Adsorption Thermodynamics of Metronidazole on the Conjugated Microporous Polymers

Abstract

Conjugated microporous polymers (CMPs) now attract extensive interests in water treatment as a kind of ideal porous absorbent with tunable porosity, large surface areas, excellent thermal and chemical stability. In this work the adsorption of metronidazole (MNZ) by CMPs was studied. Two kinds of CMPs were used and named as HCMP-1 and HCMP-2, respectively. The adsorption characteristics of MNZ by the two CMPs under different temperatures were investigated. Adsorption kinetics of MNZ on HCMP-1 and HCMP-2 under all tested temperatures fitted the pseudo-second-order model well, and adsorption quantity of MNZ by the two CMPs decreased with the increase in temperature. Adsorption thermodynamics demonstrated that adsorption of MNZ by HCMP-1 and HCMP-2 was spontaneous and exothermic in nature. This work may provide fundamental guidance for the removal of antibiotics by CMPs.