Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, State of Qatar, Doha, 2713, Qatar.
Waste Management Program, Center for Sustainable Development, College of Arts and Sciences, Qatar University, State of Qatar, Doha, 2713, Qatar.
J Environ Manage. 2021 Jun 15;288:112358. doi: 10.1016/j.jenvman.2021.112358. Epub 2021 Mar 23.
This study examines which management methods are the most recent and advanced in managing rejected brine generated from desalination plants. It also provides up-to-date information regarding the most adequate technologies that generate a minimum quantity of rejected brine via the use of minimization techniques and analyzes the method of direct disposal that has lately received noticeable improvements. It further discusses the reuse of discarded brine to recover valuable goods and sequestration of carbon dioxide. Sustainability is an important parameter that needs consideration to achieve uninterrupted operation of the discarded brine management to achieve the least environmental, social, and economic aftermath. To properly deal with any environmental issues related to brine disposal, different methods are implemented so that, in the end, higher water recovery is achievable from the desalination processes, namely brine minimization and rejection technologies (pressure retarded osmosis, microbial desalination cell technology), membrane-based technologies (vibratory shear enhanced processing, forward osmosis, electrodialysis, electrodialysis reverse, and electrodialysis metathesis, pervaporation method, thermal-based technologies (wind-aided intensified evaporation, brine concentrators, ohmic evaporator, membrane distillation, multi-stage flash distillation. This review also critically examined the two conventional approaches commonly used in life cycle assessment (LCA), when evaluating the ecotoxic effect of discarded brine. It intends to discuss the currently available methods and propose an improved method for evaluating the toxicity potential of brine on the aquatic ecosystem originated from seawater desalination plants. The Group-by-Group method takes into consideration the demerits of the two methods of the traditional method of LCA or chemical-specific approach as it provides a more holistic coverage for complicated brine to be disposed of. Recently, attention has been focused on recovering valuable metals from the discharged concentrated brine waste. Certainly, attaining marketable products from the discharged concentrated brine would offer an economic benefit and reducing the whole desalination costs. Ion imprinting polymers have potential applications in metal recovery from brine. Finding selective, more efficient, and less expensive imprinted polymers for extraction/pre-concentration of valuable ions is a vital and challenging task. Lastly, the brine should be seen as a resource and not as a waste to attain sustainability in its management approaches. Hybrid processes would be highly recommended to get the absolute transformation of the discarded brine from desalination processes to more valuable constituents.
本研究探讨了在管理海水淡化厂产生的废弃盐水方面，哪些管理方法是最新和最先进的。它还提供了有关通过最小化技术生成最小量废弃盐水的最适宜技术的最新信息，并分析了最近得到显著改进的直接处理方法。它进一步讨论了废弃盐水的再利用以回收有价值的物质和二氧化碳的封存。可持续性是一个重要的参数，需要考虑实现废弃盐水管理的连续运行，以实现对环境、社会和经济影响的最小化。为了妥善处理与盐水处置有关的任何环境问题，实施了不同的方法，以便最终从海水淡化过程中实现更高的水回收率，即盐水最小化和拒绝技术（压力延迟渗透、微生物脱盐细胞技术）、基于膜的技术（振动剪切增强处理、正向渗透、电渗析、电渗析反向和电渗析交换、渗透蒸发法、基于热的技术（风力强化蒸发、盐水浓缩器、欧姆蒸发器、膜蒸馏、多级闪蒸）。本综述还批判性地检查了生命周期评估（LCA）中常用的两种传统方法，用于评估废弃盐水的生态毒性效应。它旨在讨论当前可用的方法，并提出一种改进的方法来评估海水淡化厂产生的盐水对水生生态系统的毒性潜力。分组方法考虑了传统 LCA 方法或化学特定方法的两个方法的缺点，因为它为要处理的复杂盐水提供了更全面的覆盖。最近，人们关注从排放的浓缩盐水废物中回收有价值的金属。当然，从排放的浓缩盐水中获得有市场价值的产品将带来经济效益，并降低整个海水淡化成本。离子印迹聚合物在从盐水中回收金属方面具有潜在的应用。寻找用于提取/预浓缩有价值离子的选择性更高、效率更高、成本更低的印迹聚合物是一项重要且具有挑战性的任务。最后，应将盐水视为一种资源，而不是一种废物，以实现其管理方法的可持续性。强烈建议采用混合工艺，以使海水淡化过程中产生的废弃盐水完全转化为更有价值的成分。
