Researchers at UBC Okanagan have developed an innovative two-layer membrane filtration system capable of greatly minimizing the leakage of micro and nanoplastics from landfills into nearby water basins. The study was published in the Journal of Environmental Management.
UBCO doctoral student Mahmoud Babalar examines a sample of the dual-layer modified matrix membrane that can help retain pollutants like nano-plastics in landfill leachate, keeping them out of water supplies. Image Credit: UBCO
Dr. Sumi Siddiqua, a Professor at UBCO’s School of Engineering, along with doctoral student Mahmoud Babalar, has released a study that outlines how a double-layer membrane placed at landfills can function as a filter to prevent small pollutants from contaminating groundwater and adjacent ecosystems.
Landfills are silent threats to our environment, acting as major reservoirs for emerging pollutants. Conventional drainage systems fail against microscopic contaminants, including nanoplastics and hazardous chemicals. This allows them to infiltrate groundwater.
Dr. Sumi Siddiqua, Professor, School of Engineering, The University of British Columbia Okanagan (UBCO)
Landfills produce leachate, a polluted liquid that occurs when rainwater filters through waste, as explained by Dr. Siddiqua. While the majority of landfills are engineered to retain this liquid, recent research indicates that leachate has evolved into a significant reservoir for microscopic plastics, which may infiltrate water systems.
As plastic waste breaks down, these particles accumulate in landfill leachate. Current systems handle liquid waste, but they were never designed to completely intercept plastic micro and nano particles.
Mahmoud Babalar, Doctoral Student, School of Engineering, The University of British Columbia Okanagan (UBCO)
The study demonstrates the highest effectiveness in capturing these pollutants. The upper layer employs chemical attraction and filtration techniques to seize micro and nanoplastics. It is designed to effectively bind plastic particles, even within complex leachate that is rich in organic matter. The lower layer creates a protective barrier that repels the leftover plastic particles using electrostatic forces, thereby minimizing clogging, membrane fouling, and ensuring consistent performance over time.
The two complementary layers work together to block tiny plastic particles under harsh landfill conditions. This combination of layers allows the membrane to filter plastics while liquid can still flow, which is a critical requirement for landfill safety.
Mahmoud Babalar, Doctoral Student, School of Engineering, The University of British Columbia Okanagan (UBCO)
In numerous laboratory tests, the membrane successfully eliminated almost all microplastics and captured over 98 % of nanoplastics. Babalar states that throughout the testing process, the membrane exhibited excellent performance across several filtration cycles and could be cleaned and reused due to a systematic backwashing system.
The membrane is made from durable, chemically stable materials designed to withstand temperature changes, aggressive wastewater, and long-term exposure. Its ability to be cleaned and reused reduces waste and supports more sustainable landfill operations.
Mahmoud Babalar, Doctoral Student, School of Engineering, The University of British Columbia Okanagan (UBCO)
The researchers suggest that this technology may offer a foundation for advanced landfill liners that combine structural integrity with proactive pollution management. This finding holds considerable promise for safeguarding groundwater and surface water resources, minimizing the dissemination of contaminants, and facilitating circular waste management alongside climate-resilient infrastructure.
According to Dr. Siddiqua, the study represents a crucial advancement toward more intelligent landfill systems that confine waste and actively mitigate long-term environmental damage.
“Our unique dual-layer modified matrix membrane system is specifically engineered to handle highly contaminated, fouling-intensive raw leachate, positioning it as a foundational component of advanced waste containment. This innovative approach is essential for preventing the migration of pollutants into groundwater, and it represents a significant advancement in waste management and climate-resilient infrastructure,” said Dr. Siddiqua.
Journal Reference:
Mahmoud Babalar, M. & Siddiqua, S. (2025) Unlocking nanoplastic removal from landfill leachate - a dual-layer adsorptive PES@PMACZ@MOF & repulsive self-assembled mesoporous silica modified matrix membrane. Journal of Environmental Management. DOI: 10.1016/j.jenvman.2025.128081. https://www.sciencedirect.com/science/article/pii/S0301479725040575?via%3Dihub