Vol.:(0123456789) 1 3 Clean Technologies and Environmental Policy https://doi.org/10.1007/s10098-021-02032-z ORIGINAL PAPER Guar gum‑stabilized soil: a clean, sustainable and economic alternative liner material for landflls Subramani Anandha Kumar 1  · Evangelin Ramani Sujatha 1  · Arulazhagan Pugazhendi 2,3  · Mamdoh T. Jamal 3 Received: 13 October 2020 / Accepted: 11 January 2021 © The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature 2021 Abstract Biopolymers have attracted much attention in the feld of geo-environmental engineering as they provide a carbon–neutral alternative for soil stabilization and heavy metal removal. This study explores the possibility of using guar gum-stabilized soil (GGSS) as a landfll liner by improving the hydromechanical behaviour and heavy metal attenuation capacity of the poorly graded sand–clay mixture. The results demonstrate that the unconfned compressive strength improved by 1.75 folds, and hydraulic conductivity after 120 days of curing decreased by 2.72 × 10 5 folds at 2% guar gum addition. Additionally, it withstands adverse environmental conditions and increases the heavy metal attenuation capacity of the soil. Leachate stud- ies show that GGSS has a good capacity to adsorb heavy metals like lead, copper, cadmium and zinc. Micrographs from the scanning electron microscope demonstrate gel plug formation and bioclogging in the soil matrix with the addition of guar gum leading to favorable modifcations in the geotechnical properties of the stabilized soil. The durability of the stabilized soil strongly depends on the biopolymer concentration. The soil stabilized with a higher dosage shows better resistance against alternate cycles of wetting and drying than lower dosages due to weak inter-particle connection. Guar-stabilized soil is also more economic than conventional bentonite liners. The study demonstrates that guar gum can be considered as an ideal liner material for landflls with specifc advantages like replacing a nonrenewable material, bentonite with clean and renewable material, guar gum. * Evangelin Ramani Sujatha r.evangelin@gmail.com; sujatha@civil.sastra.edu 1 Centre for Advanced Research on Environment, School of Civil Engineering, SASTRA Deemed to be University, Thanjavur 613401, India 2 Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah 21589, Saudi Arabia 3 Department of Marine Biology, Faculty of Marine Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia