Industrial waste management

2. UNIT-4 EQUALIZATION
FLOW EQUALIZATION SIMPLY IS THE
DAMPING OF FLOW RATE
VARIATIONS SO THAT A CONSTANT
OR NEARLY CONSTANT FLOW RATE
IS ACHIEVED

3. EQUALIZATION TANK
 Effluent from the collection tank comes to the
equalization tank in wastewater treatment. The
main function is to act as buffer. To collect the
incoming raw effluent that comes at widely
fluctuating rates and position to the rest of the
ETP at steady ( Average ) flow rate. During the
peak hours ETP comes at high flow rate. The
equalization tank stores this effluent and lets it
out during the non peak time when there is no
/little incoming effluent.

4. EQUALIZATION TANK OPERATION AND
MAINTENANCE
 Keep air mixing on at all times.
 Ensure that the air flow /mixing is uniform over
the entire floor of the tank. Adjust the placement
of diffusers and the air- flow rate needed.
 Keep the equalization tank in wastewater
treatment nearly empty before the expected
peak load hours (otherwise it will over flow)
 Check and clean clogged diffusers at regular
intervals.
 Manually evacuate settled much/sediments at
least once in a year.

10. NEUTRALIZATION
 Excessively acid or alkaline waste should
not be discharged without treatment into a
reciving stream or river .

11. DAIRY INDUSTRY

12. INTRODUCTION
Dairies handling milk are classified as
receiving, bottling, condensing, dry milk powder
manufacturing, ice cream manufacturing, cheese
making and butter making.
Wastewater generated in a dairy contains
highly putrescible organic constituents. This
necessitates prompt & adequate treatment of the
wastewater before its disposal to the environment.
Almost all the organic constituents of dairy waste
are easily biodegradable. Hence, the wastewater
is amenable to biological treatment--- either
aerobic or anaerobic, or a combination of the two.

13. OPERATIONS IN A DAIRY
Following are the operations involved,
 RECEIVING
 PASTEURIZING
 BOTTLING
 CONDENSING
 DRY MILK MANUFACTURE
 CHEESE MAKING
 BUTTER MAKING
 CASEIN MAKING

25. RECEIVING
Raw milk is received from the
fields. It is weighed and tested for its
fat contents. It is stored in
refrigerated containers before further
processing.

26. PASTEURIZING
This process consists of heating
the milk to 63°C for 30 minute and
immediately refrigerating. It kills all
organisms, including the pathogenic
organisms, which may have entered the
milk through diseased animals.

27. BOTTLING
The pasteurized milk is filled in
bottles, or polyethylene sachets for
distribution to the consumers. Bottling is
invariably preceded by clarification and
filtration.

28. CONDENSING
Pasteurized milk is heated and
evaporated under vacuum. The
concentrated milk is pumped through a
closely set value that breaks up fat
globules. Sugar is added to the milk and
the sweetened milk is filled in milk
containers, packed and sent to the
consumers.

29. DRY MILK MANUFACTURE
Whole milk is preheated and
centrifuged to separate the cream from
the non-fat portion of the milk. The cream
is pasteurized and used as ice cream
mix.
The non-fat portion of the milk is further
heated and evaporated under vacuum to
a controlled percentage of solids. The
concentrated non-fat milk is then spray-
dried.

30. CHEESE MAKING
Pasteurized milk is soured by adding a
lactic acid-production bacterial culture. The
mixture is allowed to ripen under controlled
temperature. The curb is then cut with knives
and the excess whey is allowed to drain.
Further, removal of whey is done by pressing
the curb and the pressed blocks are stored
under controlled temperature & humidity for the
development of flavor & further ripening. It is
then packed & stored at low temperature.

31. CASEIN MAKING
Soured or spoiled milk is treated with
mineral acid to produce casein. The
casein is then precipitated. Casein is
used in the manufacture of plastics,
paints, resins and varnishes.

33. SOURCES
 At the receiving station and at the bottling plant
sections, the liquid wastes originate out of rinse &
washings of the bottles, cans and equipment, and
thus contain milk drippings and chemicals used for
cleaning containers and equipment.
 Wastewater from the cheese plant include mainly
the discarded whey and the wash water used for
cleaning vats, equipment, floors etc.
 Butter milk & wash water used to clean the churns,
& small quantity of butter comes out as the waste
from the butter plants.

34.  The dry milk plant wastes consists chiefly of
wash water used to clean containers and
equipments.
 The waste from the casein section includes
whey, washings and the chemicals used for
precipitation.

42. EFFECTS
 The waste is slightly alkaline in nature when
it is fresh, when it is allowed go to the stream
without treatment , a rapid depletion of the
DO content of the stream occurs.
 Though alkaline in fresh condition, the milk
waste become acidic due to the
decomposition of Lactose into lactic acid
under anaerobic condition, particularly after
complete oxygen depletion of the stream.
 At certain dilutions the dairy waste is found to
be toxic to fishes also.

46. PAPER AND PULP INDUSTRY

49. PULP AND PAPER PROCESS
The production process can be divided into 7 steps
Raw material process
Wood yard
Fibre line
Chemical recovery
Bleaching
Paper production
Products and recycling

54. TREATMENTOF WASTE WATER

63. SUGAR MILL WASTE

64. INTRODUCTION
In countries like India, Cuba & Jamaica, the
sugar is produced from sugarcanes, while in many
other places BEETROOTS are used as the raw
material for the sugar production.
A large volume of organic nature is produced
during the period of production, and they are
discharged onto the land or near by streams.
“PUTREFACTION” of the polluted stream water
caused by the heavy discharge of organic waste,
resulting in the odour nuisance near the sugar mill.

65. MANUFACTURING PROCESS
The following flow diagram shows the
manufacturing process of the sugar.

67. SOURCES OF WASTE WATER AND ITS
CHARACTERISTICS
 The filter cloths, used for filtering the juice, need
occasional cleaning. The wash water thus
produced though small in volume, contains high
BOD and suspended solids.
 A large volume of water is required in the
barometric condensers of the multiple effect
evaporators and vacuum pans.
 The water is partially or fully recirculated, after
cooling through a spray pond. This cooling water
gets polluted as it picks up some organic
substances from the vapour of boiling syrup in
evaporators and vacuum pan.

68.  The water from spray pond when overflows,
becomes a part of the waste water, and usually
of low BOD in a operating sugar mill. But
because of poor maintenance and bad operation,
some amount of sugar may enter in the
condenser water, this results in instead of being
recirculated, is discarded as a excess condenser
water.
 Due to leakages and spillages of the juice, syrup
and mollases in different also contribute some
waste water which have the very high BOD.
 Periodic washing of the floor also contribute
waste water of high BOD.
 The periodic blow off of the boiler produce
another intermittent waste discharge which is

70. EFFECTS OF WASTE ON RECEIVING WATER
 The fresh effluent from the sugar mill,
decomposes rapidly after few hours of
stagnation. It cause considerable difficulties
when their effluent gets an access to the
water courses.
 The rapid depletion of oxygen due to
biological oxidation followed by anaerobic
stabilization of the waste causes a secondary
pollution of offensive odour, black colour, and
fish mortality.

71. TREATMENT OF THE WASTES
The following flow chart shows the complete
Treatment of Sugar Mill Waste.

73. TEXTILE MILL WASTE

74. INTRODUCTION
The fibres used in the textile industry are broadly
classified into four groups,
1)Cotton 2)Woolen
3)Regenerated 4)Synthetics.
The characteristics of the waste from the mill
depends on the type of the fibers used. The pollutants
in the waste includes the natural impurities in the
fibers used, and the processing chemicals.

76. EFFECTS OF COTTON TEXTILE AND WOOLEN TEXTILE
MILL WASTES ON RECEIVING STREAMS/SEWERS.
 The crude waste, if discharged into the
sreams, cause rapid depletion of the DO of
the stream.
 The alkalinity and the toxic substances like
sulphides and chromium, affect the aquatic
life.
 The colour often renders the water unfit for
use for some industrial purposes in the
downstream side.
 The presence of sulphides makes the waste