Treatment process for wastewater from synthetic leather production

Abstract

A treatment process for wastewater from synthetic leather production comprises the following steps of: grating treatment, pH and temperature adjustment, blowing off treatment, air floatation treatment, anaerobic degradation by adding domestic sewage, aerobic degradation, precipitation and MBR treatment. The process ensures the stability of water quality by aerobic biological degradation, so that the later process requirements are reduced to ensure the effluent water quality. The removal rate of dimethylamine after the blowing off treatment reaches 81%, which solves the problem of bad odor of distilled water, and makes the dimethylamine in wastewater recyclable, thereby turning waste into treasure; and the wastewater discharge meets the standards. A treatment system for wastewater from synthetic leather production is also disclosed.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a treatment process for synthetic leather production wastewater, and also relates to a treatment system for realizing the treatment process. Background technique [0002] Polyurethane synthetic leather is a composite material that simulates the structure and performance of natural leather and can be used as a substitute for natural leather. Usually non-woven fabric is used to simulate the mesh layer, and microporous polyurethane coating is used to simulate the grain layer. The front and back of the obtained synthetic leather are very similar to leather, and have a certain degree of air permeability, which is closer to natural leather than ordinary artificial leather. Widely used in making shoes, boots, bags and ball games. [0003] According to the National Bureau of Statistics, in 2011, there were 495 artificial leather and synthetic leather enterprises...

AI Technical Summary

Problems solved by technology

[0005] The wastewater produced by the polyurethane wet production line contains a large amount of organic solvent DMF (dimethylformamide), which is often recovered through a distillation recovery tower. The recovered DMF has a purity of 99.9% and a recovery rate of 99.5%. The solid waste generated is transported to the solid waste treatment company for treatment. However, the synthetic leather production wastewater after recycling DMF still contains pollutants: dimethylformamide, dimethylamine, toluene, methyl ethyl ketone and other organic substances and A small amount of surfactants and a small amount of suspended solids, etc., need further treatment to meet the emission standards

At present, there are three major problems in the treatment of synthetic leather production wastewater: First, after the production wastewater is distilled to recover the dimethylformamide in the wastewater, the distillation wastewater contains a large amount of dimethylamine and a small amount of DMF, resulting in a COD value as high as 29259.9 mg / L; second, the distillation wastewater containing a large amount of dimethylamine is produced, and the wastewater has a foul smell, causing certain environmental problems; third, the COD value of the distillation wastewater is very unstable, which will affect the traditional sewage treatment process It caused a relatively large impact, resulting in the death of a large number of cultured bacteria in sewage treatment, and the final treatment effect was not ideal, or even failed to meet the standard

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