Comparison of sorption and desorption studies of heavy metal ions from biochar and commercial active carbon

In the first stage on the effectiveness of various operating factors such as: adsorbent dose, contact time, solution pH, initial concentration and temperature on the sorption of heavy metal ions of Cu(II), Zn(II), Cd (II), Co(II) and Pb(II) were carried out using the commercial active carbon Purolite AC 20 and biochar. It was found that the sorption capacity increases with the increasing phase contact time and concentration of the initial solution. It was found that biochar removes more efficiently heavy metal ions from aqueous solutions than the activated carbon. Sorption kinetic data provide a complex mechanism of sorption and better fit of the pseudo second order model than the pseudo first order and the intraparticle diffusion ones. In the second stage the desorption of the above mentioned heavy metal ions from the biochar and commercial activated carbon was conducted. It was proved that biochar has excellent properties and can be used as a sorbent of multi-use 0.1 M HNO3 was the best eluent for desorption of heavy metal ions in the sorption/desorption studies in the third stage. In Order to characterize the mechanism of sorption/desorption for both biochar and activated carbon, the Brunauer Emmett Teller surface area was determined and point of zero charge was measured. Moreover, the elemental analysis and the Fourier transform infrared spectroscopy were applied. The thermogravimetric and derivative thermogravimetric analyses were conducted. (C) 2016 Elsevier B.V. All rights reserved.