Removal of Pb(ǀǀ), Cu(ǀǀ), and Co(ǀǀ) from wastewater using rice straw

Abstract

The present study deals with the application of rice straw, as low-cost agricultural residues, for the adsorptive removal of pb(II) ,Cu(II) and Co(II) from its aqueous solutions. Effects of adsorbent amount, initial metal ions concentration, pH and adsorption contact time on the adsorption of pb(II) ,Cu(II) and Co(II) were investigated. Scaning Electron Microscope SEM was used to explore the morphology of the studied adsorbent. It was clearly seen that the external surface of rice straw is full of cavities. Practical separation experiments for the above-mentioned cations on rice straw column from aqueous waste solution at 0.5 ml.min-1 flow rate were carried out. Adsorption increases with increasing the pH of the solution for the studied metal ions and also increases with increasing the amount of adsorbent and stay nearly constant for pb(II) ,Cu(II) and Co(II) with no significant increase in percentage removal above 10 g.L-1. Data obtained from column experiment with flow rate of 0.5 ml min-1 showed that values of break-through capacity were found to be 32, 6 and 4 mg g-1 for pb(II) ,Cu(II) and Co(II), respectively which cleared that the percent removal was decreased with increasing the effluent volume.