化粪池化粪池是一种利用沉淀和厌氧发酵的原理，去除生活污水中悬浮性有机物的处理设施，属于初级生活处理构筑物。生活污水中含有大量粪便、纸屑、病原虫...悬浮物固体浓度为100~350mg/L，有机BOD5在100~400mg/L之间，其中悬浮性的有机物浓度BOD5为50~200mg/L。污水进入化粪池经过的沉淀，可去除50%~60%的悬浮物。沉淀下来的污泥经过3个月以上的厌氧发酵分解，使污泥中的有成稳定的无机物，易腐败的生污泥转化为稳定的熟污泥，改变了污泥的结构，降低了污泥的含水率。
Septic tank septic tank is a treatment facility for removing suspended organic matters from domestic sewage by using the principle of sedimentation and anaerobic fermentation, which belongs to the primary domestic treatment structure. There are a lot of faeces, paper scraps and pathogenic insects in the domestic sewage. The solid concentration of suspended solids is 100-350mg / L, the organic BOD5 is 100-400mg / L, and the suspended organic BOD5 is 50-200mg / L. 50% - 60% of the suspended solids can be removed by the sedimentation of sewage entering the septic tank. After more than three months of anaerobic fermentation, the precipitated sludge is decomposed into stable inorganic substances. The perishable raw sludge is transformed into stable mature sludge, which changes the structure of sludge and reduces the water content of sludge