ABSTRACT

This experiment was conducted to investigate the level of BOD in a sample, the

amount of DO in a BOD bottle and the pH meter and temperature. This experiment were

conducted in three sections. Before each experiment conducted, the sample volume and

titration catridge was selected from the tables. On the first experiment, two samples from

river and drain were selected and mix with Phenolphthalein Indicator Powder Pillow. Then,

sodium hydroxide was added using titrator and was swirled until light pink solutions appeared

before the digit displayed at the titrator was recorded and multiplied with multiplier. Then,

second experiment was conducted by adding the samples with Manganous Sulphate Powder

Pillow and Alkaline Iodide-Azide Reagent Powder Pillow into 300 ml BOD bottle and

inverted it several times. Sulfamic Acid Powder Pillow was added and inverted again before

sodium thiosulfate added into the solution while it was swirled until pale yellow. After dark

blue colour turns colourless by the addition of Starch Indicator, the digits at the titrator was

recorded. The last experiment, the pH and the temperature of the samples were recorded by

using electronic pH meter with thermometer.

The result for experiment using drain water the amount of carbon dioxide and dissolve

oxygen are 31.5 and 4.18 while in the experiment using river water are 38.5 and 2.22

repeectively. The temperature between the carbon dioxide and dissolve oxygen are 30.5 and

28.6 while the pH are 28.9 and 28.0 respectively. The water sources itself shows significance

relationship that the higher the number of digits, the more concentrations of carbon dioxide in

the sample.

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TABLE OF CONTENT

Abstract…………………………………………………………… 1

Table of Contents……………………………………………………2

1.0 Introduction ……………………………………………………….. 3

2.0 Objective ………………………………………………………….. 3

3.0 Theory ……………………………………………………………. 4-5

4.0 Diagram and Description of Apparatus ………………………….. 5-7

5.0 Experimental Procedures ………………………………………... 7-9

6.0 Results and Discussions …………………………………………. 10-13

7.0 Sample calculations ……………………………………………… 13

8.0 Conclusions and Recommendations ……………………………. 13-14

9.0 References ……………………………………………………… 14-15

10.0 Appendices …………………………………………………. 15

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INTRODUCTION

Water quality is a term used to describe the chemical, physical and biological

characteristics of water. It is defined in the Clean Water Act as the standard of purity that is

necessary for the protection of fish, shellfish and wildlife populations in the aquatic

environment, and for recreational uses in and on the water[1]. Most aquatic organisms need

oxygen to survive and grow. Some species require high dissolved oxygen such as trout and

stoneflies. Other species do not require high dissolved oxygen, like catfish, worms and

dragonflies. If there is not enough oxygen in the water the following may happen, death of

adults and juveniles, reduction in growth, failure of eggs/larvae to survive, change of species

present in a given waterbody.[2] Generally the chemical water quality tests include the

measurement of the amount of carbon dioxide, dissolved oxygen, hardness and organic

compounds. Hence, for the physical water quality the common test includes turbidity, colour,

odor, pH and the temperature of water being test. It is a measure of the condition of water

relative to the requirements of one or more biotic species and or to any human need or

purpose.

OBJECTIVE

The objective of this experiment is to determine the amount of carbon dioxide in

two source of sample water. Sodium hydroxide and phenolphthalein were used to determine

the present of carbon dioxide. This experiment also to determine the amount of dissolved

oxygen in two source of sample water using 300 ml BOD bottle. Hence, this experiment also

to determine the temperature and pH of two source of sample water.

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THEORY

The traditional significance of organic carbon in a river is the impact that it has on

dissolved oxygen. Therefore, it is generally measured using its oxygen demand, most

commonly the chemical oxygen demand (COD) or carbonaceous biochemical oxygen

demand (BOD). Carbon has a fundamental role in water quality processes which cannot be

identified by BOD alone. For example , the fraction of carbon which will settle depends

(among other things) on the fraction which is solid. To calculate the amount of carbon dioxide

in sample water is by using the range specific information below.

Table 1: Range specific information

Range (mg/L as

CO₂)

Sample volume (mL) Titration cartridge (N

NaOH)

Multiplier

10-50 200 0.3636 0.1

20-100 100 0.3636 0.2

100-400 200 3.636 1

200-1000 100 3.636 2

By using the information, the concentration of CO₂ in sample water (mg/L CO₂) can be

calculated :

Digits × multiplier

Digital titrator is used in order to get the digits.

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The amount of dissolved oxygen in 300 mL BOD bottle (mg/L O₂) also can be found by

using volume multipliers table below.

Table 2 : volume multipliers

Range ( mg/L DO) Volume (mL) Titration Cartridge

(N Na2S2O3)

Digit Multiplier

1-5 200 0.2 0.01

2-10 100 0.2 0.02

˃ 10 200 2 0.1

The concentration of the O₂ in sample water using 300 mL BOD bottle (mg/L O₂) can be

calculated by using the equation :

= Digits required × Digit Multiplier

REAGENTS AND APPARATUS

EXPERIMENT 1: CARBON DIOXIDE TEST BY DIGITAL TITRATOR METHOD

USING SODIUM HYDROXIDE

REAGENTS

1. Phenolphthalein Indicator Powder Pillows

2. Sodium Hydroxide Titration Cartridge, 3.636 N

APPARATUS

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1. Digital Titrator

2. Delivery tube for digital titrator

3. Erlenmeyer Flask,

4. Beaker 200ml

5. Platinum Series Combination pH electrode with temperature

EXPERIMENT 2: DISSOLVED OXYGEN TEST BY AZIDE MODOFICATION OF

WRINKLED METHOD

REAGENTS for 300ml BOD Bottle

1. Alkaline Iodide-Azide Powder Pillows

2. Manganous Sulfate Powder Pillows

3. Starch Indicator Solution

4. Sulfamic Acid Powder Pillows

5. Sodium Thiosulfate Titration Catridge, 0.2000 N

APPARATUS for 300ml BOD Bottle

1. Digital Titrator

2. Delivery tube for digital titrator

3. Graduated cylinder 250ml

4. Erlenmeyer Flask, 250ml

5. Beaker 200ml

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6. 300ml BOD bottle with stopper

7. Clippers for opening pillows

8. Platinum Series Combination pH electrode with temperature

EXPERIMENTAL PROCEDURES

EXPERIMENT 1: CARBON DIOXIDE TEST BY DIGITAL TITRATOR METHOD

USING SODIUM HYDROXIDE

PROCEDURES:

1.A sample volume and titration cartridge were selected.

2. A clean delivery tube was inserted into the titration cartridge. The cartridge was attached to

the titrator.

3. The delivery knob was turned to eject air and a few of titrant was dropped. The counter to

zero was reset and wiped to tip.

4. A water sample was directly collected into the titration flask by filled to the appropriate

marked.

5. The content of one Phenolphthalein Indicator Powder Pillow was added. Swirl to mixed.

Pink color was formed because no carbon dioxide was presented.

6. The delivery tube was placed into the solution and the flask was swirled. The knob was

turned on the titrator to add titrant to the solution. The flask was continue swirled and titrant

was added until the color changes to a light pink color that persists for 30 seconds (pH 8.3).

The number of digits displayed on the counter was written.

7. The concentration of CO2 sample water was calculated using the multiplier of 1.

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8. The solution was transferred into the beaker. The pH and the temperature was recorded

using Potassium Chloride Electrolyte Gel Cartridge in the Platinum Series pH Electrode.

9. Step 1 until 8 was repeated using different type of sample water and also different sample

volume and different titration cartridge.

EXPERIMENT 2: DISSOLVED OXYGEN TEST BY AZIDE MODIFICATION OF

WRINKLED METHOD

PROCEDURES:

1. A water sample in a clean 300ml BOD bottle was collected. The sample to overflow the

bottle for 2-3 minutes was allowed to make sure that air bubbles are not trapped.

2. The contents of one Manganous Sulfate Powder Pillow and one Alkaline Iodide-Azide

Reagent Powder Pillow were added.

3. The stopper was inserted immediately and without trapped air in the bottle. The bottle was

inverted several times to mixed. A flocculent precipitate was formed. It becomes orange-

brown because oxygen was presented. The flocs were settled slowly in salt water. The settled

takes about five minutes.

4. The bottle was inverted several times again and waited for the flocs settled and the top half

of the solution was cleared again. To make sure the reaction of the sample and reagents was

completed wait until the floc settled.

5. The stopper was removed and the content of one Sulfamic Acid Powder Pillow was added.

The stopper was replaced without trapped air in the bottle. To mixed inverted for several

times. The flocs was dissolved and a yellow colour was leaved because oxygen was

presented.

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6. A sample water and Sodium Thiosulfate Titration Cartridge was selected that corresponds

to the expected dissolved oxygen (DO) concentration.

7. A cleaned delivery tube was inserted into the titration cartridge. The cartridge was attached

to the titrator body.

8. The delivery knob was turned to eject a few drops of titrant. The counter to zero was reset

and the tip was wiped.

9. A graduated cylinder was used to measure the 100ml of sample volume. The sample

volume was transferred into a 250ml Erlenmeyer flask.

10. The delivery tube tip was placed into the solution and the flask was swirled while titrated

with sodium thiosulfate to a pale yellow color.

11. Two 1 ml droppers of Starch Indicator Solution was added and swirled to mixed. A dark

blue color was developed.

12. The titration was continued to a colorless end point. The number of digits required was

recorded.

13. The amount of dissolved oxygen content in water sample was calculated.

14. The solution was transferred into the beaker. The pH and the temperature of the solution

was recorded using Potassium Chloride Electrolyte Gel Cartridge in the Platinum Series pH

Electrode.

15. The step 1 until 14 was repeated for the other water sample and other sample volume and

also different titration Cartridge.

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RESULTS

Source of water (i) : Penaga River

(First Attempt)

Test Temperature ( °C)

pH Range (mg/L as CO2)

Sample volume (mL)

Titration cartridge (N NaOH)

Multiplier

Carbon dioxide, CO2

28.9 6.51 40.5 200 3.636 1

Dissolve oxygen, DO using 300 mL BOD bottle

28 6.86 2.22 100 0.2 0.02

(Second Attempt)

Test Temperature (°C)

pH Range (mg/L as CO2)

Sample volume (mL)

Titration cartridge (N NaOH)

Multiplier

Carbon dioxide, CO2

28.6 6.83 38.5 200 0.3636 0.1

Source of water (ii) : Drain water at UiTM Pulau Pinang

(First Attempt)

Test Temperature (°C)

pH Range (mg/L as CO2)

Sample volume (mL)

Titration cartridge (N NaOH)

Multiplier

Carbon dioxide, CO2

28.9 6.85 43.0 200 3.636 1

Dissolve oxygen, DO using 300 mL BOD bottle

28.3 6.74 5.4 200 0.2 0.01

(Second Attempt)

Test Temperature (°C)

pH Range (mg/L as CO2)

Sample volume (mL)

Titration cartridge (N NaOH)

Multiplier

Carbon dioxide, CO2

30.5 7.03 31.5 200 0.3636 0.1

Dissolve oxygen, DO using 300 mL BOD bottle

28.9 4.78 4.18 100 0.2 0.02

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CALCULATION

1. Concentration of CO2 in sample water (mg/L CO2) = digits × multiplier

2. Concentration of the O2 in sample water using 300 mL BOD bottle (mg/L O2)

= digits required × digit multiplier

Penaga river

First attempt

1. 40.5 × 1 = 40.5

2. 111 × 0.02 = 2.22

Second attempt

1. 385 × 0.1 = 385

Drain water at UiTM Pulau Pinang

First attempt

1. 43.0 × 1 = 43.0

2. 540 × 0.01 = 5.4

Second attempt

1. 315 × 0.1 = 31.5

2. 209 × 0.02 = 4.18

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DISCUSSION

The importance of carbon dioxide and dissolved oxygen test of sample water to

determine the chemical water quality of sample water from the range that had been decided

whether the sample water it good to use or not.

Dissolved oxygen can present in water from the atmosphere or as a byproduct of the

photosynthesis of aquatic plant. The dissolved oxygen levels are higher in the summer and

during daylight hours because this is when photosynthetic organisms produce oxygen. Carbon

dioxide can present in water from the atmosphere or living thing organism that breath out

carbon dioxide. Carbon dioxide react with water naturally, it create carbonic acid from the

mixture of both component.

The value of carbon dioxide concentration in penaga river is high compare with the

value obtained from literature. It means that the river has low oxygen amount. The value of

carbon dioxide concentration in drain water at UiTM Pulau Pinang is high too. It means that

both sample water cannot be used for human activities and aquatic life.

The value of dissolved oxygen concentration in penaga river and drain water at UiTM

Pulau Pinang are low compare with the value obtained from literature. Both sample water are

harmful to living things because amount of acid in water is high. As dissolved oxygen levels

in water drop below 5.0 mg/l, aquatic life is put under stress. The lower the concentration, the

greater the stress. Oxygen levels that remain below 1-2 mg/l for a few hours can result in

large fish kills.

The temperature in water has extremely important ecological consequences. All

aquatic organisms have preferred temperature in which they can survive and reproduce

optimally. Increasing water temperature results in greater biological activity and more rapid

growth. The significance of pH in water to determines the solubility and biological

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availability of chemical constituents such as nutrients and heavy metals. For example, in

addiction to affecting how much and what form of phosphorus is most abundant in the water,

pH also determines whether aquatic life can use it. In the case of heavy metals, the degree to

which they are soluble determines their toxicity. Metals tend to be more toxic at lower pH

because they are more soluble.

SAMPLE CALCULATION

1. To obtain the concentrations of CO2 in sample of UiTM drain water :

Concentration of CO2 in water sample (mg/L CO2) = digits x multiplier

= 38.5 x 1.0

= 38.5 mg/L CO2

2. To obtain the concentrations of O2 in sample of UiTM drain water :

Concentration of O2 in water sample (mg/L O2) = digits x multiplier

= 0.02

= 38.5 mg/L O2

CONCLUSION

From the experiment the higher the level of BOD, the lower the survivality of the

aquatic life to maintain alive. The higher the BOD the lower the level DO inside the water

system. The concentrations of carbon dioxide and dissolved oxygen in the samples depends

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on the sources of the water itself. The higher the concentrations of carbon dioxide, the higher

the digits reading at the digital titrator.

RECOMMENDATIONS

1. Make sure transfer tube is completely washed with pure water when we want to

change the reagent with a new one.

2. Make sure there is no water left trapped inside the tube when it is about to be use.

3. Use more variety source of water to be used for the experiment to obtain better results.

REFERENCE

[1] The Five Basic Water Quality Parameters. (2010).Retrieved June 2, 2013, from

http://www.waterboards.ca.gov/water_issues/programs/swamp/docs/cwt/guidance/310.pdf

[2] Water Quality. (1998). Retrieved June 2, 2013, from

http://nerrs.noaa.gov/doc/siteprofile/acebasin/html/envicond/watqual/wqintro.htm

[3] Analysis of Uncertainty in River Water Quality Modelling. (2004). Retrieved June 3, 2013,

from http://www3.imperial.ac.uk/pls/portallive/docs/1/7253966.PDF

[4] Noorzalila Muhammad Niza. (2013). Laboratory Manual of Chemical Engineering.

Distillation Column. University Teknologi Mara Pulau Pinang.

[5] Temperature . (2009). Retrieved June 2, 2013, from

http://www.ourlake.org/html/temperature.html

[6] Water Properties : pH. (2013). Retrieved June 2,2013,from

http://ga.water.usgs.gov/edu/ph.html

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[7] Carbon Dioxide. (2003). Retrieved June 2,2013, from

http://water.me.vccs.edu/exam_prep/carbondioxide.html

[8] Why Dissolved Oxygen is Important?.(1998-2002). Retrieved June 2,2013,from

http://www.lenntech.com/why_the_oxygen_dissolved_is_important.htm

[9] Biochemical Oxygen Demand . (2007). Retrieved June 3,2013,from

http://www.google.com.my/webhp?

source=search_app#output=search&sclient=psyab&rlz=1C6CHFA_enMY505MY523&q=bio

chemical+oxygen+demand&oq=BIOCHEMICAL+&gs_l=hp.3.1.0l4.1021.3011.0.4443.12.7.

0.5.5.0.174.765.5j2.7.0...0.0...1c.1.15.psyab.fFRqjregf8U&pbx=1&bav=on.2,or.r_qf.&bvm=b

v.47244034,d.bmk&fp=d0a0a0df33e7f57c&biw=1109&bih=620

[10] Addition Information of Biochemical Oxygen Demand. (2009). Retrieved June

3,2013,from http://www.polyseed.com/misc/BODforwebsite.pdf

[11] Method of Water Monitoring. (2010). Retrieved June 3,2013,from

http://water.epa.gov/type/rsl/monitoring/vms52.cfm

APPENDIX

1. Original data sheet.

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