Green soil improvement: using carbon dioxide to enhance the behaviour of clay

Abstract

This research study was conducted to improve the properties of highly plastic clay using carbonate minerals produced using carbon dioxide. The carbonates such as magnesite, siderate and calcite were produced using laboratory-scale carbonation experiments and were used to treat clay samples. The index properties, shear strength and consolidation behaviour of the treated clay samples were then investigated. The results showed that the plasticity index and activity of the treated clay decreased, and shear strength and consolidation behaviour improved. The study confirmed that magnesite had improved clay properties due to the uniform and homogeneous distribution of small crystals of magnesite in the clay compared with those of siderite- and calcite-treated soil. As the process sequesters carbon dioxide, it could be developed as an environmentally friendly soil improvement method subject to further research studies.

A comparative investigation of using microbial- and CO2-induced carbonate minerals in sustainable soil Improvement

“…The UCS result of magnesium carbonate hydrate (Nesquehonite) treated soil was lower than other carbonate minerals in this study. However, Nesquehonite (because of blade structure) had higher e ciency in clay soil in the previous study (Romiani et al 2021). Moreover, the effect of Nesquehonite by CICP with more thickness was more than needle minerals in MICP in the UCS test.…”

“…The soil specimens were prepared by mixing condensed carbonate minerals (i.e., siderite, magnesite, calcite, and calcite/dolomite). To obtain condensed carbonate minerals, the solutions were centrifuged at 8000 g for 10 min and were eventually ltered by a lter paper (Keykha et al 2021). The carbonate minerals (with a water content of about 100%) were used as soil stabilizing agents in the uncon ned compression tests.…”

“…Sustainable precipitation of carbonate minerals may provide green means of mitigating some geotechnical challenges associated with soils. Microbial-induced carbonate precipitation (MICP) and CO 2 -induced carbonate precipitation (CICP) can induce interparticle cementation and mineral precipitation in soil pore space to address geotechnical problems such as soil erosion and slope instability (Keykha et al 2017, Keykha et al 2018a, Romiani et al 2021.…”

“…According to a recent study, CICP improves soil characteristics by precipitating carbonate minerals between soil particles in an environmentally friendly method. (Romiani et al 2021). It entails capturing carbon dioxide (carbon sink) and producing carbonate minerals as a result (e.g.…”

Characterizing Microbial and CO2-Induced Carbonate Minerals: Implications for Soil Stabilization in Sandy Environments

“…Sustainable precipitation of carbonate minerals may provide green means of mitigating some geotechnical challenges associated with soils. Microbial-induced carbonate precipitation (MICP) and CO 2 -induced carbonate precipitation (CICP) can induce interparticle cementation and mineral precipitation in soil pore space to address geotechnical problems such as soil erosion, slope instability, soil reinforcement, and immobilization of heavy metals [1][2][3][4][5]. The potential of applying the MICP technology to remediate and immobilize heavy metals such as Pb in water bodies and soil sites through PbCO 3 precipitation was investigated in previous studies [5].…”