A team of scientists previously used the electrocoagulation approach to remove arsenic from drinking water.
A new way to convert the dangerous chromium-6 into the benign chromium-3 in drinking water has emerged.
Daniel Giammar, the Walter E. Browne Professor of Environmental Engineering at the School of Engineering & Applied Science at Washington University in St. Louis has found a new way to convert the carcinogenic form of chromium to the safer form by using a process called electrocoagulation.
“Electrocoagulation is the particular approach we used to introduce iron into the water,” Giammar said in a statement. “Typically, you would use an iron salt and physically add a dose to the water.
“Electrocoagulation uses two pieces of iron metal in the water, you apply a voltage between them and that is how you dose iron into the water and convert the chromium-6.”
Chromium is an odorless, tasteless metallic element that is essential to human health when found in the form of chromium-3.
Chromium-3 is found in many vegetables, fruits, meats and grains and is often included in multi-vitamins.
However, when in the chromium-6 form it has been known to cause cancer and can contaminate both soil and groundwater.
“The health effects are quite well-known,” Giammar said. “It’s very potent as an inhaled contaminant but in drinking water chromium-6 definitely has a negative impact on human health.”
Scientists have previously converted chromium-6 to chromium-3 using a chemical process involving iron.
According to Giammar, electrocoagulation systems are widely available and using electricity as opposed to chemical alteration is an easier, more precise and scalable process.
“It allows you to tailor your dose in a very easy way,” he said. “Electronic controls can be easier than chemical feeding controls.
“It also allows it to be more applicable for remote operations because you don’t have to have a source of chemicals,” he added. “You just use the same pieces of iron, and you can treat the water for a long time.”
Giammar and a team of scientists previously used the electrocoagulation approach to remove arsenic from drinking water.
Chromium-6 or hexavalent chromium gained fame when environmental activist Erin Brockovich successfully sued the Pacific Gas and Electric Co. of California over contamination in 1993. The case settled in 1996 for $333 million and the story became the focus of a major motion picture in 2000, starring Julia Roberts.
Advocacy group Environmental Working Group released a report in September identifying that 200 million Americans in all 50 states have water with chromium-6 detected in it with 138 water systems in New Jersey being identified.
However, both New Jersey government officials and other environmental advocates said the readings in New Jersey showed that the levels of chromium-6 were so low that the public is not currently at risk.
