Generally in wastewater, millions of microscopic and macroscopic organisms are widely distributed, originating from discharged domestic wastewater. These include bacteria, protozoa, viruses, and limited algal species. Many of these micro — and macroorganisms are considered harmless, and the large diversity of organisms is highly adapted to their conditions and effective in wastewater treatment and acti­vated sludge treatment within the treatment facility. Several recent publications have reported that wastewater provides an ideal medium for potential microbial growth (Kong et al., 2010; Cho et al., 2011; Christenson and Sims, 2011; Park et al., 2011a; Pittman et al., 2011; Rawat et al., 2011), irrespective of anaerobic or aerobic waste­water treatment (Abeliovich, 1986).