Removal of Lead (II) and Iron (II) ions from Aqueous Solutions Using Watermelon (Citrillus Lanatus) Peels as Adsorbent

This present work illustrates the adsorption of iron (II) and lead (II) ions from aqueous solutions onto watermelon peels. The research was carried out to assess the possible use of watermelon peels as a low cost adsorbent. The influence of the following factors; solution pH, temperature, contact time and initial metal ion concentration on the adsorption capacity has been studied. The percentage removal of the metals was observed to increase with increase in contact time; 10-40 minutes. The adsorption of the metals decrease with increase in temperature indicated the exothermic nature of the reaction. The percentage sorption of the metal ions onto the adsorbent increased with increase in pH and optimum sorption efficiency occurred at pH 2 for all the investigated metal ions. The result indicated that the watermelon peels prepared could be used effectively for the adsorption of Fe(II) and Pb(II) ions from aqueous solutions. Langmuir and Freundlich isotherms were also studied and the adsorption conformed to both models but Freundlich model fitted better because of the higher values of the correlation coefficients.

Keywords: Adsorption, Lead (II), Iron (II), Watermelon, Isotherm.