Removal of cobalt (II) ions from aqueous solution by Peganum Harmala seeds

Abstract

The batch extraction of cobalt [Co(II)] ions from an aqueous solution, utilizing the seeds of Peganum harmala has been evaluated in this study. After gathering Peganum harmala, the plants are beaten to separate the seeds, after which the seed undergo a fine filtration process to remove any debris. The prepared adsorption material is defined by Fourier transform infrared spectroscopy (FTIR). The adsorption process is conducted an incubator in 50 mL flasks. The studied process variables included pH, contact time, Co(II) concentration, adsorbent dose and reaction temperature. Co(II) is assessed with the use of a UV-vis spectrophotometer at a wavelength of 512 nm. Optimal Co(II) removal is noted at a pH of 6; increased alkalinity resulted in the generation of cobalt hydroxide. When contact time is increased from 5 to 40 min, the removal of Co(II) ions increased from 8 to 88%. This represented the maximum adsorption of Co(II) into Peganum harmala. After this time, equilibrium was achieved, with no further Co(II) extraction occurring. The higher the dose of adsorbent, the higher the degree of Co(II) ion removal; increasing the adsorbent from 0.1 to 0.4g/L result in an increase in extraction from 60 to 84%. A larger dose of adsorbent, up to 0.5 g/L, diminished further Co(II) ion subtraction. The Langmuir adsorption isotherm show a superior model fit compared with the Freundlich isotherm.