Abstract
Background: Benzene is one of the most hazardous organic pollutants in groundwater. The removal of benzene
from water is very important from a health point of view and for environmental protection. In this study, benzene
adsorption kinetics was investigated using phosphoric acid activated carbon, prepared from rice husk.
Results: An initial rapid uptake of benzene was observed and became almost constant after 40 minutes of contact.
Kinetic data was analyzed using pseudo first order, pseudo second order, and Elovich equations. Kinetic data was
well fitted to pseudo-second order models (R2 = 0.98), indicating chemisorption. Results from intraparticle diffusion
and Boyed models indicate that particle diffusion is the most probable operating mechanism and does not control
the kinetics of benzene sorption. A comparative study on the benzene adsorption revealed that the rice husk
carbon (RHC) had better benzene adsorption capacity (365 mg/g) as compared to other adsorbents.
Conclusions: In conclusion, we have demonstrated that rice husk carbons are efficient benzene adsorbents and
that they possess a good potential for benzene removal in wastewater treatment.
Keywords: Benzene, Adsorption kinetics, Rice husk, Chemical activation