The content of pollutants in chemical wastewater is very high, one is because the reaction of raw materials is not complete, the other is that a large number of raw materials or solvents used in production enter the wastewater system. Chemical industry includes organic chemical industry and inorganic chemical industry. There are many kinds of chemical products with complex components. The waste water discharged from chemical plants is called chemical waste water. Most of this kind of waste water is highly toxic, not easy to purify, has a certain accumulation effect in organisms, and has obvious oxygen consumption property in the water body, which is easy to deteriorate the water quality. In particular, some fine chemical wastewater contains a lot of organic pollutants, which are toxic to microorganisms, such as halogen compounds, nitro compounds, some dispersants or surfactants with bactericidal effect, etc.

Inorganic chemical wastewater includes the industry of making basic chemical raw materials of acid, alkali and salt from inorganic minerals. In this kind of industrial production, the main water is cooling water. The discharged wastewater contains acid, alkali, a large number of salts and suspended solids, and sometimes sulfide and toxic substances. Organic chemical wastewater has a variety of components, including synthetic rubber, synthetic plastics, man-made fibers, synthetic dyes, paints, pharmaceuticals and other processes. It has strong oxygen consumption and strong toxicity, and most of them are synthetic organic compounds, so they are highly polluting and difficult to decompose.

There are a lot of biological refractory substances in chemical wastewater, which have poor biodegradability and high chroma. Polyacrylamide can be used as decolorizer and flocculant at the same time, and it has good treatment effect for chemical wastewater.