Part $3$: Water Quality Parameters $(5$ Points$)$

Q$1.$ Multiple choice problems $[3$ Pts$]$

Which of the following statements is not true about BOD test

a$.$ The Oxygen demand in BOD is associated only with biodegradation of organic matter

b$.$ Nitrifying inhibitor should be used for BOD test of treated sewage

c$.$ The amount of nitrification microorganisms in treated sewage is scarce

d$.$ The O demand in BOD is associated with both biodegradation of organic matter and oxidation of N compounds

e$.$ Nitrifying inhibitor should be used for BOD test of untreated wastewater

Materials that can be oxidized in water bodies resulting in reduction of dissolved oxygen are known as

a$.$ Biodegradable organic materials

b$.$ Oxygen demanding materials

c$.$ Excess Nutrients

d$.$ Dissolved materials

e$.$ Pathogens

For which type of wastewater the nitrification starts almost at the same time as carbon oxida

a$.$ Untreated wastewater

b$.$ River water

c$.$ Treated wastewater

d$.$ Treated sewage

e$.$ Untreated sewage