人工湿地净化造纸废水尾水及优势植物筛选

Purification of papermaking tail-water by constructed wetlands and the screening of dominant wetland plants

通过象草、灯芯草、水葱、风车草4种植物人工湿地系统对造纸废水的处理,探讨了湿地系统对COD、NH+4-N和TP的去除能力,考察了湿地植物的净化作用与效果。结果表明,植物的引入能显著提高湿地系统对造纸废水的处理效果;植物人工湿地系统中COD、NH+4-N和TP去除率均随水力停留时间的延长而增加;4种植物人工湿地系统对COD去除效果均较好,其中水葱湿地系统最佳,COD去除率可达98%以上;水葱和灯芯草湿地系统对NH+4-N和TP的去除效果较好,其去除率分别可达85%和80%以上。综合比较4种植物的综合净化能力,水葱和风车草最好,灯芯草次之,象草最差,水葱和风车草是人工湿地处理造纸废水的适宜选择。

The purification of papermaking tail-water was studied in the four kinds of constructed wetland systems planting with Pennisetum purpureum,Juncus effuses,Scirpus validus Vahl and Cyperus alternifolius,respectively. The treatment performances of the wetlands for COD,NH+4-N and TP and the purification abilities of the wetland plants were illuminated by the laboratory experiments. The results show that the plantation of the plants is beneficial to the treatment of the tail-water in the wetlands. The removal rates of COD,NH+4-N and TP in the wastewater increase with the prolonging of the hydraulic resident time in the systems. COD in the tail-water can be efficiently removed by the four planted constructed wetlands and the highest COD removal rate over 98%is obtained in the wetland planting with Scirpus validus Vahl. The wetlands with Scirpus validus Vahl or with Cyperus alternifolius can effectively purify NH+4-N and TP,and their removal rates can reach to over 85% and80%,respectively. Based on the comprehensive analysis,the purification ability of Pennisetum purpureum is lowest among the four plants and that of Juncus effuses takes the second place; Scirpus validus and Cyperus alternifolius are both suitable for the wetland to treat papermaking tail-water due to their highest purification abilities.