Electrocoagulation: A Shocking Approach To Wastewater Treatment

Sometimes water and electricity do mix. A growing number of wastewater treatment professionals, especially those in the industrial sector, are turning to electrocoagulation — a water treatment process that uses electric current to remove various contaminants from water.

"Electrocoagulation and similar ideas have been around for years, but the technology is now gaining traction," said TJ Mothersbaugh, the business development manager forWaterTectonics, which offers the technology.

The technology is most commonly used in the oil and gas, construction, and mining industries to treat emulsified oil, total petroleum hydrocarbons, suspended solids, heavy metals, and other difficult-to-remove contaminants. Changes in regulations and growth in those industries has brought electrocoagulation to the forefront in recent years, said Mothersbaugh.

Electrocoagulation is performed by applying an electric current across metal plates that are submerged in water. Heavy metals, organics, and inorganics are primarily held in water by electrical charges. By applying another electrical charge to the contaminated water, the charges that hold the particles together are destabilized and separate from the clean water. The particles then coagulate to form a mass, which can be easily removed.

Electrocoagulation can be used as a pretreatment for processes such as clarification, reverse osmosis (RO), and ultrafiltration, or as a polish treatment at the end of traditional treatment processes. The technology typically eliminates the need for chemical or biological additives or demulsifiers. Without chemicals, there is also no need for chemical mixing tanks.

This is appealing to environmentally concerned companies, said Mothersbaugh.

"People are looking for options other than chemicals because they are dealing with wastewater that is going to be directly released into surface water," he said. More and more people want to protect the environment."

Depending on the application, electocoagulation can sometimes cut back on steps in the typical industrial wastewater treatment process, said Patricia Werner-Els, chief science officer atAdvanced Waste & Water Technology Inc.(AWWT), which offers the technology.

When you set up this technology, what it does or does not incorporate depends on the goal or purpose of the water after the process is completed," said Werner-Els. "We've had cases where we just had to use electocoagulation — no membranes, no settling tanks, no other steps."

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Taxonomy

• Electrocoagulation
• Water Treatment & Control