| In this work, a comparison study was done between different samples of activated carbon (AC) and multi-walled carbon nanotubes (MWCNT) for bromate (BrO3-) removal from water. MWCNT samples were prepared in KFUPM laboratories through specific procedures, and then all these samples were fully characterized by SEM, FTIR, EDS and TGA to ensure the required composition. The results showed that AC and MWCNTs have good capability to remove bromate from water through an adsorption/reduction mechanism on adsorbent surface. AC-Raw and AC-0.2% Ag results showed the highest adsorption capacities 0.4860 mg/g and 1.1930 mg/g, respectively at pH 7.5. CNT-Raw and CNT-1% Fe showed also good adsorption capacities 0.3220 mg/g and 0.3460 mg/g, respectively at pH 7.5. Bromate removal mechanism is considered to be through reduction process when activated carbon is used. However, in case of CNT samples the mechanism is mainly adsorption. The adsorption capacity of AC is better than that of CNT for the tested samples. Adsorption capacity increases if the pH of the solution and the adsorbent dosage decrease. The presence of co-anions also decreases the adsorption capacities of both AC and CNT. |
