Desulphurization wastewater mainly comes from gypsum dehydration and cleaning system. The impurities in wastewater mainly include suspended solids, supersaturated sulfite, sulfite and heavy metals, many of which are strictly controlled in the national environmental protection standards. Desulphurization wastewater is generally divided into pretreatment and zero discharge treatment.

The main pretreatment processes are chemical neutralization, flocculation precipitation and so on. Zero discharge treatment mainly adopts the technologies of concentration, flue gas evaporation and so on. The technology is mature, the operation is stable, and unattended can be realized.