Technology for processing comprehensive waste water from acrylonitrile and acrylic fibers production

Abstract

The invention relates to a technology for processing comprehensive chemical waste water from acrylonitrile and acrylic fibers production and is directed to the field of environment engineering technology. According to the invention, an aeration reaction, a biology hydrolysis acidification, a denitrification nitrogen removal and an aerobic biological treatment are adopted. The waste water is classified into C, N and S grade. The toxicity problem for microbes caused by the waste water is solved; the biological treatment capability and waste water processing effect are improved. The technology is characterized by simple and reasonable process flow. The operation cost is reduced. The technology is suited for industrial application and biology processing of high sulfur high nitrogen organic waste water of the same kind.

Description

technical field [0001] The invention relates to a comprehensive wastewater treatment process for the production of acrylonitrile and acrylic fiber, which belongs to the technical field of environmental engineering. The method of the invention includes grid filtration, pre-aeration, hydrolytic acidification desulfurization, anaerobic decarburization, aerobic denitrification and other biological treatment processes, and is suitable for biological treatment of high-sulfur, high-nitrogen and high-COD wastewater of the same kind. Background technique [0002] The production of acrylic fiber in our country's existing technology mainly includes four production processes of sodium thiocyanate one-step method, sodium thiocyanate two-step method, wet method and dry method, but its monomers are all acrylonitrile, usually produced by propylene ammoxidation method Acrylonitrile is obtained. The solvents used in the above process mainly include sodium thiocyanate (NaSCN), dimethylformami...

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Problems solved by technology

[0005] Invention patent CN200710176576.3 has improved it, using homogenization and sedimentation to remove suspended solids, adding iron, magnesium, calcium and other ions to reduce the microbial toxicity of wastewater, but this technology still has disadvantages such as high operating costs and large sludge production. Moreover, a large amount of sulfate radicals in the waste water are easy to form precipitates with the added metal ions, and compete with more biologically toxic substances such as cyanide, nitrile, amine, etc., resulting in a large dosage of chemicals. Furthermore, these toxic substances have not been removed from the Therefore, the toxic effect on wastewater has not been completely solved, but it has increased the cost and difficulty of wastewater treatment

[0006] Chinese patent CN99112488.X is coagulation sedimentation - anaerobic digestion - anoxic - aerobic - sand filter - activated carbon process, while Chinese CN00129461.X transforms coagulation sedimentation - anaerobic - aerobic - biochar tower process into air flotation -Aeration-Sedimentation-Acid production-Biological desulfurization-Methanation-Anoxic-Aerobic, these two patents are based on biological treatment technology, but the treatment process is long, the actual operation is difficult, and often need supplementary measures to ensure that the wastewater Discharge

[0007] Chinese patent CN200810224878.8 uses double-membrane technology to treat acrylic wastewater. Although it can ensure stable effluent quality, it has defects such as easy pollution of the membrane system, short cleaning cycle, and high investment and operation costs, and does not solve the problem of concentrated water treatment.

[0008] Chinese patent CN200810244778.1 proposes dynamic adsorption of magnetic resin for effluent after biochemical treatment, but the modified technology has resin failure and regeneration, difficult operation, high cost, and no detailed method for biological treatment technology

[0009] Chinese patent CN201010144936.3 provides an electrocatalytic aerobic treatment process, which has the disadvantages of high equipment investment and operating costs

[0010] Chinese patent CN200910087863.6 provides a combination of facultative, aerobic and coagulation-sedimentation treatment process. This technology has not yet effectively separated or removed biological toxic substances, and coagulation-sedimentation produces a large amount of mud

[0011] To sum up, the difficulty of biological treatment of acrylic industrial wastewater is that polymers that are difficult to settle naturally are easy to wrap microorganisms after entering the biochemical system, which affects the biochemical effect; after sulfite aeration makes the wastewater weakly acidic, affecting the normal operation of the anaerobic system; At the same time, the content of organic amine and ammonia nitrogen in wastewater is high, causing nitrogen pollution

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