Method of removing total cyanide in sewage by using ionic transformation and oxidative disassembling

Abstract

The invention discloses a method of removing total cyanide in sewage and especially relates to a method of removing total cyanide in sewage by using ionic transformation and oxidative disassembling, which belongs the field of environmental protection. According to the method, based on chemical characteristics of different cyanogen compounds, different removing technologies are used for a variety of cyanides of different forms; that is, a two-stage progressive SIF method of strong ionic transformation and targeted breaking is adopted for free cyanogen, high-concentration complicated cyano complexes, complex derivatives hard to degrade and coupled cyanogen; the method enables a breaking rate of total cyanogen in cyanogen-containing waste water produced by industries related to cyanogen to reach 99.99%, thereby allowing the cyanogen-containing waste water to stably meet or be superior to level 1 discharge standard as prescribed in Integrated Wastewater Discharge Standard (GB8978-1996). The method is applicable to treatment of cyanide pollutants in waste water produced and discharged in a plurality of industries, e.g., mining and mineral separation, metallurgy, mechanical processing, electroplating, chemical engineering and leather making, and has industrial popularization and application prospects.

Description

technical field [0001] The invention relates to a method for removing total cyanide in sewage, in particular to a method for removing total cyanide in sewage by ion conversion and oxidation dismantling, and belongs to the field of environmental protection. Background technique [0002] Although cyanide is a highly toxic and hazardous substance, it is a chemical product strictly controlled by the state. But at present, there are still quite a few industries in actual production, such as metallurgy, mining, electroplating, chemical industry, machining, rubber, leather, pharmaceuticals and many other industries, because of the need to discharge waste containing cyanide into water due to production needs. For example, the utilization of water in gold dressing production is about 1:3, that is, when one ton of gold ore enters the mining process, it needs 3 tons of water. Based on the estimation of a small beneficiation plant with a daily ore concentration of 500 tons, the fresh w...

AI Technical Summary

Problems solved by technology

It is summarized as follows: (1) It can only deal with simple cyanide in the free state, but it is difficult to completely and comprehensively deal with high-concentration, refractory, and complex cyanide in various forms

Especially for cyanide complexes, couples, derivatives and other kinds of cyanide, which are closely combined and difficult to break, it is basically powerless, making the treatment effect difficult to meet the national environmental protection emission requirements and the actual needs of enterprises to control pollution

For example: ① Due to the complexity and variability of cyanide species, there is a huge difference in its reduction and oxidation properties. Simple oxidation methods (alkaline liquid chlorine method, H 2 o 2 , NaClO, O 3 etc.) can only get rid of some highly reducible cyanides, and the final oxidation effect is often unsatisfactory and unstable; ② ferrous sulfate flocculation precipitation method is easy to dissociate cyanide; Very poor; ④ immature and unstable biochemical method

[0003] (2) The operating cost is high, the treatment facilities cannot be built and used, and it is difficult to meet the dual needs of energy conservation and emission reduction of enterprises

[0004] (3) The technical adaptability is poor, and it is generally difficult to change with the water volume and the concentration and composition of cyanide pollutants in the water

Alkaline chlorination treatment is widely used at present. Although it is theoretically feasible, the research test results and application practice have proved that the treatment cost of this technology is as high as 30 yuan / ton, and the total cyanide content of the effluent is still 3-10mg / l. 5-20 times more than the national emission standard value

[0005] (4) The existing technology generally has technical defects such as large area of ​​facilities, long process flow, low degree of automation, and difficult operation.

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