Reactive Dye Removal from Waste Water Using Nano Chitosan Particle

Recent studies indicated that chitosan has a high capacity for adsorption of anionic dyes in acidic media. In the present study, chitosan nano-emulsion (CNE) was prepared with a narrow size distribution based on ionic gelation by adding sodium tripolyphosphate (STPP) solution into a chitosan solution (CS). The CNE was further used for the removal of three reactive dyes with different chemical structures, C.I. Reactive Blue ۱۹, C.I. Reactive Red ۱۲۰ and C.I. Reactive Black ۵. The aim of this study was to study the influences of various experimental conditions such as the dye initial concentration, adsorbent amount, particle size, solution pH value, ionic strength of the solution on the adsorption capacity onto chitosan and nano-emulsion. The equilibrium adsorption capacities on the CS and CNE were studied with the adsorption isotherm technique. The effects of the time and temperature on adsorption capacity were evaluated and the adsorption of reactive dyes on CNE was compared to its adsorption on a conventional CS. The experimental data were then fitted into the Langmuir and Freundlich equations. The kinetics behaviors of the adsorption rates were determined quantitatively and compared by the pseudo-first-order and second-order models. The CNE showed a superior adsorption capacity in comparison to CS and the rate of adsorption and reaching to equilibrium occurred faster in CNE. The adsorption isotherm correlated better with Langmuir model and the kinetic results showed that the adsorption process was rapid and followed a pseudo-second-order model.

کلیدواژه ها:

Chitosan ، nano-emulsion ، Reactive dye ، Dye removal ، Adsorption isotherm ، Adsorption kinetics