Removal of dyes using chemically modified elephant grass in single and binary-component system

The present study investigated the potential use of citric acid-treated Elephant grass (Pennisetum purpureum), as an adsorbent for the removal of various dyes (Congo red, Erichrome black T, methyl red, and thymol blue) from aqueous solutions. The effects of initial concentration, adsorbent dosage, and temperature on the adsorption capacity of the dyes were evaluated. The results showed that Pennisetum purpureum had a high adsorption capacity for all dyes, with maximum adsorption efficiencies ranging from 74% to 98.92%, depending on the dye type and experimental conditions. The highest adsorption efficiency was recorded at 10 mg/L initial concentration for most of the dyes. The optimum adsorbent dosage was found to be 0.3 g for all dyes, except for Erichrome black T, which showed maximum adsorption capacity at 0.2 g. The maximum adsorption capacity for all dyes was observed at a temperature of 60°C, except for methyl red and thymol blue, which showed maximum adsorption at temperatures lower than 60°C. Overall, the results indicate that citric acid-treated Pennisetum purpureum has great potential as an effective and sustainable adsorbent for the removal of various dyes from wastewater.