BOTTLE WASHING AND BREWERY WASTEWATER TREATMENT
Zahid Mahmud, Project Engineer
Carborundum Irrigation Systems
Fitzgerald, GA 31750
INTRODUCTION
The bottle washings and brewery plants generate a large amount of wastewater. The wastewater from the bottle washings is low in organic contents, high in pH and volume of flow and
effluent temperature is about 45 C.  The wastewaters from the brewery are highly contaminated with soluble organics, low in nutrients, high in temperature and extremely variable for
these parameters. As the basic process in brewing is the biological fermentation of carbohydrates, high concentrations of the soluble organics result in the effluent and there are few non-
biological unit processes which can give effective treatment.
The wasteload of the breweries can be reduced quite successfully by having a strict control
on the operational cycle. Generally a brewery discharges an average of 15 population equivalents per barrel (31 gallons) of wastes. Washings and spillage account for the main biological
oxygen demand (BOD) load. Wastage of product is due in part to lack of interest as the untaxed beer may not be judged valuable enough to require elaborate precautions against loss.
Depending upon the brewing formula for each barrel of beer produced; about 10 lbs of
brewer's dried grains as animal feed and 0.5 lbs of yeast for human consumption may be
recovered.
The raw materials for the manufacture of beer are yeast, malt, hops and water with particular qualities. The malt is prepared from barley, whose grains are steeped, made to sprout
and then dried. The wort is prepared by making a mash of coarse ground malt with water,
saccharifying the starch paste, boiling the hops and cooling. When a suspension of yeast is
added, alcoholic fermentation of the wort sets in. As soon as the fermentation is completed,
the yeast and the malt residue are filtered off from the beer. The final stage is barrelling or
bottling the filtered beer.
WASTEWATER CHARACTERISTICS
Qualitative Analysis
In order to be specific, a brewery having 100,000 m3 of beer per annum was selected. The
brewery had a soda plant too and the combined waste was treated. The period of major
wastewater flows at the breweries and soda plant extends beyond the production shift (7 a.m.-
4 p.m.) and is at least from 8 a.m. to 6 p.m. on five working days per week. Much less wastewater is discharged at nights and over the weekend. Figure 1 shows the location of various
sources.
Wastewater streams from both breweries and soda plant show fluctuations in flow on both
an hourly and daily basis. Although the total quantity of wastewater release from the plant
during a working day is almost constant, the pattern of discharges throughout the day is
highly variable, with the periods of peak discharges changing from day to day and from
sampling point to sampling point. Table I gives a summary of mean, minimum and maximum
hourly flows for the sampling points during working days. The high variability of flow of the
waste streams is clearly indicated in Table I, where it can be seen that even the mean flows
from the old and new breweries and the soda plant vary significantly from day to day. Averaging these mean total wastewater flows over the four working days for which complete data
are available gives working day hourly flows of 76.4 m3/hr from the new brewery, 32.0 m3/hr
from the old brewery and 167.5 m3/hr from the soda plant. These rates would give total
quantities of wastewater of approximately 760 m3, 320 m3 and 167.5 m3 discharged from
the new brewery, old brewery and soda plant, respectively, during the 10-hr working day.
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