Biochar, compost, iron oxide, manure, and inorganic fertilizer affect bioavailability of arsenic and improve soil quality of an abandoned arsenic-contaminated gold mine spoil

  • Arsenic (As) contaminated mining spoils pose health threats to environmental resources and humans, and thus, mitigating this potential risk is worth investigating. Here, we studied the impacts of biochar, compost, iron oxide, manure, and inorganic fertilizer on the non-specifically (readily bioavailable)- and specifically- sorbed As and soil quality improvement of an abandoned mine spoil highly contaminated with As (total As = 1807 mg/kg). Compost, iron oxide, manure, and biochar were each applied at 0.5%, 2%, and 5% (w/w) to the contaminated soil; and NPK fertilizer at 0.1, 0.2, and 5.0 g/kg. The non-specifically (readily bioavailable)- and specifically- sorbed As were extracted sequentially and available P, total C and N, dissolved organic carbon, soil soluble anions, and exchangeable cations were extracted after 1- and 28-day incubation. Compost, manure, and biochar at 5% improved the total C and N and exchangeable \(K^{+}\), \(Mg^{2+}\) and \(Na^{+}\). However, manure, compost, and iron oxide at 5% reduced available P from 118.5 to 60.3, 12.6, and 7.1 mg/kg, respectively. As compared to the untreated soil, the addition of iron oxide doses reduced the readily bioavailable As by 93%; while compost, manure, inorganic fertilizers, and biochar increased it by 106–332%, 24–315%, 19–398%, and 28–47%, respectively, with a significantly higher impact for the 5% doses. Furthermore, compost reduced specifically-sorbed As content (14–37%), but the other amendments did not significantly affect it. The impacts of the amendments on the readily bioavailable As was stronger than on specifically-sorbed As; but these were not affected by the incubation period. Arsenic bioavailability in our soil increased with increasing the soil pH and the contents of Cl-, DOC, and exchangeable \(K^{+}\) and \(Na^{+}\). We conclude that iron-rich materials can be used to reduce As bioavailability and to mitigate the associated environmental and human health risk in such mining spoils. However, the carbon-, and P-rich and alkaline materials increased the bioavailability of As, which indicates that these amendments may increase the risk of As, but can be used to enhance phytoextraction efficiency of As in the gold mining spoil.

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Metadaten
Author:Albert Kobina MensahORCiDGND, Bernd MarschnerORCiDGND, Sabry M. ShaheenORCiDGND, Jörg RinklebeGND
URN:urn:nbn:de:hbz:294-90950
DOI:https://doi.org/10.1016/j.ecoenv.2022.113358
Parent Title (English):Ecotoxicology and environmental safety
Publisher:Elsevier
Place of publication:Amsterdam
Document Type:Article
Language:English
Date of Publication (online):2022/07/02
Date of first Publication:2022/03/04
Publishing Institution:Ruhr-Universität Bochum, Universitätsbibliothek
Tag:Arsenic bioavailability; Mining spoil; Risk mitigation; Soil amendments; Soil remediation
Volume:234
Issue:Article 113358
First Page:113358-1
Last Page:113358-11
Institutes/Facilities:Geographisches Institut, Bodenkunde und Bodenökologie
Dewey Decimal Classification:Naturwissenschaften und Mathematik / Geowissenschaften, Geologie
open_access (DINI-Set):open_access
faculties:Fakultät für Geowissenschaften
Licence (English):License LogoCreative Commons - CC BY-NC-ND 4.0 - Attribution-NonCommercial-NoDerivatives 4.0 International