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Lecture #11

(Distributed Sytems)

Chapra, L9 (cont.)

David A. Reckhow CEE 577 #11 1

Updated: 12 February 2013 Print version

http://www.ecs.umass.edu/cee/reckhow/courses/577/slides/577l11p.pdfhttp://www.ecs.umass.edu/cee/reckhow/courses/577/slides/577l11p.pdf

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Distributed Sources Source (or sink) that is spread out along the

stream length classical non-point sources

agricultural, urban runoff

Sediment processes sediment oxygen demand

Atmospheric deposition

David A. Reckhow CEE 577 #11 2

H

BJin Jout

SD

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Distributed source in PFR @SS

David A. Reckhow CEE 577 #11 3

H

BJin Jout

SD

0= +Udc

dxkc S

D

( ) ( )c c e Sk

eo

k x u D k x u= + 1

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0

0.5

1

1.5

2

2.5

3

0 2 4 6 8 10

Distance (miles)

Concentration(m

g/L)

David A. Reckhow CEE 577 #11 4

Increasing SD

0.9 mg/L/d

0.6 mg/L/d

0.344 mg/L/d

K=0.344/d

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0

0.5

1

1.5

2

2.5

3

3.5

4

0 2 4 6 8 10

Distance (miles)

Concentration(m

g/L)

David A. Reckhow CEE 577 #11 5

Decreasing k

0.23/d

0.344/d

0.58/d

0.88/d

SD= 0.9 mg/L/d

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Lecture #11b

(Waste Load Allocations)

Chapra, here and there

David A. Reckhow CEE 577 #11 7

Updated: 12 February 2013

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Graphical Representation

See also: Fig 1.2 from

Thomann & MuellerDavid A. Reckhow CEE 577 #11 8Miles Downstream

-2 0 2 4 6 8 10 12 14 16

DissolvedO

xygen(mg/L)

0

1

2

3

4

5

6

7

8

9

10

11

Loading

0

10

20

30

40

50

60

70

80

Fishing BoatingFishing

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WLA: Step by Step

Designate a specific water use

David A. Reckhow CEE 577 #11 9

Adopt a Water Quality Criterion

Determine action necessary

formulate several alternatives

evaluate the alternatives

Is cost

OK?

No

Yes

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WLA: breakdown of steps

Designate a specific water use

recreation: swimming, boating, aesthetics

water supply: municipal, industrial

agriculture fisheries: commercial or sport

ecological balance

Adopt a Water Quality Criterion

must support the above use

EPA red book

David A. Reckhow CEE 577 #11 10

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To next lecture

David A. Reckhow CEE 577 #11 12

http://www.ecs.umass.edu/cee/reckhow/courses/577/slides/577l12.pdfhttp://www.ecs.umass.edu/cee/reckhow/courses/577/577l12/http://www.ecs.umass.edu/cee/reckhow/courses/577/577l12/http://www.ecs.umass.edu/cee/reckhow/courses/577/slides/577l12.pdf