Removal of Lead and Cadmium Ions from Aqueous Solutions by Olive Pomace as a Low-Cost Biosorbent

Abstract

In this study, the adsorptive performance of olive pomace on lead and cadmium removal from aqueous solutions was investigated. Process parameters such as particle size, solution pH, contact time, initial ion concentration, and incubation temperature were evaluated by batch experiments. It was found that lead and cadmium adsorption follows a pseudo second order kinetics. Maximum sorption for lead and cadmium ions was obtained at pH 5.5 and 6 as 33 and 8 mg/g, respectively, with 1 g/L olive pomace loading. Adsorption isotherms were best fitted with Redlich-Peterson and Langmuir-Freundlich models for lead and cadmium adsorption, respectively. Thermodynamic calculations revealed that the adsorption process is feasible and spontaneous in nature. Point of zero charge (pHPZC) and BET surface area measurements were performed in adsorbent characterization.