Abstract Pressure retarded osmosis (PRO) is an emerging technology capable of extracting energy from salinity gradients of wastewater paired with SWRO brine. However, this process's performance is hindered by irreversible biofouling due to bacteria-containing wastewater and the sponge-like support layer of PRO membranes. In this study, chlorhexidine gluconate (CHG), a non-oxidizing biocide, was continuously added to feed solution to investigate its anti-biofouling performance during PRO. CHG showed higher anti-microbial and anti-biofilm activity than did other non-oxidizing biocides. Even at low dosages of CHG, water flux declines were greatly mitigated and benefited from the internal concentration polarization (ICP)-elevated concentrations within the active-support layer interface. CHG plays a critical role by inhibiting bacterial growth, and a 65–88% reduction of extracellular polymeric substances was achieved on the membrane surface and throughout the feed spacers. Membrane characterization demonstrated that the improved performance could be attributed to a consistent structural parameter and alleviation of ICP self-compensation effects. This study thus shows that a combination of biocide dosing and pressure assisted-osmotic backwashing can be a useful strategy for controlling biofouling during the PRO process.

中文翻译：

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通过加入葡萄糖酸氯己定改善压力延迟渗透 (PRO) 的抗生物污垢性能

摘要 压力延迟渗透 (PRO) 是一种新兴技术，能够从与 SWRO 盐水配对的废水的盐度梯度中提取能量。然而，由于含有细菌的废水和 PRO 膜的海绵状支撑层，不可逆的生物污垢阻碍了该过程的性能。在这项研究中，葡萄糖酸氯己定 (CHG) 是一种非氧化性杀菌剂，被连续添加到进料溶液中，以研究其在 PRO 过程中的抗生物污垢性能。CHG 显示出比其他非氧化性杀菌剂更高的抗微生物和抗生物膜活性。即使在低剂量的 CHG 下，水通量的下降也得到了极大的缓解，并受益于活性支撑层界面内的内部浓差极化 (ICP) 浓度升高。CHG 通过抑制细菌生长发挥关键作用，在膜表面和整个进料间隔物上实现了 65-88% 的胞外聚合物减少。膜表征表明，改进的性能可归因于一致的结构参数和 ICP 自补偿效应的减轻。因此，这项研究表明，杀菌剂剂量和压力辅助渗透反冲洗的组合可以成为控制 PRO 过程中生物污垢的有用策略。