Acid treated corn stalk adsorbent for removal of alizarin yellow dye in wastewater

Abstract

Wastewaters generated from textile industry are mostly contained high concentration of dyes pollutant. Commercial dyes are difficult to treat due to their complex structure and synthetic origin. An untreated dye discharged through the wastewater system affect the environment. Most of the conventional methods that have been used for the treatment of dye-containing wastewater had resulted in varying degree of success. In the present study, corn stalk residue from the corn industry has been used to remove the Alizarin Yellow (AY) dye. The corn stalk was treated by hydrochloric acid (HCl) in order to improve the porosity of the adsorbent for the AY dye removal. The adsorption capacity and percentage removal of AY dye at varying adsorbent dosage, initial AY dye concentration and adsorption time onto acid treated corn stalk adsorbent sample was examined by using UV-Vis spectrometer. The percentage removal and adsorption capacity increases with the adsorbent dosage, initial dye concentration and adsorption time. Maximum AY dye percentage removal of 75.85% was achieved using 0.6 g corn stalk adsorbent at 20ppm AY dye concentration. The adsorption increases rapidly in the first 10 min to about 70% and extending the adsorption time do not further increase the adsorption of the AY dyes. Adsorption data were modelled using Langmuir and Freundlich isotherms. Both models adequately described the adsorption process with RL value of 0.049 (0<RL<1) for Langmuir and n value of 0.028 (n greater than 1) for Freundlich model which indicated that the adsorption was favourable. These results showed that acid treated corn stalk has the potential to be employed as an effective absorbent for the removal of dyes from wastewater.