Investigation of plant seeds as adsorbents for lead and copper ions from aqueous solutions: Batch studies

Global water scarcity and environmental degradation by pollutants have led to researches into possible water sources and amongst them the investigations of different wastewater treatment options to remedy the situation. This study investigated the different plant seeds from Acacia Erioloba, Combretum Apiculatum and Adansonia Digitata on the removal of Lead and Copper ions from aqueous solutions through adsorption process. The corresponding points of zero charges of the plant seeds, respectively, were 5.1, 6.0 and 5.3. The removal efficiencies for lead and copper ions for the three adsorbents exceeded 90%. Batch kinetic results revealed that Pseudo-Second-Order reaction fitted the experimental data better than Pseudo-First-Order reaction model. The Intraparticle diffusion model was not solely controlling the rate of adsorption but other mechanisms were involved as well. The adsorption isotherm data was best described by the Temkin equation compared to the Langmuir and Freundlich equations. Further studies such as influence of temperature, pH and fixed bed columns should be investigated.