Department of Environmental Hydrology & Microbiology, Zuckerberg Institute for Water Research (ZIWR), Ben-Gurion University of the Negev , Sade Boker 8499000, Israel.
School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287, United States.
Environ Sci Technol. 2015 Nov 3;49(21):13050-8. doi: 10.1021/acs.est.5b03523. Epub 2015 Oct 14.
Next-generation pressure-retarded osmosis (PRO) approaches aim to harness the energy potential of streams with high salinity differences, such as wastewater effluent and seawater desalination plant brine. In this study, we evaluated biofouling propensity in PRO. Bench-scale experiments were carried out for 24 h using a model wastewater effluent feed solution and simulated seawater desalination brine pressurized to 24 bar. For biofouling tests, wastewater effluent was inoculated with Pseudomonas aeruginosa and artificial seawater desalination plant brine draw solution was seeded with Pseudoalteromonas atlantica. Our results indicate that biological growth in the feed wastewater stream channel severely fouled both the membrane support layer and feed spacer, resulting in ∼50% water flux decline. We also observed an increase in the pumping pressure required to force water through the spacer-filled feed channel, with pressure drop increasing from 6.4±0.8 bar m(-1) to 15.1±2.6 bar m(-1) due to spacer blockage from the developing biofilm. Neither the water flux decline nor the increased pressure drop in the feed channel could be reversed using a pressure-aided osmotic backwash. In contrast, biofouling in the seawater brine draw channel was negligible. Overall, the reduced performance due to water flux decline and increased pumping energy requirements from spacer blockage highlight the serious challenges of using high fouling potential feed sources in PRO, such as secondary wastewater effluent. We conclude that PRO power generation using wastewater effluent and seawater desalination plant brine may become possible only with rigorous pretreatment or new spacer and membrane designs.
下一代压力延迟渗透（PRO）方法旨在利用具有高盐度差异的水流的能量潜力，例如废水流出物和海水淡化厂盐水。在这项研究中，我们评估了 PRO 中的生物结垢倾向。使用模型废水流出物进料溶液和加压至 24 巴的模拟海水淡化盐水进行了 24 小时的台架实验。对于生物结垢测试，将废水流出物接种了铜绿假单胞菌，并且将人工海水淡化厂盐水汲取液用大西洋假交替单胞菌进行了接种。我们的结果表明，进料废水中的生物生长严重污染了膜支撑层和进料间隔物，导致水通量下降约 50%。我们还观察到，由于生物膜的发展导致间隔物堵塞，迫使水通过充满间隔物的进料通道所需的泵送压力增加，从 6.4±0.8 bar m(-1)增加到 15.1±2.6 bar m(-1)。进料通道中的水通量下降和增加的压降都不能通过压力辅助渗透反冲洗来逆转。相比之下，海水盐水汲取通道中的生物结垢可以忽略不计。总体而言，由于水通量下降和间隔物堵塞导致泵送能量需求增加而导致的性能降低，突出了在 PRO 中使用高结垢潜力的进料源（例如二级废水）的严重挑战。我们得出的结论是，只有通过严格的预处理或新的间隔物和膜设计，才能使用废水流出物和海水淡化厂盐水进行 PRO 发电。
