Lookup NU author(s): Dr Adam Jarvis
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Red mud is a highly alkaline (pH > 12) waste product from bauxite ore processing. The red mud spill at Ajka, Hungary, in 2010 released 1 million m(3) of caustic red mud into the surrounding area with devastating results. Aerobic and anaerobic batch experiments and solid phase extraction techniques were used to assess the impact of red mud addition on the mobility of Cu and Ni in soils from near the Ajka spill site. Red mud addition increases aqueous dissolved organic carbon (DOC) concentrations due to soil alkalisation, and this led to increased mobility of Cu and Ni complexed to organic matter. With Ajka soils, more Cu was mobilised by contact with red mud than Ni, despite a higher overall Ni concentration in the solid phase. This is most probably because Cu has a higher affinity to form complexes with organic matter than Ni. In aerobic experiments, contact with the atmosphere reduced soil pH via carbonation reactions, and this reduced organic matter dissolution and thereby lowered Cu/Ni mobility. These data show that the mixing of red mud into organic rich soils is an area of concern, as there is a potential to mobilise Cu and Ni as organically bound complexes, via soil alkalisation. This could be especially problematic in locations where anaerobic conditions can prevail, such as wetland areas contaminated by the spill.
Author(s): Lockwood CL, Stewart DI, Mortimer RJG, Mayes WM, Jarvis AP, Gruiz K, Burke IT
Publication type: Article
Publication status: Published
Journal: Environmental Science and Pollution Research
Print publication date: 01/07/2015
Online publication date: 12/03/2015
Acceptance date: 24/02/2015
ISSN (print): 0944-1344
ISSN (electronic): 1614-7499
Publisher: Springer Berlin Heidelberg
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