assessment of u.s. corps aerators in the san joaquin river for the port of stockton

Assessment of U.S. Corps Aerators in the San Joaquin River

for the Port of Stockton

September 2004

Jones & Stokes

Russ Brown, Tom Trexler, Megan Robinson

Goals/Objectives

• Determine the current level of performance of both aerators

• Estimate the oxygen loads from the aerators and the oxygen transfer efficiency

• Compare aerator performance to release of oxygen gas from jets and different aerator device (Biox Hose)

View of Aerator Dock

Measurement Efforts

• Measurements in Front of North Jets while Operating Both Aerators

• Measurements in Front of South Jets while using Oxygen Gas

Measurements and Estimations

• Measured Velocity and DO concentrations of upwelling and/or flow-away currents

• Estimated flow-away or upwelling width and calculated flows

• Estimated Oxygen Loads from upwelling or flow-away flows and DO pick-up (measured DO minus background DO)

Operation of Both Aerators

0.0

1.0

2.0

3.0

4.0

0.0 0.5 1.0 1.5 2.0

Average Velocity (ft/s)

Dep

th (

ft)

0 ft 5 ft North 10 ft North 15 ft North

0.0

1.0

2.0

3.0

4.0

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Average Dissolved Oxygen (mg/l)

Dep

th (

ft)

0 ft 5 ft North 10 ft North 15 ft North

Operation of South Jets with Pure Oxygen Gas

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

-5 0 5 10 15 20

Distance from Jets (ft)

Av

era

ge

Ve

loc

ity

(ft/

s)

South of Jets (5 ft) Centerline North of Jets (5 ft)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

-5 0 5 10 15 20

Distance from Jets (ft)

Av

era

ge

DO

(m

g/l)

South of Jets (5 ft) Centerline North of Jets (5 ft)

Summary

Both Aerators• DO Pick-up of 0.78

mg/l (Back. DO = 3.2 mg/l)

• Total Flow-away Flow of 90 cfs

• Total Oxygen Supply Rate of 402 lbs/day (assuming 40 ft flow-away width)

South Jets with Oxygen• DO Pick-up of 2.19

mg/l (Back. DO = 2.9 mg/l)

• Avg. Upwelling Flow of 191 cfs

• Avg. Oxygen Supply Rate of 2270 lbs/day

• Oxygen Transfer Efficiency of 45%