臭氧-过硫酸盐工艺深度处理垃圾焚烧渗沥液

针对垃圾焚烧渗沥液经"厌氧-缺氧-好氧"生物组合工艺处理后的出水COD仍在500 mg·L-1左右，且可生化性差（B/C=0.13）的问题，研究采用"臭氧-过硫酸盐"氧化体系进一步处理，以提高其可生化性。研究了臭氧和过硫酸盐投量对该废水处理的效果影响。结果表明，臭氧浓度和S2O2-8浓度分别为19.8 g·m-3和0.4 g·L-1时，且反应20 min，出水的B/C从0.13提高到0.49，表明该氧化体系适用于深度处理垃圾焚烧渗沥液生物组合工艺处理后的出水。采用紫外-可见光谱、三维荧光光谱、红外光谱和气质联用对处理系统废水中有机物进行表征分析，表明废水在"臭氧-过硫酸盐"氧化过程中芳香族化合物发生了开环、断链等反应，芳构化程度降低，不饱和的CC键被破坏，产生CO和C—O键，并生成一些结构简单的长链烷烃。自由基捕获研究表明，氧化体系中·OH和·SO4- 2种自由基均存在，以臭氧直接氧化为主。

Advanced treatment of incineration leachate by ozone-persulfate process

Fresh leachate from a municipal solid waste incineration plant was treated using a combined‘anaerobic-aerobic-anoxic’ bio-treatment process. However, the effluents from this process required further treatment prior to release due to their high chemical oxygen demand (COD) values (500 mg·L-1) and poor biodegradability (BOD5/COD ratio, B/C=0.13). An ozone-persulfate oxidation system was therefore applied for further processing of this leachate effluent to increase its biodegradability (B/C). We herein investigated the effects of ozone dosage and persulfate dosage on the oxidation process. The B/C of the leachate effluent increased from 0.13 to 0.49 within 20 min using ozone and persulfate doses of 19.8 g·m-3 and 0.4 g·L-1, respectively, thus confirming that the ozone-persulfate process is suitable for the advanced treatment of leachate effluents. To further document the degradation and transformation of the leachate effluent during the ozone-persulfate process, ultraviolet/visible light (UV-Vis) spectroscopy, excitation and emission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS) were employed to characterize the raw and treated leachate effluents. Ring-opening and chain scission reactions occurred during the oxidation process, with C=O and C—O moieties being formed from the breaking of C=C bonds. These reactions may therefore be responsible for the generation of long chain alkanes and the decrease in aromaticity. Both SO4-·and ·OH radicals were excited and captured in this system, in which ozone played a major role in the oxidation treatment process.