Wu Chung-Hsin, Chang Chung-Liang
Department of Environmental Engineering, Da-Yeh University, 112 Shan-Jiau Rd., Da-Tsuen, Chang-Hua 515, Taiwan, ROC.
J Hazard Mater. 2006 Feb 6;128(2-3):265-72. doi: 10.1016/j.jhazmat.2005.08.013. Epub 2005 Sep 22.
This study investigated the decolorization of the Reactive Red 2 in water using advanced oxidation processes (AOPs): UV/TiO2, UV/SnO2, UV/TiO2+SnO2, O3, O3+MnO2, UV/O3 and UV/O3+TiO2+SnO2. Kinetic analyses indicated that the decolorization rates of Reactive Red 2 could be approximated as pseudo-first-order kinetics for both homogeneous and heterogeneous systems. The decolorization rate at pH 7 exceeded pH 4 and 10 in UV/TiO2 and UV/TiO2+SnO2 systems, respectively. However, the rate constants in the systems (including O3) demonstrated the order of pH 10>pH 7>pH 4. The UV/TiO2+SnO2 and O3+MnO2 systems exhibited a greater decolorization rate than the UV/TiO2 and O3 systems, respectively. Additionally, the promotion of rate depended on pH. The variation of dye concentration influenced the decolorization efficiency of heterogeneous systems more significant than homogeneous systems. Experimental results verified that decolorization and desulfuration occurred at nearly the same rate. Moreover, the decolorization rate constants at pH 7 in various systems followed the order of UV/O3 > or = O3+MnO2 > or = UV/O3+TiO2+SnO2 > O3 > UV/TiO2+SnO2 > or = UV/TiO2 > UV/SnO2.
本研究采用高级氧化工艺(AOPs):紫外光/二氧化钛(UV/TiO₂)、紫外光/二氧化锡(UV/SnO₂)、紫外光/二氧化钛+二氧化锡(UV/TiO₂+SnO₂)、臭氧(O₃)、臭氧+二氧化锰(O₃+MnO₂)、紫外光/臭氧(UV/O₃)以及紫外光/臭氧+二氧化钛+二氧化锡(UV/O₃+TiO₂+SnO₂),对水中活性红2的脱色情况展开了研究。动力学分析表明,对于均相和非均相体系,活性红2的脱色速率均可近似为拟一级动力学。在UV/TiO₂体系中,pH值为7时的脱色速率分别超过了pH值为4和10时的脱色速率;而在UV/TiO₂+SnO₂体系中,pH值为7时的脱色速率超过了pH值为10时的脱色速率。然而,这些体系(包括O₃)中的速率常数呈现出pH值为10>pH值为7>pH值为4的顺序。UV/TiO₂+SnO₂体系和O₃+MnO₂体系分别比UV/TiO₂体系和O₃体系展现出更高的脱色速率。此外,速率的提升取决于pH值。染料浓度的变化对非均相体系脱色效率的影响比对均相体系的影响更为显著。实验结果证实,脱色和脱硫几乎以相同的速率发生。而且,在pH值为7时,各体系中的脱色速率常数遵循如下顺序:UV/O₃≥O₃+MnO₂≥UV/O₃+TiO₂+SnO₂>O₃>UV/TiO₂+SnO₂≥UV/TiO₂>UV/SnO₂。