不同类型底栖动物对表面流人工湿地系统水质净化的影响

研究以表面流人工湿地为研究对象,探讨不同类型底栖动物在夏季和冬季对人工湿地系统氮磷去除效果的影响,并通过人工湿地系统运行前后不同介质氮磷含量变化及不同介质微生物丰度变化进行水质净化机理分析。结果表明,夏季添加河蚌和添加田螺均能增强人工湿地系统NO3-N和TN去除效果,其中添加河蚌使得系统NO3-N和TN平均去除率较对照组分别提升37.19%和24.32%,添加田螺使得系统NO3-N和TN平均去除率较对照组分别提升22.98%和12.46%。冬季添加摇蚊幼虫使得表面流人工湿地NO3-N、TN和TP平均去除率分别在37.8%、54.0%和94.8%,与对照组相比分别增加了29.51%、15.16%和37.62%,添加河蚌和田螺受底栖动物半冬眠活动和代谢降低影响没有显著水质提升效果。这表明通过添加底栖动物可以增强表面流人工湿地运行效果,选取适合的底栖动物种类组合可能在全年提升人工湿地水质净化效果。机理研究结果表明,底栖动物通过增强底泥和基质中微生物硝化反硝化作用、植物氮吸收和基质氮吸附等促进人工湿地氮去除,通过增强下层基质磷吸附沉淀和植物磷吸收提升水质磷去除。研究结果将为底栖动物在人工湿地的...

EFFECTS OF DIFFERENT BENTHIC FAUNA ON WATER PURIFICATION IN SURFACE FLOW CONSTRUCTED WETLAND SYSTEM

In this study, the surface flow constructed wetlands were set up to explore the efficiency of different benthic fauna on nitrogen and phosphorus removal in the constructed wetland system during summer and winter. The water purification mechanism was investigated by the changes of nitrogen and phosphorus contents and microbial abundance in different media before and after the operation period. The results showed that the addition of mussel and viviparidae in summer enhanced the NO₃-N and TN removal efficiency. Compared with the control group, the average NO₃-N removal efficiency increased 37.19% and 22.98% by adding mussel and viviparidae, respectively. In addition, the addition of chironomid larvae in winter made the average removal efficiency of NO₃-N, TN and TP increase by 29.51%, 15.16% and 37.62%, respectively. However, the mussels and viviparidae did not have significant effects due to the semi-hibernation and reduced metabolism of benthic animals in winter. These results indicated that the addition of benthic fauna can enhance the purification effect in surface flow constructed wetland. When suitable combination of benthic fauna was selected, the water purification effect in constructed wetland may be improved throughout the year. The results of mechanism study showed that benthic fauna promoted nitrogen removal by enhancing microbial nitrification and denitrification, plant nitrogen uptake and substrate nitrogen adsorption. The removal of phosphorus was achieved by enhancing substrate phosphorus adsorption and precipitation as well as plant phosphorus uptake. These results could provide a theoretical basis and reasonable reference for the application of benthic fauna in surface flow constructed wetlands.