新型人工快速渗滤系统处理村镇污水工艺参数优化

在巢湖双桥河建立了中试规模的人工快速渗滤系统(CRI),系统经过一个月左右启动期后挂膜成功。通过考察不同湿干比条件下CODMn、TP、TN和NH3-N的去除效果,确定系统湿干比为1 d∶2 d,水力负荷周期为3 d。TP、TN和NH3-N在1.0 m/d的水力负荷条件下能够达到最佳的处理效果,特别是TN;而CODMn在1.3 m/d取得最佳的去除效果。综合考虑脱氮除磷和有机污染物的去除,选取水力负荷为1.0 m/d可得到最佳的出水水质。综合4种污染物的去除特点,特别考虑到对TN去除的需要,同时兼顾工程成本,填料厚度确定为1.2～1.5 m之间为最佳。选取生物陶粒、钢渣、活性炭和天然沸石为渗滤介质,研究结果表明,从去除有机污染物和TP角度考虑,选取活性炭和钢渣可达到较好的去除效果,其中钢渣对TP去除效果更佳;而活性炭具有其他4种填料不可替代的脱氮效果。以上工艺组合形式的确定将为巢湖流域CRI系统的推广提供科学依据和数据支持。

Optimizing operational parameters of new constructed rapid infiltration system in villages and towns wastewater treatment

This study evaluates the effects of wet/dry ratio,hydraulic loading,infiltration mediums and filling thickness of constructed rapid infiltration(CRI) system on the removal of selected contaminants of villages and towns sewage.Experiments were carried out in a pilot-scale CRI system established nearby Shuangqiao River,Chaohu Lake.By examining the removal effect of CODMn,TP,TN and NH3-N under different wet/dry ratios,the wet/dry ratio and hydraulic loading cycle of the CRI system were determined as 1 d∶2 d and 3 days,respectively.When the hydraulic loading was 1.0 m/d,the highest removal efficiency of TP,TN and NH3-N could be achieved,especially for TN,while 1.3 m/d was optimal for the removal of CODMn.Considering the comprehensive removal effects on nitrogen,phosphorus and organic pollutants,the hydraulic loading of 1.0 m/d was selected,which resulted in the best water quality of the effluent.The filling thickness was determined as 1.2 m to 1.5 m,considering both the economic cost and the removal characteristics of the four pollutants,especially TN.Bio-ceramics,steel slag,activated carbon and natural zeolite were selected as infiltration mediums and the results indicated that both activated carbon and slag had higher removal effects of TP and organic pollutants,slag was the best for the removal of TP,and activated carbon had unique effect on denitrification comparing to others.The results of the process combination mode provided scientific basis and data for the application of CRI system in Chaohu Lake Basin.