Crustacean polysaccharides for the geotechnical enhancement of organic silt: A clean and green alternative

Govindarajan Kannan; Evangelin Ramani Sujatha

doi:10.1016/j.carbpol.2022.120227

Crustacean polysaccharides for the geotechnical enhancement of organic silt: A clean and green alternative

Carbohydr Polym. 2023 Jan 1:299:120227. doi: 10.1016/j.carbpol.2022.120227. Epub 2022 Oct 15.

Authors

Govindarajan Kannan¹, Evangelin Ramani Sujatha²

Affiliations

¹ Centre for Advanced Research in Environment, School of Civil Engineering, SASTRA Deemed to be University, Thanjavur 613401, India.
² Centre for Advanced Research in Environment, School of Civil Engineering, SASTRA Deemed to be University, Thanjavur 613401, India. Electronic address: sujatha@civil.sastra.edu.

PMID: 36876825
DOI: 10.1016/j.carbpol.2022.120227

Abstract

Biopolymer-based soil stabilization offers a clean alternative to conventional stabilizers like cement and lime. This study investigates the possibility of using shrimp-based chitin and chitosan for stabilizing low plastic silt with organic content by investigating their effect on pH, compaction, strength, hydraulic conductivity (HC) and consolidation characteristics. X-ray diffraction (XRD) spectrum shows that no new chemical compounds were formed in the soil on additive treatment; however, results of scanning electron microscope (SEM) analysis indicate the formation of biopolymer threads that bridge the voids in the soil matrix leading to a stiffer soil matrix, with increased strength and lower HC. Chitosan showed nearly 103 % strength enhancement after 28 d of curing with no degradation. However, chitin failed as a soil stabilizing additive as it showed degradation owing to fungal bloom after 14 d of curing. Chitosan can therefore be recommended as a non-polluting and sustainable soil additive.

Keywords: Chitin; Chitosan; Hydraulic conductivity; Organic silt; Strength; TGA.