Removal of Pb(II) from aqueous solution using dithiocarbamate modified chitosan beads with Pb(II) as imprinted ions

A novel, bio-based dithiocarbamate modified chitosan beads using Pb(II) as imprinted ions (Pb–IDMCB) were prepared, characterized and applied for selective removal of Pb(II) from aqueous solutions. Batch adsorption experiments were performed to evaluate the adsorption conditions, selectivity and reusability. The results showed that the maximum adsorption capacity of Pb–IDMCB for Pb(II) was 359.68 mg/g, observed at pH 6, 30 °C. Equilibrium adsorption was achieved within 180 min. The kinetic data, obtained at the optimum pH 6, could be fitted with a pseudo-second order equation. Adsorption process could be well described by Langmuir adsorption isotherms and the maximum adsorption capacity was calculated as 500 mg/g. The selectivity coefficient of Pb(II) ions and other metal cations onto Pb–IDMCB indicated an overall preference for Pb(II) ions, which was higher than that of non-imprinted dithiocarbamate modified chitosan beads (NIDMCBs). Furthermore, Pb–IDMCB represented high stability and good repeatability. It indicated that Pb–IDMCB is a very promising biosorbent for selective removal of Pb(II) from aqueous solutions.

► Pb(II) imprinted DTC modified chitosan beads were explored for Pb(II) removal.
► Pseudo-second-order and Langmuir models best described the Pb(II) adsorption.
► The adsorption capacity in low pH was 220.74 mg/g at pH 1 and 30 °C.
► The adsorption selectivity of Pb–IDMCB for Pb(II) was higher than that of NIDMCB.