Kinetics of Reactive Species in Water Produced by Ultraviolet Light Oxidation Processes

先进氧化物工艺（AOPs），即由超紫外光氧化物生产的有效反应物种，对环境保护的创新技术有很大的关注。本研究的目的是在动力学上实现反应性物种在水中的基本信息，以促进光化学反应堆设计。模型化学：ethanol（浓度为10 ppm的浓度）及其分解中间物、水中的乙酸和氧酸，在一个带有（a） VUV（172 nm）辐射的电池循环光化学反应系统中分解，（b） VUV+UVC（185+ 254 nm） irradiation， and （c） UVC（254 nm） irradiation accompanied by HイイD22イイD22イイD2。Concentrations of reaction intermediates （acetaldehyde， formaldehyde， acetic acid， oxalic acid， formic acid） and TOC were sequentially determined; Hy D22 y D22 y D2， CO y D22 y D2 and pH changes were also traced。实验结果首先由常规动力学表达式评估，然后由一个新的反应模型在辐射化学中涉及的元素过程的研究中，H-D22-D2 O-D22-D22-D2的再生率低于那些在先前的分解实验中发现的甲醇、Formaldehyde和Formic Acid，以及在每个反应中的再生相对可靠依赖的程度。有机浓缩对TOC降解率的影响也是对有机物种的不敏感的。对整个分解过程的成功模拟是通过一项分析来完成的，该分析将羟基自由基物作为一种长期的超氧自由基物，并与那些羟基和有机衍生的自由基物进行比较，包括离子自由基物。研究工作的一部分于1999年6月在一次国际会议上介绍，APCR 99。

Advanced oxidation processes (AOPs), which utilize reactive species produced by ultraviolet-light oxidation, have attracted much attention as innovative technology for environmental conservation. The purpose of this study was to kinetically elucidate behavior of the reactive species in water for fundamental information on photochemical reactor design.Model chemicals: ethanol (concentrations of 10ppm order) and its decomposition intermediates, acetic acid and oxalic acid in water, were decomposed in a batch-recycle photochemical-reaction system with (a) VUV(172nm) irradiation, (b) VUV+UVC(185+254nm) irradiation, and (c) UVC(254nm) irradiation accompanied by HィイD22ィエD2OィイD22ィエD2. Concentrations of reaction intermediates (acetaldehyde, formaldehyde, acetic acid, oxalic acid, formic acid) and TOC were sequentially determined; HィイD22ィエD2OィイD22ィエD2, COィイD22ィエD2 and pH changes were also traced. Experimental results were evaluated first by a conventional kinetic expression, then by a new reaction model which took consideration of elementary processes incorporated in radiation chemistry.Regeneration rate of HィイD22ィエD2OィイD22ィエD2 was lower than those observed in the previous decomposition experiments of methanol, formaldehyde, and formic acid, the extent of regeneration solely depending on each reactant. Effect of organic concentration on TOC decomposition rate was also low irrespective of organic species. Successful simulation of the overall decomposition process was achieved by an analysis considering an extraordinarily long life-time of hydroperoxy radicals, compared with those of hydroxyl and organics-derived radicals including ion radicals. Part of the research work was presented at an international conference, APCRE99, in June 1999.