Magnesium hydroxide with higher adsorption capacity for effective removal of Co(II) from aqueous solutions

The removal of Co(II) from aqueous solutions using magnesium hydroxide powders was investigated as a function of pH, reaction temperature, contact time, adsorbent dosage and initial cobalt ions concentration in batch studies. The adsorption process followed pseudo-second order kinetics. Equilibrium data were fitted well in the Langmuir model and the monolayer adsorption capacity of Co(II) ions was determined as 125.00 mg/g at 318 K. Thermodynamic parameters revealed that the adsorption of Co(II) onto magnesium hydroxide was feasible, spontaneous, endothermic, with a increased randomness in nature. Magnesium hydroxide powders were found to be effective in removing Co(II) ion from aqueous solutions since it has a relatively higher adsorption capacity than other adsorbents.

► The adsorption process followed pseudo-second order kinetics.
► Equilibrium data were fitted well in the Langmuir model.
► The adsorption capacity of Co(II) ions was determined as 125 mg/g at 318 K.
► The adsorption of Co(II) onto magnesium hydroxide was feasible, spontaneous, endothermic.