Application of the response surface methodology (RSM) in heavy metal removal from real power plant wastewater using electrocoagulation

Abstract

In this study, application and efficiency of electrocoagulation (EC) in the removal of nickel and iron from real powerplant wastewater was evaluated. Fe electrode (St 12) was used as anode and cathode, connected with parallel monopolar configuration. Tests were conducted in two phases. Phase I mainly focussed on changing the range of the parameters to attain the possible range in which the tests can be conducted and also reached the optimum efficiency. A stirred batch reactor was used to define the test parameters range, including initial pH, electrical current (A), electrode distance (cm) and electrolysis time (min). Then, phase II of this study was conducted using the response surface methodology to design and optimise operational parameters. Outcomes indicated that considering pH = 8.1, d = 1 cm, I = 1.5 A and t = 18 min as operational conditions can result in 99.9% removal efficiency. Remarkably, the high correlation between experimental and predicted values (R²=99.5% and 99.6% for iron and nickel, respectively) demonstrated that the EC process is a promising method to remove heavy metals from power plant wastewater.

Keywords:

• Heavy metals
• electrochemical
• Fe electrode
• optimisation
• Minitab

Acknowledgments

The authors thank the deputy of Environmental Engineering laboratory of Civil & Environmental Engineering of IUST for their funding and technical support.

Disclosure statement

No potential conflict of interest was reported by the authors.