1

College of Science and Technology

Department of Civil Engineering

Module: Environmental Engineering II[Practical Report]

Test: Jar Test {Optimum alum dose}

1. Sample Name: muddy pond water.2. Location: Infront of the chemistry laboratory building.3. Time of sampling: 3:30 pm4. Date of testing: 17/08/20155. Observation Table:

Table #1: Record Sheet of Optimum alum dose

No. Sample Volume of

Sample (mL)

Added volume

of Alum (mL)

Concentration

of Alum (mg/L)

Turbidity (NTU)

pH

1 500 0 0 1.2 6.47

2 500 1 20 1.4 4.61

3 500 4 80 0.3 4.26

4 500 8 160 0.4 4.17

5 500 12 240 0.4 4.15

6 500 16 320 0.5 4.11

Optimum alum dose :

4mg/L

(Note) Alum solution: 1%- Ammonium sulphate solution = 1mg-Alum/mL

6. Computations:

2

0 2 4 6 8 10 12 14 16 180

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.2

1.4

0.30.4 0.4

0.5

Alum Dose(mg/l)

Turb

idity

(NTU

)

Graph #1: Relation between alum dose (mg/L) and NTU of turbidity.　

7. Results: The optimum alum dose of the sample water =4 mg/L

8. Conclusion and comment: