电化学诱发羟基自由基降解水中酚类污染物

DMPO（5，5-dimethyl-1-pyrroline-N-oxide）为自旋捕集剂，采用电子自旋共振技术（electron spin resonance spectroscopy，ESR）直接证实了经氟树脂改性的β PbO₂阳极和不锈钢网阴极构成的电化学体系中产生的羟基自由基（·OH）。通过电化学氧化水中含酚类及其前驱体污染物，发现环状结构化合物受电化学产生的羟基自由基攻击而发生开环反应产生易生物降解的有机酸，如反丁烯二酸和草酸，直至完全矿化为CO₂和水分子，苯醌是酚类污染物开环前产生的共同稳态中间体。该类污染物的电化学降解共性规律为电化学氧化技术的工业化应用和提高其处理工艺的经济性提供了理论依据。

Degradation of phenolic pollutants in water by hydroxyl radical electrochemically generated

A modified β-PbO₂ 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-1-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