efficient removal of toxic textile dye using petiole part (stem) of nymphaea alba

The removal of toxic textile dye, congo red (cr) an azo based textile dye, was investigated from aqueous solution by low cost, eco-friendly available adsorbents such as petiole part (stem) of water lily (nymphaea alba) under various experimental conditions. batch experiment was carried out at varying ph, dye concentration, contact time and particle size as well as doses of the adsorbent. cr was analyzed by a uv-visible spectrophotometer. optimum ph was found at ph 2 and 6. a relative study was done using sodium chlorite and formaldehyde treated water lily. the maximum removal of cr was obtained 94.68% using untreated water lily (ut-wl). adsorption increased with the increase of the particle size of the adsorbent. the highest removal of cr was found at a lower dose (62.5 g/g) of the adsorbent. the freundlich isotherm model was best fitted to equilibrium data obtained from the experiment. the adsorption kinetics successfully fitted to the pseudo-second-order kinetic model.