The adsorption kinetics and isoterm of activated carbon from Water Hyacinth Leaves (Eichhornia crassipes) on Co(II)

Abstract

Heavy metal waste can endanger human health and can accumulate in rivers or land. Heavy metals such as Co(II) can be removed or minimized using adsorbents such as activated carbon. The use of activated carbon from water hyacinth leaves (Eichhornia crassipes) has the potential to reduce the concentration of heavy metals in the environment as water hyacinth leaves (WHL) have the ability to adsorp both organic and inorganic compounds. This study aims to determine the appropriate adsorption kinetics and isotherm models in the process of Co(II) adsorption using activated carbon from water hyacinth leaves (ACWHL). The ACWHL can be produced from the carbonization process at 400°C for an hour and two-stage activation process (physical and chemical activation) with 30% H3PO4 as an activator and the impregnation ratio of 1:4 (w/w) for 24 hours and then activated at 600°C for 60 minutes. The analytical method used in this study was using a UV-Vis spectrophotometer. The results of the study showed that the ability of ACWHL to adsorp Co(II) followed the pseudo second-order kinetic model with R2 = 0.3086 and the Elovich isotherm with R2 = 0.664 with a maximum adsorption capacity of 140.725 mg/g. Fulfillment of this model can be assumed if the adsorption process of Co(II) on the surface of ACWHL occurs in multilayer.