Department of Chemistry, Laboratory of Chemical and Environmental Technology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Institute for Water Resources and Water Supply, Hamburg University of Technology, Am Schwarzenberg-Campus 3, 21073, Hamburg, Germany.
Environ Sci Pollut Res Int. 2018 May;25(13):12246-12255. doi: 10.1007/s11356-017-9554-8. Epub 2017 Jun 27.
The present study aims to evaluate changes in the structure-composition of natural organic matter (NOM) that occur after the application of bubbleless ozonation or peroxone treatment of surface waters. The oxidation experiments (using 0.5-2 mg O3/mg DOC, or 2:1 O:HO molar ratio) were performed in a continuous mode, using a tubular ceramic membrane contactor. Fluorescence spectroscopy (emission-excitation matrix) and liquid chromatography-organic carbon detection (LC-OCD) were mainly used for the detailed DOC characterization. In brief, the application of single ozonation resulted to high reduction of humic-like peak fluorescence intensities (50-85%) and also to the formation of two new peaks in the region of protein-like components. The co-addition of HO did not present the anticipated increase in the reduction of fluorescence intensity; however, it resulted to the further oxidation of protein-like fluorophores. LC-OCD measurements confirmed the decrease of average molecular weight of NOM during ozone treatment, due to the gradual degradation of biopolymers (14-23%) and humic substances (11-17%) towards building blocks and low molecular weight (LMW) neutrals. Advanced oxidation process (AOP) treatment by the mixture O/HO resulted in the simultaneous decrease of building blocks and LMW neutral concentrations. Conventional batch ozonation and AOP experiments were conducted using ozone-saturated solutions to investigate the effect of different contacting patterns. The results revealed that the different reaction pathways followed during bubbleless and conventional batch experiments may also influence the formation of NOM oxidation intermediates.
本研究旨在评估在应用无气泡臭氧化或过氧单硫酸盐处理地表水后，天然有机物（NOM）的结构组成发生的变化。氧化实验（使用 0.5-2 mg O3/mg DOC，或 2:1 O:HO 摩尔比）在连续模式下使用管状陶瓷膜接触器进行。荧光光谱（发射-激发矩阵）和液相色谱-有机碳检测（LC-OCD）主要用于详细的 DOC 特性描述。简而言之，单独臭氧处理导致腐殖质样峰荧光强度大幅降低（50-85%），并且在蛋白质样成分区域形成两个新峰。HO 的共同添加并未表现出预期的荧光强度降低增加；然而，它导致蛋白质样荧光团的进一步氧化。LC-OCD 测量证实，由于生物聚合物（14-23%）和腐殖质（11-17%）逐渐降解为构建块和低分子量（LMW）中性物质，臭氧处理过程中 NOM 的平均分子量降低。O/HO 混合物的高级氧化工艺（AOP）处理导致构建块和 LMW 中性浓度同时降低。使用臭氧饱和溶液进行常规分批臭氧化和 AOP 实验，以研究不同接触模式的影响。结果表明，无气泡和常规分批实验中遵循的不同反应途径也可能影响 NOM 氧化中间体的形成。
