Cleaning treatment process for cow leather

Abstract

The invention discloses a cleaning treatment process for cowhide, which orderly comprises process steps of soaking, liming, reliming, non-ammonium deliming softening and so on. The process is mainly characterized in that: soaking enzyme is mainly adopted in the step of the soaking, which greatly reduces the use level of a surfactant and the content of COD and BOD. Compared with the prior hair burning method, the liming and the reliming are characterized in that: a hair-saving liming process changes the process thought; the liming expansion is performed after hair saving and hair filtration, which reduces the content of ammonia nitrogen, the COD, the BOD and solid waste in wastewater. And waste liquid after the liming realizes recycling and achieves zero discharge. A non-ammonium deliming softening system is adopted, which reduces the content of the ammonia nitrogen in the wastewater. The use level and the discharge of sulfide and lime which are used to produce leather by the cowhide are reduced by 50 percent or so, an ammonium salt deliming process is saved, the content of the ammonia nitrogen is reduced by more than 90 percent, and the COD and suspended substances are reduced by more than 85 percent.

Description

technical field [0001] The invention relates to a process for treating cowhide in the tanning industry. Background technique [0002] Raw leather is mainly composed of collagen and keratin, mucin, mucinoid, globulin, elastin, etc. All that is needed for tanning is collagen. In order to achieve the desired feel and appearance of finished leather, it is necessary to remove unnecessary of protein removed. The conventional production process mainly uses surfactant-based water immersion agents, which will produce high BOD. The conventional liming method is the wool-destroying liming method. The disadvantages are that lime and sodium sulfide are used in a large amount, and there are many residues in the waste liquid, which seriously pollutes the environment; Decomposed, this effect will produce a large amount of solid waste and high COD, BOD, the conventional deashing and softening method uses a large amount of ammonia substances, such as ammonium sulfate and ammonium chloride, ...

AI Technical Summary

Problems solved by technology

The conventional liming method is the wool-destroying liming method. The disadvantages are that lime and sodium sulfide are used in a large amount, and there are many residues in the waste liquid, which seriously pollutes the environment; Decomposed, this effect will produce a large amount of solid waste and high COD, BOD, the conventional deashing and softening method uses a large amount of ammonia substances, such as ammonium sulfate and ammonium chloride, which makes the ammonia nitrogen content in the wastewater very high

Therefore, conventional cowhide processing brings great pressure to environmental pollution.