Removal of Paracetamol from Aqueous Solutions Using Activated Carbon Obtained from Methane Pyrolysis-Derived Carbon...

Paracetamol (PCT), along with other pharmaceutical pollutants, increasingly requires removal from wastewater, whereas carbon black produced via methane pyrolysis can serve as a reliable and sustainable carbon source for the corresponding sorbents. This study evaluates the effect of CO₂-based high-temperature activation parameters (temperature, duration, feed mass, composition of the activating gas) on the morphology, pore architecture, and PCT adsorption performance of activated carbon obtained from methane pyrolysis-derived carbon black. The sorption capacity of the activated carbon with respect to PCT, as well as the effect of initial pH (5-9) on adsorption isotherms and kinetics were studied. Among the investigated activation conditions (800-1000 °C, 60-180 min and different feed masses), the best-performing material exhibited a BET surface area of 712 m²·g^-1 and a total pore volume of 0.44 cm³·g^-1 (predominantly slit-shaped mesopores) and was obtained at 1000 °C for 180 min using a mass of 5.65 g. The resulting sorbent exhibits a PCT capacity of 629 mg·g^-1 in a neutral medium and 718 mg·g^-1 at pH 5. A physisorption mechanism with an adsorption energy of less than 8 kJ·mol^-1 was shown. The kinetics of sorption obeyed a pseudo-second-order model with equilibrium within 5 min. The results demonstrated the potential of using activated carbon produced from carbon black (a product of methane pyrolysis) to remove pharmaceutical contaminants from water.