EV350 WPR 3 EXAM QUESTIONS AND
CORRECT DETAILED ANSWERS
(2026)
Sources of water pollutants - CORRECT ANSWER (S) -point, area, mobile
theoretical oxygen demand - CORRECT ANSWER (S) -amount of oxygen
required to oxidize a substance to carbon dioxide and water, always
produces the highest yield
chemical oxygen demand - CORRECT ANSWER (S) -amount of carbon
dioxide, calculated difference between what we added and what was
left, some uncertainty
,biochemical oxygen demand - CORRECT ANSWER (S) -amount of oxygen
required by microbes to digest waste
oxygen demands ranked - CORRECT ANSWER (S) -ThOD > COD > BOD
equation for ThOD - CORRECT ANSWER (S) -stoichiometry
mg/L of compound * molecular mass * moles of oxygen in compound
ultimate BOD - CORRECT ANSWER (S) -the maximum oxygen
consumption possible when the waste has been completely degraded
number of days for ultimate BOD - CORRECT ANSWER (S) -5 days unless
otherwise specified
, Equation for ultimate BOD - CORRECT ANSWER (S) -L0(1 - e^-kt)
Equation for determining Kt - CORRECT ANSWER (S) -K T = k(20)
(theta)^T-20
where theta is determined on a range basis
Mass balance for DO sag curve - CORRECT ANSWER (S) -dM/dt =
sum(QinCin) - sum(QoutCout) +- r volume
where concentrations become dissolved osygen concentrations
Equation for initial dissolved oxygen after mixing - CORRECT ANSWER
(S) -DOa = QwDOw + QrDOr / Qw + Qr
CORRECT DETAILED ANSWERS
(2026)
Sources of water pollutants - CORRECT ANSWER (S) -point, area, mobile
theoretical oxygen demand - CORRECT ANSWER (S) -amount of oxygen
required to oxidize a substance to carbon dioxide and water, always
produces the highest yield
chemical oxygen demand - CORRECT ANSWER (S) -amount of carbon
dioxide, calculated difference between what we added and what was
left, some uncertainty
,biochemical oxygen demand - CORRECT ANSWER (S) -amount of oxygen
required by microbes to digest waste
oxygen demands ranked - CORRECT ANSWER (S) -ThOD > COD > BOD
equation for ThOD - CORRECT ANSWER (S) -stoichiometry
mg/L of compound * molecular mass * moles of oxygen in compound
ultimate BOD - CORRECT ANSWER (S) -the maximum oxygen
consumption possible when the waste has been completely degraded
number of days for ultimate BOD - CORRECT ANSWER (S) -5 days unless
otherwise specified
, Equation for ultimate BOD - CORRECT ANSWER (S) -L0(1 - e^-kt)
Equation for determining Kt - CORRECT ANSWER (S) -K T = k(20)
(theta)^T-20
where theta is determined on a range basis
Mass balance for DO sag curve - CORRECT ANSWER (S) -dM/dt =
sum(QinCin) - sum(QoutCout) +- r volume
where concentrations become dissolved osygen concentrations
Equation for initial dissolved oxygen after mixing - CORRECT ANSWER
(S) -DOa = QwDOw + QrDOr / Qw + Qr
