While regulations demand that wastewater treatment plants get nutrients out of the water, the world’s food supply may demand more — that we recover and reuse them.
Nutrients are a nuisance in our environmental waters and, by extension, a nuisance to wastewater treatment plant (WWTP) operators, especially in the United States. Federal and state regulators have been steadily rolling out more — and more stringent — effluent limits on nutrients — namely, phosphorus and nitrogen. Aggressive action is certainly necessary; eutrophication caused by nutrients results in hypoxia (oxygen depletion) and harmful algal blooms that kill aquatic life and can lead to cyanosis (“blue baby syndrome”) in humans. The aggressive way in which WWTPs are targeted, however, may seem unfairly strict and unbalanced considering the nutrient loadings of nonpoint sources, such as runoff from farmlands, which actually pollute receiving waters much more. But this burden taken on by wastewater utilities may also yield tremendous opportunity.
Whereas the current focus mainly lies on simple (or not so simple) nutrient removal, often at great cost to the municipality, the next (r)evolutionary step will be the recovery and reuse of nutrients, particularly phosphorus. It’s a virtual inevitability since phosphorus is a finite resource that otherwise must be mined from phosphate rock. Phosphorus is vitally important because, along with nitrogen and potassium, it’s an essential component of (N-P-K) fertilizer. In short, it’s needed to feed the world, and it’s in danger of running out … someday.
Special thanks to Tyler Algeo, senior water technology market analyst for BlueTech Research, an O2 Environmental Company, for supplying expertise and research materials utilized in this article. Learn more from his report, "Nutrient Removal and Recovery Market and Technology Overview."