A novel nano zero-valent iron@chitosan for effective removal of Microcystin-LR: Kinetics and adsorption mechanism

Abstract

Microcystin-LR (MC-LR) is one of the most notorious toxins liberated from cyanobacteria in drinking water sources. In this study, a skillful method access to new nanozero-valent iron @chitosan (nZVIMC) was synthesized by a facile one step method. The as-prepared nZVIMC was employed as an adsorbent for the effective removal MC-LR from aqueous solution. Transmission electron microscopy (TEM) demonstrates that nZVIMC is in quasi-spherical shape with size of around 50 nm, effect of variable parameters such as pH, contact time, initial concentration of MC-LR and adsorption properties of nZVIMC on MC-LR was further investigated. Scanning electron microscope (SEM) reveals that the particles are nearly spherical in shape with agglomeration. The results indicated that good adsorption performance was achieved at an initial pH of 5. The adsorption kinetics of nZVIMC was better fitted by pseudo-secondorder kinetics. The adsorption isotherm data was fitted well to Langmuir isotherm and then to Freundlich model, with an adsorption capacity of 68.9 mg/g at 300K. Thus, we believe that nZVIMC can be used as a low cost material for efficient removal of MC-LR from water.