Increasing energy efficiency and lowering the footprint of sewage treatment plants have been the two major factors impacting the development of STPs. Electrocoagulation is a key process in water treatment that achieves both these goals. The process uses electricity instead of expensive chemical reagents to remove contaminants from process water.
Electrocoagulation provides active cations needed for water coagulation without increasing water salinity. It can filter contaminants that are generally more difficult to remove by filtration or chemical treatment systems.
The substances that electrocoagulation can remove from water include:
- Suspended solids
- Emulsified oil,
- Total petroleum hydrocarbons,
- Refractory organics
- Heavy metals
Due to its higher efficiency and lower footprint, Electrocoagulation is on the verge of replacing coagulation and flocculation in water treatment.
How Electrocoagulation process works
The Electrocoagulation system consists of three major components: A power supply, the EC cell housing, and the electrodes. When process water enters the EC tank, multiple reactions occur simultaneously.
First, on the surface of the anode, a metal ion is driven into the water. At the same time, on the surface of the cathode, water is reduced to hydrogen gas and hydroxyl ions. While this happens, electrons flow freely from the cathode to the anode. This third action destabilizes the surface charges on emulsified oils and suspended solids.
As the reactions occur, metal ions combine with hydroxyl ions to form a large flox that includes metals and other contaminants. Due to the destabilization of surface charges, emulsified oils and suspended solids are caught within the flock. The flock is then lifted to the surface of the water by hydrogen bubbles pumped into the tank.
This combination of reactions is what makes the EC system more effective than the conventional coagulation system.
After going through the electrocoagulation process, the process water moves into a settling tank where the flock generated by electrocoagulation undergoes further reactions to make a larger flock that can float or settle down.
Applications of Electrocoagulation
- Oil and gas produced water
- Process water from mines
- Industrial storm and wastewater
- Construction stormwater
Advantages of Electrocoagulation
- Requires simple equipment and is easy to operate
- Efficiently processes dissolved metals, dyes, silica, and difficult to filter organics
- Can be easily integrated into existing process systems
- Longer lifespan than conventional systems
- Reduces the need for onsite chemical storage
- Smaller footprint than conventional systems.
Conclusion
Apart from high efficiency, high flexibility, and easy-to-scale design is a major advantage of electrocoagulation systems. Partnering with an experienced Sewage treatment plant manufacturer could help ensure further reduction in set up and maintenance costs of the EC system. Efficient EV system is critical to the low footprint and high efficiency Inovar STPs. Further on, all Inovar products are backed by annual maintenance contracts to reduce operation and maintenance.