Sugar beet pulp is an abundant, renewable and
low-cost precursor for production of activated carbon. In the
present study, sugar beet pulp based activated carbon was
prepared by using phosphoric acid as activating agent for
adsorption of methylene blue. The conditions of preparation
process had a significant influence on the adsorption of
methylene blue, and the optimal preparation conditions were
obtained as follows: liquid-to-solid ratio of 5, temperature of
450 C and phosphoric acid concentration of 3 mol/L. The
properties of sugar beet pulp based activated carbon were
characterized by nitrogen adsorption isotherm. The adsorption
increases as the increase of contact time, adsorption
temperature and pH, and initial concentration of methylene
blue. Batch kinetic studies showed that an equilibrium time
of 100 min was needed for the adsorption, and the adsorbance
of methylene blue is 244.76 mg/g at equilibration.
Kinetic models, Weber’s pore diffusion model and Boyd’s
equation were applied to the experimental data to study the
mechanism of adsorption and the controlled step. The results
showed that the adsorption kinetics followed the pseudosecond-
order type kinetic model, intraparticle diffusion was
not the rate-limiting mechanism and adsorption process was
controlled by film diffusion.