Preparation, Characterization and Application of Sulphuric Acid-Treated Soursop (Annona muricata L.) Seeds Powder in the Adsorption of Cu(II) Ions

Abstract

This work presented the adsorption of Cu(II) ions using agriculture waste coming from soursop (Annona muricata L.) seeds. The chemical treatment performed on Annona muricata L. seeds was carried out using 1.0 M H2SO4 solutions. The Fourier-transform infrared (FTIR) spectrophotometer, scanning electron microscope coupled with energy dispersive X-ray (SEM-EDX), pH of point-zero-charge (pHPZC), and pHslurry analyses were done to characterize the surface properties of the adsorbent. Experimental conditions such as contact time, adsorbent dosage, pH, and initial Cu(II) ion concentrations, all of which could affect Cu(II) ions adsorption, were studied. The adsorption kinetics was successfully described by the pseudo-second-order model. The Langmuir and Freundlich models were applied to interpret the Cu(II) ions’ adsorption at equilibrium. The isotherm data fitted well with the Freundlich model and the maximum adsorption capacity was 187.83 mg.g-1 based on the Langmuir model.