生态沟渠对农村小流域面源污染物的拦截效应研究

Intercepting Effect of Ecological Ditch on Non-point Source Pollution in Small Rural Watersheds

文章以赣南苏区"三江源"区域典型农村小流域为研究对象,针对小流域农业面源污染的实际情况,秉承"因地制宜,生态降解"的理念,构建由工程部分和生物部分有机组合而成的生态拦截沟渠系统,开展水生植物、微生物及贝类和螺类等底栖动物对农业面源污染、农村生活污水及养殖废水等污染物的联合净化研究,阐明生态沟渠系统对农村小流域面源污染拦截效应及其影响因素。研究结果表明,经过为期近半年的运行处理,生态沟渠系统出水的COD浓度降至19.63 mg/L以下,接近地表Ⅲ类水标准,DO含量为5.43 mg/L,处于Ⅱ类和Ⅲ类水之间,TP浓度降低至2.03 mg/L,NH3-N浓度下降至5 mg/L以下,TN浓度<7 mg/L;COD、NH3-N、TP和TN的总去除率分别为65.92%、90.38%、86.95%和89.03%,生态沟渠系统对农村小流域面源污染物具有较高的去除效率且运行效果良好;气温、水量和水生植物的生长期对生态沟渠去除效果具有重要作用。文章通过设计适合赣南农村小流域的生态拦截沟渠系统,运用工程、技术和生态的方法,实施赣南苏区"三江源"区域典型农村小流域面源污染物的综合防治,研究结果可为保障赣南等原中央苏区作为中国南方地区重要生态屏障地位和促进流域经济社会的可持续发展提供技术支撑。

Small typical rural watershed in the"three river source areas"was selected as the research object in Gannan Soviet Area(Ganzhou City).In accordance with its actual situation of agricultural non-point source pollution,this study built an ecological ditch system that was an organic combination of engineering and biological parts,adhering to concept of adapting to local conditions and ecological degradation.The joint purification research of aquatic plants,microorganisms and their benthic animals such as shellfish and snails on agricultural non-point source pollution,rural sewage and aquaculture wastewater was carried out.The aim was to explore the intercepting effect and its influencing factors of the ecological ditch system to prevent and control the non-point source pollution in the study areas.The results showed that COD concentration in the effluent of the ecological ditch system dropped at 19.63 mg/L,which was close to the surface water GradeⅢstandard.DO concentration is 5.43 mg/L,which was between GradeⅡand GradeⅢwater standard,and TP concentration was reduced to 2.03 mg/L,NH3-N concentration drops below 5 mg/L,and TN concentration is less than 7 mg/L.The total removal rates of COD,NH3-N,TP and TN were 65.92%,90.38%,86.95%and 89.03%,respectively.The ecological ditch system showed a high removal effect on pollutants and a stable operation effect.Air temperature,water volume and growth period of the aquatic plants had important effects on the removal effects of ecological ditch.This paper applied the methods of engineering,technology,and ecology to design the ecological ditch suitable for small watersheds in rural areas in Gannan Soviet Area(Ganzhou City).The ecological ditch was used to implement ecological treatment of non-point source pollution,and to explore water pollution control technology and ecological restoration technology in the"three river source areas".The results were helpful to provide technical support for ensuring the status of the former Central Soviet Areas such as southern Jiangxi as an important ecological barrier in southern China and promoting the sustainable development of the watershed’s economic society.