title: Effectiveness of a constructed wetland for treating alkaline bauxite residue leachate: a 1-year field study.
abstract: Increasing volumes of bauxite residues and their associated leachates represent a significant environmental challenge to the alumina industry. Constructed wetlands have been proposed as a potential approach for leachate treatment, but there is limited data on field-scale applications. The research presented here provides preliminary evaluation of a purpose-built constructed wetland to buffer leachate from a bauxite residue disposal site in Ireland. Data collected over a 1-year period demonstrated that the pH of bauxite residue leachates could be effectively reduced from ca. pH 10.3 to 8.1 but was influenced by influent variability and temporal changes. The wetland was also effective in decreasing elemental loading, and sequential extractions suggested that the bulk of the sediment-bound metal inventory was in hard-to-leach phases. Elemental analysis of Phragmites australis showed that although vegetation displayed seasonal variation, no trace elements were at concentrations of concern.
authors.affiliation: Department of Biological Sciences and The Bernal Institute, University of Limerick, Limerick, Ireland.
authors.forename: Derek
authors.initials: D
authors.lastname: Higgins
authors.affiliation: Department of Chemical Sciences and The Bernal Institute, University of Limerick, Limerick, Ireland.
authors.forename: Teresa
authors.initials: T
authors.lastname: Curtin
authors.affiliation: Department of Biological Sciences and The Bernal Institute, University of Limerick, Limerick, Ireland. ronan.courtney@ul.ie.
authors.forename: Ronan
authors.initials: R
authors.lastname: Courtney
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D007494:Ireland; D008670:Metals; D014874:Water Pollutants, Chemical; D053833:Wetlands
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D000537:Aluminum Oxide
keywords: Alkaline bauxite residue leachate; Constructed wetland; Phragmites australis