Filtering out toxic chromium from water

EPFL chemists have developed sponges to capture various target substances, like gold, mercury and lead, dissolved in solution. The sponges are actually porous crystals called metal organic frameworks, and now one exists for capturing toxic hexavalent chromium from water. Hexavalent chromium continues to contaminate water sources around the world, with one US company fined just this February for having put employees at risk. Hexavalent chromium is considered to be extremely toxic, especially when inhaled or ingested, and its use is regulated in Europe and in many countries around the world. It is thought to be genotoxic, leading to DNA damage and the formation of cancerous tumors. Now, chemists at EPFL are developing energy efficient processes for removing contaminants, this time hexavalent chromium, from water. The results are published today in the Journal of Materials Chemistry A. "Providing access to clean water is one of the most important challenges of our time," says lead author Wendy Queen of EPFL's Laboratory of Functional Materials.