International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
Study of Oxidation Ditch using Cascade Aerator for
Dairy Waste
Mrs. ReenaNitinPantawane
Assit.Prof.(Civil Engg.Dept)
Jawaharlal Darda Institute Of Engineering And Technology
Yavatmal, India.
Abstract:
Water is the gifted boom to human beings but it should be like that when it is free from impurities. But natural
water may contain so many impurities to overcome it from water the low cost treatment are preferred.
Oxidation ditch is use to reduce the impurities present in the water and also waste water. The waste water
coming from various industries is fully contaminated and need treatment in that case economic point of view
oxidation ditch is used. The waste water from processing of milk product which entirely composed of organic
material or colloidal suspended solid simpler and economical treatment is used.
For the treatment of diary waste various biological treatments are carried out which are classified are as
follows
1) Non mechanized method
a) Anaerobic lagoon
b) Oxidation pond
2) Mechanized method
a) Aerated lagoon
b) Oxidation ditch
Since milk waste containsvery little suspended matter, preliminary settling for solid removal does not result
in appreciable reduction in BOD in most cases the amount of sand and other floating in the waste is sufficient
to warrant a small screen and grit removal chamber. Oxidation ditch which use to enhance DO concentration
and COD removal efficiency of waste generated from diary wasteusingcascadeaeration along with oxidation
ditch is used to enhance the COD removal efficiency of diary waste. A cascade is provided in addition to
original setup of oxidation ditch. The sample of dairy is used for checking the COD removal efficiency.
To study of aeration system three cases are to be taken in laboratory initially simple rotor is used for aeration
for waste generated from diary. DO concentrations is calculated then only cascade aerator is used and DO
concentration is calculated. Finally the combination of both cascade and rotor is used for which oxygen
transfer coefficient was observed in the range 4.9 maximum value of oxygen transfer by aeration system was
found to be 11.9 gm/hr then COD removal efficiency is determine .
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International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
The process has given upto 96%COD removal efficiency ,while using cascade aerator withoxidation
ditch.
Treatment of Dairy Waste :
Introduction:
With increase in demand of milk products quality of milk products increased, Quantity of milk is being
collected in an organized way and processed in the dairies. It is true that with recent methods of mechanized
handling the quantity of milk lost to dairies is less but the organic matter from dairies is much higher than the
waste water from communities.
Though the waste from dairies are rich in inorganic matter .They are readily degradable like municipal
waste water and more amenable to any biological treatment however due coincide aeration aspect this is
mostly due to the no availability of suitable and economical methods and the design criteria under Indian
condition for past few years consideration work has been done on this aspect oxidation ditch is proffered.
Study of Oxidation Ditch :
Types -1)Pasveer
2) Carrousel types
The oxidation ditch was developed during 1950 at the research Institute for Public Health Engineering in
Netherlands (1982) The 1st oxidation ditch was placed in service in 1954 at Voorshopen,Holland.The plant
was designed by Dr.Pasveer known as Pasveer Ditch.
A study on comparison on Pasveer oxidation ditches are
Pasveer
Types of aerator
Carrousel
The rotor consists of a series of
Vertical aerators of several
Rows of blades arranged types have been used.
Around the horizontal centre shaft.
Depth of immersion
Sitting of aerator
Controlled by adjusting the level Controlled by a jacking screw
of outer weir from the ditch.
On the vertical shaft.
The aerator may be seated at any
The surface aerator must be
Position along the ditch.
Positioned above the deep
Section of ditch.
Construction
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Uniformly continuous channel
Uniform channel usually 2m
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International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
Usually 1.0-0.8m deep.
In depth with aerator porkers
3m Deep.
Pasveer type ditch is used to perform the COD removal efficiency of dairy waste.
Design criteria
The National Environmental research Institute Nagpur given the following standards
for oxidation ditch,
Organic loading rate -0.15 kgBOD/kg mlss
Velocity of circulation -0.3 m/s
Sludge recirculation -50 to 100 % average flow
Excess sludge produced -2.5 to 7.5 gm per capita per day
Sludge age (SRT) 30 day
Sludge Volume Index -50 to 100
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International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
Construction – Material used masonry or earth work
Oxygen requirement -1.5 to 2.0 kg O2
Per kg BOD Applied
Rotors:1) Speed of Rotation -70 to 75 rpm
2) Depth of immersion of rotor in mixed liquor 10 to 15 cm.
3) Power requirement – 1.0 kw/m length of rotor per hour.
Settling tank
1) Surface Loading -30-40 m3 /m2/day
2) Detention time -1-2 hour
3) Shape of circular clarifiers for 1 large size.
Experimental setup & operation
1) Preparation of model
The oxidation ditch is used in practice have normally following dimensions depending upon
design parameters.
Depth -1.5 m
Width -10 to 20m
Length –Depending on volume of waste to be treated.
The oxidation ditch model was prepared with uniform thickness of 1.0 mm were used.Bearings of 50mm
diameter were provided for rotors.
The experimental model was of fill and draw type and it was not possible to make
arrangement of continuous feeding cascade aerator is attached for aeration following dimensions are
adopted.
Length of ditch -1000 mm
Width of ditch -400 mm
Depth -150 mm
Total capacity -55 mm
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International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
Free board- 50 mm
Method of operation
After preparation of model and electrical connection DO test was conflicted for rotor
performance only tap water was filled in the ditch and by adding calculated amount of Na2SO3 DO of tap
water at rotor speed 65rpm, DO concentration is calculated
Dairy waste sample is collected from camp road area ,Amaravati.
DO test was conducted and then sample is aerated upto 8hours to reduced the COD removal efficiency of
dairy waste.
Characteristics of dairy waste.
1.
2.
3.
4.
BOD-3070 Mg / l
COD-4510Mg / l
PH-8.1
Suspended solid-1810Mg /l
During one month 30 readings are taken the COD of influent are tabulated as below.
Performance of oxidation ditch for various COD loadings.
FOR 24 hours aeration
S.N. Influent COD
Effluent COD
MLSS
1
2
3
4
5
250
300
350
400
500
2600
2650
2650
2650
2700
3600
4000
4500
5200
6800
COD
Removal
Efficiency
93%
93%
93%
93%
94%
PH
Room temp.
8.1
8.1
8.1
8.1
8.1
29
28.5
29
28
29
These readings are taken for 24hours aerations but due to practical difficulties it is not possible to have
aeration period 24hours only 5 reading are taken for which COD removal
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International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
Efficiency was found out upto 93%
It is to be decided to take readings for 5hours aerations.
S.N.
Influent COD
Effluent COD
MLSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
700
800
850
900
950
1000
1050
1100
1150
1250
1300
1400
1000
1550
1600
1700
1750
1800
1900
1950
2000
2050
2100
2150
2200
2250
2300
2350
2380
2400
0
30
32
40
42
50
51
53
55
60
65
68
70
72
75
78
80
82
90
95
98
100
105
108
110
110
118
120
125
130
2600
2600
2650
2650
2600
2650
2650
2650
2600
2750
2750
2750
2800
2800
2800
2800
2800
2800
2800
2850
2850
2885
2890
2900
2900
2900
2900
2900
2900
2900
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COD
Removal
Efficiency
100%
96%
96%
96%
96%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
95%
94%
95%
94%
94%
94%
94%
94%
PH
Room
temp.
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
8.1
30.5
31.5
31.5
31.5
32.0
32.0
34.0
34.5
34.0
34.5
34.8
34.9
35.0
34.0
32.0
34.0
35.0
37.0
34.0
35.2
30.2
28.9
34.2
34.9
35.0
35.0
36.0
36.8
37.2
37.0
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International Journal of Engineering Trends and Technology (IJETT) – Volume 9 Number 10 - Mar 2014
CONCLUSION & RESULT
1. For aeration period 2 hrs, COD of influent is 6800 mg/l and process has given 93% COD removal
efficiency due to practical difficulties it was not possible to have 24 hours aeration it reduces to 8
hours
2. For 8 hours aeration process has given 100% COD removal efficiency for 700 influent COD.
3. Maximum COD of dairy waste was 2400 mg/l which was treated for 8 hours and given 94% COD
removal efficiency .
Referances:
1.Adema D:
“ The Largest Oxidation Ditch for treatment of Industrial Waste”
2. Eldrige E.F.:
“Industrial Waste Treatment Practice “McGraw Hill Company (1980)
3.Garg S.K.
Industrial and Waste Disposal Engineering”
4.Govt.of Maharashtra
“Maintenance Manual For Dairy Machinery Dairy Development"
5.Siddiqi R.H.;
“Principles of Biological Treatment. Process design in Waste water.”
6.Pasveer A.:
“Tertiary Treatment with Oxidation Ditch.10 th Symposium of low cost waste treatment” Vol.2 Central
Public Healh Engineering .Research Institute ,Nagpur” (1669)
7.Stepheson Roger v.et el:
Performance of surface rotors in oxidation ditch Page-79-91 Journal of ASCU (1989)
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