Studies on adsorption/desorption of nitrobenzene and humic acid onto/from activated carbon

This paper reports results of the studies on adsorption of nitrobenzene (NB) and humic acid (HA) from aqueous solution onto activated carbon commercial (ACC) grade. Characterization of ACC showed its meso-porous nature. Fourier transform infra-red (FTIR) spectra of the ACC indicated presence of various types of functional groups on its surface. Thermo-gravimetric analysis exhibited the thermal stability of the ACC up to 300 °C. The adsorption kinetics of NB and HA onto ACC could be represented by pseudo-second-order kinetic model. The adsorption processes could be well described by a two-stage diffusion model. Thermal regeneration showed that ACC could be used for five desorption–adsorption cycles with good efficiency for NB and HA in each cycle.