邻苯二甲酸二乙酯对活性污泥脱氮除磷性能的影响

Impacts of diethyl phthalate on the performance of activated sludge for nitrogen and phosphorus removal

以邻苯二甲酸二乙酯(DEP)作为一种典型邻苯二甲酸酯,考察DEP对废水生物处理中脱氮除磷的影响,结合相关酶活性和脱氮除磷功能菌群结构的变化揭示DEP的影响机制。结果表明,DEP对COD去除无明显影响,但DEP浓度过高会对总氮、氨氮和总磷的去除有显著抑制。DEP的生物毒性导致活性污泥系统中生物量减少,并诱导污泥分泌更多的胞外聚合物(EPS)。DEP总体提高了硝酸盐还原酶(Nar)和脱氢酶活性,但抑制了亚硝酸盐还原酶(Nir)活性。DEP为100 mg/L时Nar和脱氢酶活性最高,DEP为150 mg/L时对Nir活性抑制最大,抑制率为39.02%。高通量测序表明,高浓度DEP对硝化菌属、反硝化菌属和聚磷菌属的增殖有负面影响,从而使脱氮除磷功能受到抑制。

Diethyl phthalate(DEP)was selected as typical phthalate esters to investigate the impacts of DEP on nitrogen and phosphorus removal in wastewater biological treatment,and the influence mechanisms were revealed in combination with the changes of related enzyme activities and the structure of functional flora for nitrogen and phosphorus removal.The results showed that DEP had no significant impact on COD removal,but the removals of total nitrogen,ammonia nitrogen and total phosphorus were significantly inhibited by excessive DEP concentration.The biotoxicity of DEP reduced biomass in the system and induced more EPS secretion from the sludge.DEP increased nitrate reductase(Nar)and dehydrogenase activities,but inhibited nitrite reductase(Nir)activity.The highest Nar and dehydrogenase activities were found in treatment with 100 mg/L DEP,while 150 mg/L DEP inhibited Nir activity by 39.02%.High-throughput sequencing showed that high concentrations of DEP had negative impacts on the proliferation of nitrifying bacteria,denitrifying bacteria and phosphorus accumulating organisms,and could inhibite the function of nitrogen and phosphorus removal.