Synthesis and Adsorption Potential of Bc/Feooh Nanoparticles Using Oil-Squeezed Black Cumin (Bc) Seeds as a Waste Material

Abstract

In this study, oil-squeezed black cumin seeds (BC), a waste material, were treated with NaOH to enhance the surface area and were evaluated to synthesize a BC/FeOOH/MnO2 hybrid adsorbent for crystal violet (CV) dye removal from aqueous media by adsorption process in a batch system. The effects of initial pH (3-11), adsorbent dose (0.25-1.5 g/L), reaction time (5-60 min), and initial dye concentration (50-200 mg/L) were investigated. Fourier transform infrared spectroscopy ( FTIR) and scanning electron microscopy (SEM)/ energy-dispersive x-ray spectroscopy (EDX) analyses were made before and after the adsorption process. The synthesized adsorbent has a weight ratio for Mn, Fe, Na, and Ca of % 37.29, 26.18 %, 4.38 %, and 0.84 %. The characteristic peaks of FeOOH and MnO2 were observed in the FTIR spectrum. SEM/EDX analysis confirmed the spherical flower-like architecture of MnO2 and rod-like structure of FeOOH nanoparticles. Doping FeOOH and MnO2 gave an advantage to the adsorption of cationic CV to the OH groups. In the FTIR analysis of adsorbent after adsorption, vibration bands of C-N and stretching of CH3 groups with C-H bands were observed, which may verified the CV adsorption. Optimum adsorption conditions were determined for pH of 7.2(natural), adsorbent dose of 1.5 g/L, and initial dye concentration of 50 mg/L. The dye removal efficiency and adsorbed amount of dye were calculated as 94.29% and 31.42 mg/g. The adsorbent showed a good adsorption capacity for CV.