Abstract:
Environmentally friendly way of handling industrial effluents is the most important concept
for industries direct and/or indirect contribution of a country’s sustainable development. In
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order to achieve such goals biological processes play the major role. This study was also
initiated to evaluate the treatment performance of a laboratory scale anaerobic/anoxic/aerobic
(A/A/A) bioprocess system for the removal of phosphorous from brewery wastewater. For
this purpose the treatment plant was fed with raw brewery wastewater collected from St.
George Beer Factory at three different organic loading rates (OLR) (0.5, 0.75 and 1 kg
COD/m3 day). The set-up was inoculated with sludge biomass obtained from the oxidation
ponds of Meta Abo Beer Factory. And the treatment performance of the set-up was evaluated
using the parameters PO4-3, TN, NH4+-N, NO3--N, COD, BOD5 and pH concentrations. The
results showed that brewery wastewater used in this study was medium to high strength
wastewater with COD, BOD5, PO4-3, TN,NH4+-N and NO3- -N values ranging from 1860-
3880, 484-636, 31.9-121.7, 44-78, 12.2-54.2 and 13-36 in mg/l, respectively. The set-up used
was able to achieve 80.0, 78.9 and 66.8 % removal of PO4-3, 69.7, 67.6 and 54.0 % removal
of TN, 95.67, 93.8 and 87.9 % removal of NH4+-N and 51.1, 46.5 and 44.3 % removal of
NO3- -N at 0.5, 0.75 and 1 kg COD/m3 day of OLRs, respectively. In addition to these the
bioprocess gave 97.2, 96.5 and 95.6 % removal efficiencies for COD and 92.8, 91.7 and 89.3
% removal efficiencies for BOD5 at OLRs of 0.5, 0.75 and 1 kg COD/m3 day, respectively.
The laboratory scale treatment plant performed well and gave maximum removal efficiencies
at organic loading rate of 0.5 kg COD/m3day where TP (PO4-3), TN, NH4+-N, NO3--N, COD
and BOD5 concentrations decreased from 54.9, 71, 39, 36, 2240 and 636 mg/l to 11.0, 21.5,
1.7, 17.6, 62 and 46 mg/l, respectively. There was a correspondence observed between the
maximum removal efficiency of the set-up and the increase in biomass concentration of the
system. The results of this study indicated the possibility of handling brewery wastewater
biologically in an environmentally friendly manner using A/A/A biological nutrient removal
configuration.