Fate of microplastics in a coastal wastewater treatment plant: Microfibers could partially break through the integrated membrane system

Rare information on the fate of microplastics in the integrated membrane system (IMS) system in full-scale wastewater treatment plant was available. The fate of microplastics in IMS in a coastal reclaimed water plant was investigated. The removal rate of microplastics in the IMS system reached 93.2% after membrane bioreactor (MBR) treatment while that further increased to 98.0% after the reverse osmosis (RO) membrane process. The flux of microplastics in MBR effluent was reduced from 1.5 x 10(13) MPs/d to 10.2 x 10(11) MPs/d while that of the RO treatment decreased to 2.7 x 10(11) MPs/d. Small scale fiber plastics (< 200 mu m) could break through RO system according to the size distribution analysis. The application of the IMS system in the reclaimed water plant could prevent most of the microplastics from being discharged in the coastal water. These findings suggested that the IMS system was more efficient than conventional activated sludge system (CAS) for the removal of microplastics, while the discharge of small scale fiber plastics through the IMS system should also not be neglected because small scale fiber plastics (< 200 mu m) could break through IMS system equipped with the RO system. (C) Higher Education Press 2021

Automated summary

Rare information on the fate of microplastics in the integrated membrane system (IMS) in a full-scale wastewater treatment plant was investigated. The study found that the IMS system was more effective than conventional activated sludge system (CAS) in removing microplastics. However, small scale fiber plastics could still pass through the system and be discharged.