由于工业废水成分的多样性，由几种方法组成的处理系统往往需要达到规定的排放标准。污水处理按分类方法的选择，可分为物理法、化学法、物理化学法和生物法4种方法。生物法是一种利用废水微生物代谢分化水降解有机物，由于大量的处置、投资省、特点、经济和可靠的，它是世界上更具水溶性的一种。
基于微生物在好氧条件下的生物处理，可以分为好氧和厌氧两类。在一般情况下，有氧类推适用于低浓度的污水，如乙烯装置废水;厌氧处理污泥和高浓度污水的方法。好氧生物处理可分为活性污泥法和生物膜法。活性污泥法是人工增水措施，是一种以活性污泥为基础，在污水中有机物去除的主要任务。在活性污泥中的有氧微生物必须能够在氧气存在下工作。在污水处理生化系统的曝气池中，好氧和有氧能力的增长之间的关系是积极的。
溶解氧的供应应根据需氧微生物数量、生理特性、基质性质和浓度。这样，活性污泥可以在比较好降解条件下有机物的降解。根据实验结果，结果表明，曝气池中的溶解氧保持在3 ~ 4mg/L，如果氧气供给不足，活性污泥性能差，导致废水处理效果。为了保证充足的氧气供应，必须依靠一个设备来完成，如曝气装置。
Due to the diversity of industrial wastewater components, the processing system consisting of several methods often needs to meet the prescribed discharge standards. The classification of sewage treatment can be divided into 4 methods: physical method, chemical method, physical chemistry method and biological method. Biological method is a kind of organic matter that uses Wastewater Microbial metabolism to differentiate water, and it is the most water-soluble in the world because of its large amount of disposal, investment province, characteristic, economy and reliability.
Biological treatment based on Microorganism under aerobic condition can be divided into two categories: aerobic and anaerobic. In general, aerobic analogy is suitable for low concentration sewage, such as ethylene plant wastewater, anaerobic treatment of sludge and high concentration sewage. Aerobic biological treatment can be divided into activated sludge process and biofilm process. Activated sludge is an artificial water increasing measure. It is a main task of removing organic matter in sewage based on activated sludge. Aerobic microorganisms in activated sludge must be able to work in the presence of oxygen. The relationship between aerobic and aerobic capacity is positive in the aeration tank of the sewage treatment biochemical system.
The supply of dissolved oxygen should be based on the quantity, physiological characteristics, matrix properties and concentration of aerobic microorganisms. In this way, the activated sludge can be degraded under the best degradation conditions. According to the experimental results, the results show that the dissolved oxygen in the aeration tank is kept in 3 ~ 4mg/L. If the oxygen supply is insufficient, the performance of the activated sludge is poor, which results in the treatment effect of the wastewater. In order to ensure adequate oxygen supply, we must rely on a device to complete, such as aeration device.
