Advanced treatment process for thallium-containing wastewater

Abstract

The invention provides an advanced treatment process for thallium-containing wastewater, belonging to the technical field of wastewater treatment. According to the invention, evaporation desalination,chemical oxidation, flocculent precipitation and resin adsorption technologies are adopted in a combined manner, so efficient thallium removal and desalination can be synchronously realized and a thallium emission concentration can be stably lower than 2 [mu]g / L, and thud, the method is particularly suitable for treating high-salt thallium-containing wastewater; meanwhile, the consumption of an oxidant and a flocculation precipitant, the generation amount of hazardous wastes and treatment cost in the thallium removal process can be remarkably reduced; in addition, waste acid and waste alkaligenerated in resin backwashing regeneration and transformation can be returned to the treatment process for reutilization so as to achieve reduction; and the wastewater treated through the process canserve as production water or cooling circulating water and be returned to a treatment system for use so as to achieve closed circulation of the production water.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment and relates to an advanced treatment method for thallium-containing wastewater, which is particularly suitable for the treatment of thallium in metallurgical industrial wastewater and metal recovery process wastewater. Background technique [0002] Thallium (Tl), which is accumulative, is a typical highly toxic heavy metal element, which is extremely harmful to human health. At present, my country has listed thallium as one of the key pollutants for the comprehensive prevention and control of heavy metal pollution, and the discharge requirements for thallium have become increasingly stringent. In some areas, the discharge standard for Tl in wastewater has reached below 2 μg / L. For related metal smelting, extraction and recovery of valuable metals in solid materials and other chemical industries, the control of trace Tl is becoming increasingly difficult. [0003] Wastewater generated...

AI Technical Summary

Problems solved by technology

In the actual production and treatment process, in order to achieve the chromium discharge standard in wastewater, an excessive amount of reducing agent is generally added. At present, more reducing agents are used, such as sodium sulfite, sodium bisulfite, sodium thiosulfate, and ferrous sulfide. or more, which not only leads to high total sulfur content and salt content in wastewater, but also leads to the residue of reducing agent, resulting in an increase in the consumption of oxidant and flocculant in the subsequent oxidation-flocculation-adsorption removal treatment of Tl

In addition, the COD content of wastewater generated during the extraction and recovery of valuable metals is relatively high (about 500ppm), which leads to the COD in the wastewater first consuming the oxidant and then oxidizing thallium during the oxidation of thallium, resulting in the oxidation of thallium The flocculation treatment process needs to consume a large amount of oxidant, which makes the treatment cost high and the treatment efficiency low

[0004] In addition, the waste water system generated during the extraction and recovery of valuable metals is complex and has high salinity. The salt content in the waste water directly affects the treatment performance and service life of the adsorbent. In actual operation, the resin column is often affected by the salt content in the waste water. Or the packed tower is clogged, smelly and the adsorbent is hardened so that backwash regeneration cannot be achieved

For example, the patent applications with application numbers CN201610717291.5 and CN201610683806.4 did not fully consider the problem of high salinity in industrial wastewater, and it is difficult to achieve the above removal effect by using these patented methods in practical applications

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