Evaluation of removal efficiency of phenol from synthetic aqueous solutions by Citrullus colocynthis seed ash

Background: Phenol is a prevalent pollutant found in many industrial wastewaters, and it is paid singular attention because of its special features like high toxicity, carcinogenic properties, and vital gathering ability that affects the health of humans and the environment. One of the most important technologies for the removal of phenol is the use of adsorbents. The current study investigated the removal of phenol from synthetic aqueous solutions using Citrullus colocynthis seed ash. Methods: This study is experimental and was conducted on a pilot scale. The efficiency of phenol removal by C. colocynthis seed ash was evaluated in a batch system, and different parameters such as initial concentration of phenol (10, 20, 50, and 80 mg/L), contact time (2, 5, 10, and 30 minutes), pH (2-12), adsorbent dose (0.5, 1, 3, 5, and 10 g/L), and temperature were studied. Excel software was used for data analysis. The adsorption process was modeled with Freundlich and Langmuir isotherms at controlled temperatures. Results: The results showed that the highest removal rate of phenol was obtained at a pH of 2 (83.4%), initial phenol concentration of 20 ppm (66.4%), adsorbent dose of 5 g/L (86.8%), and contact time of 10 minutes. The evaluation of correlation coefficients showed that the phenol adsorbed by C. colocynthis seed ash was in greater accordance with the Freundlich model than the Langmuir model. Conclusion: In general, the results of this study revealed that C. colocynthis seed ash has suitable potential for use in removing phenol from aqueous solutions on operation and practical scales due to its low cost and easy access.