EV350 BLOCK III WPR 3 QUESTIONS AND CORRECT DETAILED ANSWERS (2026)

EV350 BLOCK III WPR 3 QUESTIONS
AND CORRECT DETAILED ANSWERS
(2026)



1.1 Describe point and non point sources of water pollution - CORRECT

ANSWER (S) -Point: directly from one place, you can point at it, non-

moving (pipe from factory into river)




Non-Point: moving sources of pollution, area, not exactly sure where it

is coming from (cars)




1.2 Understand the sources of oxygen demanding material and how it

depletes DO - CORRECT ANSWER (S) --amount of waste being

discharged

,-amount of o2 required to dissolve waste

-relative rates of competing processes

-photosynthesis o2 raises

-respiration o2 decreases




1.3 Relate ThOD, COD, BOD and identify advantages/disadvantages -

CORRECT ANSWER (S) -ThOd/Theoretical Oxygen Demand:

is the calculated amount of oxygen required to oxidize a compound to

its final oxidation products. (stoichiometry/theoretical exercise)




COD/ Chemical oxygen demand (COD): is commonly used to indirectly

measure the amount of organic compounds in water. Most applications

of COD determine the amount of organic pollutants found in surface

water, chromic acid is hard to deal with

(takes a couple hours in a lab)

, BOD: amount of O2 required to oxidize a reduced compound by

microorganisms

(takes 5 days to test)




ThOD>=COD>BOD




1.4 Calculate theoretical O2 demand (use solution on BB) - CORRECT

ANSWER (S) -1. convert amount of given acid (mg/L) to moles




2. add up O2 in both equations to get the ratio of x moles of O2/ moles

of given acid




3. calculate given acid's total moles by using its equation and periodic

table of elements mass number