What is a good method for treating wastewater containing heavy metals such as chromium in water treatment, with low costs?
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This post was last edited by niaeies on 2016-4-21 at 11:16. What are the best methods for treating wastewater containing heavy metals such as chromium, with low costs?
First, pentavalent chromium is reduced to trivalent chromium using sodium sulfite or ferrous sulfate, after which a base is added to adjust the pH to 7–9, and chromium oxyhydroxide precipitate is formed for removal.
At high concentrations, direct precipitation is used; at low concentrations, ion exchange resins are employed for removal, while the eluate is treated by precipitation. This is the most commonly used method.
The chemical reduction precipitation method is currently a widely used technique for treating chromium-containing wastewater. The basic principle is to add a reducing agent to the wastewater under acidic conditions, thereby reducing Cr6+ to Cr3+. Then, lime or sodium hydroxide is added, causing chromium oxide to precipitate under alkaline conditions, thus removing the chromium ions. Possible reducing agents include: SO2, FeSO4, Na2SO3, NaHSO3, Fe, etc. The reduction precipitation method has the advantages of low initial investment, low operating costs, good treatment efficiency, and simple operation and management, which leads to its widespread use. However, when employing this method, the selection of a reducing agent is a crucial issue.
Well, the answer is upstairs; if you need chromium-free resin, you can come to me.
Consider using a CWL-type centrifugal extractor for removal by extraction