The Extraction and Characterization of Microplastics of Biocompost and Water Samples Collected from the Different Semi-Urban Agronurseries

Abstract

ABSTRACT Biocomposting at national and regional levels has recently been recognized as one of the feasible, nature-based solutions to prevent the accumulation and reuse of biodegradable waste in enhanced and effective mitigation measures for urban and semi-urban waste management. Recent research has mainly focused on organic compost contamination, as the negative effects of MP on soil systems have been extensively studied. According to current research, organic compost used as fertilizer on farmland contains many microplastics. In this context, microplastics (MPs) have been regarded as a global environmental problem and an emerging soil contaminant. The physico-chemical properties of water and compost samples were analyzed by APHA and AOAC methods. The extraction of microplastics was done using the density separation. In the current study, agricultural waste-based biocompost and water samples used for the production of biocompost were collected from four different agricultural nurseries in semi-urban areas of the Coimbatore city. The physicochemical properties (including heavy metal content) of the biocompost and water samples tested were on par/equal/lower than Indian standards. Interestingly, in the biocompost samples, 85% of the microplastic fragments and 15% of the fiber types were identified only in BC-B and BC-C, respectively, with different colors such as red, brown, blue, light yellow and transparency. However, no microplastics were found in the biocompost samples of BC-A and BC-D. Microplastic polymers such as polymethyl methacrylate (PMMA), polypropylene (PP), and ethylene vinyl acetate (EVA) were identified through ATR-FTIR analysis. The results suggest that semi-urban agricultural gardening may lead to the accumulation of microplastics in terrestrial environments, which may negatively impact soil and plant health. This study contributes to growing research into microplastic contamination in organic compost and its potential impact on agriculture and terrestrial ecosystems.