CDM Smith, 14432 SE Eastgate Way Suite 100, Bellevue, WA, 98007, USA; Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA.
Department of Civil and Environmental Engineering, South Dakota State University, Brookings, SD 57007, USA.
Chemosphere. 2022 Dec;308(Pt 1):136206. doi: 10.1016/j.chemosphere.2022.136206. Epub 2022 Aug 29.
Disinfection byproducts (DBPs) in treated wastewater effluents pose environmental and health risks during water reuse. Solar-TiO photocatalysis is a promising technology for degrading organic pollutants in treated effluents. In this study, total organic halogen (TOX) was used as an analytical tool to determine the efficiency of solar-TiO photocatalytic process for the dehalogenation of DBPs in water. Natural solar photocatalytic experiments using TiO particles were conducted to evaluate dehalogenation kinetics of different TOX groups formed by fulvic acid including total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI). The results showed that the mixed phase TiO (Aeroxide P25) was much more effective at TOX removal than the anatase (Hombikat UV-100) and rutile (TiOxide) TiO particles. The TOX photocatalytic degradation rates of different halogen substituents ranked as TOI > TOCl (NHCl) > TOBr > TOCl (Cl). The TOX removal followed first-order kinetics with half-lives of 42.8, 11.0, 5.0 and 2.7 min for TOCl (Cl), TOBr, TOCl (NHCl), and TOI, respectively, at the 100 mg L TiO dose. The TOX dehalogenation was enhanced at pH 9 compared to pH 5, and the addition of hydrogen peroxide had limited improvement in the TOX removal. Hydrophobic and molecular weight (MW) > 1 kDa fractions of TOCl (Cl) were more susceptible to the solar photocatalytic process than the hydrophilic and MW < 1 kDa fractions. The solar-TiO photocatalytic process also effectively removed TOX in chlorinated and chloraminated wastewater samples. The results of this study suggest that the solar-TiO photocatalysis is an effective treatment technology for TOX removal in water reuse.
处理废水中的消毒副产物 (DBPs) 在水再利用过程中会带来环境和健康风险。太阳能-TiO 光催化是一种很有前途的技术，可以降解处理废水中的有机污染物。在这项研究中，总有机卤素 (TOX) 被用作分析工具，以确定太阳能-TiO 光催化工艺对水中 DBPs 脱卤的效率。使用 TiO 颗粒进行了自然太阳能光催化实验，以评估富里酸形成的不同 TOX 基团（包括总有机氯 (TOCl)、溴 (TOBr) 和碘 (TOI)）的脱卤动力学。结果表明，混合相 TiO（Aeroxide P25）比锐钛矿（Hombikat UV-100）和金红石（TiOxide）TiO 颗粒更有效地去除 TOX。不同卤素取代基的 TOX 光催化降解速率排序为 TOI > TOCl(NHCl) > TOBr > TOCl(Cl)。在 100 mg L TiO 剂量下，TOCl(Cl)、TOBr、TOCl(NHCl)和 TOI 的 TOX 去除率分别遵循一级动力学，半衰期分别为 42.8、11.0、5.0 和 2.7 min。与 pH 5 相比，在 pH 9 时 TOX 脱卤作用增强，而添加过氧化氢对 TOX 去除的改善有限。与亲水性和 MW < 1 kDa 部分相比，TOCl(Cl) 的疏水性和 MW > 1 kDa 部分更易受到太阳能光催化过程的影响。太阳能-TiO 光催化工艺还能有效地去除氯化和氯胺化废水样品中的 TOX。本研究结果表明，太阳能-TiO 光催化是水再利用中去除 TOX 的有效处理技术。
