Analysis and estimation of microplastics from landfill leachate in Urban India from 1960 to 2022

Abstract

A rapidly developing country like India has an ever-increasing rate of consumption. With consumption comes the problem of waste generation especially the generation of municipal solid waste. Plastic, a versatile material used by various industries is commonly found as a component of MSW in unsanitary landfills. As unsanitary landfills become the cheapest and the easiest method of disposing of waste, the problem of plastic pollution is increasing day by day in the urban areas of India. With the accumulation of large amounts of plastic waste in these landfills combined with the varying environmental conditions, the larger plastic pieces disintegrate into smaller particles called microplastics. Thus, landfills are a repository of microplastics that gets transported into the soil through landfill leachate. Microplastics have garnered attention as a toxic contaminant affecting soil and water in the terrestrial ecosystem. The objective of the thesis aims to estimate the quantity of microplastics that leach out from unsanitary landfills from a period ranging from 1960 to 2022. The work also provides an estimation of the total quantity of MSW generated during the above period and the amount of landfill leachate. This is followed by an assessment of the negative impacts related to the emission of microplastics. The thesis employs a comprehensive literature review to achieve the objective and a calculation that gives an estimate of the amount of microplastics discharged along with the other objectives. After the extensive literature review and calculations, it was found that the amount of microplastics discharged into the ground through landfill leachate over the past 62 years is in the range from 6570 tonnes to 12810 tonnes cumulatively. The amount of MSW dumped in such unsanitary landfills is estimated to be about 1986 MT while the amount of leachate that percolates into the ground from landfills is about 28461 ML. The above results point out that the unsanitary landfills in urban areas are potential sources of microplastics that cannot be neglected. Therefore it is necessary that landfills must be engineered scientifically to minimize the infiltration of water into the landfill and also to reduce the leachate release into the ground,