Surface regeneration of templated PVDF membrane for efficient microalgae-rich high saline aquaculture wastewater treatment in membrane distillation

Abstract

This study investigated the use of templated PVDF membranes with intermediate flushing to revive fouled membrane during membrane distillation (MD) for sustainable high saline seawater aquaculture wastewater treatment. Results showed that superhydrophobic templated membrane with intermediate physical flushing was highly effective in reducing fouling, even after 5 cleaning cycles, when treating microalgae-rich feed with algogenic organic matter and high salinity aquaculture wastewater. Specifically, the membrane restoring flux performance by up to 97.2 %, compared to only 75.6 % for pristine membranes. In this study, intermediate flushing effectively restored the advancing and reducing contact angles of fouled templated membranes, enhancing membrane regeneration and reducing surface adhesion properties. In long-term 82-h MD tests, the superhydrophobic templated membrane still demonstrated excellent separation, achieving 99.84 % rejection rate for all components and maintaining average water permeation flux of 21.4 kg/m2.h when treating microalgae-rich feed. The study suggests that the use of superhydrophobic templated membrane with surface reviving capability holds immense potential in overcoming the challenges of membrane fouling in MD, providing a sustainable treatment solution for microalgae-rich and high salinity wastewater treatment.