New Technology Developed to Remove Heavy Metals from Water

Waste & Recycling  |  2023-05-15 00:11:11   |   By

Efficient removal of toxic metals in water such as lead is critical in ensuring safe supplies.

SEATTLE (Waste Advantage): The US Environmental Protection Agency (EPA) determined that the maximum contaminant level goal (MCLG) for lead in drinking water is zero.  Although there are current technologies that safely remove lead from water, another method of eliminating heavy metals has been developed. Researchers from the University of Chicago and Argonne National Laboratory found a more efficient technique to remove contaminants in water through modification of the ‘molecular structure of electrodes.’  

Heavy Metals in Water

There are several heavy metals that may be found in water such as arsenic, nickel, mercury, chromium, cadmium, and zinc in addition to lead. Adulteration is attributed to groundwater movement, surface water seepage, and run-off. However, some metals such as manganese, is naturally occurring. Unfortunately, if ingested, whether large or small quantities, heavy metals are toxic to the health. Hence, eliminating the presence of lethal metals in water is vital to avoid poisoning.

For example, there are several ways to get rid of lead in your tap water. You can use a water filter specifically to take out contaminants such as lead. Other means to remove the metal from drinking water is through reverse osmosis filtration or distillation.  The good news is university and laboratory researchers have found a way to improve the efficiency of removing metals from water.

Capacitive Deionization (CDI) 

CDI technology is a process that removes a range of contaminants in the water. It uses a membrane made of ‘electrode materials’ to take away metal ions from water. Researchers propose a new technique that could be more efficient by altering the molecular structure of the electrodes. The three researchers, Junhong Chen, Maria Chan, and Chris Benmore studied the best way to modify the surfaces through experimentation, machine learning, and vigorous X-rays. As a result, the trio created a CDI device that could absorb lead more efficiently. According to Chen who is also the Lead Water Strategist at Argonne, “the availability of clean water is important in the future economy and national security.” Hence, reusing water is vital in addressing the water challenge through clean energy applications that could also help move towards the circular economy.

To illustrate, the device could have several applications. It not only assists in removing toxic metals from water for a safe supply of drinking water but can also trap phosphorus and lithium that could be used for other purposes such as fertilizer and clean energy tech. Unfortunately, existing technologies do not have the ability to separate trace amounts while others cannot fully distinguish one metal from another. For instance, while lead must be removed from drinking water, calcium should remain because it is valuable to human health. CDIs are promising because they can eliminate selected metal ions with the help of carbon material in their electrodes. The team developed the device that can take away lead more efficiently using newly identified functional groups. In the next phase, the group will test other metal ions including cobalt and lithium.

Efficient removal of toxic metals in water such as lead is critical in ensuring safe supplies. The new tech developed by UChicago-Argonne researchers shows potential for other useful applications in heavy metal removal.

Courtesy: www.wasteadvantagemag.com