Yasaman Jalilian: Recycling End-of-Life Membranes into Highly Selective and Resistant Membrane - A Solution for Efficient Biorefining and Water Recovery

This doctoral research focuses on the sustainable transformation of end-of-life (EoL) reverse osmosis (RO) membranes into high-performance products for industrial water treatment and biorefining. As global membrane waste is projected to exceed 2 million modules annually by 2025, this project provides a circular economy alternative to current landfilling and incineration practices. The study aims to repurpose these "end-of-life " membranes into tailored nanofiltration (NF) or ultrafiltration (UF) tools, supporting more sustainable separation processes.

Objectives and Methodology:

The research investigates the tailoring of membrane properties for specific industrial challenges, such as the fractionation of black liquor from kraft pulping. The methodology employs advanced surface modification techniques, including:

• Controlled Oxidation: Utilizing free chlorine to dissolve the polyamide selective layer and restore the membrane structure.
• Polyelectrolyte Layer-by-Layer (LbL) Deposition: To precisely engineer surface charge, pore size, and hydrophilicity.
• Performance Evaluation: Testing modified membranes with real industrial effluents to assess chemical stability, fouling resistance, and selectivity for components like lignin and hydroxy acids.

Industrial and Environmental Significance:

The project aligns with Finland’s national strategy to double its circular economy rate by 2035. By transforming waste into a high-value resource, this research aims to reduce the environmental footprint of water-intensive industries and decrease dependence on imported membrane modules. Research indicates that such recycling strategies have the potential to significantly lower the production costs associated with membrane technology, providing a strategic economic advantage for the Finnish bioeconomy.