Department of Civil and Environmental Engineering, University of North Carolina, 9201 University City Blvd., Charlotte, NC 28223, USA; Department of Civil, Environmental and Architectural Engineering, 428 UCB, University of Colorado at Boulder, Boulder, CO 80309, USA.
Department of Chemistry and Biochemistry, California State University at Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840, USA.
Water Res. 2014 Mar 1;50:408-19. doi: 10.1016/j.watres.2013.10.049. Epub 2013 Nov 1.
Advanced oxidation processes (AOPs) are an effective treatment technology for the removal of a variety of organic pollutants in both water and wastewater treatment. However, many background constituents in water are highly reactive towards hydroxyl radicals (HO) and decrease the efficiency of the process towards contaminant oxidation. Up to 95% of the HO scavenging can come from dissolved organic matter (OM). In this study, 28 wastewater effluent samples were analyzed to find correlations between the reactivity of HO with wastewater-derived OM (known as effluent organic matter, EfOM), water quality parameters, treatment train characteristics, and fluorescence-derived data. Rate constants for the reaction between HO and EfOM (kEfOM-HO) were measured using a bench scale UV-based AOP system with methylene blue as an HO probe and confirmed using an electron pulse radiolysis method for a subset of the samples. The EfOM was characterized using a series of physicochemical parameters, including polarity, average molecular size and fluorescence. The kinetic data were analyzed with principal component analysis and Akaike Information Criterion. Four predictors were identified as dominant: chemical oxygen demand, retention onto NH2 extraction medium, fluorescence index, and total organic carbon. These four variables accounted for approximately 62% of the variability in the value of kEfOM-HO The average kEfOM-HO value for EfOM in this study was 2.5 × 10(8) MC(-1) s(-1), which is about 31% lower than the 3.6 × 10(8) MC(-1) s(-1) value determined for natural organic matter isolates and commonly used in AOP modeling.
高级氧化工艺（AOPs）是一种有效处理技术，可去除水和废水处理中多种有机污染物。然而，水中的许多背景成分对羟基自由基（HO）具有很高的反应性，降低了该过程对污染物氧化的效率。高达 95%的 HO 清除作用可能来自于溶解有机物（OM）。在这项研究中，分析了 28 个废水流出物样本，以寻找 HO 与废水衍生的 OM（称为流出物有机物，EfOM）之间的反应性与水质参数、处理途径特征以及荧光衍生数据之间的相关性。使用基于紫外线的实验室规模 AOP 系统，以亚甲蓝作为 HO 探针，测量了 HO 与 EfOM（kEfOM-HO）之间的反应速率常数，并使用电子脉冲辐照法对部分样品进行了验证。使用一系列物理化学参数，包括极性、平均分子量和荧光，对 EfOM 进行了表征。动力学数据采用主成分分析和赤池信息量准则进行了分析。确定了四个主要预测因子：化学需氧量、NH2 萃取介质的保留率、荧光指数和总有机碳。这四个变量解释了 kEfOM-HO 值变化的约 62%。本研究中 EfOM 的平均 kEfOM-HO 值为 2.5×10(8)MC(-1)s(-1)，比天然有机物分离物的 3.6×10(8)MC(-1)s(-1)值低约 31%，而该值常用于 AOP 模型。
