It was found that acetate is the best substrate among other
short chain fatty acids such as butyrate, valerate, their isoforms
and propionate in terms of yielding the highest phosphorus
removal per unit COD of VFA. However, even when the nutritional
prerequisites are strictly provided, the success of the
EBPR process also strongly depends on other factors such as
pH and temperature. Additionally, wastewater and operating
conditions such as the influent COD/TP ratio, the amount of
electron acceptor entering the anaerobic stage, and the biomass
solid retention time (SRT) can influence the efficiency of EBPR.
The solid retention time (SRT) is a unified design parameter
that is related to the steady state specific growth rate of the biomass
in a bioreactor system. It determines electron acceptor
requirement and the excess biomass production rate [9].
The technology of effective microorganisms (commonly
termed EM Technology) was developed in the 1970s at the
University of the Ryukyus, Okinawa, Japan. The inception
of the technology was based on blending a multitude of
microbes, and was subsequently refined to include principal
types of organisms commonly found in all ecosystems. These
were blended in a molasses or sugar medium and maintained
at a low pH under ambient conditions [10]