This document describes experiments conducted using an aeration unit to study oxygen transfer in water. It includes descriptions of the equipment used, which consists of an aeration tank, DO meter, diaphragm pump, flow meter, stirrer controller and electrical unit. Two experiments are described that vary the stirrer RPM and air flow rate to analyze their effects on dissolved oxygen levels over time. The results show dissolved oxygen increases with time, stirrer speed and air flow rate.

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Table of Contents
ABSTRACT ................................................................................................................................................3
INTRODUCTION.......................................................................................................................................4
PRACTICAL APPLICATIONS................................................................................................................4
EQUIPMENT & PARTS DESCRIPTION...............................................................................................5
1. Aeration Tank ...............................................................................................................................6
2. DO Meter ........................................................................................................................................6
3. Diaphgram Pump.........................................................................................................................6
4. Flow Meter.....................................................................................................................................7
5. Stirrer Controller.........................................................................................................................7
6. Electrical Unit...............................................................................................................................7
EXPERIMENT No. 01...............................................................................................................................8
EXPERIMENT No. 02.............................................................................................................................12
REFRENCES............................................................................................................................................15
Table of Figures
Figure 1: Aeration Unit (Manual) .........................................................................5
Figure 2: Aeration Tank (Manual) ........................................................................6
Figure 3: DO Meter (Manual) ...............................................................................6
Figure 4: Diaphragm Pump (Manual)...................................................................6
Figure 5: Flow Meter (Manual).............................................................................7
Figure 6: Stirrer Controller (Manual) ...................................................................7
Figure 7: Electrical Cabin (Manual) .....................................................................7

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LAB LAYOUT
Evaluation
Table
Tray DrierChemicals
Cupboard
Rotary Drier Wetted Wall Gas
Absorb. Column
AerationUnit
SolidLiquid
Extraction
Unit
IonExchange
Gas/Liq.
Absorption
Column
Distillation
ColumnUnit
Liq/Liq.
Extraction
Unit
DoorDoor

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ABSTRACT
Aeration is a unit process in which air and water are brought
into intimate contact. The contact time and ratio of air to water must be sufficient
for effective removal of unwanted gas. Following report concisely explicate the
working of an Aeration Unit and major description of equipment. Simple
experiments are added for better understanding of equipment and process of
Aeration. Observatory columns efficiently describe the effect of various factors
upon Aeration. Graphical representations make it easy to judge the trend of effect
of specific factor upon equipment.

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INTRODUCTION
The Aeration Unit allows the study of oxygen transfer
characteristics of diffused air systems, and the physical and chemical parameters,
which influence oxygenation capacity. Aeration Unit demonstrates the water
aeration process which, mainly, eliminates smell and taste from water. Aeration is
also an effective method of bacteria removal.
Two general methods can be used for the aeration of water;
1. Water-fall Aerator
2. Air Diffusion Method
The Water fall aerator works through the use of spray
nozzles, the water droplets are broken into small droplets or a thin film to enhance
counter-current air contact. In the Air Diffusion method, air is diffused into a
receiving vessel containing counter-current flowing water, creating very small air
bubbles. This ensures good water-air contact for ‘‘scrubbing’’ of the undesired
gases from water. (Manual)
PRACTICAL APPLICATIONS
In industrial water conditioning, one of the major
applications of aeration is to remove Carbon Dioxide. Aeration is also used to
oxidize the soluble Iron & Manganese to insoluble precipitates. Aeration I soften
used to reduce the Carbon Dioxide liberated by a treatment process. Air stripping
maybe used to reduce concentrations of volatile organics, such as Chloroform.

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EQUIPMENT & PARTS DESCRIPTION
The Aeration Unit used in experiment is locally fabricated
and contain six major parts. Equipment is used for the measurement of Dissolved
Oxygen in water at normal conditions of temperature & pressure.
Figure 1: Aeration Unit (Manual)
Major parts of the equipment as briefly explained later to
completely understand the working of Aeration Unit. Electrical wires, air pipe and
stirrer motor are not included in thse parts. (ATICO, 2015)

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1. Aeration Tank
The main part of the Aeration tank is
the Aeration Tank with a meschanical stirring paddle in it
to provide turbulence for better mixing of air with water.
Temperature as well as Dissolved Oxygen Meter sensors
are mounted at top of the tank.
Figure 2: Aeration Tank (Manual)
2. DO Meter
DO stands for Dissolved Oxygen
Meter and it gives the reading of amount of oxygen
dissolved in the tank at normal temperature.
Figure 3: DO Meter (Manual)
3. Diaphgram Pump
A Diaphram Pump of small duty is
also installed with the equipment. A small button is set up
on the pump to manually set the flow rate to High or Low.
Figure 4: Diaphragm Pump (Manual)

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4. Flow Meter
A flow meter in parallel to Diaphgram Pump is attached
to the euipment board to measure the flow rate of air. Scale of
the flow meter is pretty high as compared to the duty of the
pump, so it need to be replaced.
Figure 5: Flow Meter (Manual)
5. Stirrer Controller
In order to control the speed of the
stirrer a controller setup is used with high low &
moderate speeds of the stirrer.
Figure 6: Stirrer Controller (Manual)
6. Electrical Unit
An Electrical Cabnit is installed at
the top of the euipment board to control the stirrer motor
and diaphgram motor.
Figure 7: Electrical Cabin (Manual)

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EXPERIMENT No. 01
Objective
To observe the absorption of Oxygen in water at various RPM of stirrer.
Apparatus
 Aeration Tank
 DO Meter
 Stopwatch
Reagents
 Water
 Air
Procedure
 Setup the procedure as shown in the Figure 1.
 Filled the tank with distilled water.
 Inserted the probe of DO meter in the tank.
 Made sure that DO meter was properly caliberated and in working
condition.
 Switched on the air blower & adjusted the flow rate of Air .
 Switched the stirrer on & adjusted the RPM.
 Noted the readings of Dissolved Oxygen in water after regular intervals
of one minute.

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 After that changed the RPM of stirrer & again noted the Dissolved
Oxygen in water.
 Repeated the above step for High , Medium & Low speeds of the stirrer.
 Plotted the graph & compared the results. (Manual)
Observations & Calculations
Air Flow Rate = 1.75
Stirrer RPM = Low , Medium , High
Table 1: Amount of DO change w.r.t time
Sr.
No
Time (min) Dissolved Oxygen (mg/L)
1
0 8.4
2
2 8.8
3
4 9.5
4
7 11
5
8 11.5
6
10 12.3
7
12 13.1
8
15 13.9
9
16 13.9

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8
9
10
11
12
13
14
15
16
0 5 10 15 20 25
DissolvedOxygen
Time (min)
Low RPM
Medium RPM
High RPM
Graphical Representation
The following graph shows the cahnge in amount of dissolved oxygen as the time
increases.
Graph 1: DO vs Time Representation (Stirrer Speed Variation)

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Results
The Graph 1 based on the values by Table 1 shows variation
in dissolved oxygen as the time and stirrer speed changes. Dissolved oxygen shows
a significant change after 15 minutes and at high stirrer speed.
Conclusion
The results depict that Dissolved Oxygen is directly proportional to time.
𝑫𝑶 ∝ 𝑻𝒊𝒎𝒆
From the results of experiments we can also conclude that Dissolved Oxygen is
also proportional to stirrer speed. (Joseph A. Salvato, 2006)
𝑫𝑶 ∝ 𝑺𝒕𝒊𝒓𝒓𝒆𝒓 𝑺𝒑𝒆𝒆𝒅

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EXPERIMENT No. 02
Objective
To observe the absorption of Oxygen in water at various flow rates of Air.
Apparatus
 Aeration Tank
 DO Meter
 Stopwatch
Reagents
 Water
 Air
Procedure
 Setup the procedure as shown in the Figure 1.
 Filled the tank with distilled water.
 Inserted the probe of DO meter in the tank.
 Made sure that DO meter was properly caliberated and in working
condition.
 Switched on the air blower & adjusted the flow rate of Air.
 Switched the stirrer on & adjusted the RPM.
 Noted the readings of Dissolved Oxygen in water after regular intervals
of one minute.

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 After that changed the flow rate of Air & again noted the Dissolved
Oxygen in water.
 Repeated the above step for various flow rates of Air.
 Plotted the graph & compared the results. (Manual)
Observations & Calculations
Air Flow Rate = 1.75 & 2.75
Stirrer RPM = Medium
Table 2: Amount of DO change w.r.t time
Sr.
No
Time (min) Dissolved Oxygen (mg/L)
1
0 13.9
2
2 14.4
3
4 14.8
4
6 15.3
5
8 16
6
10 16.4
7
12 17.1
8
14 17.6
9
17 17.9

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8
10
12
14
16
18
20
0 2 4 6 8 10 12 14 16 18
DissolvedOxygen
Time (min)
FlowRate 1
Flow Rate 2
Graphical Representation
The following graph based on the values by Table 2 shows
the cahnge in amount of dissolved oxygen as the time increases.
Graph 2: DO vs Time Representation (Flow Rate Variation)

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Results
The Graph 2 shows variation in dissolved oxygen as the time
and stirrer speed changes. Dissolved oxygen shows a significant change after
sufficient time and at high fllow rate.
Conclusion
The results depict that Dissolved Oxygen is directly proportional to time.
𝑫𝑶 ∝ 𝑻𝒊𝒎𝒆
From the results of experiments we can also conclude that Dissolved Oxygen is
also proportional to flow rate of Air. (Joseph A. Salvato, 2006)
𝑫𝑶 ∝ 𝑭𝒍𝒐𝒘 𝑹𝒂𝒕𝒆
REFRENCES
 ATICO, 2. (2015). Retrieved Feb 2018, from Lab Manual for ATICO
Aeration Unit: https://www.aticoexport.com/product.aeration-
unit/manual.pdf
 Joseph A. Salvato, P. D. (2006). Introduction to Envoirnmental
Engineering,5th Edition. New York State Department of Health Albani, N.Y.
 Manual, A. (n.d.). Retrieved Feb 21, 2018, from Lab Manual for Aeration
Unit: https://ocw.tudelft.nl/wp-content/uploads/Aerationto.pdf