Dye disappearing act: unveiling the mystique of Acid Violet 4BS adsorption with Xanthium strumarium–derived activated carbon

In a reasoned world, color in contemporary society functions as a powerful tool to communicate information, evoke emotions, and influence decisions. This research paper focusing the benefits of activated carbon for adsorbing Acid Violet 4BS (namely AV4BS) in wastewater, utilizing Xanthium strumarium L. (namely XS) seed. Activated carbon extracted from the seed is characterized by FTIR, EDS, XRD, and SEM. FTIR analysis revealed the characteristic peaks for dye adsorption on the carbon surface. EDX revealed the presence of a significant amount of carbon, and its amorphous nature is confirmed by XRD analysis. The carbon surface area is determined by the acetic acid method, which found it to be 323 m²/g. The BET analysis reveals a surface area of 303 m²/g, and the calculated point charge of carbonized XS is 7.0 respectively. The optimal adsorption of 100 mg of activated carbon is found at pH = 2 and 40 °C. Adsorption of initial dye concentrations ranging from 20 to 70 mg/L for the duration of 90 min was found to be 96 to 79%. Adsorption kinetics followed pseudo-second-order kinetics. Langmuir and Freundlich isotherm models confirm the adsorption equilibrium, and statistical analyses such as the chi-squared (χ²) test and root-mean-square error (RMSE) back up the findings. The thermodynamic study confirmed the feasibility and spontaneous nature of the adsorption of AV4BS by carbon from Xanthium strumarium L. (XS) seed, making it a low-cost adsorbent for dye removal from wastewater, and therefore, it is an affordable cost adsorbent for the dye removal from wastewater.