Comparison and analysis of two natural adsorbents of Sorghum and Ziziphus nummularia pyrene for removal of Erythrosine dye from aquatic environments

One pollutant which seriously threatens water resources is dye. Therefore, finding a suitable method to separate the dye in water resources is very important. An adsorption process that uses low cost adsorbents is considered as an efficient strategy for this purpose. In this study, Erythrosine dye removal from an aquatic environment using natural absorbents, namely Sorghum and Ziziphus nummularia pyrene, was reviewed. The effects of different parameters such as pH, contact time, initial density, and the adsorbent amount in the batch system were investigated. The results indicated that increased temperature has no significant effect on the removal of Erythrosine dye, and the highest adsorption was achieved in the first 30 min of adsorbent- dye contact time. Also, most of the adsorption occurred at pH values of 4-8. Moreover, the highest amount of dye removal was observed in a concentration of 20 mg/L for the Ziziphus nummularia pyrene adsorbent and 5 mg/L of the Sorghum adsorbent. Also, the Langmuir and Freundlich equations were used to analyze the adsorption process, where both the Sorghum and Ziziphus nummularia pyrene adsorbents showed a better agreement with the Langmuir isotherm.