For the selective removal of arsenate (As(V)) a hybrid sorbent was prepared using a non-toxic natural organic material, chitosan, by loading a transition metal, nickel. The immobilization of nickel was achieved by coordination with a deprotonated amino group (NH2) in the chitosan polymer chain. The amount of nickel was directly correlated to the presence of the amino group and was calculated to be 62mg/g. FTIR spectra showed a peak shift from 1656 to 1637cm-1 after Ni2+ loading, indicating the complexation between the amino group and nickel, and a peak of As(V) was observed at 834cm-1. An increase of sulfate concentration from 100mg/L to 200mg/L did not significantly affect As(V) sorption, and an increase in the concentration of bicarbonate reduced the As(V) uptake by 33%. The optimal pH of the solution was determined at pH 10, which is in accordance with the fraction of HAsO4 2- and AsO4 -3. According to a fixed column test, a break through behavior of As(V) revealed that selectivity for As(V) was over sulfate. Regeneration using 5% NaCl extended the use of sorbent to up to uses without big loss of sorption capacity.
Bibliographical noteFunding Information:
This work was supported by Nano-Convergence Foundation ( www.nanotech2020.org ) funded by the Ministry of Science, ICT and Future Planning (MSIP, Korea) & the Ministry of Trade, Industry and Energy (MOTIE, Korea) [Project Number: R201400210] and the Korea Institute of Science and Technology (KIST) institutional program (2E25311).
© 2015 Elsevier B.V.
- Polymeric ligand exchagner