Abstract:
The rapidly expanding global energy demand is forcing a release of regulated pollutants into water that is
threatening human health. Among various wastewater remediating processes, electrocoagulation (EC) has scored
a monumental success over conventional processes because it combines coagulation, sedimentation, floatation
and electrochemical oxidation processes that can effectively decimate numerous stubborn pollutants. The EC
processes have gained some attention through various academic and industrial publications, however critical
evaluation of EC processes, choices of EC processes for various pollutants, process parameters, mechanisms,
commercial EC technologies and performance enhancement via other degradation processes (DPs) integration
have not been comprehensively covered to date. Therefore, the major objective of this paper is to provide a
comprehensive review of 20 years of literature covering EC fundamentals, key process factors for a reactor
design, process implementation, current challenges and performance enhancement by coupling EC with pivotal
pollutant DPs including, electro/photo-Fenton (E/P–F), photocatalysis, sono-chemical treatment, ozonation,
indirect electrochemical/advanced oxidation (AO), and biosorption that have substantially reduced metals,
pathogens, toxic compound BOD, COD, colors in wastewater. The results suggest that the optimum treatment
time, current density, pulse frequency, shaking speed and spaced electrode improve the pollutants removal ef ficiency. An elegant process design can prevent electrode passivation which is a critical limitation of EC tech nology. EC coupling (up or downstream) with other DPs has resulted in the removal of organic pollutants and
heavy metals with a 20% improved efficiency by EC-EF, removal of 85.5% suspended solid, 76.2% turbidity,
88.9% BOD, 79.7% COD and 93% color by EC-electroflotation, 100% decolorization by EC-electrochemical-AO
