Removal of Metasilicate from Aqueous Solutions with Hybrid Polymer-enhanced Ultrafiltration-electrodeionization Membrane Processes

Background: In desalination, addressing fouling challenges, particularly concerning silica, is pivotal for generating pure water from seawater and brackish sources. Efficient silica removal is vital for various applications, including power generation and electronics. Electrodeionization (EDI) has proven highly effective in achieving a high removal rate for silica. Objective: Optimize silica removal through a combined membrane approach—water-soluble polymer- enhanced ultrafiltration and Electrodeionization (EDI)—for efficient water treatment and improved water quality. Methods: The study utilized a 400 mL stirred Amicon cell for Ultrafiltration (UF) in combination with a water-soluble polymer. Additionally, a microflow EDI cell is employed, filled with Porolite A600 anion exchange resin and SST60 cation exchange resin, to optimize silica removal. Results: The water-soluble polymer-enhanced ultrafiltration achieved a 25% removal of SiO2, with the remaining silica effectively removed by EDI, resulting in a concentration of 11 μg/L. Conclusion: The combined approach of water-soluble polymer-enhanced ultrafiltration and Electrodeionization (EDI) demonstrated effective silica removal.