Melon (Citrullus colocynthis) husk, a readily available agricultural waste products in Nigeria was used as a low-cost potential adsorbent to get rid of lead from industrial wastewater. Adsorption studies were carried out on NaOH activated melon husks at constant adsorbent mass and adsorbate concentration. The contact time was varied from 1 to 100 minutes at 10 minutes interval. Lead removal was found to be rapid from the first minute and equilibrium was attained within 10 minutes. Lead adsorption by NaOH activated melon husk was found to be less dependent on contact time. Adsorption isotherms correlated well with both Langmuir and Freundlich isotherm models and their R2 values are 1. Experimental data were also evaluated to seek out out kinetic characteristics of the adsorption process. Adsorption process for the heavy metal ion was found to follow pseudo-second order adsorption kinetics with the r2 value of 0.8697. Activated melon husk was found to be efficient as adsorbent in the uptake of Pb(II) ions in industrial wastewater, thus, predisposing it as a suitable alternative for the removal of heavy metals from wastewater.
Keywords: Adsorption, Heavy Metal, Lead, melon husks, wastewater
