# Carbonized Dual-Layer Balsa Wood Membrane for Efficient Oil–Water Separation in Kitchen Applications

## TL;DR

A new balsa wood membrane was developed for efficient oil-water separation in kitchen wastewater, offering high performance and sustainability.

## Contribution

An innovative bilayer membrane combining hydrophilic and hydrophobic layers from balsa wood is introduced for oil-water separation.

## Key findings

- The membrane achieved 98.60% separation efficiency and 1176.86 Lm–2 h–1 permeation flux.
- Fouling was reduced by 98.38% with low fouling resistance (<3%) over 20 cycles.
- The membrane showed excellent mechanical strength and selective wettability for oil-water separation.

## Abstract

Wood-based membranes have garnered increasing attention due to their structural advantages and durability in the efficient treatment of oily kitchen wastewater. However, conventional fabrication methods often rely on toxic chemicals or synthetic processes, generating secondary pollutants and suffering from fouling, which reduces performance and increases resource loss. In this study, an innovative bilayer membrane was developed from balsa wood by combining a hydrophilic longitudinal layer for water transport with a polydimethylsiloxane (PDMS)-impregnated carbonized transverse layer to enhance hydrophobicity, resulting in increased separation efficiency and a reduction in fouling by 98.38%. The results show a high permeation flux of 1176.86 Lm–2 h–1 and a separation efficiency of 98.60%, maintaining low fouling resistance (<3%) over 20 cycles. Mechanical tests revealed a tensile strength of 10.92 MPa and a fracture elongation of 10.42%, ensuring robust mechanical properties. Wettability measurements indicate a 144° contact angle and a 7° sliding angle with water on the carbonized side, and a 163.7° contact angle with oil underwater and a 5° sliding angle on the hydrophilic side, demonstrating excellent selective wettability. This study demonstrates the potential of carbonized wood-based membranes as a sustainable, effective alternative for large-scale wastewater treatment.