Impacts of climate change on metal leaching and partitioning for submarine mine tailings disposalShow others and affiliations
2022 (English)In: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 184, article id 114197Article in journal (Refereed) Published
Abstract [en]
At present, there are no standardised tests to assess metal leaching during submarine tailings discharge. In this study the influence of variables known to affect metal mobility and availability (dissolved organic carbon (DOC), pH, salinity, temperature, aerated/anoxic conditions) along with variables affected by the discharge conditions (flocculant concentration, suspension) were studied in bench-scale experiments. The leaching tests were developed based on the case of a copper mine by Repparfjorden, northern Norway, which is planned to re-open in 2022.
The experiments, which had three week duration, revealed low (<6 %) leaching of metals. Multivariate analysis showed that all variables, apart from DOC, highly influenced leaching and partitioning of at least one metal (Ba, Cr, Cu, and/or Mn). The high quantity of the planned annual discharge of mine tailings to the fjord (1–2 million tonnes) warranted estimation of the leached quantity of metals. Multivariate models, using present-day conditions in the fjord, estimated leaching of up to 124 kg Ba, 154 kg Cu and 2400 kg Mn per year during discharge of tailings. Future changes in the fjord conditions caused by climate change (decreased pH, increased temperature) was predicted by the multivariate models to increase the leaching up to 55 %, by the year 2065.
The bench-scale experiments demonstrated the importance of including relevant variables (such as pH, salinity, and temperature) for metal leaching and -partitioning in leaching tests. The results showed that metal leaching during discharge is expected and will increase in the future due to the changed conditions caused by the foreseen climate change, and thereby underline the importance of monitoring metal concentrations in water during operations to determine the fate of metals in the fjord.
Place, publisher, year, edition, pages
Elsevier Ltd , 2022. Vol. 184, article id 114197
Keywords [en]
Magnafloc10, Metal leaching, Metal partitioning, Submarine mine tailings disposal
National Category
Environmental Sciences Other Environmental Engineering
Research subject
Waste Science and Technology
Identifiers
URN: urn:nbn:se:ltu:diva-93625DOI: 10.1016/j.marpolbul.2022.114197ISI: 000867669700003PubMedID: 36208554Scopus ID: 2-s2.0-85139307988OAI: oai:DiVA.org:ltu-93625DiVA, id: diva2:1704053
Note
Validerad;2022;Nivå 2;2022-10-17 (joosat);
Funder: The Northern Environmental Waste Management (EWMA) project, Research Council of Norway through NORD-SATSNING (grant number 195160); Eni Norge AS; PAMERA project, MIKON (Environmental Impacts of Industrial Development in the North) of FRAM – High North Research Centre for Climate and Environment
2022-10-172022-10-172024-03-26Bibliographically approved