الفهرس | Only 14 pages are availabe for public view |
Abstract A single-stage batch adsorber was designed for adsorption of brilliant green dye by activated carbons prepared from guava seeds (AGSC) and date pits (ADPC) based on the optimum isotherm. Experimental work was carried out for studying effect of operating parameters which are contact time (5 – 65 min), dosage (0.01 – 0.08 g), temperature (25 – 95℃),pH (3 – 10) and initial dye concentration (10 – 100 ppm). Some adsorption isotherm models was applied for instance, Langmuir (RAGSC2 > 0.99, RADPC2 > 0.95) where the maximum adsorption capacities of AGSC and ADPC were found to be 80.5 and 77.8 mg/g respectively,Freundlich (RAGSC 2 > 0.97, RADPC 2 > 0.99), Temkin (RAGSC 2 > 0.98, RADPC 2 > 0.9) andDubinin-Radushkevich (RAGSC2 > 0.82, RADPC 2 > 0.68); In addition to some adsorption kineticsmodels for example, Pseudo-first order (RAGSC2 > 0.64, RADPC> > 0.75), Pseudo-second order(RAGSC 2 > 0.99, RADPC 2 > 0.99), Elovich (RAGSC 2 > 0.95, RADPC2 > 0.96) and Intra-particle diffusion model (RAGSC 2 > 0.96, RADPC 2 > 0.88). The process efficiency was assessed by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscope, Energy-Dispersive X-ray Spectroscopy and Brunauer-Emmett-Teller where the latter showed that the specific surface area of AGSC and ADPC are 605.1 and 311.4 m2 /g respectively. The thermodynamic study proved that brilliant green adsorption on AGSC and ADPC were physiosorptive(∆GAGSC = −7.73 kJ/mole, ∆GADPC = −5.86 kJ/mole) and spontaneous at high temperature in case of AGSC (∆H = 13.4 kJ⁄mole , ∆S = 0.07 kJ⁄mole ⋅ K) while in case of ADPC the process is spontaneous at low temperature (∆H = −17.7 kJ/mole, ∆S = −0.04 kJ/mole ⋅ K). |