Method for treating polyformaldehyde production wastewater

Abstract

The invention discloses a treatment method of polyformaldehyde production wastewater, and relates to the technical field of polyformaldehyde wastewater treatment. Polyformaldehyde production wastewater sequentially passes through an adjusting tank, a polymerization reactor 1, a polymerization reactor 2, a pH callback tank, a cooling tower, a biological selector, an anaerobic hydrolysis composite reactor, an aerobic composite reactor, a radial-flow sedimentation tank, an efficient coagulative precipitation tank and a heterogeneous Fenton oxidation reactor, and water and sludge are discharged. Formaldehyde is converted into three-carbon ketose or six-carbon hexose or derivatives of the three-carbon ketose or the six-carbon hexose by adopting a formaldehyde glycan reaction principle, toxicity of the three-carbon ketose or the six-carbon hexose to microorganisms is eliminated, and biodegradability of wastewater is improved. The formaldehyde glycan reaction adopts a dual-alkali method, namely alkali metal alkali and alkaline earth metal alkali are adopted for adjusting pH and a catalyst respectively, so that the conversion rate of formaldehyde is higher, the operation cost is lower, and meanwhile, the problem of scaling is avoided. The method is economical, efficient and stable, and the treated wastewater can be directly discharged.

Description

technical field [0001] The invention relates to the technical field of polyoxymethylene wastewater treatment, in particular to a method for treating polyoxymethylene production wastewater. Background technique [0002] Paraformaldehyde is an industrial raw material with a wide range of uses. It is widely used in the synthesis of pesticides, synthetic resins and coatings, and in the preparation of fumigants. The industrial synthesis method of paraformaldehyde mostly uses methanol as raw material, and is prepared by steps such as oxidation and catalytic polymerization. The paraformaldehyde wastewater produced in the paraformaldehyde production process contains a large amount of pollutants such as formaldehyde, dioxymethylene (DOX), trioxymethylene (TOX), methanol, sodium formate, etc. It is a typical high-concentration organic compound with poor biodegradability. waste water. Formaldehyde is a commonly used disinfectant, commonly known as formalin, which can cause protein de...

AI Technical Summary

Problems solved by technology

Oxidation methods are generally not specific to formaldehyde, and other organic pollutants in wastewater will also be oxidized, which will inevitably consume a large amount of oxidant, and at the same time, the thorough oxidation reaction at normal temperature and pressure often requires the use of catalysts, and the use of catalysts will not only Increase the treatment cost, and because the catalyst generally contains rare earth or precious metals, the used catalyst is hazardous waste, and the final disposal cost of hazardous waste is very high

As formaldehyde wastewater, especially high-concentration formaldehyde wastewater, the composition and properties of the wastewater after the polymerization reaction also have certain particularities. Not only is the alkalinity and temperature higher, but it also contains higher concentrations of sugars and salts. The main organic substances treated by the activated sludge process of wastewater biological treatment are proteins and low-molecular organic acids, and there is no record of post-treatment processes for sugar substances and salt

Images