Biosorption of Congo Red from Aqueous Solution using Wheat Bran and Rice Bran: Batch Studies

Abstract

The batch adsorption experiments were carried out using low-cost agricultural by-products, wheat bran and rice bran, for the removal of Congo red from aqueous solution at pH 8.0 and temperature of 25°C. Effects of important parameters such as contact time, adsorbent concentration, adsorbent modification and ion strength were investigated. The raw biomass and loaded Congo red biomass were characterized by FT-IR. The pseudo-first order equation and pseudo-second order equation were tested and the results showed that adsorption of Congo red followed the pseudo-second order very well. The Langmuir and Freundlich equations were applied to the data related to the adsorption isotherms and the observed maximum adsorption capacities (q m ) were 22.73 and 14.63 mg g−1 for wheat bran and rice bran, respectively. The effects of adsorbent concentration and ionic strength on the Congo red adsorption were marked. The adsorption performance has been significantly improved using rice bran modified by .