This shows the specialized terms used in EarthWise Academy. This section contains all the definitions used in the various course glossaries used by each course.
Nitrogenous BOD (biochemical oxygen demand) - The stage of decomposition that occurs in biological treatment processes when specialized aerobic bacteria (nitrifiers), use DO to change ammonia to nitrate; sometimes referred to as second-stage BOD.
Non-Exceptional Quality Biosolids
Non-exceptional quality biosolids are biosolids that meet specified pollutant and pathogen reduction criteria. Criteria for non-exceptional quality biosolids are less stringent than criteria for exceptional quality biosolids.
Note: The term 'Biosolids' can be used to refer to all categories of biosolids collectively, or can be used to refer specifically to the category non-exceptional quality biosolids.
Particles that take a lengthy amount of time to settle by gravity (i.e. many hours, days, or years).
NPDES - National Pollutant Discharge Elimination System
A central mass about which other matter collects; a starting point for growth or development.
Derived from animals and plants, or may be manufactured chemical compounds. However, all organics contain carbon. Organic contaminants can be biodegradable, which means that the contaminants can be consumed by bacteria and other microorganisms. In the process of being consumed, these organics will exert an oxygen demand (BOD) which can be measured as the Biochemical Oxygen Demand (BOD) of the wastewater. Some organic contaminants (refractory organics) are resistant to biodegradation.
Waste material that comes mainly from animal or plant sources. Organic wastes generally can be consumed by bacteria and other small organisms. Inorganic wastes are chemical substances of mineral origin.
The addition of oxygen, removal of hydrogen, or the removal of electrons from an element of compound. With respect to water treatment, organic matter is oxidized to more stable substances.