Leather manufacturing method achieving three-waste discharge reduction

Abstract

The invention provides a leather manufacturing method achieving three-waste discharge reduction. The leather manufacturing method can comprehensively achieve reduction of three-waste discharge in the leather manufacturing process. Through wastewater reuse, solids are inhibited from decomposing or dissolving and are recycled; and exhaust emission is reduced through reduction of volatilization of wastewater, the solids and chemical materials. The leather manufacturing method is specially characterized in that soaking, liming, reliming, lime removal and softening, pickling chrome tannage, degreasing, retanning, neutralizing and dyeing are conducted independently, water is saved by over 70%, and energy is saved by over 20%; emission of solid waste is reduced by over 70%; the chemical materials are saved by 15% to 100%, and pollution to air due to volatilization of the chemical materials is reduced; and by the adoption of the method, the quality of leather can be improved remarkably.

Description

technical field [0001] The invention relates to the technical field of reducing the discharge of three wastes in the tanning industry. Background technique [0002] In the tanning process, a large amount of chemical raw materials are used, such as acid, alkali, salt, sulfide, lime, chrome tanning agent, fatliquoring agent, dyestuff, etc., and a considerable part of them enters the wastewater. Its water quality is characterized by containing a large number of complex components and toxic and harmful substances. It contains a lot of lime, salts, oils, ammonia nitrogen compounds, proteins, sulfides, chromium salts, dyes, hairs, leather dregs, sediment, etc., and the COD and BOD are very high. It has a wide variety of pollutants, a large coefficient of variation in water quality and quantity, and a foul smell. It is a difficult industrial wastewater to treat. At the same time, in the process of tanning, a large amount of waste solids are produced, part of which can be filtered...

AI Technical Summary

Problems solved by technology

At the same time, in the process of tanning, a large amount of waste solids are produced, part of which can be filtered out through the existing filtering equipment, and this part is a mixture composed of large broken hairs, meat residues and other substances, and these mixtures are in a semi-digested state Or melted state, long-term storage will be more harmful to the environment; the other part cannot be filtered out, and will be discharged into the environment along with the waste water; the above-mentioned waste solids are more difficult to treat

At the same time, the discharge of a large amount of waste water and waste solids will emit a large amount of malodorous gas, which will seriously pollute the air.

[0003] With the development of environmental protection technology and equipment, a relatively mature treatment process has been formed for tannery wastewater, but its effect cannot achieve the real purpose of pollution control

Wastewater, waste, and waste gas in the tanning industry are very difficult to deal with, and it is difficult for the previous tanning cleaning technology to achieve a comprehensive reduction in the discharge of three wastes

[0004] Through research, it is found that there are a large number of substances that inhibit the dispersion of collagen fibers and destructive enzymes, microorganisms, and certain decomposition products in tannery wastewater. These substances seriously hinder the recycling of wastewater and greatly damage the tannery The solids produced during the process, such as hair, meat residue, etc., once these substances are digested or melted, can only be collected and processed in the form of waste solids, but the cost of processing is too high, and the input is much higher than the output, so Difficult to be re-sourced

A large amount of waste water and waste solids are discharged or randomly landfilled, resulting in the waste of a large amount of renewable resources and secondary pollution of the environment. At the same time, a large amount of odorous gas is emitted, which further pollutes the air.

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