Novel method for treating chrome-containing wastewater and recycling chrome of chrome pigments

Abstract

The invention relates to a novel method for treating chrome-containing wastewater and recycling chrome of chrome pigments. The novel method comprises two parts, namely treating the chrome-containing wastewater and recycling the chrome of the chrome pigments. The treatment to the chrome-containing wastewater of the chrome pigments refers to carrying out pressure filtration on the chrome pigments, carrying out physical impurity removal on the chrome-containing wastewater generated in a washing process, adjusting a pH value and then carrying out exchange adsorption in an ion exchange system to ensure that effluent reaches the emission standards of China; after adsorption saturation by ion exchange resin and fiber, a regenerant is used for carrying out regeneration and transformation to obtain a high-concentration sodium dichromate concentrated solution. The recycling of the chrome refers to taking the sodium dichromate concentrated solution as a raw material for pigment production, and adding the solution to a pigment synthesis system to prepare pigment; the prepared pigment is subjected to pressure filtering, washed, dried, ground and packaged to obtain the finished product. According to the method disclosed by the invention, chrome in the wastewater can be resourcefully recycled while ensuring that hexavalent chrome in the chrome-containing wastewater in the chrome pigments is discharged after reaching the standards; the novel method is can either be big or small in scale, simple in process route, low in energy consumption, high in recovery rate of chrome and free of secondary pollution and has favorable economic benefit and social benefit.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment and recycling, and relates to a method for treating wastewater containing heavy metal hexavalent chromium and recycling chromium, in particular to a new method for treating chromium-containing wastewater containing chromium series pigments and recycling chromium. Background technique [0002] Chromium and its compounds are widely used in industry. A series of industries such as metallurgy, chemical industry, electroplating, pigments, chromium production, and pharmaceuticals will generate a large amount of chromium-containing wastewater. All chromium compounds are toxic, among which hexavalent chromium is the most toxic. Hexavalent chromium is an inhalation poison. Skin contact may cause sensitivity, inhalation may cause cancer, and it is persistently harmful to the environment. The outflow of chromium-containing wastewater not only causes serious environmental pollution, bu...

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Problems solved by technology

However, the above methods have limitations: first, the chemical precipitation method occupies a large area, requires a large dosage of chemicals, and is difficult to meet the standards stably; second, it will generate a large amount of waste chromium residue, which will cause secondary pollution if not properly handled; third, It is metal chromium that cannot be effectively recycled, resulting in waste of resources

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