20 - Application of magnetic nanocomposite in adsorptive remediation of synthetic dye-laden wastewater

Abstract

Indiscriminate disposal of dye-loaded wastewater in the aquatic ecosystem is leading to serious water pollution due to the toxic health effects of synthetic dyes. Thus to eradicate the detrimental effects of dyes studies are being conducted on the abatement of dye from wastewater. Although several treatment methods are being employed for dye-laden wastewater treatment, the adsorption process has garnered widespread attention as a cost-effective dye abatement process owing to the significant developments in the field of nanotechnology and subsequent development of a wide spectrum of low cost nanosized adsorbents which possess strong affinity toward dye species. Among several nanosized adsorbents, magnetic nanocomposites have the significant advantage in terms of their facile separation from the solution. In this chapter recent developments and application of magnetic nanocomposite in adsorptive remediation of synthetic dye-laden wastewater have been reviewed. Thereafter an attempt was taken to fabricate a novel magnetic nanocomposite comprising mixed phase MnFe2O4 and ZrO2 nanoparticles (MnF/ZrO-MNC) and its adsorptive uptake potential for an anionic dye reactive orange 16 (RO 16) was evaluated. The MnF/ZrO-MNC was characterized broadly with XRD, FEG-SEM, BET surface area, FTIR, etc., to explore its several physicochemical properties responsible for improved adsorptive sequestration of RO 16 dye. In addition, the room temperature vibrating sample magnetometer (VSM) measurements revealed the saturation magnetization of 15.29emug−1 for MnF/ZrO-MNC, which facilitates the easy magnetic separation of nanocomposite from dye solution. The RO 16 dye adsorption experiments exhibited that MnF/ZrO-MNC has enhanced dye sequestration capability (409.84mgg−1) with respect to pure MnFe2O4 (331.13mgg−1) and ZrO2 nanoparticles (284.90mgg−1). The adsorption experimental data firmly follow pseudo-second-order kinetics and the Langmuir isotherm model, thus confirming the monolayer chemical adsorption of dye molecules onto the surface of MnF/ZrO-MNC. Treatment cost analysis revealed that the cost of MnF/ZrO-MNC is 51.75$kg−1, whereas the cost involved in removal of dye is found to be in the range of 176.53–713.49$kg−1 of dye removed depending upon several experimental conditions.