Method for treating leather-making industrial wastewater

Abstract

The invention discloses a method for treating leather-making industrial wastewater, sequentially comprising the following steps of: filtering, homogenizing; air flotation sludge scraping; adding alkali and flocculant to obtain sedimentation; separating mud from water; regulating pH value back; carrying out anoxic biochemical treatment and aerobic treatment; and delivering wastewater into a membrane biological reaction tank. The membrane biological reactor is filled with cultivated activated sludge and provided with a hollow fiber membrane assembly, and water is pumped out by a dump pump afterfiltered by the membrane assembly. In the method, the hollow fiber membrane assembly is adopted to replace a secondary sedimentation tank in the traditional technique and reduce the occupied area of the treatment system; meanwhile, the problem of sludge expansion in the traditional suspension activated sludge process is solved; the quality of outflow water is stable and reliable; and the operation is relative simple and convenient.

Description

Technical field [0001] The invention relates to a method for treating wastewater, in particular to a method for treating wastewater from the leather industry. Background technique [0002] Leather production has to go through a variety of complex physical and chemical processes such as soaking, liming and dehairing, deliming, pickling, tanning, neutralization, fatliquoring, dyeing, etc., using a large number of chemical materials, such as acids, alkalis, salts, and sodium sulfide , Lime, surfactants, chrome tanning agents, fatliquors, dyes, organic additives, etc., except for a part of it is absorbed, a large part of it enters the wastewater and causes pollution. The main characteristics of tannery wastewater are: 1. The wastewater contains more tannery debris, more suspended solids (SS) and oil content; 2. The wastewater has a high concentration of organic pollutants and poor biochemical properties. (3) Containing heavy metal pollutants, the content of ammonia nitrogen is also ...

AI Technical Summary

Problems solved by technology

The main characteristics of tannery industrial wastewater are: 1. There are more tanning debris, suspended solid particles (SS) and oil in the wastewater; 2. The concentration of organic pollutants in the wastewater is high and the biochemical properties are poor

(3) Contains heavy metal pollutants, and the content of ammonia nitrogen is relatively high, and any discharge will seriously pollute the water body

[0017] Biological contact oxidation treatment of comprehensive tannery wastewater has the characteristics of impact load resistance, convenient management and operation, and small footprint, but the overall removal effect is not ideal. Currently, it is widely used in the treatment of small-volume tannery wastewater.

In addition, the removal rate of ammonia nitrogen in tannery industrial wastewater is not high, and it is difficult to achieve discharge standards

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