Biosorption Of Cu(II) Ions From Aqueous Solution Using Azadirachta indica (Neem) Leaf Powder

Abstract

Biosorption is considered as a potential method for the removal of heavy toxic metals from waste solution and as alternative to other conventional process such as precipitation, ion exchange, electrochemical treatment and evaporative recovery, especially, when the concentration of the heavy metal ion is low. In order to qualify for industrial applications, biosorbents have to be produced at low cost. In the present study, (Azadirachta indica) neem leaves Powder (NLP), was investigated for the removal of Cu(II) ions from aqueous solution. Characterisations of the NLP was conducted, and the effects of contact time, particle size, Cu(II) ion concentration as well as effect of chemical treatment were studied in batch process. Batch biosorption experiments were carried out at a fixed adsorbent dosage of 1.0 g/L, initial ion concentration of 100 mg/L, a temperature of 333K and a pH range of between 5-6. The surface area of NLP was found to be about 2.3102 m²/g. The analysis with FTIR indicated that possible hydroxyl and carboxyl functional groups are involved in metal Cu(II) ions biosorption. Adsorption isotherms were modelled by the Langmuir and Freundlich isotherm equations, with the former providing a better fit for the data. Results obtained from this study indicate that NLP is a very promising candidate for the low-cost and high-capacity removal of Cu(II) ions from aqueous solution.

Keywords: Biosorption, Neem leaf powder, Copper(II) ions, Heavy metals, Wastewater