In the process of tanning withleather dryer, it is inevitable to produce wastewater, and the pollution degree of these wastewater is relatively serious, so we need to treat it, otherwise it will cause great harm to the environment if directly discharged into nature.

1. Primary treatment

Automatic rotary fine grid intercepts large particles of solid, hair, skin edge, rotten meat, etc. in sewage; The perforated pipe of the aeration grit chamber is aerated evenly to remove the small particles of sand and gravel in the sewage; The regulating tank is aerated and stirred for 24 hours to balance the water quality and quantity. The upper and lower limits of the liquid level of the water contained in the regulating tank are determined according to the daily average water quantity. The gas volume is adjusted according to the liquid level. The tank is cleaned regularly and the air perforated pipe is dredged to ensure smooth air.

2. Oxidative desulfurization of sulfur containing wastewater

The pipes are collected separately, and the coarse and fine chromium grids are filtered; The catalyst manganese sulfate with a concentration of 40-80g / kgna2s is added twice before aeration and 2 hours after aeration; The surface aerator is forced to be oxygenated, the immersion depth of the impeller is 20mm, the desulfurization effect is tested with lead acetate test paper, and the sulfide removal rate is ≥ 95%; The waste liquor from deashing and softening of tannery ammonium salt is included in the sulfur-containing waste liquor. In the process of oxidative desulfurization, it also has the function of ammonia removal, and the removal rate of NH3-N is about 30%; Regularly clean the sludge at the bottom of the tank to ensure the treatment effect.

3. Precipitation recovery of chromium containing wastewater

The pipeline shall be collected separately, and the grid and filter cloth shall be used for filtration; Add 35% sodium hydroxide, control the reaction pH 7-8, mix and stir with compressed air for 15-30 minutes; Plate and frame pressure filtration, the solid content of chromium mud is about 20%, and the chromium content is 7-20%; Chromium removal rate > 99.5%.

Zhejiang Changxing Wuzhou Leather Machinery Co., Ltd. - is a professional manufacturer ofleather machinery.

The products are widely used in major tanning enterprises at home and abroad and exported to Indonesia, India, Bangladesh, Vietnam, Thailand, New Zealand, Pakistan, Russia, Namibia and other countries.

Wool filter, microfiltration machine and two kinds of equipment have obtained national patent products, which are not only liked by users, but also supported and recognized by environmental protection supervision departments.

We will always improve product quality, develop new products and better serve the majority of users. At the same time, we sincerely welcome colleagues in the industry to visit our company and guide our work.