Method for removing toxicity of tail water of fine chemical biochemical treatment

Abstract

The invention discloses a method for removing the toxicity of tail water of fine chemical biochemical treatment, belonging to the field of sewage treatment methods. The method comprises the following treatment steps: (a) carrying out catalytic ozonation, specifically, treating sewage in a catalytic ozonation tower which is internally filled with an iron-aluminum catalyst, wherein the iron-aluminum catalyst is prepared from the following effective components: beta-iron oxyhydroxide and aluminum oxide; (b) absorbing, specifically, carrying out further treatment on wastewater, subjected to treatment in the step (a), by using an absorption filter filled with ceramsites and magnetic resin, wherein the mass ratio of the beta-iron oxyhydroxide to the aluminum oxide in the iron-aluminum catalyst is equal to (15-20) to (80-85), and the volume ratio of the ceramsites to the magnetic resin is equal to (2-3) to (3-5). The method provided by the invention is simple to operate and low in cost, and not only can realize the non-toxic emission of the tail water, but also can improve the comprehensive index of water quality.

Description

technical field [0001] The invention belongs to the field of sewage treatment, and more specifically relates to a method for removing the toxicity of fine chemical biochemical treatment tail water. Background technique [0002] Fine chemical sewage mainly includes pharmaceutical, dyestuff, pesticide and intermediate sewage, etc. Compared with domestic sewage, its differences are: 1) It has a wide range of influent sources, complex water quality, and a large amount of refractory, carcinogenic, teratogenic , Mutagenic organic substances; 2) Organic substances are difficult to completely degrade during sewage treatment, and may even be transformed into more toxic substances. If low-concentration toxic pollutants persist in the water body for a long time, on the one hand, it will affect the operation status of the biochemical system of the sewage treatment plant in the chemical industry park, and on the other hand, it will also have many adverse effects on the environment of the...

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Problems solved by technology

Among them, the Fenton oxidation process has been widely used in various refractory sewage pretreatment and advanced treatment processes. However, this process generally consumes a large amount of chemicals, the treatment cost is high, and a large amount of chemical pollution is usually generated during the treatment process. sludge, and this kind of chemical sludge needs to be stabilized and harmlessly disposed, which further increases the input cost

The principle of chlorine dioxide and sodium hypochlorite process is to effectively utilize the oxidation of chlorine. However, it is easy to introduce excess chlorine ions into the tail water and affect the salinity of the effluent and other indicators.

[0008] It can be seen that the use of catalyst in the ozone catalytic oxidation process in the prior art application has significantly increased the ozone oxidation activity, and has a comparatively obvious effect on the removal of sewage COD; yet there are inevitable defects: 1) the preparation of the catalyst in the method The process is generally cumbersome, and the preparation process requires the input of reagents, and the input cost is high; 2) The method only focuses on the comprehensive index of COD, and does not mention the effect of reducing toxicity and emission

[0009] Magnetic resin belongs to a class of high-adsorption granular adsorbents. Its particle size is small, so pollutants are easier to diffuse to its internal pores, and magnetic resin can pass the electrostatic action of positively charged sites (containing N groups) on the resin to the water body. The medium and negatively charged pollutants are quickly adsorbed, and have the characteristics of fast mass transfer, rapid settlement, and reusability. There have been published technical solutions showing the role of magnetic resin in sewage treatment, such as Chinese Patent No. CN201010110042.2, the application The application discloses a method for the advanced treatment of biochemical tail water based on magnetic resin. The use of magnetic resin for sewage treatment has significant advantages such as simple process, convenient operation, and low operating cost. Among them, in the embodiment where this method is used to treat sewage in chemical industry parks, the effluent water quality is lower than 80 mg / L; however, only magnetic resin is used. Physical adsorption has certain limitations in the treatment capacity, and it needs to be combined with traditional treatment processes such as coagulation and air flotation to achieve the effect of advanced treatment of tail water, and the application method does not mention its role in reducing the toxicity of sewage

[0010] For the tail water after biochemical treatment of fine chemical sewage, the pH value is 7-9, and the COD value is lower than 102mg / L. Although the COD value is not high, the tail water is still highly toxic and cannot be discharged up to the standard; Water treatment processes only focus on comprehensive COD indicators, and cannot reduce the toxicity of tail water; therefore, it is urgent to develop a simple, effective, and low-cost treatment method to make the tail water of fine chemical sewage treated by biochemical treatment truly non-toxic.

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