北方地区潜流人工湿地冬季保温措施的研究

人工湿地作为一种造价较省,运行成本低的污水处理技术,目前已经得到了广泛的应用.但是在北方地区,人工湿地受到冬季气候影响,无法正常运行,降低了它的使用效率.试验针对北方冬季低温环境下,人工湿地无法正常运行的问题,对3种不同的保温措施进行历时两年的对比试验,通过对TP、TN、NH₄⁺-N和COD等4种主要污染物和人工湿地出水水温的跟踪监测,检验了不同保温措施的效果.试验结果表明:在冬季,使用薄膜法保温措施的处理系统中, COD、TN和NH₄⁺-N的去除率分别为30%~45%、40%~60%和35%~60%,比温棚法和冰封法的出水中污染物去除率高10%~20%.TP在出水中含量波动较大,去除率为19%~70%,伴有磷释放现象,但是在薄膜保温下TP的去除效果也要好于温棚和冰封.经过SPSS 16.0分析,薄膜保温的人工湿地出水水质与冰封和温棚法相比具有显著性差异.在对人工湿地曝气槽和出水口的污水水温进行监测发现,利用薄膜保温的人工湿地出水口水温高于冰封和温棚的水温,进一步证明薄膜保温可以有效提高人工湿地内的温度,为人工湿地正常运行提供了保证.而且薄膜保温措施的操作简便、造价低,适合推广应用.

The study of wintertime heat preservation measures in subsurface flow constructed wetland in northern China

As a new type of wastewater treatment technology, constructed wetland become more and more popular at present due to cheap cost, non-secondary pollution and other advantages. However, constructed wetland could not take regular operation because of cold weather in reducing its efficiency. In view of this, comparison tests on four main pollutants and the water temperature were conducted among three different insulation measures for two years. The test results indicate that COD, TN and NH₄⁺-N removal rate was 30%~45%, 40%~60% and 35%~60%, respectively, based on thin-film method of insulation measures processing system. These removel rates were approximately 10%~20% higher than the greenhouse method and frozen method. The content of TP in the water fluctuated significantly, with the removal rate ranging 19%~70% and release of P. Despite of this, the removal rate was higher than the greenhouse method and frozen method. By applying SPSS 16.0, significant difference was discovered in water quality from constructed wetland with thin-film compared with frozen method and greenhouse method. By monitoring water temperatures at the aeration tank and its outlet, it was discovered that temperature in constructed wetland with thin-film was much higher than frozen method and greenhouse method, which proved that thin-film method has ability to improve artificial wetland efficiency. Therefore, thin-film insulation measure should be promoted for its convenience and cheaper cost.