潜流人工湿地对模拟污水中β-HCH的去除效果

Removal Efficiency ofβ-HCH in Simulated Sewage by the Subsurface Flow Constructed Wetland

为了研究潜流人工湿地对污水中六氯环己烷(HCHs)的异构体β-HCH的去除效果,构建了4种潜流人工湿地装置,分别为未添加基质且未种植菖蒲(Acorus calamus)、添加基质未种植菖蒲、添加基质且种植菖蒲并添加氨苄青霉素、添加基质且种植菖蒲的人工湿地,在各人工湿地中,加入配制的β-HCH模拟污水;采用气相色谱法,测定人工湿地进水和出水中的β-HCH含量,分析人工湿地对污水中β-HCH的去除效果,并研究β-HCH在各人工湿地中的降解动力学特征。研究结果表明,添加了基质的人工湿地对污水中β-HCH的去除率明显大于未添加基质的人工湿地,表明基质对β-HCH有明显的吸附作用;在添加基质的人工湿地中种植菖蒲,使其对β-HCH的去除率提高了14.46%~16.94%,表明植物能有效提高人工湿地对β-HCH的净化能力;与未添加氨苄青霉素的人工湿地相比,添加氨苄青霉素的人工湿地对β-HCH的去除率减小了2.48%,表明氨苄青霉素对β-HCH的降解有抑制作用;添加基质且种植菖蒲的人工湿地对β-HCH的去除率达到94.20%;β-HCH在4种配置的人工湿地中的降解过程都符合一级动力学方程,在未添加基质且未种植菖蒲的人工湿地中,β-HCH的降解率过低,无法计算β-HCH在此人工湿地中的半衰期,在其它3种人工湿地中,β-HCH的半衰期分别为12.48 h、15.36 h和13.68 h。

Four subsurface flow constructed wetlands units(including no substrate or no Acorus calamus,adding substrate but no Acorus calamus,adding substrate and Acorus calamus and ampicillin,adding substrate and Acorus calamus)were built to study the removal effect ofβ-hexachlorocyclohexane and simulated sewage withβ-hexachlorocyclohexane was add.The content ofβ-hexachlorocyclohexane in the inlet and outlet water of the constructed wetland was determined by gas chromatography.The effects of substrates,Acorus calamus,and ampicillin on the removal ofβ-hexachlorocyclohexane in the constructed wetland were analyzed.The degradation kinetics characteristics ofβ-hexachlorocyclohexane in the four constructed wetlands were studied.The results showed that the removal rates ofβ-hexachlorocyclohexane in the constructed wetlands with substrate were 77.26%-94.20%.The removal rates ofβ-hexachlorocyclohexane in the constructed wetland without substrate were only 21.77%,indicating that the substrate had obvious adsorption effects onβ-hexachlorocyclohexane.The removal rates ofβ-hexachlorocyclohexane in the constructed wetland by the combination of substrates and Acorus calamus were 14.46%-16.94%higher than those with substrate-filled alone.Plants could effectively improve the purification capacity ofβ-hexachlorocyclohexane in the constructed wetland.The removal rates of the ampicillin inhibition wetland were only 2.48%lower than those of the uninhibited wetland,indicating that the degradation effect of the microorganism onβ-hexachlorocyclohexane was not obvious.The removal rates ofβ-hexachlorocyclohexane by constructed wetland combined substrates and Acorus calamus reached 94.20%,indicating that the combined removal efficiency of plants,substrates was the best in the constructed wetland system.The purification process ofβ-hexachlorocyclohexane in the four groups of constructed wetland conformed to the first-order kinetic equation.Due to the low degradation rate ofβ-hexachlorocyclohexane in the control,it was impossible to calculate the half-life ofβ-hexachlorocyclohexane.The half-lives of the other three wetlands were 12.48 h,15.36 h and 13.68 h,respectively.