Waste to resource: Applicability of fly ash as landfill geoliner to control ground water pollution Aditya Chowdhury a , Aliya Naz b , Abhiroop Chowdhury c,1,⇑ a Department of Applied Geophysics, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand 826004, India b Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand 826004, India c School of Environment and Sustainability, O.P. Jindal Global University, Sonipat Narela Road, Sonipat, Haryana 131001, India article info Article history: Available online xxxx Keywords: Fly ash Geoliner Solid waste Pollution Geopolymer Landfill abstract The major issue faced by the modern world is its waste management strategies. Coal fired thermal power plant produces fine particular respirable fly ash that cause severe health implications. Landfills are favored by urban planners to manage solid waste generated by the rapidly urbanizing world. This results in leachate production which contaminates ground water. Heavy metal pollutants (As, Cd, Cr, Cu, Fe, Hg, Fe and Pb) is identified to be leaching into the ground water in landfill sites across the globe. Fly ash based geopolymer are suitable as landfill geoliner because of it possess higher splitting tensile strength, flexural stress, and compressive strength parameters while having a low permeability. Fly ash can adsorb inorganic pollutants, hence making it a suitable candidate for application as landfill geoliner. This article focuses on use, properties of Fly ash as a candidate for landfill geoliner and also compares the fly ash production/ utilisation in major countries across the globe. Ó 2021 Elsevier Ltd. All rights reserved. 1. Introduction Increase in urban conglomeration has resulted in more and more solid/liquid waste production and to cater the needs of the people, landfills have been created near metropolitan areas to act as a waste dump. These landfill sites are normally located in the suburbs and its main purpose is proper waste management, acting as temporary storage that should be processed and recycled in waste management facilities. Waste is compacted in these sites to reduce volume and provide area for more waste storage. There are many hazards associated with landfills. Landfills are the major contributors to leachate pollution; a process by which water from precipitation percolates into the groundwater and thus pollutes the water table making it harmful for human consumption. LPI (Leachate Pollution Index) across various landfill sites in India sug- gest that groundwater resources are very likely to be potentially contaminated by leachate[1]. Landfills also generate gases due to decomposition of organic particles via microbes. Methane gener- ated from the landfills indirectly accelerate the greenhouse effect [2]. Landfills also provide breeding ground for the spreading of var- ious vector-borne diseases. Risk analysis indicates that various air- borne contamination sources like H 2 S gas that can cause pul- monary carcinogenesis and other ailments in nearby residents[3]. Natural Attenuation might be an attainable solution to the lea- chate problem. It’s success is limited in managing petroleum hydrocarbon plumes and chlorinated solvent plumes as of now. But in the foreseeable future it might serve as a means of ground- water pollution reversal[4]. Natural processes for diminishing lea- chate pollution are- (i) adsorption, (ii) ion exchange, (iii) precipitation, (iv) microbial decomposition/dilution in the Vadose zone underneath landfills [2]. Other artificial methods include Geo- liners (Landfill liners) and Bioclogging. The main issues with natu- ral methods include slow progress and unresolved cost of implementation. Landfill liners promise a sustainable and positive impact on reducing leachate contamination. It also provides a mean of recy- cling industrial waste products to mitigate environmental impacts. Liners act as a barrier, halting the migration of toxic leachate con- tents into underground aqueducts and aquifers. Single-liner sys- tems are mainly used to prevent construction and other solid waste from getting incorporated into the soil. For preventing the percolation of liquids like tar and paint, double- liner systems are implemented. The liners are surrounded by a solid drainage layer and confined by a geomembrane and a geosynthetic clay liner. Polymers are used as geomembranes and a common example is used tires, other examples include bitumen geocomposites and https://doi.org/10.1016/j.matpr.2021.10.367 2214-7853/Ó 2021 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: abhiroop.chowdhury@gmail.com (A. Chowdhury). 1 0000-0001-6985-0722. Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr Please cite this article as: A. Chowdhury, A. Naz and A. Chowdhury, Waste to resource: Applicability of fly ash as landfill geoliner to control ground water pollution, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2021.10.367