Affiliations: Environmental Research Centre, Ministry of Science and
Technology, Baghdad, Iraq | College of Engineering, Al-Mustansiryah University,
Baghdad | College of Engineering, Al-Anbar University, Baghdad
Abstract: Two systems of Fluidized Porcelanite Bioreactors (FPBR) were
designed and constructed at Al-Rustamiyah Sewage Treatment Plant, South of
Baghdad. The first system consists of Upflow Expanded Bed Reactor (UEBR) which
is connected in sequence with aerated fluidized bed reactor (AFBR), while the
other system is composed of two identical upflow expanded reactors operated in
parallel. In order to evaluate the biofilm compositions and its characteristics
on Porcelanite aggregates or fragment surfaces, an experimental measurements of
the biofilm formation using the light microscopy in fixed media have been
undertaken. Systems operation consists of various distinct phases, where
influent substrate concentrations were taken from primary sewage and clarifier
effluent of Al-Rustamiyah sewage. Three effective parameters, that could influence the rate of biofilm growth such as superficial velocity, substrate,
and biomass concentration, were investigated. The rate of biofilm was tested in
two types of aeration; the first one was aerated directly compared with second
one, which was operated by indirect aeration. Also the rate of biofilm losses
for different influent flow rates, substrate concentrations, locations of
packing bed in the reactor, and the periods of operation was evaluated. This
work showed the main following conclusions: 1. The physical, chemical and biological analyses depend on the environmental conditions to which the
attachment surface is exposed. The large portion of biofilm composition was
water with 90.4%, and with a small value of volatile fraction ranged to 9.2%,
while the fixed fraction is composed of 0.4% of total biofilm by mass. 2. Organic and chemical composition of the fixed fraction of biofilm was
determined, where the primary constituents. carbon (C) was to be 58%, and
nitrogen (N) to be 15%, and phosphorus (P) to be 2%, while the fixed solid
composition was 25%. 3. The inorganic composition of fixed fraction of biofilm
varies with chemical and organic properties of bulk water, chemical and
physical properties of media, which composes mainly of silica with (45%), and
with Fe^{+2} (20%), Mn^{+2} (14%), Al^{+3} (10%), Ca^{+2}
(6%) and Mg^{+2} (5%).
