Cyanide-containing wastewater is mainly used in electroplating, mining, smelting, petrochemical and other industries, and cyanide is a highly toxic substance that poses a serious threat to the environment and human health. Therefore, the treatment of cyanide-containing wastewater is crucial.
This article will introduce several common cyanide-containing wastewater treatment technologies:
Alkaline chlorination.
Alkaline chlorination is a commonly used method for treating cyanide-containing wastewater. This method converts cyanide into less toxic nitrogen and carbon dioxide under acidic conditions by adding the right amount of hypochlorite and alkali to the wastewater. This method has high treatment efficiency, but it is necessary to control the reaction conditions to prevent secondary pollution.
Sulfuric acid acidification method.
Sulfuric acid acidification is a more economical method for treating cyanide-containing wastewater. This method converts cyanide into less toxic thiocyanate and hydrogen sulfide under acidic conditions by adding sulfuric acid to the wastewater. Subsequently, thiocyanate can be further oxidized to sulfate, which can be used to purify wastewater. This method is simple to operate, but it needs to control the acidity to prevent secondary contamination.
Biological treatment.
Biological treatment is an emerging method for the treatment of cyanide-containing wastewater. This method uses the metabolism of microorganisms to convert cyanide into a harmless substance. The biological treatment method has the advantages of good treatment effect, low cost and no secondary pollution, but the resistance and adaptability of microorganisms to cyanide need to be further studied.