Innovative approaches to high-speed ceramic membrane filtration for microplastic mitigation in urban wastewater treatment facilities

Marine microplastics originates from various sources such as laundry wastewater, tire and road dust, and personal care products. These contaminants ultimately enter urban wastewater treatment facilities where they cannot be effectively removed through existing biological wastewater processes, resulting in their discharge into the ocean. Current analytical techniques for microplastic identification lack standardization; however, micro-Fourier transform infrared (µ-FTIR) method has attracted widespread attentions for the reliable analysis of microplastics larger than 20 µm. In this study, efforts have been devoted towards the systematic analysis of microplastic occurrences in urban wastewater treatment facilities using the fluid imaging microscopy (FlowCam) method, which is capable of detecting microplastics larger than 0.1 µm. These two methods were employed for the comparative analyses of influent and effluent samples from two major urban wastewater treatment facilities in Seoul Metropolitan city. Furthermore, high-speed ceramic membrane technology was introduced to reduce microplastics during wastewater treatment. Additionally, filtration experiments were conducted on the collected wastewater samples using a high-speed ceramic membrane to assess its effectiveness in reducing the identified microplastics. The results demonstrated that ceramic membrane achieved a high permeate flux while effectively removing microplastics from influent wastewater, including previously unidentified microplastics smaller than 20 µm. This study emphasized the potential application of ceramic membrane technology for mitigating microplastics and highlights the advantages of using FlowCam over traditional FTIR analysis for microplastic identification.