A Survey on Adsorption of Phenol from Aqueous Solutions by Sorghum and Canola and Determination of Adsorption Isotherms and Kinetics

Phenol is one of organic pollutants in industrial effluent and it is toxic to human and environment, so it must be removed before being discharged to environment. Therefore, the purpose of this study was investigating adsorption of phenol from aqueous solutions by sorghum and canola and determination of adsorption isotherms and kinetics
This study was performed in the laboratory at batch scale. The canola and sorghum plants were collected and were dried in the oven at 105AWT IMAGE in 24h and were sieved in 18-30 inches mesh. The variation of pH, dose of adsorbent, contact time, and concentration of phenol were investigated. Different models of isotherms and the rate of adsorption reaction were analyzed by comparing the coefficient (R2) of determination.
The results indicated that by increasing contact time and dose of adsorbent, adsorption amount will increase for both adsorbents, however the adsorption rate remains constant after 75 and 90 for sorghum and canola, respectively. Also adsorption rate remains constant for adsorbent doses higher than 5 g/L. The results showed that phenol removal was highest at a solution pH =3 and an initial phenol concentrantion of 10 mg/L. In these conditions, removal rate for sorghum and canola biomass was equal to 99.1 and 92.4 percent, respectively. The Langmuir equation model and pseudo- second order kinetics provided the best fit for the experimental data to both adsorbents.
Overall, the sorghum and canola plants can be used as effective absorbents to treat the aqueous solution containing phenol.