Current applications of electrocoagulation in water treatment: a review

Abstract

a b s t r a c tElectrocoagulation (EC) is known as an environmentally friendly technology for treatment of water or wastewater through a combination process of coagulation, oxidation and flotation. The rapid development of industry and agriculture, as well as the ineffective disposal of waste, may lead to a substantial increase in the loadings of water treatment. EC can be used for treatment of different types of water such as tannery and dyeing wastewater, organic wastewater, sewage, drinking water and heavy metal wastewater. An effective EC reactor system can show a good treatment efficiency but it requires a good design and operation of EC. Recently, the EC has been developed rapidly toward development of new electrodes and applicable operation modes, and thus more efficient EC systems for treatment of various water pollutants have emerged. In the present work, a brief overview of the recent research dealing with the application of electrodes and the coupling processes of EC with other technologies are presented.

Development of electrocoagulation process for wastewater treatment: optimization by response surface methodology

“…Rendering to [ 6 , 13 ] hospital is an institution that needs a huge quantity of water and abstemiously releases wastewater to an environment that contains toxic pollutants such as metal oxides, hazardous liquid waste from various units, radioactive waste, bacteria, viruses, blood, fluids, different concentration of chemical oxygen demand (COD) and biochemical oxygen demand (BOD) that affects environments in different aspects [ 14 , 15 ]. A number of technologies are functional to minimize effects of hospital wastewater generated such as ion-exchange [ 16 ], adsorption [ 6 , 17 , 18 , 19 ], coagulation-flocculation [ 6 , 18 ], electro-dialysis [ 20 ], chemical oxidation [ 6 , 21 ], reverse osmosis [ 19 , 22 , 23 ], filtration [ 24 ], ultrafiltration [ 23 , 25 , 26 , 27 ] and activated sludge [ 21 , 28 , 29 , 30 , 31 ], etc., Based on the fundamentals of wastewater treatment techniques, their advantages and disadvantages are summarized in Table 1 .…”

Comparison of batch and novel continuous electrocoagulation processes in the treatment of paint industry wash water

“…Electrocoagulation (EC) has been used since 19th century, and it is known as an environmentally friendly technology. The electrocoagulation process is a combination of coagulation, oxidation and flotation, and gives electricity an important role in water treatment [9]. Electrocoagulation studies have been done in many different fields like the agriculture and food industry [17,18,19], nutrient removal [20,21,22], microbial, bacterial or pharmaceutical removal [23,24,25], metal removal [26,27,28] and other industrial water treatments [29,30].…”

“…There have been several different electrocoagulation systems invented since early 20 th century. [9,10,11].…”

“…There are two main types of electrocoagulation treatment: continuous and batch. In the literature many different kinds of systems for both of these processes can be found [9,10,11,12]. Some earlier continuous processes are modifications of batch processes like those that Makesh et al [13,14] used.…”

Investigation on operating parameters and cost using an electrocoagulation process for wastewater treatment

“…According to (Moussa et al 2017), physical treatment is a process that concerns the physical removal of unwanted substances from wastewater without causing any change of biological and physical characteristics of water treated, while the chemical process is the addition of chemicals that react with the pollutants to remove them and the biological unit is done through application or utilization of microorganisms for the biodegradation of pollutants from wastewater. The treatment methods are implemented for the wastewater treatment such as adsorption (Mahesh et al 2016;Liu et al 2017;Kamar et al 2018), coagulation-flocculation (Liu et al 2017;Manilal et al 2017), filtration (Liu et al 2017), ion exchange (Kamar et al 2018), chemical oxidation (Mahesh et al 2016;Sharma and Mane 2017), electrocoagulation (Mahesh et al 2016;Sharma and Mane 2017;Safwat 2020), electrodialysis (Kamar et al 2018), aerobic and anaerobic (Mahesh et al 2016), etc. Electrocoagulation (EC) is important in water and wastewater treatment technology that combines electrochemical, chemical, and physical mechanisms which are based on electrochemically dissolving cationic metallic species in situ by oxidizing a sacrificial anode only with the applying of electric current (Papadopoulos et al 2020). The dissolved electrodes form a coagulant species that destabilize and trap pollutants in water and wastewater in the form of suspended particles causing them to form flocs and precipitate, which results in removing pollutants (Papadopoulos et al 2020).…”