By: Mohammad radhi bin md imran (55102215045)

By: Mohammad radhi bin md imran (55102215045)Electrocoagulation

What is electrocoagulation???Technique used for wash water treatment, wastewater treatment, industrial processed water, and medical treatment. It has proven very effective in the removal of contaminants from water. Electrocoagulation systems have been in existence for many years using a variety of anode and cathode geometries.

Fig. 1) Bench-scale EC reactor with mono polar electrodes in series connection

MethodologyThe conductive metal plates are commonly known as sacrificial electrodes. The sacrificial anode lowers the dissolution potential of the anode and minimizes the passivation of the cathode. Mono polar electrodes with cells are arranged in series. In series cell arrangement, higher potential difference is required for a given current to flow because cells connected in series have higher resistanceDuring electrolysis, positive side undergoes anodic reactions, while on negative side, cathode reactions are encountered. Coagulation process will initiated by neutralizing charges of particles by released ions. The released ions remove undesirable contaminants either by chemical reaction and precipitation, or by causing the colloidal materials to coalesce, which can then be removed by flotation.

Water containing colloidal particulates, oils, or other contaminants move through the applied electric field, there may be ionization, electrolysis, hydrolysis, and free-radical formation which can alter the physical and chemical properties of water and contaminants. The reactive and excited state causes contaminants to be released from the water and destroyed or made less soluble.

Video presentation

Comparison AdvantagesRemoves heavy metals as oxides that pass Toxicity characteristic leaching procedure (TCLP)Removes suspended and colloidal solids, Breaks oil emulsions in water.Removes fats, oil, and grease.Removes complex organics Destroys and removes bacteria, viruses and cystsDisadvantages The use of electricity may be expensive in many places.An impermeable oxide film may be formed on the cathode leading to loss of efficiency of the EC unit.High conductivity of the wastewater suspension is required.Gelatinous hydroxide may tend to solubilize in some cases.

Applications of electrocoagulationGround Water CleanupSurface Water CleanupProcess Rinse Water and Wash WaterSewage TreatmentCooling TowersWater Pretreatment