Degradation of phenolic pollutants in water by hydroxyl radical electrochemically generated
A modifiedβ-PbO_2 doped with fluoride and stainless steel net were used as anode and cathode in our previous work,respectively.Evidence for hydroxyl radicals generation in electrochemical degradation was shown by electron spin resonance spectroscopy(ESR)and 5,5-dimethyl-l-pyrroline-N-oxide(DMPO) was used as spin trapping agent.The study on electrocatalytic degradation of phenolic compounds and its precursor showed that the ring opening reaction was preceded under the attack of electrochemically generated hydroxyl radicals and the phenolic pollutants were degraded to biodegradable organic acid,such as maleic acid and oxalic acid,further mineralized to carbon dioxide and water.Benzoquinone(BQ) represents one of the first byproducts formed and is the common intermediate before the ring fracture.The common degradation pathway of phenolic pollutants offers a theoretic basis for potential application and cost-effective technology.