State of the Art of UV/Chlorine Advanced Oxidation Processes: Their Mechanism, Byproducts Formation, Process Variation, and Applications
State of the Art of UV/Chlorine Advanced Oxidation Processes: Their Mechanism, Byproducts Formation, Process Variation, and Applications
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DOI：
10.2965/jwet.19-021
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发表时间：
2019-01-01
影响因子：
--
通讯作者：
Kishimoto, Naoyuki
中科院分区：
文献类型：
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作者：
Kishimoto, Naoyuki
紫外线对氯的光解作用（uv /氯）产生HO中心点和cl -中心点，其中一部分进一步转化为Cl-2（中心点-）和ClO中心点等活性氯物质（RCS）。这些自由基是造成uv /氯工艺的高级氧化作用的原因。最近。紫外/氯工艺受到研究人员和从业人员的广泛关注，发表的关于紫外/氯工艺的论文急剧增加，本文对这些技术的现状进行了全面的回顾。基础研究表明，酸性条件有利于氯光解量子产率的变化、自由基种类的平衡位移和游离氯自由基清除作用的变化。比较研究表明，紫外线/氯工艺通常比紫外线/过氧化氢和紫外线/过硫酸盐工艺更节能。虽然人们担心RCS反应会产生不利的副产物，但在实际水体中的应用研究表明，UV/氯处理并不能很大程度上提高消毒副产物的生成。由于紫外线照射和氯化是广泛使用的单元操作，将紫外线/氯工艺安装到传统工艺中的障碍并不高。为了在未来的水处理中实现效益最大化，需要开发和优化与其他单元工艺相结合的整个工艺。
The photolysis of chlorine by ultraviolet radiation (U V/chlorine) produces HO center dot and Cl-center dot, part of which further transforms into reactive chlorine species (RCS) like Cl-2(center dot-) and ClO center dot. These radicals are responsible for the advanced oxidation effect of U V/chlorine processes. Recently. UV/chlorine processes gather much attention from researchers and practitioners and published papers on UV/chlorine processes have drastically increased, which were thoroughly reviewed in this paper for understanding the state of the art of these technologies. Fundamental studies elucidate that acidic conditions are favorable to UV/chlorine processes through a change in quantum yield of chlorine photolysis, equilibrium shifts of radical species, and a change in radical scavenger effect of free chlorine. Comparative studies reveal that UV/chlorine processes are usually more energy-efficient than UV/hydrogen peroxide and UV/persulfate processes. Although unfavorable byproducts formation by RCS reactions is apprehended, application researches in real waters show that UV/chlorine processes do not enhance disinfection byproducts formation very much. Since UV irradiation and chlorination are widely used unit operations, a barrier to install an UV/chlorine process into a conventional process is not high. It is desired to develop and optimize a whole process combined with other unit processes for maximizing benefits in water treatment in the future.