Method for treating heavy metal industrial sewage

Abstract

The invention discloses a method for treating heavy metal industrial sewage, sequentially comprising the following steps of: a, infusing sewage to be treated to a regulating tank, and staying for 6-8 hours; b, infusing supernate obtained in the step a to a reaction tank, adding medicament to perform chemical treatment for heavy metal ions; c, infusing supernate obtained in the step b to a pH adjusting tank and adjusting pH value to 9.0-10.0; d, infusing sewage obtained by the step c to a flocculation tank, adding aluminum polychlorid based on the standard of 5-10mg / L, reacting for 15-20 minutes to perform flocculoreaction; after introducing the supernate to the concentration tank, infusing the sewage in the tank at the flow rate of 3-5m / s by using a centrifugal pump to a pipe-type microfiltration membrane with the aperture of 0.05-20 microns, filtering the sewage and performing advanced treatment for the effluent obtained by entering a reverse osmosis system, and guiding the concentrated sewage back to the microfiltration concentration tank for circular filtration. The method has simplified steps and is particularly suitable for pre-treatment of high-concentration heavy metal ion sewage.

Description

technical field [0001] The invention relates to a method for treating waste water, in particular to a method for treating industrial waste water with high content of heavy metal ions. Background technique [0002] With the development of industrial production and urban modernization, environmental pollution is becoming more and more serious. Since water is the material basis for the survival and development of human beings, the problem of water pollution has attracted people's attention. Heavy metals are one of the main pollutants in the water environment, especially heavy metals such as mercury, cadmium, lead, chromium, nickel, etc. have significant biological toxicity, and trace concentrations can produce toxicity. Under the action of microorganisms, it will be transformed into more toxic organometallic compounds (such as methylmercury); or it will be bio-accumulated and enter the human body through the food chain, causing chronic poisoning. Therefore, the effective remo...

AI Technical Summary

Problems solved by technology

Metal polishing and printed circuit board wastewater is characterized by heavy metal ions: the content of hexavalent chromium, cadmium, lead, zinc, copper, etc. is quite high. The commonly used treatment methods mainly include chemical precipitation, ion exchange, electrolysis, adsorption, Solvent extraction method, evaporation concentration method and biological method, relatively speaking, the most used at present is: chemical precipitation method, the reason is that chemical precipitation method is simple and easy, suitable for treating wastewater with high concentration of heavy metal ions, but chemical precipitation method The main defect is: the settling tank process adopted in its subsequent separation process has a relatively long settling time, resulting in a large area of ​​the settling system, large investment, and limited separation effect

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