Acacia bark powder (Acacia crassicarpa) is a biomass that contains cellulose, lignin and hemicellulose as active sites of adsorbent. The purpose of this study was to determine the adsorbent dose, pH and optimum adsorbate concentration as well as the adsorption isotherm model of Rhodamine B by acacia bark powder (Acacia crassicarpa). The method used in this research is batch system adsorption.…