Stirring things up: Do surface mixers in drinking water reservoirs improve water quality?

令人兴奋的是：饮用水水库中的表面混合器是否可以改善水质？

• 批准号: NE/R013128/1
• 负责人: Danielle Wain
• 金额: $ 6.81万
• 依托单位: University of Bath
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FR013128%2F1
• 关键词: Stirring; things; up; Do; surface

Clean water is an important resource and a crucial worldwide challenge for both society and industry. Drinking water reservoirs in the UK and around the world become depleted in oxygen in the summer, when layers of different temperature form due to increased solar heating. This strong temperature stratification in the reservoir acts as a barrier to vertical transport of dissolved substances including oxygen and nutrients. All major water utilities in Great Britain use engineering interventions to attempt to mitigate the cost and water quality impacts of low oxygen in their reservoirs.Besides being lethal for fish and other aquatic organisms, low oxygen leads to the growth of nuisance algae, leading to blooms. In addition to the malodourous "pea soup" state that these blooms create, making the reservoir unappealing for recreation and as a landscape feature, the algal matter that enters drinking water treatment plants interacts with the chlorination process to create carcinogenic compounds. The stratification also creates ideal conditions for the growth of cyanobacteria, who have evolved to be able to regulate their buoyancy and location in the water column; cyanobacterial toxins are one of the key contributors to taste and odour problems in drinking water. Lack of oxygen also causes manganese in the bottom sediments to be released into the water. Like iron, manganese turns colour when oxidised (black in this case), which then makes drinking water supplies unsuitable for consumption until expensive treatment processes are utilised to remove the manganese. To deal with this problem, water utilities employ reservoir destratification systems that mix the water so that oxygen can mix downwards from the surface. There are several methods of destratification; bubble plumes have most commonly been used by water utilities in the UK, but recently utilities have been making new capital investments in surface mixers, which act by pushing water from the surface down to the bottom, creating circulation in the reservoir. Yet these destratification systems are imperfect, and utilities still suffer from water quality problems that must be dealt with through the water treatment process. Thus better understanding and optimization of destratification systems can lead to improved source water quality, lighter treatment load at drinking water plants, and a decrease in energy use by water utilities if less mixing is required.The overarching goal of this project is to improve the management of water supply reservoirs that depend upon destratification for maintaining water quality. To this end, a field campaign is proposed that has two aims:1. Assess in the field the spatial distribution of mixing and water quality in a reservoir with a surface mixer system and other interventions. 2. Determine through a modelling study if changes in water quality are due to the mixer or to natural variation in climate controls.These aims will be achieved through combined field measurements and modelling of Durleigh Reservoir. In 2015, Durleigh's bubble destratification system was replaced with a surface destratification system. Through long-term measurements in Durleigh, the performance of the mixer will be assessed throughout the summer. By modelling the reservoir without the mixer, changes in water quality can be attributed to the intervention or to natural variability in climate forcing. Through these aims, we will generate knowledge that can be used to better understand the hydrodynamics and water quality of reservoirs with artificial mixing, with a future aim of improving management of our water resources.

清洁水是对社会和工业的重要资源，也是全球至关重要的挑战。夏季，由于太阳能加热增加而导致不同温度形式的层，英国和世界各地的饮用水储水库被耗尽。储层中的这种强温度分层充当溶解物质在内的垂直运输在内的障碍，包括氧气和养分。大不列颠的所有主要水公用事业都使用工程干预措施来降低其储层中低氧的成本和水质影响。贝赛德对鱼类和其他水生生物的致命致死，低氧导致滋扰藻类的生长，导致开花。除了这些盛开所产生的卑鄙的“豌豆汤”外，使储层无法吸引娱乐和景观特征，进入饮用水处理厂的藻类物质与氯化过程相互作用，与氯化过程相互作用，以创建致癌化合物。该分层还为蓝细菌的生长创造了理想的条件，蓝细菌的生长已经发展为能够调节其在水柱中的浮力和位置。蓝细菌毒素是导致饮用水味和气味问题的关键因素之一。缺乏氧气还会导致底部沉积物中的锰释放到水中。像铁一样，当氧化时锰会变色（在这种情况下为黑色），这使饮用水供应不适合食用，直到使用昂贵的治疗过程来清除锰为止。为了解决这个问题，水电运用采用储层破坏系统，将水混合在一起，使氧气可以从表面向下混合。有几种破坏方法；泡沫羽流最常见于英国的水电图使用，但是最近，公用事业公司一直在向地表搅拌机进行新的资本投资，这些投资是通过将水从地面向下推到底部来起作用，从而在水库中产生循环。然而，这些破坏性系统是不完美的，公用事业仍遭受水质问题，必须通过水处理过程来解决。因此，更好地理解和优化破坏性系统可以改善源水质，饮用水厂的较轻处理负荷以及在需要较少混​​合的情况下减少水的能源利用。该项目的总体目标是改善依赖于维持水质的供水库的管理。为此，提出了一个实地运动，该活动具有两个目标：1。在现场评估储层中混合和水质的空间分布与表面混合系统和其他干预措施。 2.通过建模研究确定水质的变化是由于混合器或气候控制中的自然变化引起的。这些目标将通过杜利储层的合并现场测量和建模来实现。 2015年，杜利的泡沫破坏系统被表面破坏系统取代。通过杜利的长期测量，将在整个夏季评估混合器的性能。通过在没有混合器的情况下对储层进行建模，水质的变化可以归因于干预措施或气候强迫的自然变异性。通过这些目标，我们将产生知识，可以通过人工混合来更好地了解储层的流体动力和水质，并将未来的目的改善我们的水资源管理。

项目成果

Managing taste and odour metabolite production in drinking water reservoirs: The importance of ammonium as a key nutrient trigger.

• DOI: 10.1016/j.jenvman.2019.04.123
• 发表时间: 2019-08
• 期刊: Journal of environmental management
• 影响因子: 8.7
• 作者: R. Perkins;E. Slavin;T. C. Andrade;C. Blenkinsopp;P. Pearson;T. Froggatt;G. Godwin;J. Parslow;S. Hurley;R. Luckwell;D. Wain

The Effects of Surface Mixers on Stratification, Dissolved Oxygen, and Cyanobacteria in a Shallow Eutrophic Reservoir

表面混合器对浅层富营养化水库分层、溶解氧和蓝藻的影响

• DOI: 10.1029/2021wr030068
• 发表时间: 2022
• 期刊: Water Resources Research
• 影响因子: 5.4
• 作者: Slavin E