Struvite Composition and Struvite Formation from Wastewater

Struvite is a mineral compound made up of magnesium ammonia phosphate, aka "MAP." The ingredients for struvite crystal are found in the water of WWTPs and other wastewater operations because of the makeup of different forms of waste. Our drinking water contains a small amount of magnesium but can be concentrated in the anaerobic digester. Urea from human waste breaks down into ammonia and carbon dioxide (CO2) in the anaerobic digester. Phosphorus comes into the plant as phosphate from our dishwasher and laundry detergents.

The struvite chemical formula is written is NH4MgPO4•6H2O.

The anaerobic digester in combination with the pipes and pumps makes a terrific growth site for Struvite. When magnesium, ammonia, and phosphorus come together in one mole to one mole to one mole relationship in the WWTPs, CAFOs and other locations, struvite precipitates. To prevent struvite formation, one has to keep the MAP components from developing into crystals.

Struvite can also form in other locations such as RVs, bathrooms, buildings, humans, and dogs.