Simulation and optimization of copper, nickel, cadmium, and zinc removal from industrial wastewater using Aspen adsorption and RSM
Yasaman Noorbakhsh, Sara Bozorgghomi, Ahad Ghaemi
Abstract
This study investigates the challenge of heavy metal removal from industrial wastewater, focusing on environmental concerns. Conventional treatment methods are costly, energy-intensive, and produce toxic by-products. This research explores a cost-effective alternative using a weakly acidic resin (CH030) in an adsorption column to remove Copper (Cu), Nickel (Ni), Cadmium (Cd), and Zinc (Zn). The objective was to reduce metal concentrations at the column outlet to levels within the permissible limits set by USEPA standards. Simulation was performed using Aspen Adsorption software, and Response surface methodology (RSM) with central composite design was employed to identify key operational variables and optimize performance. The statistical analysis showed high R² values for Cu (0.9951), Ni (0.9939), Cd (0.9941), Zn (0.9941), and total metals (0.9943), indicating excellent model fitting. Kinetic studies confirmed that the pseudo-second-order model best described the adsorption process, and thermodynamic analysis validated the chemical nature of interactions. Operational parameters such as column height, feed flow rate, and initial metal concentration significantly influenced the adsorption efficiency, with initial concentration being the most influential factor. The optimal conditions were found to be a bed height of 288.27 cm, a flow rate of 9.28 L/s, and an inlet concentration of 301.06 mg/L. The novelty of this study lies in the integrated application of Aspen Adsorption simulation and RSM to simultaneously model and optimize the removal of heavy metals using CH030 resin, offering a scalable solution for industrial wastewater treatment.