Treatment method for acrylonitrile wastewater

Abstract

The invention relates to a treatment method for acrylonitrile wastewater. The treatment method comprises the following steps: (1) introducing the acrylonitrile wastewater to be uniformly blended, andadjusting the pH to be 6.5-8.5; (2) feeding the acrylonitrile wastewater into an electric flocculation to be adjusted; (3) feeding the acrylonitrile wastewater into a floatation tank to be treated; (4) adopting a filter for further treatment; (5) feeding the acrylonitrile wastewater into an oxidation pond for oxidation treatment; (6) filtering the acrylonitrile wastewater with an ultrafiltration membrane system; and (7) concentrating and separating the acrylonitrile wastewater with a reverse osmosis membrane system. According to the method, biological cultures are not cultured, the starting time of the system is short, and the wastewater concentration fluctuation impact resistance is high; by adopting electric flocculation and ozone reaction, ferric salt and aluminum salt are not input additionally, and other ions are not introduced into the wastewater; after integrated treatment of electric flocculation, a filter and the oxidation pond, organic matters are small in blockage to the ultrafiltration membrane and the reverse osmosis membrane, and the system can operate in a relatively long time stably and no secondary pollutants are generated; the treated wastewater can reach a related standard rule, sustainable development of acrylonitrile production can be supported, and the device and the method have considerable economic benefits.

Description

Technical field [0001] The invention belongs to the technical field of industrial wastewater treatment, and specifically is a treatment method of acrylonitrile wastewater. Background technique [0002] As an important chemical raw material, acrylonitrile is widely used in the fields of manufacturing acrylic fiber, nitrile rubber, ABS industrial plastics and synthetic resins. At present, acrylonitrile is mostly produced in China by the propylene ammoxidation method. However, the wastewater produced mainly contains toxic and harmful substances such as acrylonitrile, acetonitrile, cyanide, acrolein, cyanopyridine and a large number of difficult-to-degrade organic substances. Toxic and harmful substances and organic matter are directly discharged into environmental water bodies, which will cause high toxicity and potential "three-induced" toxicity in the water body. Therefore, from the perspective of protecting the environment and conducive to the sustainable development of acryloni...

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Problems solved by technology

[0003] Chinese patent CN201110371133.6 discloses "an integrated treatment method for acrylonitrile production wastewater", which adopts a process flow of: regulating tank→A / O biochemical treatment→ultrafiltration→reverse osmosis device; the treatment method uses A / O The disadvantages of biochemical treatment of acrylonitrile wastewater are: on the one hand, it is difficult to cultivate suitable bacteria; High pressure, and the cleaning and maintenance of the treatment device are relatively frequent, so it cannot run stably for a long time

[0004] Chinese patent CN201410313166.9 discloses "a membrane technology integrated treatment method for high-concentration acrylonitrile wastewater". Permeable membrane; the CODcr of acrylonitrile wastewater treated by this process is 19985.3mg / L, the chromaticity is 4268 degrees, and the turbidity is 232.0NTU. High-efficiency filters are used to capture particulate dust and suspended solids below 0.5um, because they cannot be effectively removed The organic matter in the wastewater makes the microfiltration membrane or ultrafiltration membrane easily fouled, and the wastewater treatment device cannot operate normally; and after treatment, the CODcr of the wastewater is still around 1000 mg / L, which cannot meet the requirements of GB31571-2015 "Petrochemical Industry Pollution The provisions of the emission standard

In this process, bacteria that degrade cyanide need to be cultivated and enriched, and the system takes a long time to start. When the oxidation tank is oxidized with sodium hypochlorite, the chlorinated hydrocarbons in the wastewater will increase, and chlorinated hydrocarbons are a carcinogen. , teratogenic, mutagenic substances

[0006] Chinese patent CN201410136538.5 discloses "A Sequencing Batch Electro-Fenton Device and Method for Advanced Treatment of Acrylonitrile Wastewater". To add FeSO 4 Adding sodium sulfate and sodium chloride as supporting electrolytes will not only increase the cost of treatment chemicals, but also increase the ion concentration of treated wastewater

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