邻苯二甲酸二(2-乙基己基)酯对硝化型曝气生物滤池的影响及其去除效能

为探究邻苯二甲酸二(2-乙基己基)酯(DEHP)对硝化反应的影响及其去除情况,采用2座下向流硝化型曝气生物滤池进行对比实验.其中一座滤池进水DEHP浓度为100 μg/L,另一座滤池进水中不添加DEHP作为空白对照.对比实验期间氨氮负荷先后调整为0.6 kg NH4+-N/(m3·d)和1.5 kg NH4+-N/(m3·d)2个工况.通过60 d的对比实验,结果发现,2种工况下进水加DEHP的滤池,出水亚氮积累率分别为83.92%和80.71%,氨氮去除率分别为97.52%和49.39%;进水不加DEHP的滤池,出水亚氮积累率分别为64.15%和49.37%,氨氮去除率分别为98.77%和49.34%.DEHP的加入均促进了滤池出水中亚氮的积累,但对氨氮的去除不产生影响.进水加DEHP的滤池在0.6 kg NH4+-N/(m3·d)氨氮负荷下运行时,氨氮去除率沿水流方向逐渐提高,在滤床深度为1 400 mm处达到98.40%.亚氮积累率沿水流方向呈现先升高后降低的趋势,在滤床800 mm处达到最高值94.21%.在2个工况条件下,下向流硝化型曝气生物滤池对DEHP的平均去除率分别为91.71%和89.38%.大部分DEHP是在滤池进水端200 mm之内去除的.

Di (2-ethylhexyl) phthalate removal and its effects on a nitrification biological aerated filter

To study the effects of di (2-ethylhexyl) phthalate (DEHP) on nitrification and its removal, two biological aerated filters were operated in parallel for 60 days. One filter's influent was with 100 μg/L DEHP while the other's was not. The two filters were run with the same ammonia loadings of 0.6 and 1.5 kg NH4+-N/(m3·d) successively. All results showed that, nitrite accumulation ratio in effluent reached 83.92% and 80.71%, and ammonia nitrogen removal efficiency reached 97.52% and 49.39% respectively under the two ammonia loadings for the filter fed with 100 μg/L DEHP. For the filter without DEHP adding, nitrite accumulation ratio in effluent were 64.15% and 49.37%, and the ammonia nitrogen removal efficiency were 98.77% and 49.34% respectively. DEHP in influent accelerates the nitrite accumulation but has no negative effects on ammonia removal. For the filter with DEHP in influent under the ammonia loading of 0.6 kg NH4+-N/(m3·d), percent of ammonia removal increased gradually along the flow direction and reached 98.40% at the filter bed depth of 1 400 mm. Nitrite accumulation ratio increased gradually and then decreased along the flow direction with the maximum accumulation ratio of 94.21% reached at the filter bed depth of 800 mm. The DEHP average removal efficiencies were 91.71% and 89.38% respectively under the two ammonia loadings. Most DEHP removal occurred in the initial 200 mm filter bed.