Civil and Environmental Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel; Grand Water Research Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Water Res. 2013 Nov 1;47(17):6628-38. doi: 10.1016/j.watres.2013.08.036. Epub 2013 Sep 14.
The concept of suppressing biofouling formation using an antibacterial feed spacer was investigated in a bench scale-cross flow system mimicking a spiral wound membrane configuration. An antibacterial composite spacer containing zinc oxide-nanoparticles was constructed by modification of a commercial polypropylene feed spacer using sonochemical deposition. The ability of the modified spacers to repress biofilm development on membranes was evaluated in flow-through cells simulating the flow conditions in commercial spiral wound modules. The experiments were performed at laminar flow (Re = 300) with a 200 kDa molecular weight cut off polysulfone ultrafiltration membrane using Pseudomonas putida S-12 as model biofilm bacteria. The modified spacers reduced permeate flux decrease at least by 50% compared to the unmodified spacers (control). The physical properties of the modified spacer and biofilm development were evaluated using high resolution/energy dispersive spectrometry-scanning electron microscopy, atomic force microscopy and confocal laser scanning microscopy imaging (HRSEM, EDS, AFM and CLSM). HRSEM images depicted significantly less bacteria attached to the membranes exposed to the modified spacer, mainly scattered and in a sporadic monolayer structure. AFM analysis indicated the influence of the modification on the spacer surface including a phase change on the upper surface. Dead-live staining assay by CLSM indicated that most of the bacterial cells attached on the membranes exposed to the modified spacer were dead in contrast to a developed biofilm which was predominant in the control samples.
采用抗菌进料间隔物抑制生物污垢形成的概念在模拟螺旋缠绕膜结构的台式横流系统中进行了研究。通过使用超声化学沉积对商业聚丙烯进料间隔物进行改性，构建了含有氧化锌纳米粒子的抗菌复合间隔物。在模拟商业螺旋缠绕模块中流动条件的流动池中将改性间隔物抑制膜上生物膜发展的能力进行了评估。实验在层流（Re = 300）条件下进行，使用 200 kDa 分子量 cutoff 聚砜超滤膜，以铜绿假单胞菌 S-12 为模型生物膜细菌。与未改性间隔物（对照）相比，改性间隔物使渗透通量下降至少降低了 50%。使用高分辨率/能量色散光谱-扫描电子显微镜、原子力显微镜和共聚焦激光扫描显微镜成像（HRSEM、EDS、AFM 和 CLSM）对改性间隔物和生物膜发展的物理性质进行了评估。HRSEM 图像显示，与暴露于未改性间隔物的膜相比，附着在膜上的细菌明显减少，主要呈分散的、零星的单层结构。AFM 分析表明，改性对间隔物表面的影响包括上表面的相变化。CLSM 的死活染色测定表明，与主要在对照样品中占主导地位的生物膜相比，暴露于改性间隔物的膜上附着的大多数细菌细胞已死亡。
