Treatment process for tannery wastewater

Abstract

The invention discloses a treatment process for tannery wastewater and relates to the technical field of sewage treatment. The treatment process comprises the following steps: enabling high-concentration wastewater to flow into a grid canal and an adjusting tank 1, performing pretreatment through coagulating sedimentation, Fenton oxidation and coagulating sedimentation, and feeding the effluent into a pre-hydrolysis acidification tank; enabling floor washing water to flow into the grid canal and an adjusting tank 2, enabling the effluent to flow into the pre-hydrolysis acidification tank, mixing the effluent with the high-concentration wastewater, and performing hydrolysis and acidification; pumping the effluent into a UASB (upflow anaerobic sludge blanket) reactor, enabling the effluent to flow into a settling pond 1, enabling upper clear water of the settling pond 1 to flow into an air stripping tank, further feeding the effluent into a primary A / O (anoxic / oxic) tank, enabling the effluent to flow into a settling pond 2, enabling upper clear water to flow into a secondary A / O tank, feeding the effluent into a settling pond 3, and feeding upper clear water into a middle water tank; enabling boiler water to flow into the grid canal and an adjusting tank 3, performing coagulating sedimentation, and enabling upper clear water into the middle water tank; and filtering the effluentby using a fiber sphere filter, and feeding the effluent into a monitoring tank. By adopting the treatment process, a good treatment effect on pollutants such as SSs (suspended solids), CODs (chemical oxygen demands), ammonia nitrogen and organic matters in tannery wastewater can be achieved, and the effluent can meet the emission standard of GB 21902-2008.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, in particular to a process for treating tannery wastewater. Background technique [0002] Tannery wastewater is the wastewater discharged during the leather production process. Usually animal skins are salted or soaked in water to make them swell, add lime, flesh out, dealkalize, then tan with tannins or chrome, fatliquor and soften, and finally dye them. Processed into leather. The main characteristics of tannery wastewater are high pollutant concentration, complex composition, and a large amount of toxic and harmful substances. [0003] Tannery wastewater mainly includes: washing tower water (cleaning heat exchanger water), boiler water, tanning water, bucket washing water, condensation water and floor flushing water. Among them, the tanning water mainly contains leather base cloth dander, etc., and the SS is high; the tanning water, bucket washing water and condensation water contai...

AI Technical Summary

Problems solved by technology

[0004] Due to the complex process of leather production and long processing cycle, the quality and quantity of wastewater in each processing section vary greatly, and the operation of each section cannot guarantee synchronization. Therefore, the comprehensive water quality and quantity of leather wastewater vary drastically, and contain a large number of biologically toxic substances. It has brought great difficulty to the treatment of wastewater

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