臭氧-CNTs预沉积耦合方法缓解膜污染研究  

Mechanism of the Hybrid Pre-ozonation and CNTs Pre-deposition Technology for Fouling Control

作　　者：郭瑾[1] 曾嘉 魏娜 王宇飞[1] 吴曜辰 刘秋杉 刘国涵 GUO Jin;ZENG Jia;WEI Na;WANG Yufei;WU Yaochen;LIU Qiushan;LIU Guohan(National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城镇污水深度处理与资源化利用技术国家工程实验室,北京100124

出　　处：《北京工业大学学报》2024年第12期1486-1500,共15页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(51778014)。

摘　　要：以腐殖酸(humic acid,HA)和海藻酸钠(sodium alginate,SA)作为模型污染物,考察了臭氧预氧化和碳纳米管(carbon nanotubes,CNTs)预沉积联合技术对膜污染形成过程和形成规律的影响。通过测定HA和SA物化特性的变化,结合膜滤过程中比通量变化,辅以Hermia模型和传统滤饼过滤模型,分析了臭氧预氧化和CNTs预沉积缓解膜污染的机理。结果表明,经臭氧氧化后,HA和SA的电负性和亲水性增强,且由于发生微絮凝作用,粒径增大。臭氧预氧化对于HA造成的膜污染无明显改善作用,当氧化后HA粒径接近基膜孔径时,膜孔被完全堵塞甚至加重膜污染;臭氧破坏了SA的凝胶特性,大幅缓解了膜表面的滤饼层污染。不同孔径的基膜进行CNTs预沉积后,表面CNTs层可以拦截吸附部分HA和SA分子,从而缓解了HA和SA造成的膜污染。0.45μm PVDF基膜孔径与CNTs层的孔径相差最大,经CNTs预沉积后,在膜表面形成一层致密的过滤层,缓解膜污染的幅度最大。臭氧预氧化与CNTs预沉积联用后,在CNTs沉积量较高的情况下能够缓解HA造成的膜污染,对SA造成的膜污染也起到明显缓解作用,在有效降低膜表面滤饼形成的同时,能够延长膜孔堵塞时间或增加膜孔堵塞到滤饼的过渡阶段时间。To investigate the impact of the hybrid pre-ozonation and carbon nanotubes(CNTs)predeposition technology on fouling control,humic acid(HA)and sodium alginate(SA)were selected as model pollutants.The fouling mechanism was systematically analyzed with the transformation of normalized flux,Hermia model,conventional cake-layer fouling filtration model,and the changes of foulants'physicochemical properties.Results demonstrate that the electronegativity and hydrophilicity of HA and SA are further enhanced after pre-ozonation,and the ozone-induced micro-flocculation increases their nano-particle size.Pre-ozonation displays limited effect on membrane fouling caused by HA,as the membrane pores are completely blocked since their approaching particle size of ozonated HA and the pore size of membrane,which aggravates the fouling.Ozone can destroy the gel properties and remarkably alleviate the cake-layer fouling caused by SA.After CNTs pre-deposition on membrane with different pore size,the CNTs layer can intercept the HA and SA molecules and alleviate the membrane fouling.The denser layer forms by CNTs on the PVDF membrane with pore size of 0.45μm,alleviates membrane fouling to the greatest extent.With a higher amount of CNTs loading,the combination of pre-ozonation and CNTs pre-deposition can effectively alleviate the membrane fouling induced by HA.As for the SA,the hybrid technology plays an outstanding role in fouling control.It effectively reduces the formation of cake layer,and prolongs the pore blocking time,and increases the transition stage from pore blocking to cake filtration as well.

关 键 词：臭氧预氧化 碳纳米管 膜污染 Hermia模型 传统滤饼过滤模型 膜改性 

分 类 号：U461[机械工程—车辆工程] TP308[交通运输工程—载运工具运用工程]