Post on 13-Apr-2018
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Lagoon System M;ath - EUProblemsAnswer Key
The Division o Water Qualitymakes no claim as the accuracy o
any answers provided herein
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W Chapter 13 WASTE TREATMENI PONDS 35
Chapter 13 Achievement Test1. TheBOD concentrationofthe wastewaterenteringapondis190 mg/L. Iftheflowtothe pondis360,000gpd,howmanyIbs/dayBOD enterthe pond?
ANS 51-0 CJ5
2. A8.S-acrepondreceivesaflow of280,000gpd. I f the influentflow has aBODcontentof240 mg/L whatisthe organicloadingrate in lbs/day/aconthepond?
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cSCut-COVl \ 2.3. TheBOD enteringawastetreatmentpondis210mg/L. I f theBOD concentrationinthepondeffluentis 43 mg/L what is theBODremoval efficiencyofthepond?
2.l0 ,:,fL - 43> ~ 100 f2.. ,0 VV )::J L
ANS ~
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236 WB hapter 13 WASTE TREATMENI PONDS
4. A 22-acre pond receives aflow of 3.6 acre-feet/day. What is the hydraulic loading onthe pond n in./day?=... < CA.
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\ Lit.;=: 2....0 .< VJVj5. The BOD entering a waste treatment pond s 162 mg/L. the BOD concentration inthe pond effiuent is 71 mg/L what is the BOD removal efficiency of the pond?
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6. The flow to.a waste treatment pond is 200 gpm. the BOD concentration of the water is218 mg/L how many pounds of BOD are applied t the pond daily?L. 1 - WI 4 ......= ICl vJ = 0 0 ' . v () ~ . . . , L or::;;. '( _
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W Chapter 3 W STE TRE TMENT PONDS 237
Chapter 13-Achievement Test-Cont'd7. The flow to apond is 75,000 gpd with a BOD content of 138 mg/L The pond has anaverage width of 230 ft and an average length of 390 ft. What is the organic loading
rate in Ibs/day/ac on the pond?"2."?;p +\- . .3.9..CLf'-+:>, ' )&0 '" zr I ~ . L )
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38 WB Chapter 13 WASTE TREATMENI PONDS
10. A waste treatment pond has a total volume o 18.2 ac-ft. the flow to the pond is0.51 ac-ft/day what is the detention time of the pond in days?
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11. A 0.7-MGDwastewater flow has a BOD concentration of2840 mg/L. Using anaverage of 0.2Ibs/day BOD/person what is the population equivalent o thiswastewater flow?'Z5 31.-1 l LtlsLl 0 ',5' L < 0. :1- fv'\ G> \
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