State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
Institute for Future Initiatives, The University of Tokyo, Tokyo 113-8654, Japan.
Sci Total Environ. 2021 Mar 15;760:143348. doi: 10.1016/j.scitotenv.2020.143348. Epub 2020 Oct 29.
Biofouling caused by the growth of the biofilm is the main bottleneck that limits the effective operation of thin-film composite (TFC) membrane in the forward osmosis (FO) process. This study investigated the combined effects of graphene oxide (GO) immobilized thin-film nanocomposite (TFN-S) membrane and Pseudomonas quinolone signal (PQS)-based quorum quenching on biofouling mitigation, especially under the operation of pressure-retarded osmosis (PRO) mode, and the influence of methyl anthranilate (MA) inhibitor on the composition and structure of biofilm was also evaluated. Synthetic wastewater was used as the feed solution, in which the model strain Pseudomonas aeruginosa was added to simulate biofouling. The results showed that GO modification and MA addition both efficiently mitigated flux decline and EPS secretion, but the interference of PQS pathway on biofouling control was better than GO embedding. TFN-S membrane with MA addition exhibited superior anti-biofouling performance based on the combined effects of GO and MA. The alleviated concentration polarization and enhanced hydrophilicity of the TFN-S membrane reduced the flux decline in the early stage. Additionally, the antibacterial property of GO inhibited the viability of the attached bacteria (under PRO mode) and MA further mitigated the EPS secretion and biofilm development in the later stage. In the presence of PQS inhibitor MA, live/total cells ratio was 15% and 13% higher than that of TFC membrane in FO and PRO modes, respectively. Furthermore, exogenous addition of MA led to a relatively loose biofilm structure, resulting in high membrane permeability in the biofouling formation process.
生物膜的生长引起的生物污损是限制薄膜复合（TFC）膜在正向渗透（FO）过程中有效运行的主要瓶颈。本研究考察了氧化石墨烯（GO）固定化薄膜纳米复合（TFN-S）膜和基于假单胞菌喹诺酮信号（PQS）的群体感应淬灭对减轻生物污损的联合作用，特别是在压力延迟渗透（PRO）模式下的运行，以及甲基邻氨基苯甲酸（MA）抑制剂对生物膜组成和结构的影响。采用合成废水作为进料溶液，其中添加了模式菌株铜绿假单胞菌来模拟生物污损。结果表明，GO 改性和 MA 添加都能有效地减轻通量下降和 EPS 分泌，但 PQS 途径对生物污损控制的干扰优于 GO 嵌入。基于 GO 和 MA 的协同作用，添加 MA 的 TFN-S 膜表现出优异的抗生物污损性能。减轻的浓差极化和增强的亲水性使 TFN-S 膜在早期的通量下降得到缓解。此外，GO 的抗菌性能抑制了附着细菌的活力（在 PRO 模式下），而 MA 进一步减轻了 EPS 的分泌和生物膜在后期的发展。在存在 PQS 抑制剂 MA 的情况下，FO 和 PRO 模式下活/总细胞比分别比 TFC 膜高 15%和 13%。此外，外源添加 MA 导致生物膜结构相对疏松，在生物污损形成过程中具有较高的膜渗透性。
