Projects / Programmes
The immobilisation and leaching of toxic trace elements in alkali-activated materials prepared from locally available waste and by-products
| Code |
Science |
Field |
Subfield |
| 2.01.00 |
Engineering sciences and technologies |
Civil engineering |
|
| Code |
Science |
Field |
| 2.01 |
Engineering and Technology |
Civil engineering |
Toxic trace elements, leaching tests, immobilization, alkali activation, steel slag, fly ash, waste mineral wool, sample preparation, durability.
Researchers (1)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
35473 |
PhD Majda Pavlin |
Chemistry |
Head |
2021 - 2023 |
0 |
Organisations (1)
Abstract
The overall aim of this post-doctoral project is to gain knowledge on the immobilisation and leaching of various toxic trace elements (TEs) from alkali-activated materials (AAMs) prepared using three different locally available precursors (steel slag, coal-burned fly ash and waste mineral wool; Slovenia). Many parameters such as the particle size of the precursors, the initial preparation of the paste, the curing regime and the sample ageing under different conditions can significantly affect the final properties of the material. In the present work, these parameters will be systematically evaluated with respect to increasing/decreasing the leaching of TEs from AAMs. Since the long-term stability of the material is important, durability tests will be included and samples of AAMs will also be subjected to the leaching tests. Depending on the sample (granular or monolithic), different leaching tests will be performed and the results will be compared with each other and with the Slovenian legislation, where the maximum allowable concentration for toxic TEs are available (values for inert, non-hazardous or hazardous waste). Toxic TEs studied in this work include elements such as As, Ba Cd, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se in Zn. An assessment of the environmental impact due to the leaching of TEs from AAMs is an indicator of the sustainability of materials and an important and necessary tool for proper environmental risk assessment. Accumulation of contaminants can threaten ecosystems and human health by leaching TEs from AAMs (and other construction materials) into aquatic and terrestrial environments. Many studies have demonstrated the suitability of AAMs in terms of mechanical properties and durability, but to successfully bring them to the market, they need to be thoroughly evaluated from an environmental perspective. Comprehensive studies with different mix designs, constituents, and influencing parameters affecting the leaching of toxic TEs from AAMs are necessary to identify different options to minimise the potential toxicity of this construction material and achieve effective waste management strategies. Since alkali activation can reduce/increase toxic TEs in eluates, initial preparation and curing conditions are critical to obtain a long-term stable final product that ensures efficient immobilisation. This should be considered when conducting research. However, the selection of the appropriate leaching method is critical to evaluate the degree of leaching for the material under study. Testing and comparing different leaching methods for AAMs will also be part of the proposed work. In an interdisciplinary manner, in this study technical knowledge (preparation and characterization of AAMs) with environmental aspects (assessment of environmental risks by performing different leaching tests) and knowledge of analytical chemistry (determination of TEs in leachates obtained by leaching AAMs) will be combined. This approach is important and necessary to follow the circular economy strategy by reducing mineral waste and increasing its recyclability and reuse.
