Dried Leaves of Bougainvillea glabra Plant for the Removal o Lead Ions from Aqueous Solution by Adsorption

Abstract

The presence of heavy metals in wastewater poses a critical environmental issue and there is a tendency to use natural biosorbents to overcome this problem. In the present study, the dried leaves of Bougainvillea glabra (BLB) were chosen as a biosorbent material for lead removal from aqueous solutions. Batch adsorption experiments were performed under various experimental conditions including: contact time, biosorbent weight, initial ions concentration and solution pH. The results showed that lead removal percentage on BLB reached equilibrium after 90 minutes. The maximum percent removal for lead was found as 84.65% at the initial concentrations of 25 mg/l. Data were analyzed by the pseudo first and second order kinetic models and the results indicated that the pseudo-second order model best fitted the experimental data (R2>0.98). The biosorption of lead by BLB was also successfully described by the intraparticle diffusion mechanism. Equilibrium models were also applied to fit the data and the Langmuir model showed the best fit (R2>0.99). Surface characterization of the biosorbent revealed the presence of many active surface groups capable of binding the adsorbate ions. In conclusion, the study revealed that BLB could be suggested as an eco-friendly biosorbent for the removal of lead ions from aqueous solutions.