复合垂直流人工湿地对有机磷阻燃剂的净化

Study on purification of organophosphorus flame retardants by integrated vertical-flow constructed wetlands

为探索有效处理有机磷阻燃剂(OPFRs)废水的方法,本文构建了复合垂直流人工湿地(IVCWs),探究不同进水C/N比与是否曝气等运行工况下系统对磷酸三(1-氯-2-丙基)酯(TCPP)的去除效率影响,并观察目标物在湿地系统各介质中的迁移行为及相关机理.结果表明,不同工况下IVCWs对TCPP去除效果存在显著差异.与进水C/N=3时系统对TCPP去除率(52.28%±11.64%)相比,增加进水C/N、曝气和两者联用可使去除率分别提高至(68.77%±2.49%),(57.21%±1.76%)和(89.64%±1.94%).通过分析系统中各相累积量发现,植物(0.09%)和基质(3.30%)中TCPP的累积有限.火山岩(162.39~435.01ng/gdw)和沸石(131.67~407.74ng/gdw)中TCPP含量显著高于土壤(32.63~149.94ng/gdw).植物体内,与菖蒲(432.95ng/gdw)、香蒲(665.21ng/gdw)相比,风车草(1288.82ng/gdw)更易TCPP累积.不同植物中TCPP主要富集在根部,有向叶片转移的趋势.探究IVCWs对TCPP的去除潜能及迁移行为,对系统缓解OPFRs污染具有积极意义.

It is urgent to explore the efficient treatment methods to purify organophosphorus flame retardant(OPFRs) wastewater. integrated vertical-flow constructed wetlands(IVCWs) was built, the influence of varied operating conditions of inlet water, C/N ratio and aeration on the removal efficiency of TCPP was investigated, and the migration behaviors of TCPP in each medium of the wetland system was observed to gain insights into the relevant mechanism. The results showed that there were significant differences in the removal of TCPP among different operating conditions. Compared with the removal rate of TCPP(52.28%±11.64%) when the inlet water C/N=3, increasing C/N ratio, aeration value and the two factors combined can increase the removal rate to(68.77%±2.49%),(57.21%±1.76%) and(89.64%±1.94%). By analyzing the cumulative amount of each phase in the system, it was found that the accumulation of TCPP in plants(0.09%) and substrate(3.30%) was limited. The concentration of TCPP in igneous rock(162.39~435.01 ng/g dw) and zeolite(131.67~407.74 ng/g dw) was significantly higher than that in soil(32.63~149.94 ng/g dw). In plants, compared with Acorus calamus(432.95 ng/g dw) and Typhae latifolia(665.21 ng/g dw), Cyperus alternifolius(1288.82 ng/g dw) was more likely to accumulate TCPP. TCPP was mainly concentrated in the roots of different plants and tends to transfer to leaves. Exploring the removal potential and migration behavior of IVCWs for TCPP has positive significance to mitigate OPFRs pollution.