Tannery wastewater refers to the wastewater produced in the preparation and tanning stage of tannery, that is, in the process of wet operation. Tannery wastewater is characterized by large discharge, high pH value, high chroma, various pollutants and complex components. The main pollutants include heavy metal chromium, soluble protein, dander, suspended solids, tannin, lignin, inorganic salt, oil, surfactant, dye and resin, etc.
Tannery wastewater refers to the wastewater produced in the preparation and tanning stage of tannery, that is, in the process of wet operation. Tannery wastewater is characterized by large discharge, high pH value, high chroma, various pollutants and complex components. The main pollutants include heavy metal chromium, soluble protein, dander, suspended solids, tannin, lignin, inorganic salt, oil, surfactant, dye and resin, etc.
Tannery wastewater is generally treated by "pretreatment + biochemical treatment" process, which can meet the comprehensive wastewater discharge standard or industry drainage standard.
The pretreatment usually uses the process of oil separation + air flotation / coagulation sedimentation. In the pretreatment stage, the oil and heavy metal pollutants are removed before entering the biochemical treatment stage. In the biochemical treatment stage, the biodegradability of wastewater is improved by hydrolysis acidification tank, and then the wastewater can meet the discharge requirements by aerobic treatment.