Abstract
Present work used squeezed processed
Nigella sativa
seeds (PSNS) for water remediation for the first time. (PSNS) has no recorded use in literature. Present work used
Nigella sativa
seeds after extracting oil which have several medical uses. PSNS shows high performance for water remediation according to present study, in addition it is safe edible material. Processed squeezed
Nigella sativa
seeds (PSNS) were used for the removal of cadmium and nickel ions form the aqueous solutions. PSNS was characterized by energy-dispersive X-ray spectroscopy (EDS) which indicate that major elements present in PSNS surface are carbon, nitrogen and oxygen elements with other minor elements such as potassium, calcium and magnesium, and Fourier-transform infrared (FTIR) before and after metal ion removal to indicate functional groups responsible for the adsorption. Scanning electron microscopy (SEM) images and Brunauer–Emmett–Teller (BET) indicate the low porosity of PSNS and small surface area. Batch experiments were conducted to study metal ions removal indicated that Cd and Ni ions required 30 and 60 min to reach equilibrium respectively. Studies on metal ion solution pH indicated that pH 5 and 4 have the highest metal ion removal for Cd and Ni respectively. As PSNS Particle size decrease the amount of the metal ions removed increases. isothermal studies indicated that adsorption of Cd fit to Langmuir isotherm and Ni to Freundlich isotherm. Kinetic studies showed that adsorption of Cd and Ni fit to pseudo second order kinetic model which means that adsorption on PSNS is chemisorption with adsorption capacity of 9.78 and 4.53 mg g
–1
for Cd and Ni ions respectively. According to the enthalpy data of thermodynamic study, adsorption of Cd is exothermic process, but it is endothermic for Ni ion.