Assessment of water quality in the upper Brantas River through microplastic-associated biofilms and heavy metal accumulation

Abstract

Microplastics are a significant threat to aquatic ecosystems, including the upper Brantas River in Indonesia, by acting as carriers for biofilms that accumulate pollutants like heavy metals. This study analyses the biofilms on microplastics collected from the Brantas River and assesses water quality parameters (temperature, pH, current velocity, DO, BOD, TDS, nitrate, phosphate, TSS) using Canonical Correlation Analysis (CCA) to explore relationships with microplastics. FTIR is used to identify microplastic polymers. SEM-EDX analyses heavy metal content in biofilms. Microplastics, mainly fragments (60–75%), range from 18.11 to 3.31 particles/L. Polymers identified include PE, PVC, PP, HDPE, LDPE, PET, PC, and nylon. SEM-EDX detects heavy metals (Fe, Zn, Cd, Hg, Pb, Cr) in biofilms. Bacterial counts are significantly higher in biofilms on microplastics than in river water. These findings are crucial for ecosystem management and pollution mitigation strategies.