CAJ | 학술논문

膜污染是限制膜生物反应器(MBR)广泛应用的主要技术瓶颈之一。今通过研究浸没式 MBR 中溶解性微生物产物(SMP)及其聚集尺度的演变过程，深入解析 SMP 对膜污染的作用机理。在单膜丝微滤膜分离实验中考察了 MBR污泥特性，包括污泥浓度(MLSS)、胞外聚合物(EPS)和SMP及其有机物组分等对膜污染的影响行为。结果表明，MLSS、EPS和SMP浓度与膜污染发展速率(ΔTMP/Δm)均呈正向相关。膜污染发展速率与MBR中活性污泥混合液(AS)中SMP的相关性(rp=0.126)远小于滤饼层污泥混合液(CS)中的SMP (rp=0.871)。SMP中的蛋白类和多糖类物质是造成膜污染的主要成分。MBR中的SMP在膜截留作用下出现显著的聚集结构变化和聚集尺度增加的现象。通过荧光光谱指纹图谱(EEMs)对比和共聚焦荧光显微镜(CLSM)观测发现：相比MBR出水，AS中的SMP存在显著的类蛋白峰和较高荧光强度的类腐殖酸峰，CS中的SMP聚集尺度显著增大，粒度可达100μm以上，并具有较强的疏水性能和黏度，可加快膜表面滤饼层(或凝胶层)的生成进程，导致膜污染的发生。通过对膜表面滤饼层结构和组分的分析，当AS中的SMP浓度低于0.4 mg TOC×(g SS)-1时，膜表面较易形成污泥滤饼污染层，反之，则倾向于生成凝胶污染层。因此，SMP及其聚集态物质是造成膜污染的主要因素，应在膜污染控制方面予以重要关注。
막오염시한제막생물반응기(MBR)엄범응용적주요기술병경지일。금통과연구침몰식 MBR 중용해성미생물산물(SMP)급기취집척도적연변과정，심입해석 SMP 대막오염적작용궤리。재단막사미려막분리실험중고찰료 MBR오니특성，포괄오니농도(MLSS)、포외취합물(EPS)화SMP급기유궤물조분등대막오염적영향행위。결과표명，MLSS、EPS화SMP농도여막오염발전속솔(ΔTMP/Δm)균정정향상관。막오염발전속솔여MBR중활성오니혼합액(AS)중SMP적상관성(rp=0.126)원소우려병층오니혼합액(CS)중적SMP (rp=0.871)。SMP중적단백류화다당류물질시조성막오염적주요성분。MBR중적SMP재막절류작용하출현현저적취집결구변화화취집척도증가적현상。통과형광광보지문도보(EEMs)대비화공취초형광현미경(CLSM)관측발현：상비MBR출수，AS중적SMP존재현저적류단백봉화교고형광강도적류부식산봉，CS중적SMP취집척도현저증대，립도가체100μm이상，병구유교강적소수성능화점도，가가쾌막표면려병층(혹응효층)적생성진정，도치막오염적발생。통과대막표면려병층결구화조분적분석，당AS중적SMP농도저우0.4 mg TOC×(g SS)-1시，막표면교역형성오니려병오염층，반지，칙경향우생성응효오염층。인차，SMP급기취집태물질시조성막오염적주요인소，응재막오염공제방면여이중요관주。
Membrane fouling is the main bottleneck of the membrane bioreactor (MBR) and its widespread application. In this paper, a lab-scale submerged MBR treating synthesis wastewater was operated to examine the affecting mechanisms and correlation of soluble microbial products (SMP) with membrane fouling. A single-fiber microfiltration set-up was fabricated and applied to evaluate the importance of sludge properties of different sludges, including MLSS, EPS, SMP and their organic components, to the fouling evolution rate. It was revealed that MLSS, EPS and SMP all show positive correlation with the fouling rate (ΔTMP/Δm). However, the importance of SMP separated from MBR activated sludge (AS) to fouling rate (rp= 0.126) is rather lower than that of SMP in MBR cake sludge (CS) (rp=0.871). The protein and polysaccharide in CS-SMP, other than humic-like substances, were proved to be the major substances affecting fouling layer formation. Both the examination by fluorescence excitation emission matrix (EEM) and the observation under confocal laser scanning microscopy (CLSM) display that the SMP have to transform in the term of surface properties and size distribution with the development of membrane filtration. The AS-SMP has obvious protein-peak compared with MBR effluent, which implies that the protein is preferentially intercepted by membrane compared with other organic components. Whilst, after the membrane interception, the SMP in CS has a size as large as 100μm, which would facilitate the cake layer formation and hence is determinative for the fouling evolution. A comprehensive observation of fouled membrane surface with CLSM also demonstrates that there are two types of fouling layer on the membrane surface, i.e. cake-dominant and gel-dominant fouling layer, both of which are highly depend on the content of AS-SMP in SMBR. It was noted that the SMP in SMBR and cake sludge is the major foulant. The present work is valuable for understanding of the membrane fouling mechanisms and also for proposing the strategies for membrane fouling control in SMBR.