electrocoagulation

 

The treatment of water and wastewater using electrocoagulation (EC) is a newer method. It combines the benefits of electrochemistry, flotation, and coagulation. Electric current is used in an electrochemical procedure to eliminate dissolved, emulsified, or suspended contaminants from water. Because it is an environmentally benign choice that may create the least sludge, requires no chemical additions, and has the smallest footprint without impacting the water quality after treatment, electrochemical wastewater treatment technology has started to recover attention. 

 Principle of electrocoagulation 

It's essential principle is based on how water molecules respond in a redox reaction to a strong electric field. In the process of oxidizing the anode material, coagulating agents are released, forming metal hydroxide complexes that neutralize particulate materials and produce agglomerates. 

 Working  

A number of processes happen at once when the water moves through the electrocoagulation cell. A metal ion is first injected into the water. Water is hydrolyzed into hydrogen gas and hydroxyl groups on the surface of the cathode. In the meantime, electrons easily flow to destabilize the surface charges on emulsified oils and suspended particles. Large coagulants that trap suspended particles, heavy metals, emulsified oils, and other pollutants occur as the process progresses. In the final downstream solid's separation and filtering process phases, the flocs are eliminated from the water. 

Treatment Steps for Ultimate Effect 

The use of electrocoagulation can be used to both novel and established therapeutic procedures. To meet water quality objectives, the latter stages of solids separation can be carried out utilizing settling tanks, dissolved air flotation, media filtration, ultrafiltration, and other technologies, depending on the application. 

 Purpose of coagulation 

Small particles are combined into bigger aggregates (flocs) by the process of coagulation, which also serves to adsorb dissolved organic materials onto particulate aggregates for later removal during solid/liquid separation. 

Advantages of Electrocoagulation Water Treatment 

Since chemical coagulation/flocculation employs chemical coagulants/flocculants like metal salts or polyelectrolytes, electrocoagulation water treatment has a significant advantage over other methods like chemical coagulation/flocculation (CC/CF). A suitable anode material is electrolytically oxidized to produce the coagulants in situ during electrocoagulation, which produces significantly less sludge. 

Another key benefit of electrocoagulation water treatment over CC/CF and other traditional water treatment techniques is that it can handle oily water, where the presence of an electric current can aid in the electrocoagulation of oil droplets. The method has a variety of uses, including the treatment of wastewater from the oil and gas sector, food industry, paper industry, refinery, and water containing heavy metals. It may also be used to treat wastewater from tanneries and textile mills. 

Application and intended user 

•  Removal of recalcitrant and challenging compounds. 

•  Elimination of color. 

•  Breakdown of emulsions, elimination of detergents and tensioactive. 

•  Improved COD and BOD elimination. 

•  Enhancing the biodegradability of difficult effluents to boost the effectiveness of subsequent treatments. 

•  Adding a simple secondary or tertiary treatment to already established plants. 

•  Future norms and guidelines for rejecting limitations from the EU and other agencies. 

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