A comparison study of granular activated carbon modification by FeCl3 under the acidic and basic condition for arsenic removal from water.

The present study deals with the effect of two different conditions for modification of raw granular activated carbon (GAC) with FeCl₃ under acidic granular activated carbon (AGAC) and basic granular activated carbon (BGAC) conditions for removal of arsenic – As(V) – from aqueous solution. X-ray diffraction, scanning electron microscopy, and Brunauer–Emmett–Teller (BET) were used for structural properties. Obtained images show that for raw GAC most of the peaks are related to SiO₂ and graphite, but, for AGAC related to Fe₂O₃, Fe₃O₄, and SiO₂, and for BGAC related to Fe₃O₄ and hydrogen aluminum silicate. Surface area and total pore volume of raw GAC > AGAC > BGAC. Kinetics study for arsenic removal by raw GAC and BGAC obeyed pseudo-first-order model, but, AGAC obeyed pseudo-second-order model. Isotherm study showed that raw GAC has a good fit with Langmuir model, and AGAC and BGAC have a good fit with Freundlich model. The adsorption capacity of AGAC, BGAC, and raw GAC (As(V) concentration = 0.3 mg/L) was 22.7, 18.33, and 14.35 mg/g, respectively. It was concluded that modified raw GAC under the acidic condition had better than basic condition. [ABSTRACT FROM AUTHOR]