Microplastics in the continuous biofilm reactor: Occurrence, fate, and removal

Abstract

Abstract The occurrence of microplastics in a continuous biofilm reactor during the process over a period of 53 days poses a concern for the quality of the treated water. The aim of this study seeks to expand the knowledge of the dynamic of microplastics inside biofilm reactors by investigating their occurrence, fate, and removal. A 91.5 L continuous laboratory-scale reactor consists of four compartments, anoxic-1, anoxic-2, aerobic (A2O), and sedimentation. It was fed with raw domestic wastewater from a residential scale of the wastewater treatment plant in Bandung, Indonesia. In order to investigate the occurrence of microplastics inside a biofilm reactor, it is crucial to consider into account all treatment stages. The results showed that the abundance of microplastics in the influent and the final effluent were 810 MP/L and 10 MP/L respectively. The A2O process in this study demonstrated a high potential for microplastics removal from residential wastewater, in which it could be removed 99.18% of microplastics. The highest abundance was retained in the sludge. The remaining was found in the biofilm and in the final effluent. Microplastics less than 500 μm in size with the abundant microplastics types of fiber, and fragments were detected most frequently in the samples. Moreover, polyester (PES) and cotton were the dominant polymer types in the biofilm reactor detected by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR).