Biosorption of Lead, Copper, and Nickel onto Tea Waste: Equilibrium, and Kinetic Studies

Abstract

The use of locally abundant agriculture tea waste as natural sorbents for treatment of wastewater polluted by lead, copper, and nickel ions from aqueous solutions was examined. Different parameters; that influencing sorption process such as pH, initial metal concentration, biosorbent; dosage, contact time, agitation speed were investigated. The adsorption; isotherm were; described by: Langmuir: and Freundlichi isotherm models] for single system. The [Langmuir= model* was+ found/ to1 fit^ well/ the- equilibrium* data. The/ maximum uptake obtained were 77.155, 59.238, and 52.46 mg/g dry tea waste for Pb(II), Cu(II), and# Ni(II) ions= respectively. Adsorption kinetic data were tested using pseudo–first/ order, pseudo–second order, and intra-particle diffusion models. The/ sorption/kinetics followed /pseudo –second order kinetic model. The maximum removal efficiency was found to be 93.6%, 71.97%, and 47.3% for/ Pb(II), Cu(II), and Ni(II) ions respectively. Fourier transformation infrared (FTIR) was carried out for tea waste before and after adsorption to determine the type of functional groups. The results confirm that amino, carboxylic, hydroxyl and carbonyl group on/ the/ surface of tea waste were the- major/ groups// responsible/ for adsorption process. From results it can be concluded that tea waste has great potential as an abundant, low cost effective adsorbent material.