5.3 Figure 5.4 described the major organism groups

important to environmental engineering, many of

which are used in treatment of domestic, agricultural,

and industrial wastes. Identify the major organism

groups listed in this figure (for example, viruses, bacte-

ria, algae, protozoa, rotifers) that: (a) use solar energy to

transfer oxygen into wastewater stabilization ponds

(that is, lagoons), (b) are key organisms in the removal

of the organic matter that makes up BOD in waste-

water, (c) are single-cell organisms found in biological

wastewater treatment and resource recovery systems

that feed on bacteria and algae, (d) are multicellular

organisms found in biological wastewater systems,

(e) include the gram-positive organism, Nocardia,

which is normally found in wastewater treatment/nplants, but if it experiences excessive growth, can result

in foaming and poor settling of solids in the secondary

settling reactor (that is, clarifier).