STP based on Electrolytic Coagulation

09 Apr, 2013 . 4 mins read

Author: Harish Madhani

Domestic and industrial wastewater has the following major contaminants that makes the wastewater unsuitable to be discharged in any form anywhere.

1. Dissolved organic and inorganic impurities of which part are bio degradable and rest

Biodegradable
Non biodegradable incalcitrant and toxic.

2. Colloidal mater.
3. Suspended solids.
4. Fats, oil and grease.
5. Detergents.
6. Heavy metals.
7. Colour.
8. Odor causing componenets.
9. Pathogenic and other microorganisms.

Conventional system of wastewater treatment is biological aerobic, anaerobic and chemical.

Aerobic biological systems removes some of the above mentioned contaminants which are easily biodegradable but the rest of the contaminants remain. Such systems occupy lot of space, consumes electrical energy and deplete atmospheric oxygen. To treat 1 MLD wastewater aerobically depletes atmospheric oxygen of 400 kilograms per day. This will need 25 to 30 MLD of air which would be converted into green house gas carbon dioxide. This needs 400,000 treats to supply the oxygen to treat the wastewater aerobically. Biological systems needs to maintain biomass concentration, pH and temperature in the wastewater for better performance. Most of the contaminants mentioned above cannot be removed and prove toxic to the microbes and maintain their concentration. The result therefore the systems eventually fail. These systems have long start up time and cannot be started and stopped at will. More over biological systems are odor causing.

Anaerobic systems are suitable for more concentrated effluents and are prone to major problems as with aerobic system.

Chemical systems removes one contaminant and introduces another.

Electrolytic wastewater treatment systems can remove and treat all of the above mentioned contaminants in small space, consuming less energy, does not deplete atmospheric oxygen, has accelerated start up, can be started and stopped at will, there is no need to maintain biomass concentration, pH and temperature and does not generate odor.

Electro Processors adopts three major electrolytic processes to treat the effluent.

1] Electrolytic Advanced Oxidation

2] Electro Coagulation and

3] Electro Flotation.

1] Electrolytic Advance oxidation :

Oxidation is achieved when an electron is lost or taken away where as reduction is achieved by the gain of electrons. In the process of electrolysis direct oxidation takes place at the surface of the anode where electrons are removed from the organic molecules to directly oxidize it and from a catalyst which is oxidized, becomes an oxidizing agent to oxidize other organic molecules and are reduced. At the cathode reduction takes place at the surface of the cathode which acts as electron donor. Thus in the process of electrolysis REDOX reactions are predominant. At the same time because of some inorganic impurities in effluent generates in situ strong and potent oxidants that helps further in the process of oxidation.

Biological oxidation :

ORGANIC + O2 + bacteria à CO2 + NH3 + energy

Biological synthesis :

ORGANIC + O2 + bacteria + energy à C5H7NO2 (new bacterial cells)

Electro oxidation :

DIRECT ANODIC OXIDATION : ORGANIC - e- à CO2 + H20

AND : Mn – e- à M(n+1) (OXIDIZING AGENT)

INDIRECT CATALYTIC OXIDATION : ORGANIC + M(n+1) à CO2+H20+N2+Mn

Process of electro oxidation is to mineralize the organics where no new bacterial cells are formed or synthesized and therefore does not generate sludge. Where as in the biological system new bacterial cells are synthesized, generating excess biomass as sludge.

2] Electro Coagulation :

Most of the contaminants are charged particles responsible to maintain stability and diffuses double layer. By passing electrical current the charge on contaminants are destabilized compressing the double layer and helps particles to come together. In the process of electrolysis, cations are generated that combine with electrolytically generated anionic hydroxides simultaneously at the cathode by reducing water, having potent coagulating and flocculating properties. These coagulants and flocculants removes even colloidal particles by complexation improving the quality of treatment.

3] Electro Flotation :

Operating the system at the proper voltage and current imparts flotation energy to the coagulated particles that will help them to float on the surface and separated out with a skimmer.

Electrolytic processes are custom designed and can remove all of the above mentioned pollutants from the effluent environmental friendly and is not affected by the toxicity present in the waste stream.

The product is modular in construction and can be built to any capacity.

Contact:

Mr.Harish Madhani
Electroprocessors,
Office 14, 2nd floor Aditya Shagun Mall
Pashan NDA Road Bavdhan
Pune 4110021
Tel 91-20-66750428
Fax 91-20-66750429
M. No. 09823388687