Abstract
Decreased water quality and increased treatment costs due to excess manganese (Mn) in drinking-water supplies are critical issues globally. To combat on-going and emerging taste and odour issues with Mn and other contaminants (e.g., algal toxins), many utilities are using engineered oxygenation or aeration (EOA) systems to improve water quality in lakes and reservoirs. Resultant shifts in key biogeochemical and physical processes are still poorly understood, often leading to inefficiently managed systems. Paired with knowledge gaps regarding environmental drivers of Mn and the complexity of Mn redox kinetics, Mn problems persist. This review presents the state of current research in areas critical to optimisation of EOA mitigation of Mn, with focus on i) Mn biogeochemical cycling within drinking-water reservoirs; ii) influences of local catchment geology, hydrology, and land use on Mn dynamics; and iii) Mn management using different EOA approaches. The importance of considering the combined implications of these factors for successful Mn management in reservoirs is highlighted by an evaluation of relevant field-based studies; a wide range in EOA performance is observed, from a 97 % decrease in soluble Mn up to a ∼400 % increase in total Mn. Despite the breadth of studies that consider Mn in water-supply systems, there are still several areas of research which warrant further investigation, including: the influence of natural sources and anthropogenic activities on Mn within a given catchment, Mn speciation and transport in stratified and destratified lakes and reservoirs, and optimal site-specific EOA strategies for Mn mitigation.
| Original language | English |
|---|---|
| Article number | 127573 |
| Journal | Journal of Environmental Management |
| Volume | 395 |
| DOIs | |
| State | Published - Dec 2025 |
Funding
This study was conducted as part of the Water Informatics: Science and Engineering ( WISE ) Centre for Doctoral Training, including research studentships for SP and JR, which was funded by the UK Engineering and Physical Sciences Research Council , Grant No. EP/L016214/1. LB and EH were supported by Royal Society Grant IES\R2\242155 - International Exchanges 2024 Global Round 2. EH was also supported by the Watershed Dynamics and Evolution Science Focus Area through the Department of Energy Biological and Environmental Research program. The authors thank two anonymous reviewers for their constructive comments and valuable feedback, which helped improve the clarity and quality of this publication. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( https://www.energy.gov/doe-public-access-plan ).
Keywords
- Aeration
- Drinking water
- Manganese
- Oxygenation
- Reservoirs