LAUSR

ABSTRACT The pollution of water by toxic dye materials poses life-threatening havoc to aquatic organisms and terrestrial life. To keep water potable and clean of these toxic chemicals, research has been focused on developing efficient and eco-friendly materials to remove these effluents from water. In the present study, a CuO/NiO-biomass micro-/nano-composite adsorbent was fabricated using the seed pod of Bauhinia tomentosa to remove methylene blue (MB) from wastewater. Adsorbent characterization was done by Fourier transform infrared spectroscopy, UV-Vis Spectroscopy, scanning electron microscopy, dynamic light scattering, pH of point zero charge, and energy-dispersive X-ray. Results showed the formation of heterostructure particles having cavities and pore spaces that were loaded with MB molecules after adsorption. Adsorption was optimum at pH 12, reaching equilibrium in 30 min and occurring through chemical interaction between the adsorbent and MB molecules at a rate of 0.01 g/mg/min. Isotherm modeling of the adsorption process favored the Freundlich model, indicating the presence of several layers of dye molecules on the adsorbent at maximum monolayer capacity of 770.96 mg/g. Desorption experiments revealed that optimum regeneration of CuO/NiO-BTSP can be achieved using as low as 0.1 M HNO3.