不同基质垂直流人工湿地对高污染河水中磷的去除效果

Phosphorus removal of vertical flow constructed wetlands using difference substrates for purifying highly polluted river water

通过炉渣、砾石对磷的等温吸附和吸附动力学实验及分别以它们为基质构建的垂直流人工湿地实验,考察了这两种基质对磷的吸附性能及其所构建的湿地对高污染河水中磷的去除效果.结果表明,炉渣对磷的吸附能力更强、吸附速率更快且具有更好的抗冲击负荷能力.炉渣的等温吸附特征与Freunlich方程拟合更好,而砾石吸附更符合Langmuir方程.准二级方程能较好地反映两种基质对磷的吸附动力学特征.在进水平均磷浓度4 mg·L-1、水力负荷0.05 m·d-1条件下,以炉渣和砾石为基质的垂直流人工湿地对磷的平均去除率可达到76%和65%,预期使用年限分别为11—15 a和3—4 a,且炉渣能很好地形成有利于磷去除的环境.因此,以炉渣为基质的湿地更适于处理高污染河水.

Phosphorus adsorption isotherms and adsorption kinetics of slag and gravel were studied, and two vertical flow constructed wetlands filled with the different substrates was constructed to investigate the phosphorus removal efficiency of highly polluted fiver water. The results showed that slag had much higher phosphorus adsorption ability than gravel. It was better that the adsorption isotherms of slag qualified Freunlich equation, and gravel fitted Langmuir equation. The phosphorus adsorption kinetics of both substrates could be very well described by pseudo-second-order kinetic equations. In the slag-filled and gravel-filled systems, the average phosphorus removal efficiencies were 76% and 65% respectively, and the life expectancies were estimated to be 11-15 a and 3-4 a, when the phosphorus concentration of influent was 4 mg·L^-1 and the hydraulic loading rate was 0.05 m·d^-1. Moreover, the slag-filled system created a good environment for phosphorus removal. Therefore, the slag-filled system was the optimal wetland for phosphorus removal from highly polluted fiver water.