Novel membrane-integrated ultrasonic atomization system for energy-efficient treatment of dye-polluted wastewater

Abstract

Dye-contaminated wastewater must be treated before its release into water bodies, as it poses serious environmental and health concerns. Although conventional methods involving pressure-driven membrane separation processes are widely used to treat dye-containing wastewater, they are often energy-intensive due to high-pressure requirements. To overcome these limitations, this study introduces a novel ultrasonic atomizing membrane system designed for energy-efficient dye removal from wastewater. This innovative system consists of a membrane composite fabricated via deposition of a thin, selective chitosan-crosslinked GO (GO-CS) layer on a commercial polyamide substrate, integrated into a high-frequency ultrasonic atomizer. The addition of CS chemically modified GO, which resulted in enhanced hydrophilicity and increased surface charge of the composite membrane. The ultrasonic atomizing membrane system exhibited a high pure water flux of up to 129 ± 13 LMH. With the GO-CS (v/v = 1/0.5) membrane composite, the system achieved impressive dye rejection rates of 90 % for methyl orange (MO) and 99 % for both Congo red (CR) and disperse blue 1 (DB1). The stability test showed sustained performance with a 99 % CR rejection rate and a flux of 60.0 ± 10.6 LMH. Reusability test further confirmed high membrane efficiency, with 93 – 99 % CR rejection and a permeation flux of 85.5 ± 3.6 LMH. These findings prove that the proposed novel ultrasonic atomizing membrane system could be an effective energy-saving alternative for the treatment of dye-contaminated wastewater.