Graduate School of Water Resources, Sungkyunkwan University (SKKU), 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 16419, Republic of Korea; Biological and Environmental Science & Engineering (BESE), Water Desalination and Reuse Center (WDRC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia; Faculty of Engineering and IT, University of Technology, Sydney (UTS), PO Box 123, Broadway, NSW, 2007, Australia.
Center for Water Resource Cycle Research, Korea Institute of Science and Technology, 39-1 Hawolgok-Dong, Seongbuk-Gu, Seoul, 136-791, Republic of Korea.
Water Res. 2017 Nov 1;124:227-237. doi: 10.1016/j.watres.2017.07.064. Epub 2017 Jul 25.
Four dual media filters (DMFs) were operated in a biofiltration mode with different engineered environments (DMF I and II: coagulation with/without acidification and DMF III and IV: without/with chlorination). Designed biofilm enrichment reactors (BERs) containing the removable reverse osmosis (RO) coupons, were connected at the end of the DMFs in parallel to analyze the biofilm on the RO membrane by DMF effluents. Filtration performances were evaluated in terms of dissolved organic carbon (DOC) and assimilable organic carbon (AOC). Organic foulants on the RO membrane were also quantified and fractionized. The bacterial community structures in liquid (seawater and effluent) and biofilm (DMF and RO) samples were analyzed using 454-pyrosequencing. The DMF IV fed with the chlorinated seawater demonstrated the highest reductions of DOC including LMW-N as well as AOC among the other DMFs. The DMF IV was also effective in reducing organic foulants on the RO membrane surface. The bacterial community structure was grouped according to the sample phase (i.e., liquid and biofilm samples), sampling location (i.e., DMF and RO samples), and chlorination (chlorinated and non-chlorinated samples). In particular, the biofilm community in the DMF IV differed from the other DMF treatments, suggesting that chlorination exerted as stronger selective pressure than pH adjustment or coagulation on the biofilm community. In the DMF IV, several chemoorganotrophic chlorine-resistant biofilm-forming bacteria such as Hyphomonas, Erythrobacter, and Sphingomonas were predominant, and they may enhance organic carbon degradation efficiency. Diverse halophilic or halotolerant organic degraders were also found in other DMFs (i.e., DMF I, II, and III). Various kinds of dominant biofilm-forming bacteria were also investigated in RO membrane samples; the results provided possible candidates that cause biofouling when DMF process is applied as the pretreatment option for the RO process.
四个双介质过滤器（DMF）以不同的工程环境（DMF I 和 II：有/无酸化的凝结和 DMF III 和 IV：有/无氯化）在生物过滤模式下运行。含有可移动反渗透（RO）优惠券的设计生物膜富集反应器（BER）在 DMF 的末端并联连接，以通过 DMF 流出物分析 RO 膜上的生物膜。根据溶解有机碳（DOC）和可同化有机碳（AOC）评估过滤性能。还定量和分馏了 RO 膜上的有机污染物。使用 454 焦磷酸测序分析液体（海水和流出物）和生物膜（DMF 和 RO）样品中的细菌群落结构。用氯化海水进料的 DMF IV 在其他 DMF 中对 DOC 包括 LMW-N 和 AOC 的去除率最高。DMF IV 还能有效减少 RO 膜表面的有机污染物。细菌群落结构根据样品相（即液体和生物膜样品）、采样位置（即 DMF 和 RO 样品）和氯化（氯化和非氯化样品）进行分组。特别是，DMF IV 中的生物膜群落与其他 DMF 处理不同，表明氯化对生物膜群落的选择性压力强于 pH 调整或凝结。在 DMF IV 中，几种好氧氯抗性生物膜形成细菌，如 Hyphomonas、Erythrobacter 和 Sphingomonas 占优势，它们可能提高有机碳降解效率。在其他 DMF（即 DMF I、II 和 III）中也发现了各种嗜盐或耐盐有机降解菌。还在 RO 膜样品中研究了各种优势生物膜形成细菌；结果提供了可能的候选者，当 DMF 工艺作为 RO 工艺的预处理选项应用时，这些候选者可能导致生物污染。
