Aquatic Pollution and Coastal Management

Unit 7 : Microbial pollution

7.3.Sewage-Fungus complex
The biological component of the activated sludge system is consists of microorganisms. Cell makeup depends on both the chemical composition of the wastewater and the specific characteristics of the organisms in the biological community.Bacteria, fungi, protozoans, and rotifers constitute the biological component, or biological mass, of activated sludge. In addition, some metazoans, such as nematode worms, may be present. However, the constant agitation in the aeration tanks and sludge recirculation are deterrents to the growth of higher organisms.

Fungi are also a constituent of activated sludge. These multicellular organisms metabolize organic compounds and can successfully compete with bacteria under certain environmental conditions in a mixed culture. In addition, a small number of fungi are capable of oxidizing ammonia to nitrite, and fewer still to nitrate. The most common sewage fungi are Sphaerotilus natans and Zoogloea sp.