Membrane Water Treatment Volume 11, Number 5, September 2020 , pages 323-331 DOI: https://doi.org/10.12989/mwt.2020.11.5.323 |
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Reuse potential of spent RO membrane for NF and UF process |
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Zhi Chien Ng, Chun Yew Chong, Muhammad Hamdan Sunarya, Woei Jye Lau,
Yong Yeow Liang, See Yin Fong and Ahmad Fauzi Ismail
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Abstract | ||
With the increasing demand on reverse osmosis (RO) membranes for water purification worldwide, the number of disposed membrane elements is expected to increase accordingly. Thus, recycling and reuse of end-of-life RO membranes should be a global environmental action. In this work, we aim to reuse the spent RO membrane for nanofiltration (NF) and ultrafiltration (UF) process by subjecting the spent membrane to solvent and oxidizing solution treatment, respectively. Our results showed that solvent-treated RO membrane could perform as good as commercial NF membrane by achieving similar separation efficiencies, but with reduced water permeability due to membrane surface fouling. By degrading the polyamide layer of RO membrane, the transformed membrane could achieve high water permeability (85.6 L/m2.h.bar) and excellent rejection against macromolecules (at least 87.4%), suggesting its reuse potential as UF membrane. More importantly, our findings showed that in-situ transformation on the spent RO membrane using solvent and oxidizing solution could be safely conducted as the properties of the entire spiral wound element did not show significant changes upon prolonged exposure of these two solutions. Our findings are important to open up new possibilities for the discarded RO membranes for reuse in NF and UF process, prolonging the lifespan of spent membranes and promoting the sustainability of the membrane process. | ||
Key Words | ||
end-of-life membrane; RO; UF; oxidizing agent; membrane transformation | ||
Address | ||
Zhi Chien Ng, Chun Yew Chong, Woei Jye Lau, Ahmad Fauzi Ismail: Advanced Membrane Technology Research Centre (AMTEC), Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia Muhammad Hamdan Sunarya: School of Applied Science, Republic Polytechnic, 9 Woodlands Avenue 9, 738964, Singapore Yong Yeow Liang: Faculty of Chemical and Natural Resources Engineering, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Kuantan, Pahang, Malaysia See Yin Fong: Oneness Water Sdn Bhd, 21, Jalan Serendah 26/39, Kawasan Perindustrian HICOM, Seksyen 26, 40400 Shah Alam, Selangor, Malaysia | ||