Fur is a pure natural clothing material derived from nature. Fur and leather making are both sub industries of the leather industry, and the biggest difference between the two is that fur products require full preservation of the natural advantages of the fur coat, that is, seeking to preserve the fur. Leather making requires hair removal, and the cleaner the removal, the better. So during the fur processing, a large amount of salt is used to soak the fur and protect its fur, and the resulting wastewater contains high concentrations of sodium ions and chloride ions.

The wastewater from fur processing contains a large amount of chemical materials, such as acids, alkalis, salts, degreasers, chrome tanning agents, dyeing auxiliaries, dyes, etc. These chemical materials are only50%～70%Can be absorbed into the product, while the remaining part is discharged into the water, resulting in high chromium ion content and high chromaticity in the water;In addition, during the fur processing, the oils and soluble proteins in the raw materials also enter the water, resulting in a high concentration of suspended solids in the water. At the same time, many components of the residual additives in fur wastewater are classified as environmental hormone pollutants.

Fur processing wastewater belongs to high concentration organic refractory industrial wastewater, and its treatment has always been a key and difficult point in the field of water treatment. The key steps in treating wastewater from fur processing are decolorization and improving the biodegradability of the wastewater. In anaerobic biological methods, decolorization and reduction can be achieved through the anaerobic respiration of microorganisms, but the reaction rate is slow and the process takes up a large area. Although physical and chemical treatment methods are fast, they are costly, and the addition of chemical reagents poses a risk of secondary pollution.

The steps for treating wastewater from fur processing are as follows:

Fur processing wastewater enters the regulating tank through the inlet pipe, where it is stirred and mixed to regulate the water quality and quantity of the wastewater.

The adjusted water enters the decolorization tank through the inlet pipe, mixes with chlorine dioxide, and is stirred using the decolorization tank agitator;Chlorine dioxide destroys the molecular structure of pollutants in wastewater, and the pollutants in the wastewater are oxidized and decomposed. The oxidized and decomposed wastewater enters the sedimentation zone, and the three-phase separator in the decolorization tank achieves solid-liquid separation.

Wastewater enters the lower part of the anaerobic electrolysis tank through the inlet pipe of the tank;After entering the anaerobic electrolysis tank, the wastewater moves up and down along the baffle, passing through the sludge beds of each reaction chamber in the facultative, anoxic, and anaerobic sections. The sludge in the reaction tank moves with the up and down flow of the wastewater and the rise of biogas. The blocking effect of the baffle and the settling effect of the sludge itself also reduce the flow rate of the sludge. Therefore, a large amount of sludge is trapped in the reaction tank, and the microorganisms in the reaction tank are in full contact with the organic matter in the wastewater. Facultative bacteria in the facultative stage, heterotrophic bacteria in the anoxic and anaerobic stages hydrolyze organic matter in wastewater into organic acids, decomposing large molecular organic matter into small molecular organic matter, and converting insoluble organic matter into soluble organic matter. The wastewater after anaerobic reaction is separated into sludge, water, and methane gas by the three-phase separator of the anaerobic electrolytic cell. The sludge sinks to the lower part of the anaerobic electrolytic cell under the action of gravity, and excess sludge is discharged through the sludge discharge valve at the bottom of the anaerobic electrolytic cell;The methane waste gas generated by the anaerobic electrolytic cell is collected and discharged through the gas collection pipe at the top of the reaction tank;Adding electrodes as electron acceptors for microbial anaerobic respiration,Realize microbial electricity production,By increasing the abundance and activity of microorganisms in the reaction system, the decolorization and detoxification of wastewater can be promoted. The treated wastewater enters the aerobic tank inlet pipe through the overflow weir of the anaerobic electrolysis tank and the outlet pipe of the anaerobic electrolysis tank.

Wastewater enters the middle and lower parts of the aerobic tank through the inlet pipe, and is evenly distributed under the action of the water distribution triangular cone. The aeration disc generates a large number of microbubbles, and the oxygen measurement and control machine regulates the operation of the blower according to the oxygen content to ensure that the dissolved oxygen in the aerobic tank water is greater than2mg/L;Activated sludge adheres and grows on the surface of the aerobic tank packing material, without flowing with water. Due to the strong agitation of the rising airflow, the biofilm is constantly renewed;Under sufficient oxygen supply conditions, aerobic microorganisms on the surface of the aerobic tank packing degrade organic matter in wastewater;The updated biofilm sinks to the lower part of the aerobic tank under the action of gravity and is discharged through the bottom aerobic tank discharge valve;The treated wastewater flows out through the overflow weir of the aerobic tank.

Wastewater enters the downstream area of the filter through the filter inlet pipe and filter distribution pipe. The air generated by the aeration pipe in the downstream area intersects with the wastewater in the downstream area packing material for biochemical reaction. At the same time, the downstream area packing material filters the wastewater. The wastewater enters the upstream area through the return plate and undergoes biochemical reaction in the upstream area packing material. At the same time, the upstream area packing material filters the wastewater. The sludge generated in the downstream and upstream areas sinks into the sludge area and is discharged through the filter sludge discharge valve at the bottom of the sludge area. The treated water in the filter is discharged through the filter overflow weir and filter outlet pipe to meet the standard.

Sediments and sludge discharged from decolorization tanks, anaerobic electrolysis tanks, aerobic tanks, and filter tanks are transported outside after concentration and dehydration.