Department of Chemistry, Université de Montréal, Montréal, QC H2V 0B3, Canada; NSERC-Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada.
NSERC-Industrial Chair on Drinking Water, Department of Civil, Mining and Geological Engineering, Polytechnique Montréal, Montréal, QC H3T 1J4, Canada.
Sci Total Environ. 2022 Feb 20;808:152137. doi: 10.1016/j.scitotenv.2021.152137. Epub 2021 Dec 2.
Biological ion exchange (BIEX) refers to operating ion exchange (IX) filters with infrequent regeneration to favor the microbial growth on resin surface and thereby contribute to the removal of organic matter through biodegradation. However, the extent of biodegradation on BIEX resins is still debatable due to the difficulty in discriminating between biodegradation and IX. The objective of the present study was to evaluate the performance of BIEX resins for the removal of organic micropollutants and thereby validate the occurrence of biodegradation. The removals of biodegradable micropollutants (neutral: caffeine and estradiol; negative: ibuprofen and naproxen) and nonbiodegradable micropollutants with different charges (neutral: atrazine and thiamethoxam; negative: PFOA and PFOS) were respectively monitored during batch tests with biotic and abiotic BIEX resins. Results demonstrated that biodegradation contributed to the removal of caffeine, estradiol, and ibuprofen, confirming that biodegradation occurred on the BIEX resins. Furthermore, biodegradation contributed to a lower extent to the removal of naproxen probably due to the absence of an adapted bacterial community (Biotic: 49% vs Abiotic: 38% after 24 h batch test). The removal of naproxen, PFOS, and PFOA were attributable to ion exchange with previously retained natural organic matter on BIEX resins. Nonbiodegradable and neutral micropollutants (atrazine and thiamethoxam) were minimally (6%-10%) removed during the batch tests. Overall, the present study corroborates that biomass found on BIEX resins contribute to the removal of micropollutants through biodegradation and ion exchange resins can be used as biomass support for biofiltration.
生物离子交换 (BIEX) 是指使用不频繁再生的离子交换 (IX) 过滤器，有利于微生物在树脂表面生长，从而通过生物降解去除有机物。然而，由于难以区分生物降解和 IX，BIEX 树脂的生物降解程度仍存在争议。本研究的目的是评估 BIEX 树脂对有机微量污染物的去除性能，从而验证生物降解的发生。通过生物和非生物 BIEX 树脂的批量试验，分别监测了可生物降解的微量污染物（中性：咖啡因和雌二醇；负性：布洛芬和萘普生）和具有不同电荷的不可生物降解的微量污染物（中性：莠去津和噻虫嗪；负性：PFOA 和 PFOS）的去除情况。结果表明，生物降解有助于咖啡因、雌二醇和布洛芬的去除，证实了 BIEX 树脂上发生了生物降解。此外，生物降解对萘普生的去除贡献较低，可能是由于缺乏适应的细菌群落（生物：24 小时批量试验后 49%；非生物：38%）。萘普生、PFOS 和 PFOA 的去除归因于 BIEX 树脂上先前保留的天然有机物的离子交换。非生物降解和中性微量污染物（莠去津和噻虫嗪）在批量试验中仅被去除了 6%-10%。总体而言，本研究证实了 BIEX 树脂上发现的生物量通过生物降解有助于去除微量污染物，并且离子交换树脂可用作生物过滤的生物量支持。
