Removal of copper ions from aqueous solution by papaya seeds

Abstract

Biosorbent has caught the attention in recent days because of its cheap price and its availabilty. Papaya seed is one of the biosorbent which can be obtained easily from Malaysia. Biosorbent was used to remove heavy metal in a simple and cheaper ways as compared to other conventional methods. This research was conducted to study how different parameters affect the adsorption capacity of the papaya seeds. The parameters include pH of the solution, initial metal ion concentration, biosorbent dosage and agitation rate. The results showed that the optimum condition for the removal of copper is at pH 5, copper solution with 200 mg/L, biosorbent dosage of 0.8 g and agitation rate of 200 rpm by using working volume of 150 mL. The highest percentage removal of copper was observed with 93% at 200 rpm and the equilibrium time reached at 90 minutes. The Field- Emission Scanning Electron Microscope and Fourier Transform Infrared Spectrometer analysis revealed that the adsorption was observed by the changing of the rough surface of papaya seeds to smooth surface of papaya seeds and also the –OH group was involved during the adsorption process.