处理农村污水的跌水充氧接触氧化技术设计研究

为了满足太湖地区农村污水处理占地面积小、除磷脱氮效率高、管理简单、运行和建设费用低的要求,研发了厌氧-跌水充氧接触氧化-人工湿地的组合工艺,并进行了工程试验研究.重点研究了跌水充氧接触氧化的设计及运行参数;接触氧化池内采取弹性填料与组合填料以1:1的比例混合装填,平面布置密度为45根/m2时,可使微生物量与跌水充氧能力之间达到平衡;相邻两池间经济有效的跌水高度为0.5 m;竖缝间距5 cm的挡板对水流的分散效果较好,有利于提高充氧效果;水力停留时间越小充氧效果越好,但由此带来的污染物负荷升高又会使污染物去除效果下降,故水力停留时间宜取2.4 h左右.

Study on the Design of Waterfall Aeration Contact Oxidation for Rural Sewage Treatment

In order to meet the technical requirements of smaller occupancy area,higher efficiency of nitrogen and phosphorus removal,easier maintenance and lower operation and construction cost in the treatment of rural sewage in Lake Taihu valley,a full-scale experiment on the use of the combined process of anaerobic/waterfall aeration contact oxidation/ constructed wetland was carried out.The design and operation parameters for waterfall aeration contact oxidation were mainly investigated.The oxygen supply ability of waterfall aeration can meet the demand of microorganism mass and pollutant removal when the elastic packing and assorted packing are arranged in the ratio of 1:1 and the plane density is 45 trails per square meter in contact oxidation tank.The cost-effective height of water dropping between two neighbors is 0.5 m.The dropping baffle with longitudinal slot of 5cm spacing disperses the waterfall better so as to benefit the aeration.When the hydraulic retention time(HRT) descends,the aeration is strengthened;however,the loading rate of pollutants is enhanced and results in the decline of removal efficiency.So the preferable HRT is about 2.4 h.