Application of experimental design methodology to optimize acetaminophen removal from aqueous environment by magnetic chitosan@multi-walled carbon nanotube composite: Isotherm, kinetic, and regeneration studies

Acetaminophen is a widely used drug worldwide and is frequently detected in water and wastewater as a high-priority trace pollutant. This study investigated the applicability of the adsorption processes using a composite of magnetic chitosan and multi-walled carbon nanotubes (MCS@MWCNTs) as an adsorbent in the treatment of acetaminophen. The model was well fitted to the actual data, and the correlation coefficients of R² were 0.9270 and 0.8885, respectively. The maximum ACT removal efficiency of 98.1% was achieved at ACT concentration of 45 mg L^-1, pH of 6.5, MCS@MWCNTs dosage of 400 mg L^-1, and the reaction time of 23 min. The result shows that BET specific surface area of 640 m² g^-1. The adsorption isotherms were well fitted with the Langmuir Model (R² =0.9961), depicting the formation of monolayer adsorbate onto the surface of MCS@ MWCNTs. The maximum monolayer adsorption capacity of 256.4 mg g^-1 was observed for MCS@MWCNTs. The pseudo-second order kinetic model well depicted the kinetics of ACT adsorption on MCS@MWCNTs (R² =0.9972). Desorption studies showed that the desorption process is favored at high pH under Alkaline conditions. The results demonstrate that the MCS@MWCNTs is an efficient, durable, and sustainable adsorbent in water purification treatment.