炼化企业污水处理厂恶臭治理设施排放特征及污染控制策略

Emission characteristics and control strategy of odor treatment processes in refinery wastewater treatment plants

以某炼化企业污水处理厂为研究对象,对其恶臭治理设施外排气体的组成特征及其健康风险进行了分析。外排气体中的恶臭物质主要是氨、硫化氢、非甲烷总烃、芳香烃、有机含硫化合物;其中,氨、硫化氢、甲硫醇、甲硫醚、二甲二硫、二硫化碳和4-乙基甲苯的浓度均高于嗅阈值;甲硫醇、硫化氢的理论臭气浓度最高,是关键的致臭物质;生化设施恶臭治理单元的外排气体对污水厂整体恶臭污染的贡献度最高(77%);外排气体中,20种恶臭污染物的非致癌健康风险指数(HItotal≈10^(−4))和终生致癌风险(LCRtotal≈10^(-8))低。

The efflux gases from three odor treatment units in a typical urban refinery wastewater treatment plant(WWTP)were analyzed in this study.The composite characteristics and health risks were investigated.The dominant odor pollutants in all the three efflux gases were ammonia,hydrogen sulfide,non-methane hydrocarbon,aromatic hydrocarbon and organic sulfides.The concentrations of ammonia,hydrogen sulfide,methanethiol,methyl sulfide,dimethyl disulfide,carbon disulfide and 4-ethyltoluene all exceeded the odor thresholds.Methyl mercaptan and hydrogen sulfide had high theoretical odor concentration compared to other pollutants and were key odor-causing substances.The efflux gas from odor treatment unit of wastewater biological processes contributed to 77%of discharged odor load of the whole WWTP.The total noncarcinogenic health risk index(HItotal≈10^(−4))and lifetime cancer risk(LCRtotal≈10^(−8))of the twenty odor pollutants in three efflux gases were very low.