewage sludge amended soil was similar with activated sludge, and was very different from background soils. The activated sludge was the main source of PCDD/Fs in sludge amended soils. This study explored the affection of pollution levels of PCDD/Fs in the farmland soils because of the application of activated sludge, and revealed the sources of pollution and contamination patterns of PCDD/Fs in sewage sludge amended soils.