A novel dual-function antiscalant carboxymethyl cellulose-graft-protocatechuic acid for efficient scaling and biofouling prevention

Abstract

Despite antiscalants playing a critical role in desalination and cooling water systems, their potential to support microbial growth pose a significant threat to water treatment processes by promoting biofouling. In this work, a novel dual-function antiscalant carboxymethyl cellulose-graft-protocatechuic acid (CMC-g-PA) was prepared using plant-derived antibacterial protocatechuic acid (PA) and natural polysaccharide cellulose, and its scale inhibition effect on CaSO4 scale and antibacterial performance on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were evaluated. Results indicated that the inhibition efficiency against CaSO4 scale and the induction time of CaSO4 crystallization process in the presence of CMC-g-PA were remarkably enhanced compared to unmodified CMC. Microscope and XRD characterizations demonstrated significant alterations in the crystal morphology and size of the formed scale using CMC-g-PA as antiscalant. Molecular dynamics (MD) analysis also showed that CMC-g-PA could intensively interact with the crystal plane of CaSO4 with the binding energy reaching 746.73 kcal/mol, thereby affecting crystal growth and causing crystal distortion. Additionally, an obvious inhibitory effect of CMC-g-PA on the growth of E. coli and S. aureus was observed, attributed primarily to the antibacterial activity of the introduced phenolic hydroxyl groups. In short, bio-derived CMC-g-PA, characterized in its environmental-friendliness, antiscaling efficiency and antibacterial activity, holds immense potential for mitigating scaling and biofouling in desalination/cooling water systems.