Accepted Papers - 3.pdf - UNESCO

of waste water generated. Hence the waste water
treatment plant is designed for a capacity of
treating 75 kld per day.
EXPERIMENTAL PROGRAMME
• At the first step, the waste water discharged
from the various points are collected and
transported to the common collecting tank.
• The floating material and foreign particles in
the raw water are removed by means of
installing bar screens before the collecting tank.
• The raw water is collected in the equalization
tank after regular screening is over.
• The homogenous effluents is pumped into the
aeration tank, where surface fixed aerator is
provided for aeration purpose.
• The outlet from the aeration tank is fed into
the settling tank by gravity.
• The settled biomass is again recirculated back
into the aeration tank to maintain the mixed
liquor suspended solids. If the biomass is
excess, it is sent to the sludge drying beds for
dewatering.
• The dewatered effluent is again collected in the
collection cum equalization tank for further
treatment.
• The supernatant clear effluent from settling
tank flows by gravity and collected in the semi
treated effluent collection tank.
• From the semi treated effluent tank, the effluent
is pumped through the Pressure Sand Filter
followed by Activated Carbon Filter for
removal of fine suspended particles and colour
present in the treated effluent.
• The outlet from the activated carbon filter is
found to meet the standard limits and let out
for collecting in the storage tank.
• The collected water is pumped for utilizing
gardening purpose.
The method of treatment of effluent is shown
in flow chart.
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WASTE WATER TREATMENT PLANT
FLOW CHART
BAR SCREEN
COLLECTION TANK
AERATION TANK
SETTLING TANK
TREATED EFFLUENT SUMP
PRESSURE SAND FILTER
ACTIVATED CARBON FILTER
TREATED EFFLUENT
GARDENING
Re-cycle
SLUDGE
DRYING
BED
LABORATORY ANALYSIS
The sample of raw water was collected from
the collecting tank to analyze the basic characteristic
of sewage. The sample of water collected was given
to the Tamilnadu Water Supply and Drainage Board
testing laboratory for analysis. The results are given
in the Table 1.
Table 1 : CHARACTERISTIC OF RAW
WATER
No. Parameter
Characteristics
Raw Sewage
1 PH 7.40
2 Total suspended solids 86
3 Total dissolved solids 1722
4 COD 184
5 BOD 75