Heavy metals removal from aqueous environments by electrocoagulation process– a systematic review

Heavy metals pollution has become a more serious environmental problem in the last several decades as a resultreleasing toxic materials into the environment. various techniques such as physical, chemical, biological, advancedoxidation and electrochemical processes were used for the treatment of domestic, industrial and agriculturaleffluents. the commonly used conventional biological treatments processes are not only time consuming but alsoneed large operational area. accordingly, it seems that these methods are not cost-effective for effluent containingtoxic elements. advanced oxidation techniques result in high treatment cost and are generally used to obtain highpurity grade water. the chemical coagulation technique is slow and generates large amount of sludge.electrocoagulation is an electrochemical technique with many applications. this process has recently attractedattention as a potential technique for treating industrial wastewater due to its versatility and environmentalcompatibility. this process has been applied for the treatment of many kinds of wastewater such as landfillleachate, restaurant, carwash, slaughterhouse, textile, laundry, tannery, petroleum refinery wastewater and forremoval of bacteria, arsenic, fluoride, pesticides and heavy metals from aqueous environments. the objective of thepresent manuscript is to review the potential of electrocoagulation process for the treatment of domestic, industrialand agricultural effluents, especially removal of heavy metals from aqueous environments. about 100 publishedstudies (1977–2016) are reviewed in this paper. it is evident from the literature survey articles thatelectrocoagulation are the most frequently studied for the treatment of heavy metal wastewater.