Silicon-containing wastewater treatment method

Abstract

The invention relates to a silicon-containing wastewater treatment method. The silicon-containing wastewater treatment method provided by the invention comprises: adding a nucleation coagulant aid to silicon-containing wastewater and mixing the silicon-containing wastewater with the nucleation coagulant aid, wherein the nucleation coagulant aid is an insoluble solid which serves as a growing core capable of allowing granular micro-substances that are suspended in water and not easy to coagulate to aggregate, grow up and settle; and regulating the pH of the silicon-containing wastewater between 3.5 and 9. The treatment method provided by the invention has the advantages of applicability to silicate wastewater discharged in various processes, capability of thoroughly solving the problem that SiO2 in the silicon-containing wastewater is easy to gel, mild using conditions, simple operation process and capability of enabling treated wastewater to reach discharge standards.

Description

technical field [0001] The invention relates to a method for treating silicon-containing wastewater. Background technique [0002] At present, in the process of catalyst production in the petrochemical industry, a large amount of silicon-containing wastewater with high pH (pH value above 11) is produced in the molecular sieve workshop, and the silicate contained therein is represented by SiO 2 The meter can be as high as 2.0% to 4.0%, and it is quite stable. These wastewaters are generally alkaline. If they are directly discharged into natural water bodies, as the pH decreases, the SiO 2 Gel or flocs sink out to form white water, pollute water bodies, and block waterways. If the soluble SiO in these wastewaters is not 2 Thorough treatment means discharge, which will cause immeasurable pollution and damage to the environment. [0003] There is no relevant report abroad on the treatment of this kind of wastewater. Larger domestic manufacturers use the method of neutraliza...

AI Technical Summary

Problems solved by technology

However, using the method of first neutralization and then sedimentation, it is easy to produce a large amount of gel, high water content, large volume, difficult to press filter into a cake, and the sedimentation speed is slow, the residual turbidity is high, and the sedimentation colloid is not easy to filter and remove. If the existing flocculants on the market are used for treatment, the cost will be higher and the production cost will be increased.

[0004] Commonly used water treatment agents such as polyaluminum (PAC), polyacrylamide (PAM) and polyacrylic acid have no effect or very poor effect on the treatment of the above-mentioned silicon-containing wastewater. The gel problem cannot be solved, so the effect is not satisfactory; the use of dimethyl diallyl ammonium chloride homopolymer or copolymer to treat this kind of wastewater has a certain effect, but the dosage of the agent is large, which increases the production cost and cannot be applied