A Bi-MOF-based composite sponge equipped with antibacterial heterogeneous membranes for effective phosphate removal from wastewater

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-09, Vol.496, p.154024, Article 154024
• Main Authors: Lu, Bing, Wang, Gang, Zhao, Lin, Wang, Shiyong, Dong, Shuangshi
• Format: Article
• Language: English
• Subjects: CAU-17; Composite sponge; Heterogeneous membranes; Phosphorus adsorption
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.154024

Four synergistic effects on phosphate adsorption of CCHM@sponge. [Display omitted] •Combines CAU-17 and CSA membrane (CCHM@sponge) for enhanced phosphate removal.•CCHM@sponge demonstrates an impressive adsorption capacity of 58.31 mg g−1.•CCHM@sponge demonstrates excellent selective adsorption of phosphate.•A synergetic mechanism for phosphate adsorption with CCHM@sponge is proposed. The excessive presence of phosphate in water leads to eutrophication, thereby disrupting the ecological balance of freshwater resources. Recently, metal–organic frameworks (MOFs)-based adsorbents exhibit high efficiency in terms of phosphorus-locking; however, their powdered form is prone to leakage and challenging to recover. Herein, a novel antibacterial heterogeneous membrane, composed of CAU-17 and chitosan (CCHM) was constructed on an inexpensive cellulose sponge (CCHM@sponge), through chemical cross-linking and self-loading techniques. This innovative approach effectively enhances phosphate removal capabilities. The cross-linking of chitosan (CS) with glutaraldehyde (GA) leads to a positively charged polymer network, effectively immobilizing CAU-17 and imparting antibacterial properties to CCHM@sponge, thereby preventing biological contamination erosion. Due to the synergistic adsorption mechanism involving electrostatic attraction, ligand exchange, hydrogen bonding, and surface complexation, the adsorption capacity (qe) of CCHM@sponge is remarkable, reaching 58.31 mg P g−1. The CCHM@sponge exhibits excellent selectivity, effectively removing phosphate even in the presence of highly competitive anions. It manifests that the regeneration capacity remained at 74.9 % of the initial adsorption capacity following 7 cycles of desorption. Furthermore, in actual water samples, CCHM@sponge effectively eliminated 91.8 % of the phosphate within 90 min. This innovative approach presents a novel pathway for advancing the development of integrated MOFs-based adsorbents, thereby demonstrating significant potential for practical applications.