Southern Nevada Water Authority (SNWA), P.O. Box 99954, Las Vegas, NV 89193-9954, United States.
Walter and Eliza Hall Institute of Medical Research (WEHI), 1G, Royal Parade, Parkville VIC 3052, Australia; Water Research Australia (WaterRA) Melbourne based position hosted by Melbourne Water, 990 La Trobe St, Docklands VIC 3008, Australia.
Harmful Algae. 2021 Nov;109:102099. doi: 10.1016/j.hal.2021.102099. Epub 2021 Oct 12.
Cyanobacterial blooms produce nuisance metabolites (e.g., cyanotoxins and T&O compounds) thereby posing water quality management issues for aquatic sources used for potable water production, aquaculture, and recreation. A variety of in-lake/reservoir control measures are implemented to reduce the abundance of nuisance cyanobacteria biomass or decrease the amount of available phosphorous (P). This paper critically reviews the chemical control strategies implemented for in-lake/reservoir management of cyanobacterial blooms, i.e., algaecides and nutrient sequestering coagulants/flocculants, by highlighting (i) their mode of action, (ii) cases of successful and unsuccessful treatment, (iii) and factors influencing performance (e.g., water quality, process control techniques, source water characteristics, etc.). Algaecides generally result in immediate improvements in water quality and offer selective cyanobacterial control when peroxide-based alagecides are used. However, they have a range of limitations: causing cell lysis and release of cyanotoxins, posing negative impacts on aquatic plants and animals, leaving behind environmentally relevant treatment residuals (e.g., Cu in water and sediments), and offering only short-term bloom control characterized by cyanobacterial rebound. Coagulants/flocculants (alum, iron, calcium, and lanthanum bentonite) offer long-term internal nutrient control when external nutrient loading is controlled. Treatment performance is often influenced by background water quality conditions, and source water characteristics (e.g., surface area, depth, mixing regimes, and residence time). The reviewed case studies highlight that external nutrient load reduction is the most fundamental aspect of cyanobacterial control. None of the reviewed control strategies provide a comprehensive solution to cyanobacterial blooms.
蓝藻水华会产生有害代谢物（例如，蓝藻毒素和三卤甲烷前体化合物），从而对用于饮用水生产、水产养殖和娱乐的水生水源的水质管理造成问题。为了减少有害蓝藻生物量的丰度或减少可用磷（P）量，实施了各种湖泊/水库控制措施。本文批判性地回顾了用于湖泊/水库蓝藻水华管理的化学控制策略，即杀藻剂和营养物固着混凝剂/絮凝剂，强调了（i）它们的作用方式，（ii）成功和不成功处理的案例，以及（iii）影响性能的因素（例如，水质、过程控制技术、原水特性等）。杀藻剂通常会立即改善水质，并在使用基于过氧化物的杀藻剂时提供选择性蓝藻控制。然而，它们具有一系列限制：导致细胞裂解和蓝藻毒素释放，对水生植物和动物产生负面影响，留下与环境相关的处理残留物（例如，水中和沉积物中的 Cu），并且仅提供以蓝藻反弹为特征的短期水华控制。当控制外部营养负荷时，混凝剂/絮凝剂（明矾、铁、钙和镧膨润土）提供长期的内部营养控制。处理性能通常受到背景水质条件和原水特性（例如，表面积、深度、混合方式和停留时间）的影响。回顾的案例研究强调，减少外部营养负荷是蓝藻控制的最基本方面。所回顾的控制策略都没有提供蓝藻水华的综合解决方案。
