TABLE 141 Types of Biochemical Oxygen Demand

There are several types of BOD that enter an activated sludge process. Total BOD is the sum of all types of BOD found in the influent to the activated sludge process. Forms of particulate BOD are the solids such as cellulose that can be degraded. Much particulate BOD is removed in the primary clarifier, and unless adequate HRT is provided in the aeration tank, par-ticulate BOD is adsorbed to the surface of floc particles in the aeration tank and is not degraded. Forms...

TABLE 151 Oxygen Requirement Groups of Bacteria

CBOD removal Denitrification Floc formation Methane production in anaerobic digesters biological and operational purposes. These purposes are (1) the oxidation of cBOD to provide carbon and energy for cellular activity, growth, and reproduction (production of MLVSS), (2) oxidation of cBOD to provide energy for endogenous respiration (destruction of MLVSS), and (3) oxidation of nBOD or nitrification. Of the many operational requirements known to affect nitrifying bacteria or nitrification,...

Methemoglobinemia

Methemoglobinemia

The term ''methemoglobinemia'' or ''blue baby syndrome'' refers to the disease experienced by an infant who consumes groundwater contaminated with nitrate ions. When an infant consumes formulae made with groundwater contaminated with nitrate ions, the ions are easily converted to nitrite ions in the infant's digestive tract. The nitrite ions that enter the infant's circulatory system bond quickly to the iron in the hemoglobin or red blood cells (Figure 1.4). Figure 1.4 Methemoglobinemia. If...