Nutrients like nitrogen, phosphorus, and potassium are  a double-edged sword . As key components of fertilizers, they are  essential for life on Earth, but become a threat to human health and the environment when they are in excess and run off into water courses and wastewater.

When we throw a plastic bottle in the right waste container, we feel virtuous because we have done our part for the environment. However, we cannot imagine the huge effort that will be needed to ensure that our bottle is effectively recycled.

News of increased desertification has made headlines. Yet this process is not well understood.