Leaching of copper and nickel in soil-water systems contaminated by bauxite residue (red mud) from Ajka, Hungary: the importance of soil organic matter

Lockwood, Cindy L.; Stewart, Douglas I.; Mortimer, Robert J. G.; Mayes, Will; Jarvis, Adam P.; Gruiz, Katalin; Burke, Ian T.

Abstract

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 m3 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.

Citation

Lockwood, C. L., Stewart, D. I., Mortimer, R. J. G., Mayes, W., Jarvis, A. P., Gruiz, K., & Burke, I. T. (2015). Leaching of copper and nickel in soil-water systems contaminated by bauxite residue (red mud) from Ajka, Hungary: the importance of soil organic matter. Environmental science and pollution research, 22(14), 10800-10810. https://doi.org/10.1007/s11356-015-4282-4

• Journal Article Type: Article
• Acceptance Date: Feb 24, 2015
• Online Publication Date: Mar 12, 2015
• Publication Date: 2015-07
• Deposit Date: Nov 10, 2015
• Publicly Available Date: Nov 23, 2017
• Journal: Environmental science and pollution research
• Print ISSN: 0944-1344
• Electronic ISSN: 1614-7499
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 22
• Issue: 14
• Pages: 10800-10810
• DOI: https://doi.org/10.1007/s11356-015-4282-4
• Keywords: Kolontár, Ajka, Red mud, Nickel, Copper, DOC, Soil organic matter, Solid phase extraction
• Public URL: https://hull-repository.worktribe.com/output/381074
• Publisher URL: http://link.springer.com/article/10.1007%2Fs11356-015-4282-4
• Additional Information: The final publication is available at Springer via http://dx.doi.org/10.1007/s11356-015-4282-4