| dc.description.abstract |
Disinfection using nitrogen-doped titanium dioxide polyvinylidene fluoride membrane (N-TiO2-PVDF) was studied. The effect of solution pH (4–10) and quantity of Escherichia coli (2.6 × 108 CFU/l–1.04 × 109 CFU/l) on disinfection efficiency and permeate flux was evaluated. The membranes were reused multiple times to test their durability and robustness. The disinfection efficiency increased with time and reduced with increasing E. coli concentration. The disinfection effectiveness of 2.02 log reduction value (LRV) was obtained at pH 7 and contact time of 50 min and was attributed to weak repulsive surface charges. At acidic pH (pH 4), disinfection effectiveness was 1.72 LRV by the 50 th minute. The disinfection was lower due to E. coli developing acid shock proteins. At basic pH (pH 10), disinfection effectiveness was 1.72 LRV by the 50 th minute and attributed to the overall negative charge of nitrogen-doped titanium dioxide nanoparticles and E. coli cells. Notably, as the contact time was increased to 75 min and beyond, 8.42 LRV was achieved irrespective of the solution pH. Also, the highest relative flux of 0.302 was obtained at pH 7 and 1.04 × 109 CFU/l. Higher relative flux value of 0.424 was observed with the lowest E. coli concentration of 2.6 × 108 CFU/l due to reduced biofouling. The photocatalytic membrane was reused in repeated 5 cycles with very minimal reduction in disinfection efficiency (1.92%) and relative flux (0.08), thus demonstrating good reuse potential and high durability. To our knowledge, this study is the first to investigate the durability and reuse potential of N-TiO2-PVDF when disinfecting E. coli–loaded water. |
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