进水CODCr负荷对MBR去除雌激素的影响

为了探究MBR进水COD_Cr负荷对雌激素去除的影响,设置了不同进水ρ(COD_Cr)下的3组MBR,检测其对E1(雌酮)和EE2(17α-乙炔基雌二醇)的去除效果,并通过污泥浓度、污泥粒径以及微生物数量分析,揭示MBR污泥特性对E1和EE2去除效果的影响. 结果表明,尽管进水ρ(COD_Cr)差异较大,但3组MBR均取得了较好的COD_Cr及NH₃-N去除效果. 出水ρ(SEs)(SEs为类固醇雌激素)随进水ρ(COD_Cr)的增加而降低,当初始ρ(SEs)均为50 μg/L时,进水ρ(COD_Cr)为93.00、295.27、504.40 mg/L的MBR出水中ρ(E1)、ρ(EE2)平均分别为3.26、3.02、1.17 μg/L和4.76、4.46、2.64 μg/L. 随着初始ρ(SEs)的提高,出水中ρ(E1)、ρ(EE2)均有不同程度提高,当初始ρ(SEs)升至200 μg/L时,MBR出水中ρ(E1)、ρ(EE2)平均值分别为5.61、5.64、3.82 μg/L和8.14、7.87、6.57 μg/L. 相同条件下,MBR对E1的去除效果显著优于EE2.相关性分析表明,E1、EE2去除负荷均与COD_Cr去除负荷显著负相关,与NH₃-N去除负荷显著正相关(P<0.05),MBR中E1、EE2的去除是由有机物共代谢和硝化共代谢共同作用的结果,硝化过程与雌激素降解过程呈相似的环境条件要求. 

Influence of Influent CODCr Loading on Steroid Estrogens Removal in MBR

In order to investigate the effects of influent COD_Cr load on estrogens removal, three laboratory-scale membrane reactors (MBR) with different influent COD_Cr concentrations were set to compare the removal performance of estrone (E1) and 17α-ethinyl estradiol (EE2). MLSS, particle size and bacterial amount were measured to explore the effects of sludge characteristics on E1 and EE2 removal. The results showed that all three MBRs systems achieved high efficiency on COD_Cr and NH₃-N removal irrespective of influent COD_Cr concentrations. The concentrations of E1 and EE2 in effluent decreased with the increase of influent COD_Cr concentration at the same initial concentration of steroid estrogens. With a constant influent concentration of SEs at 50 μg/L, and the concentrations of COD_Cr at 93.00,5.27 and 504.40 mg/L in MBRs, the average effluent concentrations of E1 and EE2 were 3.26,3.02,1.17 μg/L and 4.76,4.46,2.64 μg/L, respectively. The concentrations of E1 and EE2 in the effluent increased along with the initial steroid estrogens. With a constant influent concentration of SEs at 200 μg/L, the average effluent concentrations of E1 and EE2 were 5.61,5.64,3.82 μg/L and 8.14,7.87,6.57 μg/L, respectively. MBR achieved a better removal efficiency of E1 than EE2 under the same conditions. Pearson correlation analysis indicated that E1, EE2 removal loads were negatively correlated to COD_Cr removal load while positively correlated to NH₃-N removal (P<0.05), which suggested that E1, EE2 degradation in MBR were done by both organic matter co-metabolism and nitrification co-metabolism, and similar environment conditions as nitrifying process were required.