The use of grinded white kidney beans to remove the congored dye from aqueous solutions by adsorption

The present study was conducted to evaluate the efficiency of white kidney beans as low cost adsorbent of the Congo red dye. The results show that the best contact time was 90 mints with removal efficiency (R%) 73%, the results also that there was a direct correlation between the increase in the adsorbent weight and the increase in R%, with R% up to 76.7 , while the initial dye concentration does not affect the adsorption process. From the results it been noticed that the adsorption of the congo red dye was the highest in the acidic medium with R% 73.3 and the lowest R% was observed in the alkali medium. The isotherm studies show that the freudlish isotherm fit well with experimental data rather than the Langmuir isotherm.