Industry status and characteristics of tannery wastewater
In daily life, leather products such as bags, leather shoes, leather clothes, leather sofas, etc. are ubiquitous. In recent years, the leather industry has developed rapidly. At the same time, the discharge of tannery wastewater has gradually become one of the important sources of industrial pollution.
Tanning generally includes three stages of preparation, tanning and finishing. In the preparation section before tanning, the sewage mainly comes from washing, soaking, dehairing, liming, deliming, softening and degreasing; the main pollutants include organic waste, inorganic waste and organic compounds. The wastewater in the tanning section mainly comes from washing, pickling, and tanning; the main pollutants are inorganic salts and heavy metal chromium. The waste water in the finishing section mainly comes from washing, squeezing, dyeing, fatliquoring and dedusting sewage, etc. Pollutants include dyes, oils and organic compounds. Therefore, tannery wastewater has the characteristics of large water volume, large fluctuations in water quality and water volume, high pollution load, high alkalinity, high chroma, high content of suspended solids, good biodegradability, etc., and has certain toxicity.
Sulfur-containing waste water: Liming waste liquid produced by ash-alkali dehairing in the tanning process and corresponding washing process waste water;
Degreasing wastewater: In the degreasing process of tanning and fur processing, the waste liquid formed by treating raw hide and oil with surfactant and the corresponding wastewater of washing process.
Chromium-containing wastewater: the waste chrome liquor produced in the chrome tanning and chrome retanning processes, and the corresponding wastewater in the washing process.
Comprehensive wastewater: a general term for various wastewater generated by tanning and fur processing enterprises or centralized processing areas, and directly or indirectly discharged to comprehensive wastewater treatment projects (such as production process wastewater, domestic sewage in factories).
Post time: Jan-17-2023
