Electric Effluent Treatment Plant or Electrocoagulation (EC) Plant :
Process in Electric Effluent Treatment Plant known as Electrocoagulation (EC).
Electrocoagulation (EC) is a technique used for wastewater treatment, industrial processed water, and medical treatment. Electrocoagulation has become a rapidly growing area of wastewater treatment due to its ability to remove contaminants that are generally more difficult to remove by filtration or chemical treatment systems, such as emulsified oil, total petroleum hydrocarbons, refractory organics, suspended solids, and heavy metals.
In the EC process, the coagulant is generated by electrolytic oxidation of an appropriate anode material. In this process, charged ionic species—metals or otherwise—are removed from wastewater by allowing it to react with an ion having an opposite charge, or with floc of metallic hydroxides generated within the effluent.
Electrocoagulation offers an alternative to the use of metal salts or polymers and polyelectrolyte addition for breaking stable emulsions and suspensions. The technology removes metals, colloidal solids and particles, and soluble inorganic pollutants from aqueous media by introducing highly charged polymeric metal hydroxide species. These species neutralize the electrostatic charges on suspended solids and oil droplets to facilitate agglomeration or coagulation and resultant separation from the aqueous phase. The treatment prompts the precipitation of certain metals and salts.
- Sludge formed by EC tends to be readily settable and easy to de-water, compared to conventional alum or ferric hydroxide sludges, because the mainly metallic oxides/hydroxides have no residual charge
- Wastewater treated by EC gives palatable, clear, colorless and odorless water.
- Flocs formed by EC are similar to chemical floc, except that EC floc tends to be much larger, contains less bound water, is acid-resistant and more stable, and therefore, can be separated faster by filtration.
- EC can produce effluent with less TDS content as compared with chemical treatments, particularly if they can be precipitated as hydroxides. If this water is reused, the lower TDS level contributes to a reduced water recovery cost.
- The EC process has the advantage of removing the smallest colloidal particles, because the applied electric field neutralises any residual charge, thereby facilitating the coagulation.
- The EC process generally avoids excessive use of chemicals and so there is reduced requirement to neutralize excess chemicals and less possibility of secondary pollution caused by chemical substances added at high concentration as when chemical coagulation of wastewater is used.
- The electrolytic processes in the EC cell are controlled electrically and with no moving parts, thus requiring less maintenance.