lead adsorption from synthetic wastewater by prosopis mimosaceae sawdust

background lead is a toxic metal with a poor electrical conductivity. this metal can be hazardous and poisonous even in low concentrations. objectives the objective of this study is the evaluation of prosopis mimosaceae sawdust as a low-cost adsorbent for removal of the lead from effluents. materials and methods the experiment was conducted in a batch system and the effect of ph, the amount of adsorbent, contact time, and the initial concentration of lead were examined. the most common isotherms and kinetics of adsorption were applied to analyze lead adsorption and the reaction rate, also the morphological characteristics of prosopis mimosaceae sawdust were determined before and after the separation process by using scanning electron microscope (sem). results according to the results, the maximum efficiency of lead adsorption was 96.12%, which was obtained in ph of 7, contact time of 30 minutes, and 10 g/l of adsorbent. with the increase of the initial concentration of lead, the adsorbed metal at first increased, but later the removal percentage decreased. the data from this study indicated a good correspondence with both isotherms of longmire and freundlich. the kinetic analysis indicated that lead adsorption is consistent with the second-degree kinetic adsorption model (r2 = 1). conclusions according to the high efficiency of lead removal by the sawdust of prosopis mimosaceae, this method can be applied as an efficient and low-cost method for the removal of lead.