Surface functionalized plant residue in cu2+ scavenging: Chemometrics of operational parameters for process economy validation

Abstract

Wastes obtained from the nuts of dika fruits (Irvingia gabonensis) were treated with EDTA in surface functionalization for the adsorption of Cu2+. EDTA functionalized Irvingia gabonensis (EIG) showed strong stretching vibration of C=O. Morphological appearance of EIG showed fibrous appearance of agrowastes while the Branneur-Emmer-Teller (BET) surface area was low. Optimum pH was obtained to be 5 while adsorption equilibrium time was rapid. The adsorption data fitted best into the Freundlich adsorption isotherm and the Langmuir maximum monolayer adsorption capacity was 73.53 mg/g. The Pseudo-second order kinetics model best described the kinetics of the Cu2+-EIG adsorption system. The adsorption energy of the Dubinin-Radushkevich modeling was 5.51 kJ/mol, indicating that Cu2+ uptake onto EIG was a more of physical in nature. Correlation analysis validated the strength of relationship between concentration, equilibrium time and quantity adsorbed. The regression model estimated using the ordinary least square estimator (OLSE) indicates that every 1 unit temperature change will cause a 20.5 % uptake of Cu2+ thus presented an economical process.

Keywords

• Irvingia gabonensis, Chemometrics
• Cu2+
• Process economy