Sustainable utilization of biopolymers and biocement in aggregation of granular materials

Abstract

Soil stabilisation through materials such as lime or cement have considerable environmental penalty due to high embodied energy of the cementitious material. Biogeotechnology allows cement formation with dramatically reduced carbon footprint and promises a sustainable soil improvement method. In the current study, investigations were performed to evaluate the effect of biopolymer Xanthan gum and Microbially Induced Calcite Precipitation (MICP) on cementation of sands as well as sand-clay mixtures individually as well as in combination. The unconfined compressive strength tests and micrographic analysis through scanning electron microscope and energy dispersive X-ray spectroscopy results revealed that synergistic effect of biopolymer and MICP resulted in superior performance. Water absorption test indicated that the Xanthan gum was susceptible to water attack and incorporation of MICP helped in addressing the concern. Therefore, the present study was successful in overcoming the individual limitations of biopolymer and MICP as a sustainable soil stabilisation technology.

Purification and Characterization of Gum-Derived Polysaccharides of Moringa oleifera and Azadirachta indica and Their Applications as Plant Stimulants and Bio-Pesticidal Agents

“…The images also revealed the presence of clay mixture, which could be the result of mixing the plant gum polysaccharide into the soil particles, which is said to increase the surface strength and stability of the particles (Figure 11). Similar results were observed in a study conducted by Ramachandran et al [56]. The EDX analysis revealed the elemental composition present in the soil, which correlated with the soil analysis report (Figure 12).…”

“…The addition of polymers such as xanthan and cellulose to the soil reduced the rate of soil erosion by 80% [79]. Microscopic investigation of sand mixed with xanthan gum polysaccharide revealed biopolymer bridging between pores and the formation of biopolymer clay matrix [56]. Likewise, in another study, strong bonding between the void gaps of dispersive soils were observed after the addition of xanthan gum [80].…”