Adsorption of Congo Red from Solution by Rice Husk in Batch Mode

Rice husk, an agriculture byproduct, was used to adsorb congo red (CR) from aqueous solutions. Variables of the system, including contact time, pH, salt concentration, and equilibrium CR concentration, were adopted to study their effect on CR adsorption. The results showed that when the equilibrium concentration of CR increased, quantity of CR adsorption onto rice husk increased correspondingly. The equilibrium data was fitted well by the Langmuir and freundlich isotherm model. The process was spontaneous and endothermic in nature.