Case Study
Sewage Treatment - UK sewage
treatment works serving a large town and surrounding
villages. The plant treats a mixture of domestic and
trade effluent, and in particular the effluent from
a snack foods manufacturer. This sewage treatment facility
suffered from three distinct problems:
- The primary settlement tanks were badly affected
by gross volumes of floating solids.
- The main feeder channels between the primary screens
and the primary settlement tanks were blocked with
thick sludge type deposits of fats and solids. The
grease and fat was fibrous in appearance.
- The sludge consolidation tanks were badly affected
by gross floating solids. (photo 1).
Floating sludge and poor sludge compaction was also
causing a major problem with the sludge consolidation
tanks. Instead of decanting liquor to be returned to
the primary tanks, the decanted return was heavily contaminated
with fatty sludges. This in turn affected the performance
of the feeder channels to the primary settlement tanks
and aggravated the problem of floating sludge on the
primary tanks. Sludge was poorly consolidated which
had an adverse affect on the performance of the digester.
BioTreat microbial formulations were pre-assimilated
with the incoming effluent and dosed on a regular basis
into the stream. After four weeks the primary settlement
tank performance was significantly improved with only
a small volume of floating sludge evident. This was
easily controlled and efficiently dealt with by the
surface scrapers. The problem of ‘layering’
of the sludge and the formation of a sludge blanket
had been eliminated. The cleaning routines of the main
feeder channels were reduced to once a week with only
a general hose down of the channels now required. BOD
from the primary tank was reduced improving the performance
in the activated sludge plant. The most noticable area
of improvement centred on the sludge consolidation tanks
(photo 2).
Photo 1. Consolidation tank prior
to treatment
Photo 2. Consolidation tank two
weeks after treatment.
Daily Flow 25 mega-litres.
Additional Information
For additional information please contact BioTreat
info@biotreat.co.uk
.
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