UPSI student make visited to 2 river They found that one of thearound Tg. Malim to complete their river polluted and more fish task in doing exp. To study the died . sample of river of water So they took the The other river sample of the river and In your opinion has clean and study the content of why fish died?? clear water. the water.
Higher BOD, means that there is dissolvedoxygen in the water, as aerobic bacteria uses up nearly all of it for respiration.Hence less dissolved oxygen available for the fish to use for respiration, So fish will died.
From your observation what is deferencebetween river A and river B?Which water has low content of theoxygen ? why??
PROCEDURE1. 5 beaker were labelling with A, B, C, D and E.2. 100 mL of pond water are collected and pour into beaker A.3. *The D.O probe was placed in the beaker A to read the initial D.O concentration directly.4. The result were recorded in Data Logger Spreadsheet Program.5. Steps 1 to 4 were repeated by using different samples of water which are drain water, distilled water, aquarium water and pipe water which the samples of water is poured into beaker B, C, D and E respectively.
6. The samples were let until 5 days and D.O probes was placed again in these samples to read the final D.O concentration.7. BOD value was determined by the following formula: B.O.D value = Final D.O – Initial D.O p*Note that, before put the sensor into the next sample of water, rinse the sensor with distilled water.
Beaker Water samples Initial D.O Final D.O B.O.D value (mg/L) (mg/L) (mg/L) A Drain water 3.6 4.563 0.963 B Distilled water 4.263 4.675 0.412 C Pond water 3.975 4.625 0.65 D Aquarium water 3.725 4.588 0.863 E Pipe water 4.1 4.638 0.538