Non-degradable triazine substrates of atrazine and cyanuric acid hydrothermally and in supercritical water under the UV-illuminated photocatalytic cooperation.
Non-degradable triazine substrates of atrazine and cyanuric acid hydrothermally and in supercritical water under the UV-illuminated photocatalytic cooperation.
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在紫外光催化作用下，阿特拉津和三聚氰酸在水热和超临界水中不可降解的三嗪底物。
DOI：
10.1016/s0045-6535(02)00786-5
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发表时间：
2003
期刊：
影响因子：
8.8
通讯作者：
H. Hidaka
中科院分区：
文献类型：
--
作者：
S. Horikoshi;H. Hidaka
二氧化钛对空气和水中有机污染物的光降解可产生强氧化作用。一些既不能被细菌生物降解也不能被热降解的内分泌干扰物如2，4-二氯苯氧乙酸（;）、2，4-二氯苯酚（;）、壬基酚（;;）、双酚A（;）、邻苯二甲酸二乙酯（;）等可以被TiO 2光催化处理降解。然而，不完全的光矿化，当TiO 2光催化降解某些内分泌干扰物的处理，部分发生。例如，具有三嗪骨架的莠去津农药即使通过光催化过程也不能完全矿化;莠去津的光降解最终停止在氰尿酸的中间步骤，氰尿酸即使在长时间光照后也不能光降解（）。在这项研究中，阿特拉津和氰尿酸的分解进行了一个装置结合光催化降解超临界水（scH 2 O）或热水（hyH 2 O）。在120 ml Hastelloy间歇式反应器中，在623 K和683 K温度下，分别采用超临界水和超临界水与紫外光照射下的TiO 2光催化分散体系协同作用降解阿特拉津和氰尿酸。高温高压下的光催化降解方法已发现适用于在160 °C和20 atm（）的连续流动条件下乙酸和2-氯联苯的光催化氧化。此外，还报告了高温高压下多氯联苯的湿式过氧化物氧化（）。本研究的主要目的如下。(i)（ii）在超临界水或超临界水存在下，TiO 2颗粒对莠去津和氰尿酸的催化分解作用，以及TiO 2与超临界水或超临界水的协同作用;（iii）与莠去津或氰尿酸的化学结构有关的氮和氯原子的矿化率（仅含氮）。
Strong oxidation by titanium dioxide photocatalysis can occur by photodegradation of organic contaminants in air and water. Some endocrine disruptors such as 2,4-dichlorophenoxy acetic acid (; ; ; ), 2,4-dichlorophenol (; ; ; ), nonylphenol (; ), bisphenol A (), diethyl phthalate (; ), etc. which can be neither biodegraded by bacteria nor degraded thermally can be degraded by TiO2photocatalytic treatment. However, incomplete photomineralization partly occurred, when TiO2photocatalytic degradation is employed for the treatment of certain endocrine disruptors. For example, no atrazine pesticide having triazine skeleton can be completely mineralized even by a photocatalytic procedure; the photodegradation of atrazine ultimately stops at the intermediate step of cyanuric acid, which cannot be photodegraded even after long illumination times (). In this study, the decomposition of atrazine and cyanuric acid was carried out with a device combining photocatalytic degradation in supercritical water (scH2O) or hydrothermal water (hyH2O). Atrazine and cyanuric acid can be degraded by the cooperation of either scH2O or hyH2O and UV illuminated TiO2-photocatalytic dispersed system under the fixed pressure of 23 MPa at 623 K or 683 K in a 120-ml Hastelloy batch reactor. The photocatalytic degradation method under high temperature and pressure has found appropriate for the photocatalytic oxidation of acetic acid and 2-chlorobiphenyl under continuous flow conditions at 160 °C and 20 atm (). In addition, the wet peroxide oxidation of PCBs by high temperature and pressure has been reported (). The main aims of this research are following. (i): the degradation of atrazine and cyanuric acid within the scH2O or hyH2O, (ii) the decomposition of atrazine and cyanuric acid catalyzed by TiO2particles under scH2O or hyH2O, and the synergistic effect for several reactions with TiO2and scH2O or hyH2O, and (iii) the mineralization yield of nitrogen and chlorine atoms concerning the chemical structures of atrazine or cyanuric acid (only nitrogen).