分层填料地下渗滤系统处理农村分散生活污水

Rural decentralized sewage treatment by layered-filling SWIS

为了解决农村生活污水直接排放造成的地表水以及地下水污染问题,本研究采用2种混合填料(5%粉煤灰+95%土壤和5%腐熟干牛粪+95%土壤)分层装填的3种不同结构的地下渗滤系统进行农村分散生活污水处理。结果表明,系统对污水中各主要污染因子都有较好的去除作用,且能承受一定的污染负荷波动;除总氮外,系统出水各项指标最低满足《地表水环境质量标准》中Ⅲ类标准,出水外排不会造成地表水污染;添加腐熟牛粪大大提高了系统总氮、硝氮的去除效率,出水稳定后满足地下水环境质量Ⅲ类标准。在应用过程中,建议选择2种填料填充高度各半的填充模式,以便各项指标均能达到最优处理效果。

To solve the problem of surface water and groundwater pollution resulted from rural sewage-di- rectly discharged, 3 different subsurface wastewater infiltration systems（SWIS） structured from 2 mixed stuffing （5% fly ash ＋ 95% soil and 5% decomposed cow dung ＋ 95% soil） were established for the treatment. The results revealed that main pollution factors of the sewage were removed effectively, and the systems could with- stand certain pollution load fluctuations. Except total nitrogen （TN） , the maximum concentrations of COD, total phosphorus （TP） , ammonia nitrogen（ NH3-N） met the III criteria specified in surface water quality standardand, and the water directly discharged didn＇ t pollute the surface water. The adding of decomposed cow dung in soil greatly improved removal efficiency of TN and nitrate,the stable discharged water met the criteria III specified in groundwater quality standard. For further application, the pattern of 2 mixed stuffing respectively filling half of the height was suggested to achieve the best treatment effect for each pollution indicators.