Browse by author
Lookup NU author(s): Dr Will Mayes, Professor Paul Younger, Professor Adam Jarvis
Constructed wetlands are an established treatment technology for a diverse range of polluted effluents. There is a long history of using wetlands as a unit process in treating acid mine drainage, while recent research has highlighted the potential for wetlands to buffer highly alkaline (pH >12) drainage. This paper reviews recent evidence on this topic, looking at wetlands treating acidic mine drainage, and highly alkaline leachates associated with drainage from lime-rich industrial by-products or where such residues are used as filter media in constructed wetlands for wastewater treatment. The limiting factors to the success of wetlands treating highly acidic waters are discussed with regard to design practice for the emerging application of wetlands to treat highly alkaline industrial discharges. While empirically derived guidelines (with area-adjusted contaminant removal rates typically quoted at 10g Fe m2/day for influent waters pH >5.5; and 3.5-7g acidity/m2/day for pH >4 to <5.5) for informing sizing of mine drainage treatment wetlands have generally been proved robust (probably due to conservatism), such data exhibit large variability within and between sites. Key areas highlighted for future research efforts include: (1) wider collation of mine drainage wetland performance data in regionalised datasets to improve empirically-derived design guidelines and (2) obtaining an improved understanding of nature of the extremophile microbial communities, microbially-mediated pollutant attenuation and rhizospheral processes in wetlands at extremes of pH. An enhanced knowledge of these (through multi-scale laboratory and field studies), will inform engineering design of treatment wetlands and assist in the move from the empirically-derived conservative sizing estimates that currently prevail to process-based optimal design guidance that could reduce costs and enhance the performance and longevity of wetlands for treating acidic and highly alkaline drainage waters.
Author(s): Mayes WM, Batty LC, Younger PL, Jarvis AP, Kõiv M, Vohla C, Mander U
Publication type: Article
Publication status: Published
Journal: Science of the Total Environment
Year: 2009
Volume: 407
Issue: 13
Pages: 3944-3957
Print publication date: 15/06/2009
ISSN (print): 0048-9697
Publisher: Elsevier
URL: http://dx.doi.org/10.1016/j.scitotenv.2008.06.045
DOI: 10.1016/j.scitotenv.2008.06.045
Altmetrics provided by Altmetric