Alvarez-Corena Jose R, Bergendahl John A, Hart Fred L
Department of Civil & Environmental Engineering, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA, 01609, USA; Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA, USA.
Department of Civil & Environmental Engineering, Worcester Polytechnic Institute, 100 Institute Rd., Worcester, MA, 01609, USA.
J Environ Manage. 2016 Oct 1;181:544-551. doi: 10.1016/j.jenvman.2016.07.015. Epub 2016 Aug 5.
The extent and kinetics of degradation of 1,4 dioxane, n-nitrosodimethylamine (NDMA), tris-2-chloroethyl phosphate (TCEP), gemfibrozil, and 17β estradiol in a prepared aqueous matrix by means of UV/TiO2 (ultraviolet light/titanium dioxide) oxidation was evaluated. Degussa P25 TiO2 was employed as a photocatalyst excited by UV light in a 1 L water-jacketed batch photoreactor. The rate of degradation was modeled using a pseudo-first order rate model and the Langmuir-Hinshelwood rate model with a high correlation. Degradation rate constants were found to be maximum at pH 5.0 and 1.5 g L(-)(1) TiO2 dose. For these conditions first order rate constants, values were as follows: 0.29 min(-1) for 1,4 dioxane, 0.50 min(-1) for NDMA, 0.12 min(-1) for TCEP, 0.61 min(-1) for gemfibrozil, and 0.53 min(-1) for 17β estradiol. While for the Langmuir-Hinshelwood rate model, the following constants were found: 0.11 Lmg(-1) and 2.81 mgL(-1) min(-1) for 1,4 dioxane, 0.12 Lmg(-1) and 4.35 mgL(-1) min(-1) for NDMA, 0.06 Lmg(-1) and 1.79 mgL(-1) min(-1) for TCEP, 0.21 Lmg(-1) and 3.27 mgL(-1) min(-1) for gemfibrozil, and 0.15 Lmg(-1) and 3.43 mgL(-1) min(-1) for 17β estradiol. In addition, specific byproducts of degradation were identified using GC/MS analysis. The results obtained from the kinetics analysis showed that UV/TiO2 oxidation is a promising process for treating trace organic contaminants in water, but further research is needed to better understand how to incorporate these findings into pilot and full-scale designs. The toxicity of oxidation byproducts, and their potential for interacting with other compounds should be considered in the treatment of contaminated waters using the UV/TiO2 oxidation process.
通过紫外光/二氧化钛（UV/TiO₂）氧化，评估了在配制的水基质中1,4 - 二氧六环、N - 亚硝基二甲胺（NDMA）、磷酸三（2 - 氯乙基）酯（TCEP）、吉非罗齐和17β - 雌二醇的降解程度和动力学。在1升带水夹套的间歇式光反应器中，使用德固赛P25二氧化钛作为光催化剂，由紫外光激发。降解速率采用拟一级速率模型和具有高度相关性的朗缪尔 - 欣谢尔伍德速率模型进行模拟。发现降解速率常数在pH 5.0和1.5 g L⁻¹的二氧化钛剂量下最大。对于这些条件，一级速率常数的值如下：1,4 - 二氧六环为0.29 min⁻¹，NDMA为0.50 min⁻¹，TCEP为0.12 min⁻¹，吉非罗齐为0.61 min⁻¹，17β - 雌二醇为0.53 min⁻¹。而对于朗缪尔 - 欣谢尔伍德速率模型，得到的常数如下：1,4 - 二氧六环为0.11 L mg⁻¹和2.81 mg L⁻¹ min⁻¹，NDMA为0.12 L mg⁻¹和4.35 mg L⁻¹ min⁻¹，TCEP为0.06 L mg⁻¹和1.79 mg L⁻¹ min⁻¹，吉非罗齐为0.21 L mg⁻¹和3.27 mg L⁻¹ min⁻¹，17β - 雌二醇为0.15 L mg⁻¹和3.43 mg L⁻¹ min⁻¹。此外，使用气相色谱/质谱分析鉴定了特定的降解副产物。动力学分析结果表明，UV/TiO₂氧化是处理水中痕量有机污染物的一种有前景的方法，但需要进一步研究以更好地理解如何将这些发现纳入中试和全规模设计中。在使用UV/TiO₂氧化工艺处理受污染水体时，应考虑氧化副产物的毒性及其与其他化合物相互作用的可能性。
