1. Introduction
Allowing municipal wastewater to be released to the environment can make a lot of problems. The wastewater
may be treated by physicochemical or biological processes. Biological treatment is preferred solution for improving
the municipal wastewater treatment. Recently the biological process is the main treatment system in municipal
wastewater plant. The performance of a biological process is often enhanced through bioaugmentation of one or
more species of specialized microorganisms (Semrany et al. 2012, Erdogan et al. 2011, Karamalidis et al. 2010).