污水处理过程中苯系物和氯代烃三相分布规律

为研究污水处理过程中曝气对苯系物中苯、甲苯和二甲苯以及氯代烃中三氯甲烷、四氯化碳、三氯乙烯和四氯乙烯去除的影响,设计了2个反应器,模拟污水处理过程,一个为活性污泥反应器,另一个为没有活性污泥的对照反应器.结果表明,在液相中,30.6%的TOC未经微生物降解而直接因曝气逸散到气相.苯系物的逸散比例达到了100%;三氯甲烷、四氯化碳、三氯乙烯和四氯乙烯的逸散比例分别为27.5%、39.0%、42.4%和38.5%.同时利用密闭水箱研究了生物处理单元中苯系物和氯代烃三相分布规律.在厌氧阶段,固相中苯、甲苯、二甲苯、三氯甲烷、四氯化碳、三氯乙烯和四氯乙烯占总量比例分别为38.7%、43.6%、38.0%、28.8%、24.3%、15.3%和20.5%.在曝气阶段,苯系物全部被去除,氯代烃总量略有下降.二沉池阶段,固相中三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯占总质量的比例分别为5.2%、20.1%、6.8%和0%. 

Distributions of BTEX and Chlorinated Hydrocarbons in Three Phases During Wastewater Treatment Processing

In order to investigate the influence of aeration on removal of BTEX(benzene,toluene,xylene) and chlorinated hydrocarbons(chloroform,carbon tetrachloride,trichloroethylene,tetrachloroethylene) during wastewater treatment processing,two lab-scale parallel reactors with and without activated sludge were designed to simulate wastewater treatment processing.The results indicated that 30.6% of TOC in the liquid phase volatilized during aeration without microbial decomposition.The volatilization ratio of BTEX reached 100%,and the ratios of chloroform,carbon tetrachloride,trichloroethylene and tetrachloroethylene were 27.5%,39.0%,42.4% and 38.5%,respectively.At the same time,a dedicated tank was used to study the distribution of BTEX and chlorinated hydrocarbons in the three phases.Under the anaerobic condition,the percentages of benzene,toluene,xylene,chloroform,carbon tetrachloride,trichloroethylene and tetrachloroethylene in the solid phase were 38.7%,43.6%,38.0%,28.8%,24.3%,15.3% and 20.5%,respectively.In the aeration process,all BTEX were removed,and the amounts of the chlorinated hydrocarbons were decreased slightly.At the end of the secondary sediment process,the distribution ratios of chloroform,carbon tetrachloride,trichloroethylene and tetrachloroethylene in solids were 5.2%,20.1%,6.8% and 0%,respectively.