1. _______ are found in agricultural wastes.
a) Pesticides
b) Phenols
c) Proteins
d) Grease
Explanation: There are different chemical constituents found in wastewater. The wastewater resulting from agriculture consists of pesticides. The industrial wastewater contains phenols.
2. _________ is determined by measuring the dissolved oxygen used by microorganisms during the biochemical oxidation of organic matter in 5 days at 20˚C.
a) BOD5
b) COD
c) TOC
d) ThOD
Explanation: BOD5 is the oxygen equivalent of organic matter. It is determined by measuring the dissolved oxygen used by microorganisms during the biochemical oxidation of organic matter in 5 days at 20˚C.
3. How are many forms of nitrogen present in wastewater?
a) 3
b) 4
c) 2
d) 5
Explanation: There are different types of nitrogen present in wastewater. Basically, our types of nitrogen are present. They are organic nitrogen, ammonia nitrogen, nitrate nitrogen and nitrite nitrogen.
4. After how many days will nitrogen will be oxidized to nitrite and nitrate?
a) 9
b) 10
c) 10-12
d) 14-15
Explanation: After 10-12 days, nitrogen will be oxidized to nitrite and then nitrate. Nitrogen in the presence of oxygen gets converted to nitrite and then gets converted to nitrate.
5. ______ is determined by measuring the dissolved oxygen used during the chemical oxidation of organic matter in 3 hours.
a) COD
b) BOD
c) ThOD
d) TOC
Explanation: It is the oxygen equivalent of organic matter. Chemical Oxygen Demand is determined by measuring the dissolved oxygen used during the chemical oxidation of organic matter in 3 hours.
6. Which of the following is used for a small concentration of organic matter?
a) COD
b) TOC
c) BOD
d) ThOD
Explanation: The organic carbon existing in the wastewater is injected to a sample of the wastewater in a special device in which the carbon is oxidized to carbon dioxide then carbon dioxide is measured and used to quantify the amount of organic matter in the wastewater. This method of TOC measurement is only used for small concentration of organic matter
7. Which of the following indicates that the water body has been used for waste disposal?
a) Chlorides
b) Nitrates
c) Phosphates
d) Ammonia
Explanation: High concentrations of chlorides indicate that the water body has been used for waste disposal. Chlorides affect the biological process when present in high concentrations.
8. What is the maximum concentration of total solids present in wastewater?
a) 350 mg/L
b) 720 mg/L
c) 1200 mg/ L
d) 850 mg/L
Explanation: The concentration of total solids present in weak wastewater is 350 mg/ L. The concentration of total solids present in strong wastewater is 1200 mg/ L. The medium range consists of 720 mg/ L.
9. What is the TSS effluent concentration for 7 days?
a) 30 mg/L
b) 45 mg/L
c) 25 mg/L
d) 40 mg/L
Explanation: TSS stands for total suspended solids. Effluent TSS concentration for average of 30 days is 30 mg/L. The average 7 day concentration for effluent containing TSS is 45 mg/L.
10. The BOD test is carried out for how many days?
a) 1 day
b) 2 days
c) 5 days
d) 6 days
Explanation: The BOD test is carried out for 5 days. BOD is a biological oxygen demand. It is the amount of Dissolved oxygen utilized by bacteria to carry out biochemical reactions.