PERBANDINGAN MODEL ISOTERM BIOSORPSI Cd TERLARUT DALAM AIR DENGAN BIOSORBENT ASPERGILLUS NIGER

Abstract

Due to the increasing awareness of the deleterious ecological effects of toxic Cd, the adsorption of Cd from aqueous solutions by Aspergillus niger biomass was studied. The aim of this work was to find the exact adsorption isotherm model to predict the single system adsorption by the Aspergilfus niger biomass. The batch sorption experiments were carried out in 50 ml conical flasks. Weighed amounts (8,5 to 57, 2 mg) of Aspergillus niger biomass were introduced into a number of conical flasks, to which 25 ml of Cd solutions of increasing concentrations from 20,28 to 24,435 mg/L were added. The amount of Cd accumulated on biomass was calculated as the difference between the amount present in control experiments and that remaining in solution after equilibrium with biomass. Four adsorption isotherm models, namely Freundlich Isotherm Model, Langmuir Isotherm Model, Sips Isotherm Model, dan Toth Isotherm Model, were fitted to the experimental data. The Toth Isotherm Model and The Sips Isotherm Model· were superior, which provided the least average relative error (6,035 % and 6,013 %). The maximum sorption was seen at pH 6. ltis 143.093 mglg sorbent.