Gu Zhepei, Chen Weiming, Li Qibin, Wang Ying, Wu Chuanwei, Zhang Aiping
Key Laboratory of Treatment for Special Wastewater of Sichuan Province Higher Education System, College of Chemistry and Materials Science, Sichuan Normal University Chengdu 610066 China
Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University Chengdu 611765 China.
RSC Adv. 2018 Sep 26;8(57):32461-32469. doi: 10.1039/c8ra06543h. eCollection 2018 Sep 18.
A microwave (MW)-activated peroxydisulfate (PDS) process was applied to remove recalcitrant organics in concentrated leachate. In this study, the optimum activation conditions were studied using the absorbance at 254 nm (UV) and color number removal efficiencies and by comparison of the different processes. The inner oxidation mechanism was investigated by ultraviolet-visible (UV-vis) spectrophotometry and three-dimensional (3D) excitation-emission matrix (EEM) tests. The results show that oxidation effects followed the order MW/PDS > MW/HO > heat/PDS. The efficiencies of chemical oxygen demand (COD) removal, UV, and color number were 45.50%, 48.95%, and 88.35%, respectively. The biodegradability was enhanced to 0.23 under optimum conditions (initial pH of 3, MW irradiation power of 450 W, PDS dosage of 3.5 g L, and reaction time of 10 min). The UV-vis spectra suggest that the humification degree and aromaticity of organics in the concentrated leachate greatly declined in the MW/PDS process. 3D EEM spectra indicate that the molecular weight of organic substances in the concentrated leachate decreased markedly and that the constitution of the organics became simpler after the MW/PDS process. In a word, the MW/PDS process is a promising method for concentrated leachate treatment.
采用微波（MW）活化过二硫酸盐（PDS）工艺去除浓缩渗滤液中的难降解有机物。本研究通过254nm处的吸光度（UV）、色数去除效率以及不同工艺的比较，研究了最佳活化条件。通过紫外可见（UV-vis）分光光度法和三维（3D）激发发射矩阵（EEM）测试研究了内部氧化机理。结果表明，氧化效果顺序为MW/PDS>MW/HO>热/PDS。化学需氧量（COD）去除率、UV去除率和色数去除率分别为45.50%、48.95%和88.35%。在最佳条件下（初始pH为3、MW辐照功率为450W、PDS投加量为3.5g/L、反应时间为10min），生物降解性提高到0.23。UV-vis光谱表明，在MW/PDS工艺中，浓缩渗滤液中有机物的腐殖化程度和芳香性大大降低。3D EEM光谱表明，MW/PDS工艺后，浓缩渗滤液中有机物的分子量显著降低，有机物组成变得更简单。总之，MW/PDS工艺是一种有前景的浓缩渗滤液处理方法。
