Prof. Am Jang’s team (Sustainable WAter Treatment, SWAT lab.) in the Department of Civil and Environmental Engineering (first author: Dr. Hongrae Im) has successfully developed a next-generation membrane-based recovery platform capable of converting fatty acids contained in food waste into high-value precursors for energy and chemical materials. Conventional membrane processes have long suffered from structural limitations, such as membrane fouling and wetting, which lead to reduced selectivity and decreased recovery efficiency. To overcome these challenges, the research team introduced a supported liquid membrane contactor (SLMC) system that integrates superhydrophobic surface modification with selective organic extractant impregnation. This approach enabled highly selective and efficient recovery of target fatty acids even from the complex matrix of food-derived waste streams.  

A key achievement of this study is the pioneering application of optical coherence tomography (OCT) for real-time monitoring of fouling and wetting transitions occurring on membrane surfaces and within membrane pores. By visualizing and quantifying these microscale structural changes, the team successfully identified the primary causes of performance deterioration and established an operational framework capable of actively controlling process conditions. Using OCT-based wetting and fouling signals, the researchers proposed an “intelligent membrane operation strategy” that accurately determines optimal cleaning and replacement intervals, thereby significantly enhancing long-term operational stability and fatty-acid recovery efficiency.

Furthermore, the researchers systematically elucidated the material transport mechanisms within the SLMC system by investigating the synergistic effects between superhydrophobic membrane surface modification and the chemical properties of selective extractants. Through this approach, they developed an integrated solution capable of simultaneously addressing three major technical bottlenecks: membrane fouling and wetting suppression, enhancement of selective mass transfer, and low-energy/high-efficiency fatty acid recovery. Owing to its robust performance, the developed technology shows strong potential for expansion into a universal circular-resource platform applicable not only to food waste but also to desalination brines, spent battery leachates, and other complex multicomponent aqueous systems.

This research provides significant academic and industrial value by presenting a sustainable resource, upcycling strategy that transforms low-value waste streams into high-value chemical materials, thereby transcending the traditional paradigm of waste treatment. The work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT), and its excellence and novelty were recognized through publication in top-tier international journals in the environmental and energy fields, including Water Research (IF 12.4, JCR top 1.0%) and Chemical Engineering Journal (IF 13.2, JCR top 3.0%).

Title: Efficiently enhanced short-chain fatty acids (SCFAs) recovery from food waste condensate: Real-time wettability monitoring with supported liquid membrane contactor

Authors: Hongrae Im (First author, Sungkyunkwan University), Duc Anh Nguyen (Sungkyunkwan University), Dong-gun Jun (Sungkyunkwan University), Sojeong Jang (Sungkyunkwan University), Am Jang (Corresponding author, Sungkyunkwan University)

Journal: Water Research

DOI: https://doi.org/10.1016/j.watres.2025.123093

Title: Enhanced anti-wetting and anti-fouling performance of superhydrophobic supported liquid membrane contactors for selective short-chain fatty acid recovery from food waste leachate

Authors: Hongrae Im (First author, Sungkyunkwan University), Semi Lee (Sungkyunkwan University), Duc Anh Nguyen (Sungkyunkwan University), Duc Viet Nguyen (Ghent University), Di Wu (Ghent University), Am Jang (Corresponding author, Sungkyunkwan University)

Journal: Chemical Engineering Journal

DOI: https://doi.org/10.1016/j.cej.2025.168433

Figure 1. Schematic of short-chain fatty acid recovery from food waste



Figure 2. Mechanism, recovery efficiency, and mass transfer behavior of fatty acid from food waste streams

Figure 3. Physicochemical properties of modified membranes

Figure 4. Real-time monitoring of the physical properties of the membrane surface