Highly efficient removal of As(V) from aqueous solutions using a novel octanuclear Zn(II)-based polymer: Synthesis, structure, properties and optimization using a response surface methodology

A novel octanuclear Zn(II)-based polymer, (Zn-8(BTEC)(2)(ATZ)(2)(mu(3)-OH)(2)(mu(2)-OH)(4) (H2O)(2)](n) (1), was hydro thermally assembled using 5-amino-l-H-tetrazole (HATZ) with 1,2,4,5-benzenetetracarboxylic acid (H4BTEC). Complex 1 was characterized by single-crystal X-ray diffraction and TG. Owing to its unique characteristics, the ability of the [zn(8)(BTEC)(2)(ATZ)(2)(mu(3)-OH)(2)(mu(2)-OH)(4)(H2O)(2)](n) to remove As(V) from aqueous solutions was investigated (The form of As(V) is AsO43-). A series of experimental conditions of adsorption were studied, which included the pH value, contact time, adsorbent dose, adsorption temperature, initial concentration and shaking speed. The experimental results showed that complex 1 had a higher stable and relatively high (> 98%) As(V) removal rate at pH 7-11. The adsorption process fitted well to the Langmuir model and the pseudo second-order kinetic model. And the optimal adsorption conditions were also examined using a Box-Behnken design response surface methodology. In addition, complex 1 was further characterized by elemental analysis (CHN), photoluminescence(PL), XRD, IR spectroscopy before and after adsorption As (V).