Comprehensive Analysis of Microplastic Dynamics in Gyeongan Stream

This study provides a comprehensive analysis of microplastic dynamics in Gyeongan Stream. Over a two-month period, microplastic concentrations were measured at four locations. The results showed a decrease in concentrations downstream but an increase at the downstream curve site (Gyeongan 9). This pattern suggests spatial variability, with higher concentrations found in the slow-flowing sections of the stream. Effluents from the wastewater treatment plant (WWTP) maintained relatively constant microplastic concentrations, suggesting they are not significant sources of microplastics in Gyeongan Stream. The primary types of microplastics identified were polypropylene (PP) and polyethylene (PE), whereas polyester and polytetrafluoroethylene (PTFE) were more prevalent in the WWTP effluents, indicating that household waste and textile washing are key contributors. Most microplastics ranged from 20 to 45 μm in size, with smaller particles becoming more abundant downstream; this was probably due to the effects of water flow and sedimentation. The elevated microplastic concentrations observed upstream, particularly at the downstream bend (Gyeongan 9), likely resulted from slower water flow and subsequent accumulation. This study provides critical baseline data for understanding microplastic pollution in rivers, highlighting the need for ongoing monitoring and further research on microplastics in river sediments.