Influence of H2SO4 in Modification of Texture and Surface Functionalities of Activated Carbon

فاقد چكيده فارسي

The present work studies the influence of H2SO4 as a sulfur-containing chemical agent for modification of activated carbon (AC) surface properties and especially functionalities. The modified AC sample was prepared by mixing the strong solution of H2SO4 (98 %wt.) with the base adsorbent under the impregnation ratio of 200 cm3/5 g at room temperature for 12 h. The virgin and acid-impregnated AC were characterized using several analyses including BET, pHpzc, CHNS/O, FTIR, XPS and SEM-EDAX. SEM micrographs and EDAX results showed that the impurities of the sorbent were successfully removed during the acid-washing process. On the other hand, a loss of porosity and available surface area was established via the results of N2 adsorption/desorption analysis. FTIR and XPS results confirmed introduction of oxidized forms of sulfur functional groups onto the AC surface.The affinity of AC and AC-H2SO4 towards mercury was also compared; under the determined adsorption conditions (initial pH of solution: 7, initial concentration of Hg (II): 200 ppm, temperature: 30 oC, adsorbent dosage: 1 g/lit, agitating time and speed: 24 h and 200 rpm), the equilibrium adsorption capacity of AC-H2SO4 (140 mg/g) was found larger than AC (100 mg/g).