Removal of Selenium and Other Heavy Metals from Recycling Plant’s Wastewater

Umicore has selected GE’s (USA) Advanced Biological Metals Removal Process (ABMet*) wastewater bioreactor technology to remove selenium and other heavy metals from wastewater discharges at Umicore’s precious metals recycling facility near Antwerp, Belgium. The first full-scale installation of GE’s ABMet technology in Europe, this project will help Umicore to achieve low parts-per-billion (ppb) levels of heavy metals in wastewater discharges. Commercial operation will begin by the end of 2013.

ABMet is a proven, reliable way to remove elevated levels of selenium, nitrate and metals found in wastewater streams in many industrial, mining and utility applications, such as at coal-fired power plants. The simple, low-energy system can achieve up to 99 percent removal of selenium and can discharge treated effluent containing 5 ppb or less of selenium, depending on wastewater makeup.

In pilot trials performed at Umicore’s Hoboken, Belgium, facility the ABMet system proved to be the ideal technology for this application. It employs biofilters seeded with selected strains of naturally occurring, non-pathogenic microorganisms to produce treated effluent wastewater that meets or exceeds the stringent regulatory standards for removal of selenium and other heavy metals. The ABMet system at Umicore’s Hoboken plant will be able to treat an average 160 m3/hour (1,013 gpm) of wastewater.

“GE’s ABMet technology is a key part of our strategy to be able to meet new regulations and also to demonstrate Umicore’s commitment to eco-friendly operations,” said Peter van Herck, manager environmental affairs, Umicore Hoboken. “This unique product helps us to meet important, but challenging regulations, because our facility produces a waste stream containing a varying makeup of metals, depending on what we are recycling.”

“GE’s ABMet wastewater bioreactor technology has demonstrated its advantages in many applications in North America, and now we are beginning to roll it out to Europe,” said Jeff Connelly, vice president, engineered systems—water and process technologies for GE Power & Water. “GE always strives to provide the technology and expertise our customers need to solve their most difficult and important problems, and as the Umicore installation shows, this commitment delivers significant benefits to our customer.”

The Hoboken facility recovers a range of precious and specialty metals from recycled consumer and industrial goods, and as a result, produces a highly complex wastewater stream requiring different unit operations to remove and recover metals before discharge.

The ABMet system comprises microbes seeded in a bed of activated carbon that acts as a growth medium so that the microbes can create a biofilm. Wastewater passes through the biofilm and a reduction reaction occurs, facilitating the conversion of soluble selenium into elemental selenium, which is then removed from the system along with other metals and nitrate. A proprietary molasses-based product is used as a nutrient for the microbes, and other than the addition of the nutrient, the system is self-sustaining once established.