Zinc(II) removal from model chloride and chloride–nitrate(V) solutions using various sorbents

Zinc(II) complexes removal from aqueous chloride and chloride-nitrate(V) solutions was realized using different type of sorbents such as an ion exchangers of the chelating type (Lewatit MonoPlus TP220, Purolite S984), strongly basic (Lewatit MonoPlus SR7, Purolite A400TL, Dowex PSR2, Dowex PSR3) and weakly basic (Purolite A830) anion exchangers as well as the adsorbent resin Lewatit AF5. The kinetic and equilibrium studies using the static method were carried out in order to examine the rate of zinc(II) removal as well as to obtain the maximum adsorption capacities. The obtained experimental data were analyzed by means of different kinetic and isotherm models as well as the corresponding parameters were calculated. The desorption and reuse studies (three cycles of sorption/desorption) were also discussed. Lewatit MonoPlus TP220 showed the highest efficiency of zinc(II) removal and the maximum sorption capacity was equal to 620 mg/g. The kinetics of zinc(II) sorption is well described by the pseudo-second order kinetic model. The interactions between the sorbent and zinc ions are strong because no quantitative zinc desorption was observed (40% using nitric(V) and sulfuric(VI) acids for Lewatit MonoPlus TP220).