| dc.description.abstract | Rubber stem bark is a fair amount waste in South Sumatera which is potential to be utilized. This study utilized the rubber stem bark as chromium and lead ion heavy metal biosorbent in the water. The method used was batch method which observation parameters included the influence of biosorbent particle size, pH, and contact time. The optimum condition was determined by Duncan test. Results showed that the optimum condition of Cr(VI) biosorption occured at 100 mesh particle size, pH 2, and 1 hour contact time, whereas the optimum condition of Pb(II) biosorption occur at 100 mesh particle size, pH 7, and 1 hour contact time. Biosorption equilibrium of chromium and lead followed the Freundlich isotherm model (linearity = 98.80% and 93.92%). Maximum adsorption capacity based on the Freundlich equation was 0.55 mg Cr(VI) and 0.98 mg Pb(II) for one gram of adsorbent. | en |
