Removal of Safranin Dye from Aqueous Solution using Surfactant-Modified Carbonized Olive Stones

The adsorption study of safranin dye by surfactant modified carbon MCOS produced from olive stone under batch adsorption process was undertaken to check the influence of varying different experimental conditions; initial safranin concentration, pH, adsorbent dosage, temperature, counter ions and time on safranin removal by our adsorbent. Physiochemical characterizations including moisture content, ash content, bulk density etc. was also undertaken. Two well known adsorption isotherms (Langmuir and Freundlich) and three kinetic models (pseudo first and second order, intra particle diffusion) were used to better understand the mechanism involved in the adsorption process. Our collected results showed that there was an increase in adsorption capacity of MCOS as initial dye concentration, dose and number of counter ions in solution increased; pHpzc was at pH 6.6 while maximum adsorption capacity was 7.30mg/g obtained at pH 7. Langmuir isotherm which implies monolayer coverage by MCOS well represented our equilibrium data with a higher correlation coefficient value of while kinetic study showed that adsorption process followed pseudo second order kinetic model. RL and n values obtained from both adsorption isotherms used indicates a favorable adsorption process. The spontaneity and exothermic nature was confirmed by negative ΔG° and ΔH° values, though spontaneity reduced as temperature increased. Hence, MCOS can serve as an ecofriendly and cheap alternative for removing safranin from industrial waste effluents.