Abstract：
Fenton and Fenton-like processes, which could produce highly reactive species to degrade organic contaminants, have been widely used in the field of wastewater treatment. Therein, the chemistry of Fenton process including the nature of active oxidants, the complicated reactions involved, and the behind reason for its strongly pH-dependent performance, is the basis for the application of Fenton and Fenton-like processes in wastewater treatment. Nevertheless, the conflicting views still exist about the mechanism of the Fenton process. For instance, reaching a unanimous consensus on the nature of active oxidants (hydroxyl radical or tetravalent iron) in this process remains challenging. This review comprehensively examined the mechanism of the Fenton process including the debate on the nature of active oxidants, reactions involved in the Fenton process, and the behind reason for the pH-dependent degradation of contaminants in the Fenton process. Then, we summarized several strategies that promote the Fe(II)/Fe(III) cycle, reduce the competitive consumption of active oxidants by side reactions, and replace the Fenton reagent, thus improving the performance of the Fenton process. Furthermore, advances for the future were proposed including the demand for the high-accuracy identification of active oxidants and taking advantages of the characteristic of target contaminants during the degradation of contaminants by the Fenton process.
摘要：
芬顿和类似芬顿的过程，可以产生高活性物质来降解有机污染物，在废水处理领域得到了广泛的应用。其中,Fenton工艺的化学性质，包括活性氧化剂的性质，所涉及的复杂反应，以及其强烈依赖pH的性能的背后原因，是Fenton和类Fenton工艺在废水处理中应用的基础。然而，关于芬顿过程的机制仍然存在矛盾的观点。例如,在此过程中，对活性氧化剂（羟基自由基或四价铁）的性质达成一致共识仍然具有挑战性。本文综合考察了Fenton过程的机理，包括对活性氧化剂性质的评论辩论，涉及芬顿过程的反应，以及Fenton过程中污染物的pH依赖性降解的背后原因。然后，我们总结了几种促进Fe(II)/Fe(III)循环的策略，通过副反应减少活性氧化剂的竞争性消耗，更换芬顿试剂,从而提高了Fenton工艺的性能。此外，提出了未来的进展，包括对活性氧化剂的高精度识别的需求，以及在Fenton工艺降解污染物过程中利用目标污染物的特性。
