The experimental impregnation ratios strongly affected the physical
characteristics of coffee grounds activated carbon. The optimum
impregnation ratio was found to be 0.5 to obtain higher specific surface
area (224.7 m2/g) and micropore volume (0.07986 cm3/g). FTIR indicated
that the presence of functional groupO–H,N–H, C–H, C_O, –OH, C–Oand
P–O–C in coffee grounds activated carbon. Impregnation ratio of 2.5 and
0.5 was optimum for the removal of total iron (77%) and PO4–P (84%),
respectively at 10 g dosages and pH 8.1. The optimum pHwas 13 for total
iron removal and pHb5 and pHN11 for PO4–P removal onto the coffee
grounds. The adsorption capacity of total iron increased with an increase
of the adsorbent dosage. But it was exceptional for PO4–P removal which
showed fluctuation trend possibly due to the effect of foreign ions present
in the leachate.