Humic acid removal from water using a novel fabricated antifouling carbon nanotube bucky - paper membrane and effect of operating parameters

In present work, a novel supported bucky paper (BP) membrane was fabricated and evaluated for humic acid (HA) removal from water. For better understanding the effect of operating variables, response surface methodology (RSM) was also applied. Three independent parameters namely TOC concentration (5, 10 and 15
mg l-1), operating time (10, 20 and 30 min) and transmembrane pressure (TMP) (1, 2 and 3 bar) were selected for TOC removal (%) and permeate flux analysis.
The results revealed that the membrane could effectively remove HA primarily through electrostatic repulsion and then adsorption mechanisms. The study also showed that about 65% and 35% of the removed HA were through repulsion and adsorption mechanisms respectively. Based on analysis of variance (ANOVA), it was showed that the effect of TMP was strongly significant on the removal and flux (P-value <0.05). In addition, statistical test confirmed that RSM based on the Box–Behnken was a suitable method for optimizing the main operating variables for HA rejection using BP membrane (R2=0.97). At optimum condition (TMP of 1.5 bar, TOC concentration of 12.7
mg l-1) and operating time of 13.5 min, removal obtained 67.4% and the flux was 233.4 lm-2h-1.
In general, the synthesized BP membrane showed a relatively good rejection of HA and revealed antifouling properties over the filtration time.