FIELD VALIDATION OF Electrocoagulation Treatment for Oily Wastewater at a Steel Mill

Oily wastewater is a significant byproduct across various industries, including steel production, posing environmental and health risks. Steelmaking is particularly water-intensive, with an estimated 75,000 gallons required to produce 1 ton of steel, although recycling reduces this to 13,000–23,000 gallons per ton.1 Water serves multiple purposes in steelmaking, including equipment cooling, scale removal, steam generation, lubrication, and pollution control.
 

In the U.S. steel sector, forming and finishing processes contribute to wastewater discharge, ranging from 160 to 2,160 gallons per ton of steel. Extrapolating data from this demonstration and U.S. annual steel production of 89.5 million metric tons in 2022,2 the total oily wastewater generated across steel plants amounts to approximately 1.8 million gallons per year.
 

The U.S. Department of Energy’s (DOE’s) Industrial Efficiency and Decarbonization Office (IEDO) is interested in the potential of replacing chemical flocculation (CF) with electrocoagulation (EC) technology, as it could yield significant water and oil savings. This Industrial Technology Validation (ITV) project validated the ability of an atmospheric EC system to treat oily wastewater from a cold-rolling steel operation at the Cleveland- Cliffs steelmaking facility in Cleveland, Ohio. Researchers found that the EC technology was effective in treating oily wastewater, enhancing tramp oil collection, increasing electricity consumption along with an associated increase in greenhouse gas emissions,3 and reducing the facility’s reliance on chemicals. These results led to significant cost savings and benefits.