School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 102488, China.
State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing 100875, China.
J Hazard Mater. 2024 Dec 5;480:136139. doi: 10.1016/j.jhazmat.2024.136139. Epub 2024 Oct 11.
Eutrophication has significantly challenged the treatment of algae-contaminated water. Ultrafiltration has become an essential method for water purification, though frequent on-line chemical cleaning is necessary to maintain membrane permeability. This study aims to systematically investigate the impact of various chemical cleaning agents on the release of dissolved organic matters and toxic by-products, particularly from algal cells. Through a series of controlled experiments, Microcystis aeruginosa cells were exposed to different cleaning agents (HCl, NaOH, NaClO), and the resulting DOM and by-products were characterized. Special attention was paid to the release of intracellular organic matter (IOM) and extracellular organic matter (EOM). Results revealed that NaClO significantly oxidized IOM, leading to the formation of humic-like substances and halogenated organic compounds (TOX), including 15 types of halogenated by-products detected by UPLC/ESI-tqMS. Furthermore, the release of toxic microcystin LR (MC-LR) was traced primarily to IOM. The removability of these contaminants by UF and reverse osmosis (RO) membranes was analyzed, revealing that over 50 % of the toxic by-products passed through UF membranes, and 10 % still penetrated RO membranes, raising significant concerns for downstream water quality and drinking water safety.
富营养化对藻类污染水的处理提出了巨大挑战。超滤已成为水净化的重要方法，但为了保持膜的渗透性，需要频繁地在线化学清洗。本研究旨在系统地研究各种化学清洗剂对溶解有机物和有毒副产物释放的影响，特别是来自藻类细胞的释放。通过一系列对照实验，将铜绿微囊藻细胞暴露于不同的清洗剂（HCl、NaOH、NaClO），并对所得的 DOM 和副产物进行了表征。特别关注了细胞内有机物（IOM）和细胞外有机物（EOM）的释放。结果表明，NaClO 显著氧化了 IOM，形成了类腐殖质和卤代有机化合物（TOX），包括通过 UPLC/ESI-tqMS 检测到的 15 种卤代副产物。此外，有毒微囊藻毒素 LR（MC-LR）的释放主要源自 IOM。通过超滤和反渗透（RO）膜对这些污染物的去除能力进行了分析，结果表明，超过 50%的有毒副产物通过超滤膜，而 10%的仍穿透 RO 膜，这对下游水质和饮用水安全构成了重大威胁。
