College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, PR China; Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, PR China.
College of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266033, PR China.
J Environ Manage. 2017 Apr 15;191:244-251. doi: 10.1016/j.jenvman.2017.01.021. Epub 2017 Jan 20.
In this study, the transformation of dissolved organic matter (DOM) in nanofiltration concentrated leachate during three ozone-based oxidation processes (i.e., O, O/HO and O/UV) was investigated. The transformation characteristics of DOM were evaluated by gel filtration chromatography (GFC), XAD-8 resin fractionation, excitation-emission matrix fluorescence spectroscopy (EEM) and Fourier transform infrared spectroscopy (FTIR). Compared with O-alone process, the removal efficiencies of COD, TOC, and color were improved in O-combined processes (i.e., O/HO and O/UV) approximately by 10-15%, 7-15%, and 15-20%, respectively. Humic acid (HA) was completely degraded and preferentially reacted with the oxidants during ozonation processes. HA was first converted into fulvic acid (FA), and then the majority of these intermediates were further converted to hydrophilic fraction (HyI). The GFC results indicated that the broader molecular weight distribution of DOM was observed, and high molecular weight DOM (i.e., 0.45 μm-100 kDa) was successfully converted to low molecular weight organics in the range of 1-10 kDa after ozonation reactions. The EEM spectra also showed that HA and FA were effectively converted into HyI after ozonation for 90 min. It is suggested that ozone-based oxidation processes could effectively change the DOM distribution and fluorescence features of concentrated leachate.
在这项研究中，考察了三种基于臭氧的氧化过程（即 O、O/HO 和 O/UV）中纳滤浓缩渗滤液中溶解有机物（DOM）的转化。通过凝胶过滤色谱（GFC）、XAD-8 树脂分级、激发发射矩阵荧光光谱（EEM）和傅里叶变换红外光谱（FTIR）评估了 DOM 的转化特征。与单独的 O 过程相比，O 结合过程（即 O/HO 和 O/UV）中 COD、TOC 和颜色的去除效率分别提高了约 10-15%、7-15%和 15-20%。臭氧化过程中，腐殖酸（HA）被完全降解并优先与氧化剂反应。HA 首先转化为富里酸（FA），然后这些中间体中的大部分进一步转化为亲水性部分（HyI）。GFC 结果表明，观察到 DOM 的更宽分子量分布，并且在臭氧化反应后，高分子量 DOM（即 0.45 μm-100 kDa）成功转化为 1-10 kDa 范围内的低分子量有机物。EEM 光谱还表明，HA 和 FA 在臭氧化 90 分钟后有效地转化为 HyI。这表明基于臭氧的氧化过程可以有效地改变浓缩渗滤液中 DOM 的分布和荧光特征。
