The impact of microplastics on water quality, heavy metals, and health risks in bioflocbased tilapia farming systems

Along with microplastics, pollution of heavy metals, including iron (Fe), zinc (Zn), and copper (Cu), in freshwater ecosystems poses a serious environmental threat that can adversely affect human health. This study investigates the use of biofloc technology to reduce microplastic and heavy metal contamination while improving water quality. By utilizing microbial aggregates that capture microplastic and heavy metal particles through flocculation and biosorption processes, four experimental treatments were applied, i.e.: A (without biofloc and microplastics); B (with biofloc, without microplastics); C (with biofloc and low-density polyethylene microplastics); and D (with biofloc and high-density polyethylene microplastics). The results indicate that fish in Treatment B maintain a stable condition, with reduced biochemical oxygen demand (BOD) value and controlled heavy metal accumulation. Furthermore, the Target Hazard Quotient (THQ) values suggest that consumption of fish from all treatments does not incur a significant health risk, despite the bioaccumulation of Cu, Fe, and Zn at varying concentrations. The application of biofloc technology demonstrates effectiveness in mitigating pollution and enhancing food safety.