Black & Veatch Weftec.09 Werf/crtc Testing...

BUILDING A WORLD OF DIFFERENCE®

WERF/CRTC TESTING INDICATES THAT NO NEW CLARIFIER BASINS ARE NEEDED TO DOUBLE PLANT’S CAPACITY

JIM FITZPATRICK, CHRISTINE ELLENBERGER, KENNY BLANTON: BLACK & VEATCH BILL HURLEY, SHANE BENNER: ORANGE COUNTY UTILITIES

STATE POINT ANALYSIS 9

140

8 7

120 100 80

86% TML

50% RAS

90% RAS

57% ML

100% ML

71% TML

100% TML

80% RAS

100% TRAS

0

Vesilind Equation

4

5,500

300 90th Percentile 10th Percentile Daily Average 7 per. Mov. Avg. (Daily Average) 30 per. Mov. Avg. (Daily Average) Linear (Daily Average)

5,000

250

Sludge Volume Index, mL/g

4,500 4,000 3,500 3,000 2,500 90th Percentile 10th Percentile Daily Average 7 per. Mov. Avg. (Daily Average) 30 per. Mov. Avg. (Daily Average) Linear (Daily Average)

150

100

50

1,000

Ja n08

-0 7 O ct

Ju l-0 7

7 -0 pr A

7 Ja n0

-0 6 O ct

Ju l-0 6

-0 6 pr A

6

n08 Ja

-0 7 O ct

7 l-0 Ju

pr -0 7 A

07 nJa

-0 6 O ct

6 l-0 Ju

pr -0 6

Ja n0

HISTORICAL SVI DATA

8,000

10,000

12,000 14,000

70

Test 1 Test 2 Test 3 Average

20

Design Underflow State-Point (Peak) State-Point (Design)

12

60

50

10

40

8

30

6

20

10

0

0

2,000

4,000

6,000

8,000

10,000

12,000

Design Underflow State-Point (Peak) State-Point (Design)

8

20

4

0 2,000

4,000

6,000

8,000

10,000

12,000

14,000

Solids Concentration, (mg/L)

VESILIND FLUX CURVE COMPARISON 70

14 April 10/11 2008 Test (SVI = 145) Flux w/o Ekama (SVI=165) Flux w/ Ekama (SVI=165)

Design Underflow State-Point (Peak) State-Point (Design)

50

10

50

10

40

8

40

8

30

6

30

6

4

20

4

20

4

2

10

2

10

2

0

0

0

0

14,000

Solids Concentration (mg/L)

Peak Overflow Peak Underflow Design Overflow

0

2,000

4,000

6,000

8,000

10,000

Solids Concentration (mg/L)

SPA FOR 43 ML/d (11.25 mgd) AADF DESIGN

12,000

14,000

12

Peak Overflow Peak Underflow Design Overflow

0

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

Solids Concentration (mg/L)

SPA FOR 57 ML/d (15 mgd) AADF DESIGN

15

CONCLUSIONS

5

0 DSSin

FSS

ESS

DSSeff

DSS/FSS TEST RESULTS

• The DSS/FSS test results suggested that peripheral density-current baffles should help improve tank hydrodynamics and effluent quality. • Based on the results of the state-point analyses, no additional clarifier settling areas appeared necessary for the initial planned expansion to 43 ML/d (11.25 mgd) AADF or for the next planned expansion to 57 ML/d (15 mgd) AADF. • Clarifier internals and RAS pumping capacity were recommended to be upgraded to accommodate the higher flow rates. • Aeration basin expansions should be designed to keep the MLSS below 4,500 mg/L for the initial planned expansion to 43 ML/d (11.25 mgd) AADF and below 4,200 mg/L for the next planned expansion to 57 ML/d (15 mgd) AADF.

THIS POSTER WAS PRESENTED AT WEFTEC 2009 FOR MORE INFORMATION WRITE

12

60

SPA FOR EXISTING FACILITIES AT 28 ML/d (7.5 mgd) AADF

10

16

40

0

14 April 10/11 2008 Test (SVI = 145) Flux w/o Ekama (SVI=165) Flux w/ Ekama (SVI=165)

60

20

12

Flux (lb/ft²/d)

Peak Overflow Peak Underflow Design Overflow

2

60

COLLECTING SAMPLE FOR ESS AND DSSeff

70

14 April 10/11 2008 Test (SVI = 145) Flux w/o Ekama (SVI=165) Flux w/ Ekama (SVI=165)

80

0

Flux (lb/ft²/d)

6,000

FITTED VESILIND FLUX CURVE

0 A

n06

200

4,000

Flux (kg/m /hr)

• DSS/FSS tests were conducted to assess the effectiveness of clarifier flocculation and hydrodynamics.

2,000

MLSS (mg/L)

Flux (lb/ft²/d)

Phased expansions are planned for the Northwest Water Reclamation Facility to increase the average daily flow capacity from 28 ML/d to 43 ML/d and then to 57 ML/d (7.5 mgd, 11.25 mgd and 15 mgd, respectively). The secondary clarifiers were tested in accordance with WERF/CRTC protocols to evaluate upgrade alternatives.

• Mixed liquor settling tests were conducted to develop a plant-specific solids settling flux curve, which was then used in a series of state-point analyses to assess overflow and underflow capacities. • Peripheral density-current baffles were recommended as a result of the DSS/FSS test results. • The state point analyses indicated that the planned upgrades could be accommodated without additional clarifier settling area.

1

Solids Flux (lb/ft²/d)

5

0

100

where: Vs = interface settling velocity (m/h or ft/d), X = solids concentration (mg/L), Vo = maximum settling velocity (m/h or ft/d), and k = sludge-specific settling parameter (L/mg).

6

WWTP (SVI) NWRF (145) Northwest Cobb (50) Northwest Cobb (94) Northwest Cobb (140) ICMB Train 1 (79) ICMB Train 3 (153) Rocky River (88) St Peters (80) Rocky River (91) McDowell (-) Sun City (125) Daigger (145)

kX

2

Solids Flux (kg/m²/hr)

Vs = Voe-

7

0

10,000

24

120

Thickens Better

10

3

Total Suspended Solids Concentration (mg/L)

ABSTRACT

8,000

OBSERVED SETTLING VELOCITY AS A FUNCTION OF MLSS

STIRRED MIXED LIQUOR SETTLING TEST

Flux (kg/m /hr)

COLLECTING SAMPLE FOR DSSin

6,000

MLSS (mg/L)

2

Ja

4,000

Settles Faster

OBSERVED SOLIDS/WATER INTERFACE HEIGHTS

CLARIFIER NO. 1 AT THE NWRF

Mixed Liquor Suspended Solids, mg/L

2,000

Elapsed Time (hh:mm)

8

HISTORICAL MLSS DATA

2

0

9

1,500

3

1

0 0:00 0:02 0:04 0:06 0:08 0:10 0:12 0:14 0:16 0:18 0:20 0:22 0:24 0:26

FSS TESTING

2,000

4

[email protected] OR VISIT www.bv.com

©Copyright, Black & Veatch Corporation, 2009. All rights reserved. The Black & Veatch name and logo are registered trademarks of Black & Veatch Holding Company. Other service marks and trademarks may be registered trademarks or trademarks of their respective companies.

20

67% ML

100% ML

5

Solids Flux (kg/m2/hr)

40

28% ML

6

2

60

y = 9.395188e-0.000380x R2 = 0.990729

Flux (kg/m /hr)

NORTHWEST WATER RECLAMATION FACILITY APOPKA, FLORIDA

160

Interface Settling Velocity (m/hr)

Solids/Water Interface Height (cm)

DSS/FSS TESTING