| Autor: |
Jiang, Jie1 (AUTHOR), Luo, Haohao1 (AUTHOR) luo_hh@st.gxu.edu.cn, Ou, Xiaoduo1 (AUTHOR), Wang, Shufei1 (AUTHOR), Su, Jian2 (AUTHOR), Chen, Junlin1 (AUTHOR) |
| Předmět: |
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| Zdroj: |
Environmental Technology. Sep2024, Vol. 45 Issue 23, p4951-4963. 13p. |
| Abstrakt: |
This study aimed to evaluate the potential of replacing fly ash (FA) with bauxite tailing (BT) slurry for geopolymer synthesis and investigate the long-term leaching behaviour of BT slurry/FA geopolymers (BFGs) for heavy metal immobilisation. The mechanical properties and heavy metal immobilisation efficiency of BFGs were tested, and numerical simulations were conducted to assess their environmental impact as a backfill material. The results showed that the incorporation of 5 Wt.% BT increased the early compressive strength of the geopolymer without any additional treatment. A small quantity of Cu2+ improved the mechanical strength, while excess heavy metals harmed the geopolymer. Heavy metal immobilisation efficiency decreased with increased heavy metal addition and exceeded 99.9% for Pb2+ and Cu2+ when simulating acid rain leachate. The modified Elovich equation described the leaching kinetics of Cu2+ well, and the leaching rate decreased with time. Numerical analysis indicated that Cu2+ leaching from landfill leachate occurred in three phases, with an initial increase followed by a gradual decrease, stabilisation, and diffusion into the surrounding soil layer. This study provides insight into the material's long-term stability and environmental performance, offering a scientific basis for relevant engineering applications. Highlights: Direct utilisation of unprocessed tailing slurry to synthesise geopolymer. The leaching pattern of Pb2+ and Cu2+ under acidic conditions was explored. The modified Elovich equation effectively describes the leaching kinetics of Cu2+. The environmental impact of bauxite tailings slurry-based geopolymers was evaluated. [ABSTRACT FROM AUTHOR] |
| Databáze: |
GreenFILE |
| Externí odkaz: |
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