Treatment of desizing wastewater by ceramic membrane combined with PVA self-forming dynamic membrane

Membrane technology is an efficient approach for separation of polyvinyl alcohol (PVA)-starch desizing wastewater. However, fouling caused by complex components remains a challenge in industrial-scale applications, leading to reduced flux and frequent chemical cleaning. Here, we utilize PVA components in wastewater to form a self-forming dynamic membrane (SFDM) on substrate surface during filtration, thereby improving the anti-fouling properties of the ceramic membrane as well as its retention performance for small molecule starches generated through decomposition in a high temperature and strong alkali system. We investigated the effects of pore sizes in porous ceramic on starch separation performance and dynamic membrane formation in the simulation system of PVA-starch. In an industrial desizing wastewater treatment system, we verify the stability and reproducibility of SFDM technology. The results demonstrate that ceramic membranes with a pore size of 20 nm are conducive to forming complete SFDMs, resulting in an increase in starch retention from 75.6 % to 99.9 %, while maintaining flux at 59 L·m⁻²·h⁻¹. The removal rates of COD, TOC and turbidity are 76.2 %, 68.3 % and 99.9 %. SFDMs can form quickly and reduce irreversible fouling on ceramic membranes. The use of ceramic-supported PVA SFDM provides valuable insights for applying ultrafiltration technology to complex wastewater.