摘要
为了探讨微波(MW)/铁碳(Fe-C)/H2O2类芬顿反应对填埋场渗滤液膜滤浓缩液(简称"渗滤液浓缩液")中难降解有机物,系统研究了双氧水投量、Fe-C投量、初始pH值、微波输出功率和反应时间对浓缩液中有机污染物的去除规律,通过类比实验研究了MW/Fe-C/H2O2体系的反应协同作用;此外,采用紫外-可见和三维荧光光谱表征了浓缩液中溶解性有机物的分子结构变化;最后,利用SEM-EDS和XRD等表征对反应前后的Fe-C材料的催化机理进行了解析.结果表明,在双氧水投量为10 mL·L^-1,Fe-C投量0.8 g·L^-1,初始pH值为3,微波输出功率为450 W,反应时间为12 min时,其COD、腐殖质和色度的去除率达到了70.06%、94.61%和98.86%.与此同时,控制实验表明MW/Fe-C/H2O2具有较强的协同作用,且对有机物的降解效果远好于其他体系.经过MW/Fe-C/H2O2体系处理后,浓缩液中溶解性有机物的芳香性程度和腐殖质缩合度逐渐降低,并且腐殖质等大分子难降解有机物大幅去除,可生化性(BOD/COD值)也大幅提升.一方面,Fe-C材料包含了多种铁基氧化物等活性物质可与H2O2形成非均相芬顿反应;另一方面,在酸性条件下铁缓释淋滤产生的铁离子会与H2O2形成芬顿反应.并且,微波辐射作用可一定程度上强化上述过程,从而加速了有机物的去除.因此,MW/Fe-C/H2O2体系能够快速高效的对渗滤液浓缩液进行预处理,研究为高浓度有机废水的处理提供了借鉴.
In this study, the Fe-C catalyzed H2O2 process enhanced by microwave radiation (MW/Fe-C/H2O2 process) was applied to the pre-treatment of refractory organics in landfill leachate membrane concentrates. The effects of H2O2 dosage, Fe-C dosage, initial pH, and microwave intensity on refractory organics removals were systematically investigated. In addition, the synergetic effect of MW/Fe-C/H2O2 process was investigated. Transformation of dissolved organic matter was explored by UV-Vis and 3D-EEM analysis. Finally, the material (Fe-C) were characterized by SEM-EDS and XRD in order to explore the catalysis mechanism of MW/Fe-C/H2O2 process. Results show that the removal rates of COD, humic substances (indicated by absorbance at 254 nm), and color number (CN) were 70.06%, 94.61%, and 98.86%, respectively, under conditions of H2O2 dose=10 mL·L^-1, Fe-C dose=0.8 g·L^-1, initial pH=3, microwave power=450 W, and reaction time=12 min. Moreover, the MW/Fe-C/H2O2 process exhibited a significant synergetic effect, and the treatment efficacy of MW/Fe-C/H2O2 process was much better than that of any other processes performed in this study. After the treatment of MW/Fe-C/H2O2 process, the aromatics and humic substances in dissolved organic matter were gradually reduced in membrane concentrates. Meanwhile, the biodegradability (BOD/COD ratio) was improved significantly. According to SEM-EDS and XRD analysis results, the treatment efficacy of MW/Fe-C/H2O2 process can be attributed to several aspects:① Fe-C material contained a variety of active matters, such as iron-based oxidants, that can react with H2O2 to form heterogeneous Fenton system;②the acidic ambient accelerated iron leaching, therefore homogeneous Fenton system was formed by Fe2+ and H2O2;and ③microwave radiation promoted the reaction kinetics,thus enhanced the removal of organic pollutants. In conclusion, MW/Fe-C/H2O2 process was efficient in the pre-treatment of refractory organics in membrane concentrates from landfill leachate. This study aimed to provide a technical reference for the treatment of high organic wastewater.
作者
李民
王颖
冉刚
冯可
张爱平
LI Min;WANG Ying;RAN Gang;FENG Ke;ZHANG Aiping(Collage of Chemistry and Material Science of Sichuan Normal University, Chengdu 610068;Rainwater Tech Co. Ltd., Chengdu 610046;Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756)
出处
《环境科学学报》
CAS
CSCD
北大核心
2019年第7期2143-2151,共9页
Acta Scientiae Circumstantiae
基金
四川省大学生创新创业训练计划(No.201810636158)
