Method for extracting bromine from bromine-containing wastewater

Abstract

The invention relates to a method for extracting bromine from bromine-containing wastewater, which comprises the following steps: pretreatment: filtering the bromine-containing wastewater so that the turbidity of the filtered bromine-containing wastewater is lower than the preset value; acidification: adding hydrochloric acid or sulfuric acid into industrial wastewater containing bromide ions to adjust the pH value of the industrial wastewater to 3-5; oxidation: adding an oxidizing agent into the acidified industrial wastewater for oxidation to generate bromine; extraction: adopting n-dodecane as an extraction agent, and extracting bromine from an aqueous phase to an n-dodecane phase; liquid separation: performing liquid separation on the two-phase solution added with the extraction agent, wherein the upper layer is an oil phase, and the lower layer is an aqueous phase; separating the aqueous phase from the oil phase; rectification: rectifying the n-dodecane and bromine solution obtained by the liquid separation so that bromine is separated from n-dodecane to obtain a bromine product. In the method provided by the invention, bromine is extracted by a solvent extraction process; compared with the traditional technology, the use of steam is greatly saved, the cost of whole bromine extraction is remarkably reduced, and better economic benefits are obtained.

Description

technical field [0001] The invention belongs to the technical field of industrial wastewater treatment, in particular to a method for extracting bromine from bromine-containing wastewater. Background technique [0002] Bromine is one of the important chemical raw materials. A wide variety of inorganic bromides, bromates and bromine-containing organic compounds derived from it have special value in the development of national economy and science and technology. Aromatic organic bromides are widely used in pharmaceuticals, pesticides, dyes, etc. When bromination reactions are used to prepare aromatic organic bromides, the utilization rate of bromine is only 50%, so it will produce hydrobromic acid, bromine Industrial wastewater rich in bromide ions such as sodium chloride and potassium bromide. If the bromine in hydrobromic acid, sodium bromide, and potassium bromide is extracted into raw material bromine, the cost will be greatly reduced, considerable economic benefits will ...

AI Technical Summary

Problems solved by technology

The air blowing method is currently the main bromine extraction method in my country. Although the air blowing method has strong adaptability to the bromine content of raw materials and is easy to automate control, it requires huge equipment and high energy consumption.

At the same time, bromine extraction by air blowing method is seriously affected by temperature, and when the temperature is low, the blowing effect becomes worse