Evaluation of activated carbons based on Palm Kernel Shell as absorbent of Cr (VI)

Chromium is a heavy metal in wastewater that should be removed from the environment due to negative effects on living organisms and environmental impacts. The potential of palm kernel shell (PKS), as agricultural waste, to remove Cr (VI) from aqueous solution was evaluated in a one at a time process. Effective parameters such as pH (2–8), temperature (20–80 °C), contact time (10-120 min), adsorbent concentration (0.1–1 g/L), and initial Cr (VI) concentration (10-100 mg/L) were all studied to attain the maximum removal efficiency. The results showed that a strong dependence of the adsorption capacity on pH was observed, the adsorption capacity increases as pH value decreases and the optimum pH value is pH= 2.0. The other optimal conditions for maximum adsorption efficiency are temperature 40 °C, contact time 45 min, adsorbent concentration 0.5 g/L and initial Cr(VI) concentration 10 mg/L. The equilibrium data for chromate adsorption well fitted to Freundlich equation, with maximum adsorption capacity of 125 mg/g. Removal efficiencies of 100% were achieved in 120 min at a Cr (VI) dose of 10 mg/L.[1,2]