Key Definitions:
Ammonia: Ammonia, the primary nitrogen by-product of organic decomposition, is a gas that is highly soluble in water. Depending on the pH of the water, ammonia can be in the ionized form (NH4+) or un-ionized form (NH3). When ammonia concentrations exceed saturation, ammonia will volatilize as NH3. Ammonia in water does not have any odors, but volatilized ammonia is responsible for most of the odors coming from manures from animal pens and when manure is spread on agricultural fields.
Cation: A cation is a positively charged mineral or molecule. For example sodium (Na+), potassium (K+), and calcium (Ca2+) are cations soluble in water. Ammonium ion (NH4+) is also a cation when dissolved in water.
Cation exchange: Cation exchange occurs when one cation is exchanged for another. With zeolite, sodium (Na+), potassium (K+), and calcium (Ca2+) are cations within the zeolite structure that can be exchanged with other cations in solution. Ammonium ion (NH4+) is a cation that is actively exchanged with zeolite’s cations within zeolite’s lattice structure. In this way, zeolite can sequester ammonia from aqueous solutions, including fresh animal manures.
Concentrated Animal Feeding Operations (CAFOs): The term CAFO has legal significance with respect to number and type of animals confined. However, for our purposes CAFOs can refer generically to any large-scale animal production facility that also concentrates manure collection. This includes large dairy, cattle, swine and poultry operations, but conceptually could also include animal shelters, zoos, and other animal management facilities large enough where manure disposal is an expense and/or liability.
Eutrophication: Eutrophication is the degradation of aquatic systems that occurs with excessive enrichment of algal nutrients, primarily soluble nitrogen and phosphorus. Eutrophic waters are characterized by uncontrolled algal growth (particularly blue-green algae, or more properly known as cyanobacteria), reduced biodiversity, noxious odors, poor water clarity and frequent fish mortality. A major cause of eutrophication is the nutrient losses from concentrated animal management systems and agricultural runoff reaching downstream rivers, lakes and reservoirs.
Nitrification: Nitrification is an important bacterially mediated, chemical transformation that converts ammonia into nitrite (NO2–) and then into nitrate (NO3–). Nitrate is highly soluble and easily transported in water. A major loss of nitrogen from agricultural fields is from nitrate leaching into surface and ground waters.