An engineer at Washington University in St. Louis has found a way to convert chromium-6 into common chromium-3 in drinking water, making it safer for human consumption.

Chromium is an odorless, tasteless metallic element. One form, chromium-3, is essential to human health and is found in many vegetables, fruits, meats and grains and is often included in multi-vitamins.

Chromium-6 can have adverse health effects when it is found in water supplies.Its cancer-causing cousin, chromium-6, occurs naturally but is also produced by industry, and can contaminate both soil and groundwater.

According to research, chromium-6 is potent as an inhaled contaminant, and in drinking water can have a negative impact on human health.

Scientists have previously converted chromium-6 to chromium-3 in a chemical process using iron. During the course of the research, published in the journal Environmental Science & Technology, researchers used electricity to do the job.

Electrocoagulation is the approach used to introduce iron into the water. According to researchers, typically, one would use an iron salt and physically add a dose to the water. Electrocoagulation uses two pieces of iron metal in the water. When a voltage is applied between them, the iron is dosed into the water and converts the chromium-6.

Electrocoagulation systems are widely available, and researchers find that using electricity as opposed to chemical alteration is an easier, more precise and scalable process.

The research team previously used the electrocoagulation approach to remove arsenic from drinking water; this is one of the first times it has been done to convert chromium in drinking water into a safer form. Researchers hope to use the same technique with selenium, a metal that's typically difficult to remove from water.