Tags

Type your tag names separated by a space and hit enter

Oxidative transformation of iron monosulfides and pyrite in estuarine sediments: Implications for trace metals mobilisation.
J Environ Manage. 2017 Jan 15; 186(Pt 2):158-166.JE

Abstract

Iron monosulfides are the initial iron sulfide minerals that form under reducing conditions in organic-rich sediments. Frequently referred as monosulfidic black ooze (MBO), these sediments exists in a range of anoxic systems including estuaries, coastal wetlands and permeable reactive barriers. The objective of this study was to investigate the transformation of solid phase sulfur, iron fractions and trace metals mobilisation in organic-rich hypersulfidic sediments during dredging. Two sediments from geographically contrasting sites in the Peel-Harvey Estuary were collected and subjected to oxidation through resuspension over 14 days. During oxidation, redox potential rapidly and continuously increased, although minimal change in pH was observed in both sediments. The majority of FeS was oxidised within 48 h. Although not as dynamic as FeS, unusually high rates of FeS2 oxidation were measured in both sediments at circumneutral pH, with between 39 and 58% of FeS2 oxidised over 14 days. The rapid oxidation of FeS2 may be attributed to the presence of nano-size FeS2 crystals (≈550-860 nm) with a high surface area. Before resuspension, solid bound Fe(total) was most abundant as measured by HCl-extractable Fe(II), followed by organic bound Fe(total) and oxide bound Fe(total). There was a marked decrease in these three fractions in both sediments during resuspension, with an increase in Fe(III) fraction. No significant release of trace metals was observed during resuspension of sulfidic sediments. However, disturbance to these estuarine sediments increases Fe(III) formation and further deteriorates the environment through smothering biological surfaces, deteriorating food sources and the quality of benthic habitats.

Authors+Show Affiliations

Southern Cross GeoScience, Southern Cross University, PO Box: 157, Lismore, 2480, NSW, Australia. Electronic address: girish.choppala@scu.edu.au.Southern Cross GeoScience, Southern Cross University, PO Box: 157, Lismore, 2480, NSW, Australia.Southern Cross GeoScience, Southern Cross University, PO Box: 157, Lismore, 2480, NSW, Australia.Southern Cross GeoScience, Southern Cross University, PO Box: 157, Lismore, 2480, NSW, Australia.Southern Cross GeoScience, Southern Cross University, PO Box: 157, Lismore, 2480, NSW, Australia.Global Centre for Environmental Remediation (GCER), University of Newcastle, Callaghan Campus, 2308, NSW, Australia.Southern Cross GeoScience, Southern Cross University, PO Box: 157, Lismore, 2480, NSW, Australia.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

27394083

Citation

Choppala, Girish, et al. "Oxidative Transformation of Iron Monosulfides and Pyrite in Estuarine Sediments: Implications for Trace Metals Mobilisation." Journal of Environmental Management, vol. 186, no. Pt 2, 2017, pp. 158-166.
Choppala G, Bush R, Moon E, et al. Oxidative transformation of iron monosulfides and pyrite in estuarine sediments: Implications for trace metals mobilisation. J Environ Manage. 2017;186(Pt 2):158-166.
Choppala, G., Bush, R., Moon, E., Ward, N., Wang, Z., Bolan, N., & Sullivan, L. (2017). Oxidative transformation of iron monosulfides and pyrite in estuarine sediments: Implications for trace metals mobilisation. Journal of Environmental Management, 186(Pt 2), 158-166. https://doi.org/10.1016/j.jenvman.2016.06.062
Choppala G, et al. Oxidative Transformation of Iron Monosulfides and Pyrite in Estuarine Sediments: Implications for Trace Metals Mobilisation. J Environ Manage. 2017 Jan 15;186(Pt 2):158-166. PubMed PMID: 27394083.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Oxidative transformation of iron monosulfides and pyrite in estuarine sediments: Implications for trace metals mobilisation. AU - Choppala,Girish, AU - Bush,Richard, AU - Moon,Ellen, AU - Ward,Nicholas, AU - Wang,Zhaohui, AU - Bolan,Nanthi, AU - Sullivan,Leigh, Y1 - 2016/07/06/ PY - 2016/02/14/received PY - 2016/06/23/revised PY - 2016/06/27/accepted PY - 2016/7/11/pubmed PY - 2017/3/14/medline PY - 2016/7/11/entrez KW - Eutrophic sediments KW - Iron monosulfide KW - Iron partitions KW - Mineralogy KW - Oxidation KW - Pyrite KW - Trace elements SP - 158 EP - 166 JF - Journal of environmental management JO - J Environ Manage VL - 186 IS - Pt 2 N2 - Iron monosulfides are the initial iron sulfide minerals that form under reducing conditions in organic-rich sediments. Frequently referred as monosulfidic black ooze (MBO), these sediments exists in a range of anoxic systems including estuaries, coastal wetlands and permeable reactive barriers. The objective of this study was to investigate the transformation of solid phase sulfur, iron fractions and trace metals mobilisation in organic-rich hypersulfidic sediments during dredging. Two sediments from geographically contrasting sites in the Peel-Harvey Estuary were collected and subjected to oxidation through resuspension over 14 days. During oxidation, redox potential rapidly and continuously increased, although minimal change in pH was observed in both sediments. The majority of FeS was oxidised within 48 h. Although not as dynamic as FeS, unusually high rates of FeS2 oxidation were measured in both sediments at circumneutral pH, with between 39 and 58% of FeS2 oxidised over 14 days. The rapid oxidation of FeS2 may be attributed to the presence of nano-size FeS2 crystals (≈550-860 nm) with a high surface area. Before resuspension, solid bound Fe(total) was most abundant as measured by HCl-extractable Fe(II), followed by organic bound Fe(total) and oxide bound Fe(total). There was a marked decrease in these three fractions in both sediments during resuspension, with an increase in Fe(III) fraction. No significant release of trace metals was observed during resuspension of sulfidic sediments. However, disturbance to these estuarine sediments increases Fe(III) formation and further deteriorates the environment through smothering biological surfaces, deteriorating food sources and the quality of benthic habitats. SN - 1095-8630 UR - https://www.unboundmedicine.com/medline/citation/27394083/Oxidative_transformation_of_iron_monosulfides_and_pyrite_in_estuarine_sediments:_Implications_for_trace_metals_mobilisation_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0301-4797(16)30428-5 DB - PRIME DP - Unbound Medicine ER -