The wastewater production, pollutant composition and content of coal chemical process vary greatly with the type of raw coal, the place of production, the processing technology of coal, the method of refining chemical products, the degree of processing and the level of equipment management. Wastewater often contains dozens of inorganic and organic pollutants, including solid suspended solids, ammonia and ammonium salts, sulfides, and heavy metals. It contains easily degradable organic substances, such as aliphatic compounds, phenolic compounds and benzene compounds, degradable organic substances, such as pyrrole, naphthalene, furan, imidazole, etc., refractory organic substances mainly include pyridine, carbazole, biphenyl, triple a polycyclic aromatic compound such as benzene and a heterocyclic compound containing S, N, and 0.
The nitrogenous substances in the wastewater can lead to eutrophication of the water body, and the algae grow and grow in large quantities, so that the water body is deprived of oxygen, and the water quality deteriorates and becomes odorous. The ammonia nitrogen in the wastewater can also be converted into nitrate nitrogen in the water. Infants drinking water containing a certain concentration of nitrate nitrogen can cause leukemia. Most of the carbon-containing compounds in the wastewater are oxygen-consuming substances, which will seriously deplete the dissolved oxygen in the water and cause the water to decay. Sulfide in wastewater is also one of the substances that produce acid rain. The phenolic compounds in the wastewater are prototype toxicants, and the excessive concentration will weaken the degradation of pollutants by microorganisms in the water. Therefore, if the coal chemical wastewater is discharged into the natural world without treatment or treatment that can not reach standard, it will not only cause serious pollution to the soil, water and air, but also affect the growth of animals and plants and human health.