A biotechnological perspective on sand filtration for drinking water production

Gravity-driven sand filters are the dominant groundwater treatment technology for drinking water production. In the past, physicochemical reactions were often assumed to play the main role in the removal of contaminants, but recent breakthroughs showcase the vital role of microorganisms. In this Current Opinion, we thoroughly assess the current understanding of biology in sand filters and explore the potential benefits of shifting toward designs aimed at promoting biological reactions. We highlight the main bottlenecks and propose key areas to be explored toward the next generation of sustainable, resource-efficient groundwater biofilters.