利用有机覆盖物处理的人工湿地外排焦化废水研究

目的]为进一步降低污染物浓度,提高钢铁企业水资源循环利用率。方法]采用水平潜流人工湿地处理外排焦化废水,通过监测分析进出水中浊度、化学需氧量(COD),总氮(TN)和总磷(TP)含量,探讨冬季人工湿地植物层不添加及添加有机覆盖物对钢铁企业外排焦化废水净化水平的影响。结果]在低温季节,水力停留时间为5d时,不添加有机覆盖物人工湿地对外排焦化废水浊度,COD,TN和TP的平均去除率分别为68.55%,14.94%,14.20%和71.26%;添加有机覆盖物人工湿地对外排焦化废水浊度、COD,TN和TP的平均去除率分别为72.54%,21.62%,20.50%和71.88%;有机覆盖膜的保温作用使得COD去除率升幅达44.68%,TN去除率升幅达44.45%。结论]在植物层添加有机覆盖物作为保温材料,可以提高人工湿地在低温条件下的净化效率。

A Study on Treatment of Discharged Coking Wastewater by Constructed Wetlands Using Organic Mulches

Objective] The paper aims to further reduce pollutant concentration and improve the reclamation rate of wastewater in iron and steel enterprises. Methods] We adopted two sets of horizontal subsurface flow constructed wetlands for the treatment of discharged coking wastewater in iron and steel enterprises, and investigated the impacts of wetland vegetation with and without organic mulches on the treatment of discharged coking wastewater by constructed wetland in winter through the monitoring and analyzing the turbidity, chemical oxygen demand(COD), total nitrogen(TN), and total phosphorus(TP) concentrations in influent and effluent. Results] In low-temperature season, the hydraulic retention time was 5 days, the average removal rates of turbidity, COD, TN, and TP was 68.55%,14.94%,14.20% and 71.26% in constructed wetland without organic mulches while the average removal rates of those in constructed wetland with organic mulches was 72.54%, 21.62%, 20.50% and 71.88%, respectively. The removal rates of COD and TN increased by 44.68% and 44.45%, respectively. Conclusion] Organic mulches could be used as insulating material to help increase the purification rate of constructed wetland under the low-temperature condition.