Excellence in Research: Hybrid Ceramic Membrane Bioreactor and Reverse Osmosis Processes for the removal of Micro and Nano plastics from Municipal Wastewater

Microplastics (MPs) and nanoplastics (NPs) have become ubiquitous and pervasive pollutants throughout the world. They can be easily ingested by living organisms and pose new risks to human and ecosystem health as they accumulate in the environment and enter the food chain. MPs and NPs have been found in all environmental media including air, water, soils, and sediments.

In addition, MPs/NPs are increasingly being detected in the effluents of municipal wastewater treatment plants which have become major sources of plastic pollutants for surface water systems including lakes, rivers, estuaries, and oceans. The overarching goal of this project is to explore the development of a novel wastewater treatment and reclamation process that could remove MPs (0.1-5 micron) and NPs (1-100 nanometer) while producing clean water for potable and non-potable usages.

To advance this goal, the Principal Investigators (PIs) propose to design, build, and evaluate an integrated system consisting of an anaerobic membrane bioreactor with flat-sheet ceramic microfiltration membranes, an aerobic membrane bioreactor with tubular ceramic ultrafiltration membranes, and a reverse osmosis membrane module with flat sheet membranes. The successful completion of this project will benefit society through the generation of fundamental knowledge to advance the development of more efficient and cost effective processes for the treatment and reclamation of wastewater contaminated by plastic particles.

Additional benefits to society will be achieved through outreach and educational activities including the mentoring of three graduate students and six undergraduate students at Prairie View A&M University.

Membrane bioreactors (MBRs) have emerged as promising systems for the treatment and reclamation of wastewater contaminated by MPs and NPs. However, most commercial MBRs utilize polymeric microfiltration (MF) or ultrafiltration (UF) membranes, which are prone to loss of performance due to fouling. In addition, polymeric MF/UF membranes can also release MPs and NPs during operation due to membrane abrasion and damage.

The goal of this project is to test the hypothesis that MBRs with ceramic MF/UF membranes can efficiently remove MPs and NPs from wastewater without the performance limitations of MBRs with polymeric membranes. To test this hypothesis, the Principal Investigators (PIs) propose to carry out an integrated experimental and modeling research program that combines bench scale lab experiments with computational fluid dynamics (CFD) modeling and atomistic molecular dynamics (MD) simulations.

The bench scale experiments will consist of filtration studies designed to investigate the removal of MPs and NPs from municipal wastewater using ceramic membrane bioreactors (CMBRs) followed by reverse osmosis (RO) with the goal of producing a clean water permeate for potable and non-potable usages. For the filtration experiments, the PIs propose to test both an anaerobic CMBR with flat-sheet MF membranes and an aerobic CMBR with tubular UF membranes.

In addition to the filtration experiments, the PIs propose to carry out CFD simulations to guide/optimize CMBR system design and characterize the mechanisms of ceramic membrane fouling in wastewater containing NPs and MPs. Finally, the PIs propose to conduct atomistic MD simulations to probe and unravel the molecular interactions between model plastics and ceramic membranes that control the removal of MPs/NPS from wastewater in CMBR systems.

The successful completion of this project has the potential for transformative impact through the generation of fundamental knowledge and data to advance the design and implementation of more efficient and cost effective processes to treat and reclaim wastewater contaminated by MPs and NPs. To implement the education and outreach activities of the project, the PIs plan to integrate the findings from this research into existing undergraduate and graduate courses at Prairie View A&M University to provide students with new project-based learning opportunities in environmental engineering with a focus on membrane filtration technologies and water quality.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.