China is a leather manufacturing country and consumption country, the output and demand are very huge. The leather industry has caused great pollution to the environment. With the concept of environmental protection deeply rooted in the people, whether the pollution discharge of leather wastewater can be effectively solved directly affects whether the leather industry can continue to survive, develop healthily and steadily.
Leather production is mainly wet operation, through physical, chemical and mechanical processes of various raw materials into finished leather. Because most of the work has water as the medium, the preliminary statistics of each production of 1 ton of raw material skin to discharge 60~120 tons of wastewater. In the process of leather production, there is a huge amount of water consumption and sewage discharge demand. Leather wastewater is a kind of industrial wastewater which is difficult to treat. The application of decanter centrifuge to the treatment of tannery wastewater is a technological progress.
Analysis of tannery wastewater, sewage mainly comes from the wet operation preparation section and tanning section of tannery production, including soaking wastewater in leather soaking section, degreasing section wastewater, soaking and removing ash and washing section wastewater, acid leaching wastewater, chrome tanning process wastewater and dyeing grease wastewater, which makes the converging wastewater contain a large amount of organic matter (protein, dye, grease), inorganic matter (sulphide chromium salt, etc.) and sediment harmful substances such as wool residue oil sludge. The practice shows that good economic and environmental benefits can be obtained by using decanter centrifuge to participate in the treatment of tannery wastewater. It can not only change the working environment of leather processing place, but also make the pollutants stable Standard, and the cost of wastewater treatment per ton can be reduced by nearly half, realizing the win-win of environmental and economic benefits.
The idea of decanter centrifuge participating in tannery wastewater treatment:
Leather wastewater-coarse filtration pretreatment-dosing precipitation-lying decanter centrifuge solid-liquid separation-material recycling.
Horizontal centrifuge involved in tannery wastewater treatment process:
According to different tannery processes, the general components of sewage were analyzed. Through biochemical method, the organic components were decomposed and transferred, and the inorganic components were flocculated and precipitated by horizontal screw centrifuge. After purification, the water quality is up to standard and the organic compost is used as fertilizer.
decanter centrifuge to participate in tannery wastewater treatment station setup:
The main facilities are grille, pre-regulating tank, primary settling tank, oxidation ditch, secondary settling tank, air floatation tank, sludge thickening tank, sludge scum recovery facility and medicament dosing facility;
Pretreatment: waste water through fine grille can intercept a large number of floating matter, iron oxide and suspended matter, it can achieve the purpose of continuous removal of various shapes of small debris, verify the normal operation of subsequent treatment process equipment, in order to reduce the load of subsequent treatment structures;
Precipitation regulation: the waste water is treated by the grille machine and enters the regulating tank. It adjusts the water quantity and water quality while removing the oil slick in the water through the oil collecting pipe;
Flocculation and precipitation: germicidal disinfection of hypochloric acid, precipitation of metal alkali lime, regulation ph sulfuric acid, flocculant.