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

Abstract

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 and adjusted 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.