Extraction and characterization of microplastics in biomined good earth fractions: assessment of urban and suburban landfill sites, India

Abstract

The sustainability of biomined landfill sites mainly depends on the profitable valorisation of landfill mined wastes based on the physical and chemical properties of the materials. This study focuses on the extraction, concentration, and characterization of microplastics (MPs) as an emergent pollutant in biomined good earth fractions derived from five landfill sites in West Bengal, India: Baruipur, Dhapa, Madhyamgram, Chandannagar, and Howrah. The concentration of MPs in these samples ranged from 11,500 ± 707.1 to 34,500 ± 7778.2 particles/kg having average sizes 1000–2000 µm. Morphological analysis revealed that fragments, films, and fibers are the common MP types across all samples, with sky, black, and red being the predominant colours. µFTIR analysis identified HDPE and LDPE as the primary polymers in the good earth materials derived from all landfill sites, followed by PP, Cellophane, PVC, PS, EPM, EPS, and PET. Pollution Load Index (PLI), Polymer Hazard Index (PHI) and Potential Ecological Risk Index (PERI) were used to assess the risk of good earth materials. PLI values indicated relatively low pollution load, while elevated PHI values exceeding 1000 were noted in Howrah, Dhapa, and Chandannagar due to the presence of PVC. The study suggests the need for standardized methods to extract and quantify MPs in good earth products from landfill sites and the development of protocols or guidelines for the application of good earth in sustainable development projects.