阳离子红染料的光解脱色研究

在半序批式光反应器中,研究了反应温度、pH、起始染料浓度、载气类型、氧气流量和紫外光光强等因素对阳离子红X GRL染料去除率和初始量子产率的影响。染料的去除率由缺氧时的9 1%提高到有氧时的38 8%,初始量子产率由缺氧时的0 15mol·einstein-1提高到有氧时的1 03mol·einstein-1。实验证明了184 9nm紫外光可与溶解氧及气相氧气作用生成O3,O3受紫外光辐照及在较高pH时还会形成·OH链增长反应,二者皆显著地提高染料的去除率和初始量子产率。pH、温度、起始浓度和光强等对去除率影响都较大。初始量子产率受起始浓度及光强等的影响较小,但受pH的影响很大:由pH3 15的0 75mol·einstein-1提高到pH9 24的1 08mol·einstein-1。有氧条件下,光解脱色主要由光直接脱色、O3氧化脱色和·OH脱色等三种机理组成。

RESEARCH OF PHOTODEGRADATION OF CATIONIC RED X-GRL IN WASTEWATER

In a semi-batch reactor, the photo degradation of Cationic Red X-GRL was investigated under the influence parameters such as temperature, pH, initial concentration of Cationic Red X-GRL, oxygen flow rate, kind of carrier gas, and light intensity. This study confirms that the degradation rate of Cationic Red X-GRL is elevated from 9.1% in anoxic system to 38.8% in oxygen-aerated system, and the initial quantum yield is elevated from 0.15 mol einstein~(-1) to 1.03 mol einstein~(-1). The temperature, pH, initial dye concentration, and light intensity can enhance the photo degradation rate obviously, but only pH can enhance the initial quantum yield violently from 0.75 mol einstein~(-1) at pH 3.15 to 1.08 mol einstein~(-1) at pH 9.24. Molecular oxygen existed in gaseous and aqueous phase irradiated by UV-light is the key source of the formation of ozone and hydroxyl radical. The photo degradation process in the oxygen-aerated system consists of the ozonation, hydroxyl radical oxidation and photolysis.