Comparative sorptive removal of direct red-28 dye from water using acid, base and 2-propanol treated okra stem powder

Summary: Use of agro-waste material for adsorption is studied now-a-days extensively. But the main problem is their low adsorption capacity as compared to synthetic adsorbents. So, in the following study, adsorption capacity of Okra stem powder had been investigated after chemical modification by acid, base and 2-propanol for adsorption of Direct Red-28 dye from water in batch mode. The results indicated that as compared to untreated biosorbent , acid treated and 2-propanol treated biosorbents had more adsorption capacity, i.e. 1.86, 2.74 and 6.61 mg.g/sub -1/ correspondingly, whereas base treated biosorbent had lower adsorption capacity for this anionic dye, i.e.1.02 mg.g/sub -1/. (author)