Assessing the capacity of biochar to stabilize copper and lead in contaminated sediments using chemical and extraction methods

Wang, Mingming; Ren, Liangsuo; Wang, Dayang; Cai, Zuansi ; Xia, Xuefeng; Ding, Aizhong

Abstract

Because of its high adsorption capacity, biochar has been used to stabilize heavy metals when remediating contaminated soils; to date, however, it has seldom been used to remediate contaminated sediment. In this study, a biochar was used as a stabilization agent to remediate Cu-and Pb-contaminated sediments, collected from three locations in or close to Beijing. The sediments were mixed with a palm sawdust gasified biochar at a range of weight ratios (2.5%, 5%, and 10%) and incubated for 10, 30, or 60 days. The performance of the different treatments and the heavy metal fractions in the sediments were assessed using four extraction methods, including diffusive gradients in thin films, the porewater concentration, a sequential extraction, and the toxicity characteristic leaching procedure. The results showed that biochar could enhance the stability of heavy metals in contaminated sediments. The degree of stability increased as both the dose of biochar and the incubation time increased. The sediment pH and the morphology of the metal crystals adsorbed onto the biochar changed as the contact time increased. Our results showed that adsorption, metal crystallization, and the pH were the main controls on the stabilization of metals in contaminated sediment by biochar.

Citation

Wang, M., Ren, L., Wang, D., Cai, Z., Xia, X., & Ding, A. (2019). Assessing the capacity of biochar to stabilize copper and lead in contaminated sediments using chemical and extraction methods. Journal of Environmental Sciences, 79, 91-99. https://doi.org/10.1016/j.jes.2018.11.007

• Journal Article Type: Article
• Acceptance Date: Nov 7, 2018
• Online Publication Date: Nov 16, 2018
• Publication Date: 2019-05
• Deposit Date: Nov 8, 2018
• Publicly Available Date: Nov 16, 2018
• Journal: Journal of Environmental Sciences
• Print ISSN: 1001-0742
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 79
• Pages: 91-99
• DOI: https://doi.org/10.1016/j.jes.2018.11.007
• Keywords: biochar, sediment, heavy metal, stabilization assessing,
• Public URL: http://researchrepository.napier.ac.uk/Output/1348170
• Contract Date: Nov 8, 2018