Decolorization of reactive red 198 by adsorption onto ZnCl 2 activated pistachio hull wastes

 In the present study, activated carbon obtained from pistachio hull waste ash was used as an adsorbent for the successful removal of reactive red 198 dye from aqueous solutions. 

 The effect of various operating parameters such as initial concentration of dye (20-200 mg/L), contact time (5-270 min), adsorbent dosage (0.1-5 g/L) and pH (2-12) was investigated. Furthermore, equilibrium isotherms were used to identify the possible mechanism of the adsorption process. 

 Maximum adsorption capacity of the adsorbent was 253.67 mg/g at pH 2, initial concentration of 80 mg/L and 25°C, when 95.13% of the dye was removed. Furthermore, the equilibrium data were also fitted to the Langmuir and Freundlich equilibrium isotherm models. It was found that the data fitted to Freundlich (R2 = 0.9289) better than Langmuir (R2 = 0.8839) model. 

 It was concluded that the activated carbon obtained from pistachio hull waste ash can be used for dyes removal from water and wastewater.