Bod Labsheet

FACULTY OF CIVIL AND ENVIRONMENTAL ENGINEERINGDEPARTMENT OF WATER RESOURCES AND

ENVIRONMENTAL ENGINEERING

ENVIRONMENTAL ENGINEERING LABORATORY

LABORATORY INSTRUCTION SHEETS

SUBJECT CODE BFC 3121

EXPERIMENT CODE MA3

EXPERIMENT TITTLEBIOCHEMICAL OXYGEN

DEMAND

COURSE CODE

KOD ETIKA PELAJAR(KEP)

JAB. KEJ. SUMBER AIR & ALAM SEKITARFAKULTI KEJURUTERAAN AWAM & ALAM SEKITAR

KUiTTHO

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___________________________ Tandatangan Pelajar

Nama : _______________________________

No. Matrik :____________________________

Tarikh :________________________________

FACULTY OF CIVIL AND ENVIRONMENTAL ENGINEERINGDEPARTMENT OF WATER RESOURCES AND

ENVIRONMENTAL ENGINEERING

ENVIRONMENTAL ENGINEERING LABORATORY

SHORT REPORT

SUBJECT CODE BFC 3121

EXPERIMENT CODE &

TITTLE

COURSE CODE

DATE

STUDENT’S NAME

GROUP

GROUP MEMBER’S NAME 1.

2.

3.

4.

5.

NAME OF LECTURER/ INSTRUCTOR/ TUTOR DATE OF SUBMISSION

MARKS ATTENDANCE/ DISCIPLINE /10%

INTRODUCTION /5%

DATA ANALYSIS /15%

RESULTS /15%

DISCUSSION /25%

CONCLUSION /5%

REFERENCES /5%

TOTAL /80%

EXAMINER COMMENTS: APPROVAL STAMP

FACULTY : CIVIL AND ENVIRONMENTAL ENGINEERING

PAGE NO: 1/4

DEPARTMENT : WATER RESOURCES AND ENVIRONMENTAL ENGINEERING

EDITION : MA3

REVISION NO: 03LAB : ENVIRONMENTAL ENGINEERING

LABORATORY

EXPERIMENT : BIOCHEMICAL OXYGEN DEMAND ( BOD)

EFFECTIVE DATE : 01/12/07

AMENDMENT DATE: 20/11/07

1.0 OBJECTIVE

To measures the strength of the water sample ( water, wastewater, etc) based on the amount of oxygen needed to stabilize the organic matter in the sample.

_____________________________________________________________________________________

2.0 LEARNING OUTCOMES

i) the student be able to describe the importance of BOD in the environmental studies.ii) the students be able to measure the BOD of samples with the right sample size.

______________________________________________________________________________

3.0 THEORY

Biochemical Oxygen Demand is a common, environmental procedure for determining the extent to which oxygen within a sample can support microbial life. This method is popular in many environmental laboratories analyzing waste water, compost, sludge, and soil samples.

When a measurement is made of all oxygen consuming materials in a sample, the result is termed “ Total Biochemical Oxygen demand “ ( TBOD ) , or often just simply “ Biochemical Oxygen Demand “ (BOD). Because the test is performed over a five day period, it is often referred to as a “ five Day BOD “, or a BOD5.

In addition, this procedure is only suitable for samples void of serious matrix interferences. To gain a broader appreciation of oxygen demand, additional avenues of interest may be explored including CBOD (carbonaceous oxygen demand), COD (chemical oxygen demand), and TOC (total organic carbon).

Because of complications measuring this ultimate BOD (BODu), BODu is usually extrapolated from laboratory 5-day BOD bottle tests BODt = BODu ( 1 – e-kt )

In many biological treatment plants, the facility effluent large numbers of nitrifying organisms which are developed during the treatment process. These organisms can exert an oxygen demand as they convert nitrogenous compounds (ammonia and organic nitrogen) to more stable forms (nitrites and nitrates). At least part of this oxygen demand is normally measured in a five day BOD.

Sometimes it is advantageous to measure just the oxygen demand exerted by organic (carbonaceous) compounds, excluding the oxygen demand exeried by the nitrogenous compounds. To accomplish this, the nitrifying organisms can be inhibited from using oxygen by the addition of a nitrification inhibitor to the samples.The result is termed “Carbonaceous Biochemical Oxygen Demand “ or BOD.

PREPARED BY : ROSLINDA SESWOYA

SIGNATURE :

DATE : 20 NOVEMBER 2007


PAGE NO: 2/4


EDITION : MA3

LAB : ENVIRONMENTAL ENGINEERING LABORATORY

REVISION NO: 03




4.0 EQUIPMENT & REAGENTS :

1. 5 units 300 mL BOD Bottles

2. Incubator , capable of maintaining 20 ± 1 0c

3. 100 mL beaker

4. 100 mL graduated cylinder

5. 2 units 25 ml meaning pipettes

6. DO meter

7. pH meter

8. Phosphate Buffer

Dissolve 8.5g KH2PO4, 21.7g K2HPO4, 33.4g Na2HPO4, and 1.7g NH4Cl in deionized water. Adjust pH to 7.2, if necessary, with either 1 N H2SO4 or NaOH. Dilute to one liter.

9. Magnesium Sulfate Dissolve 22.5g MgSO4.7H2O and dilute to one liter.

10. Calsium Chloride Dissolve 27.5g CaCl2 and dilute to one liter. 11. Ferric Choloride Dissolve 0.25g FeCl3.6H2O and dilute to one liter. NOTE: To prepare dilution water, add one mL of each of the four solutions listed above to one liter of deionized water. Saturate with DO by drawing a vacuum through the solution.

5.0 PROCEDURES

1. Collect the sample.2. Measure the pH of the sample. 3. BOD measurement

- Determine the sample size - Determine three sample size volume ( number of BOD bottles)- Prepare a blank of dilution water

6.0 RESULTS AND CALCULATION

Write the results in bench sheet


PAGE NO: 3/4


EDITION : MA3


REVISION NO: 03




7.0 DATA ANALYSIS

7.1 Calculate for the average BOD

7.2 Show all the calculation and state if any of the data needs to thrown out.

7.3 The dillution water blank can not deplete more than 0.2 mg/L. Was this criteria met?

7.4 Does you sample shows ’a toxic effect’?

7.5 Could you rely on your BOD results? Why?

7.5 By referring to Sewage/Effluent Standard (DOE, Malaysia ) could your sample be discharge to river untreated? If not, suggest the associated treatment for BOD removal.

8.0 DISCUSSION

Q1. a) Calculate the min / max volume of sample to be added to prepare as estimated BOD _____________ mg/L.

b) Why must samples containing cautic alkalinity or acidity be adjusted before preparing BOD dilution?

c) The completed composite sample arrive in the lab at eg:_________________,_______________) What is the latest day and time the sample can be started for BOD.

d) Describe the function of BOD bottle’s cap and seal water.

Q2. a) Why must samples containing residual chlorine be dechlorinated before preparation of BOD dilutions?

b) What reagents are required to chemically dechlorinate a BOD sample?

c) What must be done to samples which have been dechlorinated or adjusted for pH variations?


PAGE NO: 4/4


EDITION : MA3


REVISION NO: 03




Q3. a) State the formula to calculatei) seed correctionii) BOD5 (seeded)

b) Calculate the seed correction and BOD5 (seeded) for the data given as below

BOD5 of Seed Material 95 mg/L

Dilution #1 mL of seed material 2 mL

mL of sample 100 mL

Start D.O. 7.8 mg/L

Final D.O. 2.9 mg/L

Q4. a) 30 mL of wastewater are placed in a 300 mL BOD bottle. The sample is diluted to fill the bottle. The DO concentrations at the beginning and the end of 5-day incubation period are 7.3 mg/L and 1.8 mg/L respectively. What is the BOD?

b) The BOD5 of a wastewater was determined to be 250 mg/L. If the reaction coefficient was 0.23 l/d, calculate i) ultimate BOD, ii) BOD3 and iii) BOD remaining at 3 days

Q5. a) What is seeding process in BOD measurement? b) Explain preparation of seed material. c) What materials can be used to seed a BOD sample

Q6. What is the significance of dissolved oxygen ?

Q7. a) With regard to precision, ten percent duplicate or replicate samples should be run. This would result in one duplicate sample or one replicate sample being run every ten samples. Differentiate replicate and duplicate sample

b) When are DO levels at their highest and their lowest and why?

Bench sheet

BIOCHEMICAL OXYGEN DEMAND ( BOD)

Date:

Time :

Analyst:

Sample Details:

Source:

pH 0C

Pretreatment:

Alkalinity/Acidity

Sample Volume : __________mL

I N NaoH : __________mLI N N2SO4:__________mL

Comments:

Sample Type

Sample ID

Volume Sample( mL)

DilutionFactor

Initial DO(mg/L)

Final DO( mg/L)

DO Depletion( mg/L)

BOD(mg/L)

BOD---

Blank

BOD---

Blank

BOD---

Blank

Average BOD( show the calculation)

Cancelled Data/ Result:

BOD__ =

BOD__ =

BOD__ =

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Bod Labsheet