9. Consi der t he f ol l owi ng st at ement s about Di ssol ved oxygen and Bi ol ogi cal Oxygen Demand:
- 1 . Higher amount of wastes decreases the dissolved oxygen content of water.
- 2 . Higher value of BOD indicates high level of microorganisms in water.
- 3 . BOD is limited to biodegradable materials thus reliable for measuring pollution load.
Which of the above statements is/are correct?