Improved A/O (anaerobic/aerobiotic) technique for treating acrylonitrile wastewater

Abstract

The invention relates to an improved A / O (anaerobic / aerobiotic) technique for treating acrylonitrile wastewater, which is characterized in that an aerobiotic tank of the A / O technique is divided into three parts O1, O2 and O3 of which the retention time ratio is 1:3:2, the O1 region adopts a fixed filler suspension membrane to ensure the sludge concentration of the O1 region to be 5000-8000 mg / L and the sludge load to be 1.5-2.5 kg / (kg.d), and the BOD (biochemical oxygen demand) removal rate can reach 50% above; the sludge load of the O2 region is less than or equal to 0.25 kg / (kg.d), and the nitration efficiency is enhanced; by adopting the suspended spherical filler suspension membrane, the biomembrane has microcosmic oxygen-deficient environment inside, thereby implementing simultaneous nitrification and denitrification and being beneficial to total nitrogen removal; by adopting an activated sludge process in the O3 region, the sludge load is less than or equal to 0.1 kg / (kg.d), so that the nitration is continued and performed thoroughly; and the activated sludge metabolism in the O3 region is in the endogenous respiration period, so that the sludge generation amount of the technique is reduced by more than 40%. The aerobiotic tank is divided into the three regions, and different forms of biochemical processes are adopted for different regions, so that the denitrification efficiency can reach 95% above, thereby lowering the organic nitrogen pollutant content in the acrylonitrile wastewater.

Description

technical field [0001] The invention relates to the technical field of waste water treatment, in particular to an improved A / O process for treating acrylonitrile waste water which is difficult to degrade waste water. Background technique [0002] Acrylonitrile is an important chemical raw material, which is widely used in the manufacture of chemical products such as ABS plastic, nitrile rubber, acrylic fiber and synthetic resin. In recent years, the production scale of acrylonitrile has continued to expand, and the environmental pollution caused by the industrial wastewater produced in the production process has increasingly attracted people's attention. Studies have shown that the existence of trace amounts of acrylonitrile in the water environment will cause high toxicity and potential "three-caused" toxicity in the water body. In the list of toxic chemicals for priority control and the blacklist of pollutants for priority control in water determined by my country, acrylon...

AI Technical Summary

Problems solved by technology

These polymers generally exist in colloidal or dissolved forms in water, are difficult to be hydrolyzed and utilized by microorganisms, and cannot be effectively removed, which is the main reason why the COD discharge of acrylonitrile wastewater does not meet the standard

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