高负荷地下土壤法处理有机污水的模拟实验研究

针对传统地下污水渗滤系统的主要缺陷,提出了采用人工土壤提高系统的污水承载能力,采用多层过渡结构增大颗粒有机物的接触氧化表面积,采用高渗透性夹层增加氧气供应,以提高污水地下处理系统的水力负荷,延长其使用寿命.以我国南方典型的红壤土、砂和砾石为填充材料进行了实验室模拟实验,供试污水来自中国科学院广州地球化学研究所生活小区.结果显示,在25 cm/d的水力负荷下,系统没有被堵塞的迹象,采用每天2次投配污水的方式(每次12.5 cm),渗透系数为0.6 cm/min的土柱可以达到很好的出水效果,其COD、BOD5、SS、TN和TP去除率分别达到81.5%、84.6%、88.8%、82.6%和98%.

Experimental study on subsurface soil absorption system for organic wastewater treatment at high hydraulic loading

In order to promote the wastewater loading capacity,a renovated subsurface adsorption system was designed by the authors.In this system,artificial soil was used to improve the permeability of the system;the soil beneath wastewater distribution pipes was layered such that the permeability of the soil layers decreases downwards so as to disperse the particulate organic matter(POM);a highly permeable aeration layer was sandwiched to improve oxygen supply to the soil column.This design is expected to significantly accelerate the biodegradation rate of POM and,thus,can enhance greatly hydraulic loading of subsurface soil sewage treatment system.A test was conduced to purify sewage with a modeling cylinder filled by red clay,sand and gravel.The result showed that with hydraulic loading of 25 cm/d(irrigating equally twice for one day) the average removal rates of COD,BOD_5,SS,TN,and TP were 81.5%,84.6%,88.8%,82.6% and 98%,respectively.