Electrochemical treatment of phenolic wastewater: Efficiency, design considerations and economic evaluation

Abstract
Anodic oxidation of phenol at a graphite electrode has shown good treatment efficiency. The removal efficiency was a function of the current applied, with around 70% phenol removal efficiency at a current of 2.2 A. After about 5 months of operation, there was no sign of deterioration of the graphite bed. An empirical relationship was developed relating phenol removal efficiency to the current. The relationship showed excellent prediction of the experimental data. Furthermore, a methodology for calculating the cell capacity was developed. The relation between the cell capacity and phenol residual concentration was modelled using a non linear model. Preliminary design procedure for the electrochemical cell was illustrated and the designs results for nine different wastewater conditions were tabulated. Economic evaluation of the process under different scenarios was presented and compared with other processes.