Permanganate (Carus Chemicals) is now widely accepted for oxidation of chlorinated alkenes, such as PCE and TCE, plus their daughter products. Permanganate does not directly oxidize chlorinated alkanes, such as TCA, nor does it oxidize benzene. There are two forms of permanganate, KMnO4 and NaMnO4. The oxidation reaction for KMnO4 with a chlorinated ethene such as TCE can be written as follows:
2KMnO4 + C2HCl3 → 2CO2 + 2MnO2 + 2K+ + 3Cl– + H+
The by-products of this reaction are carbon dioxide, potassium ions (if permanganate is used), hydrochloric acid (disassociated as hydrogen and chloride ions), and insoluble manganese dioxide. The hydrochloric acid is typically reacted with ubiquitous iron hydroxides. The insoluble manganese dioxide can cause problems during injection, if proper steps are not taken.
There are many issues associated with the effective delivery of permanganate, such as purple water, health and safety, metals impurities, manganese precipitation, proper dosing, neutralization, etc. Redox Tech has injected nearly 100,000 pounds of potassium permanganate. We can assist with your design and injection.