Work

Synergistic solidification of heavy metal tailings by polyethylene glycol (PEG) and microorganisms

Year: 2024

Type: article

Abstract: A significant amount of tailings rich in heavy metals is left behind after mining, causing environmental pollution due to long-term storage. In recent years, microbial-induced carbonate precipitation (MICP) has shown potential to solidify and stabilize heavy metal-contaminated soils. However, high concentrations and complex mixtures of heavy metals have toxic effects on microorganisms , resulting in decreased carbonate yield. Additionally, tailings sand often has a small particle size and poor permeability, which significantly reduces the solidification uniformity when using traditional grouting methods. To address these challenges, a low pH treatment method using PEG-MICP was proposed. This method increased the unconfined compressive strength (UCS) of tailings sand by 2.5 times and significantly improved soil uniformity while substantially reducing exchangeable heavy metal ions . Microscopic analysis showed that the introduction of PEG modifies the morphology of calcium carbonate , transforming calcite from a mineral to sheet-like and faceted forms, thus enhancing solidification efficiency. This study suggests that PEG-MICP has broad application prospects for solidifying heavy metal-contaminated tailings sand.

Source: Environmental Technology & Innovation

DOI: 10.1016/j.eti.2024.103788

Authors: Shaogeng Chen, Bo Kang, Fusheng Zha, Xiaobo Chen

Institution: Hefei University of Technology

Language: English

Topic: Microbial Applications in Construction Materials

Subfield: Environmental Engineering

Field: Environmental Science

Domain: Physical Sciences

SDGs: Responsible consumption and production, Industry, innovation and infrastructure

Open Access status: gold

Estimated APC paid: $2,440