Degradation of Polyamide Nanofiltration Membranes by Bromine: Changes of Physiochemical Properties and Filtration Performance

• DOI: 10.1021/acs.est.1c00206
• Publication Date: 2021-04-16T02:08:54Z
• Authors: Huihui Zhao; Linyan Yang; Xueming Chen; Mei Sheng; Guomin Cao; Lankun Cai; Shujuan Meng; Chuyang Y. Tang
• Keywords: Nanofiltration; Filtration (mathematics); Degradation

The potential coexistence and interaction of bromine polyamide membranes during membrane-based water treatment prompts us to investigate the effect on membrane performance. For fully aromatic NF90 exposed under a mild bromination condition (10 mg/L), incorporation resulted in more negatively charged (-13 vs -25 mV) hydrophobic (55.2 58.9°) surfaces narrower pore channels (0.3 0.29 nm). permeabilities neutral solutes were reduced by 64 69-87%, respectively, which was attributed decreased effective radius hydrophilicity. NaCl permeability 90% as synergistic result enhanced size exclusion charge repulsion. further exposure (100 500 mg/L bromine) surface (61.7 65.5°) minor reduction for solute (1-9%). Compared with chlorine, different efficiency properties (e.g., atomic size, hydrophilicity) opposite trends and/or degrees variation physicochemical filtration performance membranes. incorporation, shift disappearance three characteristic bands, increased O/N ratio calcium content indicated degradation pathways N-bromination bromination-promoted hydrolysis conditions (480 mg/L·h). ring-bromination occurred after severe (4800-24,000 semi-aromatic NF270 underwent similar but less significant deteriorated compared NF90, requires explanation.