一、补充：
I. supplement:
化粪池是一种小型污水处理系统，包括一个水池及化粪系统。污水在进入水池时，细菌会对污物进行无氧分解，并会使固体废物体积减少，再经过沉淀后排出，水质污染程度就会降低。
The septic tank is a small sewage treatment system, including a water tank and a septic system. When the sewage enters the pool, the bacteria will decompose the sewage without oxygen, and reduce the volume of solid waste. After sedimentation, the sewage will be discharged, and the water pollution will be reduced.
二、作用：
II. Function:
1、 保障生活社区的环境卫生，避免生活污水及污染物在居住环境的扩散。
1. Ensure the environmental health of the living community and avoid the diffusion of domestic sewage and pollutants in the living environment.
2、 在化粪池厌氧腐化的工作环境中，杀灭蚊蝇虫卵。
2. Kill the eggs of mosquitoes and flies in the working environment of anaerobic septic tank.
3、 临时性储存污泥，有机污泥进行厌氧腐化，熟化的有机污泥可作为农用肥料。
3. Temporary storage of sludge, anaerobic decomposition of organic sludge, mature organic sludge can be used as agricultural fertilizer.
4、 生活污水的预处理(一级处理)，沉淀杂质，并使大分子有机物水解，成为酸、醇等小分子有机物，改善后续的污水处理。
4. Pretreatment (primary treatment) of domestic sewage, precipitation of impurities, hydrolysis of macromolecular organics into acids, alcohols and other small molecular organics, and improvement of subsequent sewage treatment.