市政污水二级出水中溶解性有机质在紫外/氯处理过程中的转化特性

紫外/氯高级氧化技术是一种新型的水处理技术,可有效氧化去除多类有机污染物,但目前较为缺乏紫外/氯处理真实污水过程中溶解性出水有机质(dEfOM)转化特性的研究.采用紫外光谱、荧光光谱和傅里叶变换离子回旋共振质谱(FT-ICR-MS)探究了两个市政污水二级出水中dEfOM在紫外/氯处理过程中的转化特性,同时对该过程中形成...

Transformation Characteristics of Dissolved Organic Matter During UV/Chlorine Treatment of Municipal Secondary Effluent

As an emerging advanced oxidation technology, UV/chlorine treatment is capable of effectively oxidizing various organic pollutants. Till now, the transformation of dissolved effluent organic matter (dEfOM) in real wastewater during UV/chlorine treatment remains unclear. In this study, ultraviolet and fluorescence spectroscopy were combined with Fourier transform ion cyclotron resonance mass spectrometry to probe the transformation of dEfOM in two municipal secondary effluents during UV/chlorine treatment. Meanwhile, the newly formed chlorinated byproducts (Cl-BPs) are particularly concerned. Generally, aromatic compounds and fluorescent components could be readily removed after UV/chlorine treatment, and most of the dEfOM underwent transformation rather than mineralization. Protein-like components, which accounted for the largest proportion of fluorescent components, were subject to a preferential reaction. UV/chlorine treatment could result in the degradation of CHOS compounds and the formation of CHO compounds. During this process, unsaturated and reduced compounds of large molecules were preferentially removed, whereas saturated and oxidized compounds with low molecular weight were produced. Moreover, the concentrations of trihalomethanes and haloacetic acids increased substantially after UV/chlorine treatment. In total, 255 and 133 Cl-BPs were detected in the respective effluents after UV/chlorine treatment. In addition, 12 and 43 possible precursor-Cl-BPs pairs were identified, respectively, based on electrophilic substitution and addition reactions by means of mass difference analysis. This study is expected to provide fundamental information for practical application of the UV/chlorine treatment process.