Novel alginate particles decorated with nickel for enhancing ciprofloxacin removal: Characterization and mechanism analysis.

The extensive occurrence of antibiotics (such as ciprofloxacin) in aqueous environment had raised severe concerns due to their impacts on humans and the ecosystem. In this study, a novel nickel alginate particles adsorbent had been successfully developed by combining an alginate matrix with nickel ion through immobilization and crosslinking technology and then was applied for the batch adsorption study of ciprofloxacin to evaluate its potential performance. The as-prepared adsorbent exhibited excellent adsorption performance at the condition of the pH 7 and 328.15 K, and the results indicated that the maximum adsorption capacity was 135.18 mg g-1. The isotherm and kinetic studies were well fitted to the Langmuir and pseudo-second-order models, respectively. A thermodynamics analysis displayed that the ciprofloxacin adsorption process was endothermic, feasible and spontaneous. The as-prepared adsorbent before and after adsorption was characterized through SEM, EDX and XPS analyses, and the particle size of the as-prepared adsorbent was roughly 914 µm. Hydrogen bond, the cation bonding bridge and n-π electron-donor-acceptor interaction might be the driving force of the ciprofloxacin adsorption process. This study demonstrated that this as-prepared adsorbent was a promising and efficient material for the ciprofloxacin adsorption from the aqueous solution.