Despite extensive research on microplastics (MPs) present in solid organic waste, the precise impact of MPs on the vermicomposting process remains poorly understood. The objective of this research was to assess the influence of particular MP polymers on the vermicomposting procedure. To investigate the effects of MP particles on vermicomposting, low-density polyethylene (LDPE) and polyethylene terephthalate (PET) particles were added to organic material. As vermicomposting process indicators, the germination index (GI), carbon-to-nitrogen (C/N) ratio, survival rate, pH, and electrical conductivity (EC) were identified. In this study, the survival rate, pH, C/N, EC, and GI values indicated that the addition of different varieties of MP polymers had a detrimental effect on composting that was direct and proportional. PET and LDPE significantly reduced earthworm survival rates by 10.51% and 14.52%, respectively. The addition of LDPE resulted in a substantial decrease in pH, likely attributable to its chemical constituents. Furthermore, treatments involving LDPE exhibited elevated electrical conductivity (EC) and carbon-to-nitrogen (C/N) ratio values. Nevertheless, the germination index (GI) effect of LDPE was markedly lower than that of PET. The findings of this research will contribute to the comprehension of the ecotoxicological impacts that polymer MPs have on the process of vermicomposting.
