Researchers developed a new type of biochar by treating reed powder with CaCl2 and specific heating conditions. This biochar has a high ability to absorb organic pollutants like Bisphenol A. The modified biochar showed a 364.5% increase in adsorption capacity compared to the original biochar. The improvement was due to changes in pore distribution, functional groups, aromaticity, and defects in the biochar caused by the treatment process. This study helps in finding better ways to make materials that can effectively remove pollutants from the environment.