Sono-assisted Adsorption of Nitrate by Fe-modified Chitosan-Zeolite Composite Material
Nitrate pollution has become a significant concern due to its adverse effects on human health and the environment. This study investigates the formulation and determination of the potential of Fe-modified chitosan-zeolite (CZF) composite material as an effective adsorbent for the removal of nitrate. The surface and structural characteristics of the CZF composites were examined using physico-chemical characterizations including, SEM, XRD and FTIR analysis. Experiments have been carried out to determine the influence of various factors involving, the pH of nitrate solution, contact time, adsorbent dose and initial concentration on the adsorption of nitrate under sonication conditions. All the experimental data were perfectly fitted in the Langmuir and Freundlich isotherm model. The maximum nitrate adsorption capacity of the CZF composite was found to be 5.213 mg g−1. Pseudo-first order, pseudo-second order and intra-particle diffusion models were suited for this adsorption study. According to the computed thermodynamic characteristics, the nature of the nitrate adsorption process was spontaneous and exothermic. The adsorbent was successfully regenerated under alkaline condition. Experimental results demonstrate that ultrasonication plays an important role in the increment of nitrate uptake on CZF composite from aqueous solution. Detailed study was done on the causes and side effects of the discharge of nitrate into the water bodies. To find a solution to treat the nitrate in the wastewater, a physico-chemical method was developed using the Fe-modified chitosan-zeolite composite that can absorb the nitrate in the wastewater thereby resulting in nitrate -free water. SEM, XRD and FTIR analysis was carried out to understand the structural morphology and presence of functional groups on the composite material. The nitrate adsorption study was successfully fitted for kinetics, isotherm and thermodynamic parameters. The purpose of desorption study was to reuse the composite material for further adsorption study. This study represents the 95% of nitrate adsorption study with the help of synthesized Fe-chitosan-zeolite composite.