Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate
Abstract Arsenic (As) and antimony (Sb) from mining-affected waters are efficiently removed in two treatment peatlands (TPs) in Northern Finland. However, the exact mechanisms behind this removal are not well resolved. Thus, the present study combines results from microcosm experiments and pilot-sca...
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ftunivoulu:oai:oulu.fi:nbnfi-fe2022041929479 2023-07-30T04:05:50+02:00 Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate Kujala, K. (Katharina) Laamanen, T. (Tiina) Khan, U. A. (Uzair Akbar) Besold, J. (Johannes) Planer-Friedrich, B. (Britta) 2022 application/pdf http://urn.fi/urn:nbn:fi-fe2022041929479 eng eng Elsevier info:eu-repo/semantics/openAccess © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). https://creativecommons.org/licenses/by/4.0/ Antimony Arsenic Cold climate Ecophysiology Mining-affected waters Peatlands info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2022 ftunivoulu 2023-07-08T19:59:10Z Abstract Arsenic (As) and antimony (Sb) from mining-affected waters are efficiently removed in two treatment peatlands (TPs) in Northern Finland. However, the exact mechanisms behind this removal are not well resolved. Thus, the present study combines results from microcosm experiments and pilot-scale TPs on the effects of microbes, temperature, and carbon substrate to elucidate the role of peat microorganisms in As and Sb removal. The main As and Sb species in TP inflow water are arsenate and antimonate. In peat microcosms, they were quantitatively reduced, however, at rates about 20–400 times lower than previously reported from pure cultures, likely due to excess of other terminal electron acceptors, such as nitrate and sulfate. Addition of the microbial inhibitor sodium azide inhibited reduction, indicating that it is indeed microbially mediated. Arsenite and antimonite (re)oxidation, which is in situ likely limited to upper, oxic peat layers, was likewise observed in peat microcosms. Only for antimonite, oxidation also occurred abiotically, likely catalyzed by humic acids or metals. Process rates increased with increasing temperature, but all processes occurred also at low temperatures. Monitoring of pilot-scale TPs revealed only minor effects of winter conditions (i.e., low temperature and freezing) on arsenic and antimony removal. Formation of methylated oxyarsenates was observed to increase As mobility at the onset of freezing. From different carbon substrates tested, lactate slightly enhanced arsenate reduction and antimonate reduction was stimulated by acetate, lactate, and formate. However, a maximum rate enhancement of only 1.8 times indicates that carbon substrate availability is not the rate-limiting factor in microbial arsenate or antimonate reduction. The collective data indicate that microorganisms catalyze reduction and (re)oxidation of As and Sb species in the TPs, and even though temperature is a major factor controlling microbial As and Sb reduction/(re)oxidation, low inflow concentrations, ... Article in Journal/Newspaper Northern Finland Jultika - University of Oulu repository |
institution |
Open Polar |
collection |
Jultika - University of Oulu repository |
op_collection_id |
ftunivoulu |
language |
English |
topic |
Antimony Arsenic Cold climate Ecophysiology Mining-affected waters Peatlands |
spellingShingle |
Antimony Arsenic Cold climate Ecophysiology Mining-affected waters Peatlands Kujala, K. (Katharina) Laamanen, T. (Tiina) Khan, U. A. (Uzair Akbar) Besold, J. (Johannes) Planer-Friedrich, B. (Britta) Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
topic_facet |
Antimony Arsenic Cold climate Ecophysiology Mining-affected waters Peatlands |
description |
Abstract Arsenic (As) and antimony (Sb) from mining-affected waters are efficiently removed in two treatment peatlands (TPs) in Northern Finland. However, the exact mechanisms behind this removal are not well resolved. Thus, the present study combines results from microcosm experiments and pilot-scale TPs on the effects of microbes, temperature, and carbon substrate to elucidate the role of peat microorganisms in As and Sb removal. The main As and Sb species in TP inflow water are arsenate and antimonate. In peat microcosms, they were quantitatively reduced, however, at rates about 20–400 times lower than previously reported from pure cultures, likely due to excess of other terminal electron acceptors, such as nitrate and sulfate. Addition of the microbial inhibitor sodium azide inhibited reduction, indicating that it is indeed microbially mediated. Arsenite and antimonite (re)oxidation, which is in situ likely limited to upper, oxic peat layers, was likewise observed in peat microcosms. Only for antimonite, oxidation also occurred abiotically, likely catalyzed by humic acids or metals. Process rates increased with increasing temperature, but all processes occurred also at low temperatures. Monitoring of pilot-scale TPs revealed only minor effects of winter conditions (i.e., low temperature and freezing) on arsenic and antimony removal. Formation of methylated oxyarsenates was observed to increase As mobility at the onset of freezing. From different carbon substrates tested, lactate slightly enhanced arsenate reduction and antimonate reduction was stimulated by acetate, lactate, and formate. However, a maximum rate enhancement of only 1.8 times indicates that carbon substrate availability is not the rate-limiting factor in microbial arsenate or antimonate reduction. The collective data indicate that microorganisms catalyze reduction and (re)oxidation of As and Sb species in the TPs, and even though temperature is a major factor controlling microbial As and Sb reduction/(re)oxidation, low inflow concentrations, ... |
format |
Article in Journal/Newspaper |
author |
Kujala, K. (Katharina) Laamanen, T. (Tiina) Khan, U. A. (Uzair Akbar) Besold, J. (Johannes) Planer-Friedrich, B. (Britta) |
author_facet |
Kujala, K. (Katharina) Laamanen, T. (Tiina) Khan, U. A. (Uzair Akbar) Besold, J. (Johannes) Planer-Friedrich, B. (Britta) |
author_sort |
Kujala, K. (Katharina) |
title |
Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
title_short |
Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
title_full |
Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
title_fullStr |
Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
title_full_unstemmed |
Kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
title_sort |
kinetics of arsenic and antimony reduction and oxidation in peatlands treating mining-affected waters:effects of microbes, temperature, and carbon substrate |
publisher |
Elsevier |
publishDate |
2022 |
url |
http://urn.fi/urn:nbn:fi-fe2022041929479 |
genre |
Northern Finland |
genre_facet |
Northern Finland |
op_rights |
info:eu-repo/semantics/openAccess © 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). https://creativecommons.org/licenses/by/4.0/ |
_version_ |
1772818084340432896 |