市政污泥挥发性有机物及浸出液毒性相关性分析

Correlation analysis of volatile organic compounds components and the leaching toxicity in sewage sludge

污泥干化处理是污泥无害化处置的主要方式,但目前较少对污泥及其浸出液中挥发性有机物(VOCs)组分及生物毒性进行研究。为探讨污泥VOCs组分与浸出液生物毒性的相关性,以干化前后的市政污泥作为研究对象,通过吹扫捕集-气相色谱质谱法(PT-GCMS)识别干化前后污泥及其浸出液中VOCs成分,同时以发光细菌抑制率表征浸出液毒性。结果发现,在污泥中鉴定出19种VOCs成分,浸出液中鉴定出31种VOCs成分。干污泥浸出液VOCs成分主要为酮类、醛类、醇类和含硫化合物,湿污泥浸出液VOCs成分主要为含硫化合物、卤代烃和酮类。干化后污泥总挥发性有机物含量(TVOC)降低,但浸出液的结果与之相反。干污泥浸出液中TVOC对发光细菌的EC50为51.31μg/L,湿污泥浸出液相应的值为81.80μg/L,毒性与TVOC含量显著正相关,说明干污泥浸出液毒性较强,且VOCs组分可能是导致其毒性较大的主因之一。污泥VOCs成分的释放可能对环境存在风险,在污泥无害化处置时需考虑对VOCs组分的监控和处理。

Sludge drying is the major item of sludge harmless disposal.However,few studies have focused on the volatile organic compounds(VOCs)components and biological toxicity in sludge and its leaching solution.In order to find out the relationship of VOCs components and the leaching toxicity in sewage sludge,the sewage sludge be⁃fore and after drying were taken as research object,the components of volatile organic compounds in sludge were detected by purge trap gas chromatography mass spectrometry(PT-GCMS),and leaching toxicity was characterized by inhibition rate of luminescent.The results showed that 19 VOCs were identified in sludge and 31 VOCs were identified in leaching solution.The major VOCs components of dry sludge extraction were ketones,aldehydes,alco⁃hols and sulfur compounds,while the major VOCs components of wet sludge were sulfur compounds,halogenated hydrocarbons and ketones.The total volatile organic compounds(TVOC)content of sludge decreased after drying while the TVOC content of dry sludge leaching solution was higher than that of wet sludge.The EC50 of the TVOC in dry sludge leaching solution to luminescent bacteria was 51.31μg/L while the EC50 of wet sludge was 81.80μg/L.In addition,the leaching toxicity significantly increased with the increase of TVOC content.These results suggested that the leaching toxicity of dry sludge was higher and the VOCs components in sewage sludge might be one of the major cause for the higher toxicity.The environmental risk may increase with the release of VOCs in sludge,there⁃fore,the monitoring and treatment of VOCs should be considered during the harmless disposal of sludge.