CUED Publications database

Assessing long-term stability of cadmium and lead in a soil washing residue amended with MgO-based binders using quantitative accelerated ageing

Shen, Z and Hou, D and Xu, W and Zhang, J and Jin, F and Zhao, B and Pan, S and Peng, T and Alessi, DS (2018) Assessing long-term stability of cadmium and lead in a soil washing residue amended with MgO-based binders using quantitative accelerated ageing. Science of the Total Environment, 643. pp. 1571-1578. ISSN 0048-9697

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Abstract

© 2018 Elsevier B.V. A soil washing residue (SWR) (containing 90% clay, cadmium (Cd2+) of 132 mg/kg, lead (Pb2+) of 3410 mg/kg) was stabilized with MgO (M) and MgO + bioapatite (MB) respectively at a dosage of 5% in w/w. The stability of the metals in original and amended SWRs was assessed after immediate treatment and using a laboratory accelerated ageing method simulating 26, 52, 78 and 104 years in field conditions. The dissolved Cd2+ and Pb2+ from the SWR in Toxicity Characteristic Leaching Procedure (TCLP) leachates significantly reduced (by 96.84–99.06%) by both amendments after immediate treatment. The stabilization remained effective within simulated 26 years as the TCLP leached Cd2+ and Pb2+ kept below regulatory levels. This immobilization was mainly due to the increased non-bioavailable Cd2+ and Pb2+ from sequential extraction tests in SWR by the amendments. At simulated 52 years, the TCLP leached Cd2+ from M and MB exceeded regulatory level by 106% and 1% respectively. Large amounts of Cd2+ and Pb2+ were leached out by 36.74–48.18% regardless of the treatments at simulated 104 years. Although bioapatite can significantly aid the stabilization of metals by MgO, the stabilization effectiveness for both treatments diminished at simulated 52 years and from 52 to 104 years.

Item Type: Article
Uncontrolled Keywords: Accelerated ageing Cd and Pb stabilization Heavy metal MgO Soil washing residue
Subjects: UNSPECIFIED
Divisions: Div D > Geotechnical and Environmental
Depositing User: Cron Job
Date Deposited: 21 Jul 2018 20:07
Last Modified: 27 Oct 2020 07:49
DOI: 10.1016/j.scitotenv.2018.06.321