Kritikos Demetrios E, Xekoukoulotakis Nikolaos P, Psillakis Elefteria, Mantzavinos Dionissios
Department of Environmental Engineering, Technical University of Crete, Polytechneioupolis, Chania, Greece.
Water Res. 2007 May;41(10):2236-46. doi: 10.1016/j.watres.2007.01.048. Epub 2007 Mar 13.
The degradation of reactive black 5 (RB 5), a representative diazo dye found in textile effluents, by means of ultraviolet irradiation (9W UVA) over TiO(2) suspensions, ultrasound irradiation (80kHz, 135W) and their combined application was investigated. Several commercial TiO(2) catalysts were screened and an anatase Hombicat UV 100 sample exhibited considerable activity in terms of solution decoloration, COD and ecotoxicity reduction. Photocatalytic degradation increased with increasing TiO(2) loading (in the range 0.05-1g/L) and decreasing dye concentration (in the range 120-20mg/L) and solution pH (in the range 9-2.6). At the typical conditions employed in this study (60mg/L dye, 0.25mg/L catalyst, ambient pH=5.8, oxygen sparging), complete decoloration was achieved after 60min of reaction. Addition of H(2)O(2) up to 0.01M hindered degradation, scavenging the photogenerated holes and hydroxyl radicals. Ultrasound irradiation resulted in low decoloration, e.g. less than 10% after 60min at 60mg/L dye and oxygen sparging and slightly improved under an argon atmosphere. The simultaneous application of ultraviolet and ultrasound irradiation resulted in increased decoloration compared to that achieved by photocatalysis and sonolysis operating separately; moreover, the overall sonophotocatalytic effect was greater than the additive effect of the two processes, implying possible synergy.
研究了通过紫外光照射（9W UVA）、超声照射（80kHz，135W）及其联合应用对活性黑5（RB 5，一种在纺织废水中发现的代表性重氮染料）的降解情况。筛选了几种商用TiO₂催化剂，锐钛矿型Hombicat UV 100样品在溶液脱色、化学需氧量（COD）降低和生态毒性降低方面表现出相当高的活性。光催化降解随着TiO₂负载量增加（在0.05 - 1g/L范围内）、染料浓度降低（在120 - 20mg/L范围内）以及溶液pH值降低（在9 - 2.6范围内）而增加。在本研究采用的典型条件下（60mg/L染料、0.25mg/L催化剂、环境pH = 5.8、通入氧气），反应60分钟后实现了完全脱色。添加高达0.01M的H₂O₂会阻碍降解，它会清除光生空穴和羟基自由基。超声照射导致的脱色率较低，例如在60mg/L染料且通入氧气的情况下，60分钟后脱色率低于10%，在氩气氛围下略有改善。与单独进行光催化和超声分解相比，紫外光和超声照射同时应用导致脱色率提高；此外，总的声光催化效果大于这两个过程的加和效应，这意味着可能存在协同作用。
