Efficacious elimination of salts from a convoluted ethylene glycol-water solution employing nanofiltration membranes

Abstract

ABSTRACT In the current scientific studies, a flat-sheet module pilot plant with an HPP-200 nanofiltration membrane was employed to process an ethylene glycol-water mixture from Jayshree Chemicals, Ankleshwar, India, that contained a significant amount of sodium sulfate. The membrane clogged due to degradation fueled by the excessive salt concentration. Hence, the solution was treated because it was diminished, and the impact of dilution was investigated. Consequently, fouling occurs due to increased flux and reduced concentration polarization. 294, 490, and 784 Kpa pressures were applied to the solution. With the dilution factor, the flow rises while the rejection decreases. Rejection rates range from 97% for membrane plugging without dilution to 92% for five folds and 85% for ten folds dilution. The efficacy of chemical cleaning was investigated using 2% solutions of citric acid and ethylenediamine tetra acetic acid (EDTA). Fourier-transform infrared (FTIR) spectroscopy analysis revealed alterations in membrane structure resulting from interactions with the sodium sulfate feed solution. Scanning Electron microscope (SEM) analysis showed substantial fouling on the membrane surface, which was successfully eliminated through chemical cleaning process. The implementation of dilution and pressure control strategies demonstrated efficacy in the mitigation of fouling phenomena and the enhancement of membrane performance. The efficacy of EDTA in flux recovery (69.84%) was superior to that of citric acid (55.77%) during chemical cleaning processes. These findings have potential to facilitate the implementation of nanofiltration technology in industrial wastewater treatment processes on commercial scale.