Chemometrics validation of adsorption process economy: Case study of acetaminophen removal onto quail eggshell adsorbents

Abstract

The potential of quail eggshells for acetaminophen (PCM) removal in aqueous solution was studied. Calcination greatly increased the surface area of the raw quail eggshell (RQES). Hence, surface area as determined by the Brunauer-Emmet-Teller (BET) surface and porosity analyzer are 680.80 m2/g for RQES while calcinated quail eggshell (CQES) had 927.30 m2/g. The scanning electron microscopic (SEM) analysis revealed pores useful for uptake of PCM. Adsorption process for the uptake of PCM onto RQES and CQES was pH-dependent with optimum pH of 7 and 6 respectively. The Freundlich adsorption isotherms suggested a multilayer adsorption of PCM unto RQES and CQES. The Dubinin Raduskevich (D-R) model best described the adsorption processes. The energy of adsorption obtained from the model for the two adsorption systems were 23.57 and 8.4515 kJ.mol−1 suggesting that chemisorption occurred within the systems. The maximum monolayer adsorption capacities were 10.00 and 15.15 mg/g for uptake of PCM unto RQES and CQES respectively. Pseudo-second-order model best explained the kinetics of the adsorption processes, adsorption process was established to be feasible and feasibility increased with temperature. The process economy validation by Ordinary Least Square (OLS) cum ridge estimator followed by model performance judgment using the test mean squared error (TMSE) revealed 32% and 22.8% in PCM quantity adsorbed per unit changes in time and temperature respectively. Hence, a valid justification for economy friendliness of the prepared adsorbents in acetaminophen removal.

Keywords

• Acetaminophen
• Adsorption
• OLS
• Eggshell