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Department of Civil & Environmental Engineering University of Utah. Sediment Oxygen Demand & Nutrient Flux Studies in Jordan River. Dr. Ramesh Goel Assistant Professor Civil & Environmental Engineering University of Utah. CONCEPT ON SEDIMENT OXYGEN DEMAND (SOD). Water. O 2. Nutrients.
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Department of Civil & Environmental EngineeringUniversity of Utah Sediment Oxygen Demand & Nutrient Flux Studies in Jordan River Dr. RameshGoel Assistant Professor Civil & Environmental Engineering University of Utah
CONCEPT ON SEDIMENT OXYGEN DEMAND (SOD) Water O2 Nutrients Sediments Organics etc
SEDIMENT OXYGEN DEMAND SOD is a combination of all of the oxygen-consuming processes that occur at or just below the sediment-water interface. Most of the SOD at the surface of the sediment is due to the biological decomposition of organic material and the microbially facilitated nitrification of ammonia SOD several centimeters into the sediment is often dominated by the chemical oxidation
Pump Pump Howto Measure SOD? DOT = Sediments + Water column DOW = Water column only SOD = DOT – DOW
Methodology Schematic of SOD Chamber
CONTROL ANALYSIS
SOD Rate Estimation Equation used for the SOD rate: SOD t = sediment oxygen demand rate (g/m2d) b = slope of the oxygen-depletion curve (mg/L-min) V = the volume of the chamber (L) A = the area of bottom sediment covered by the chamber (m2) 1.44 = units-conversion constants SOD20 = the rate at 20°C t = in °C Source: Parkhill and Gulliver, 1997
SOD- 2300S site Initial linear data is used Slope of SOD 1 = 0.0065 mg/L-min Slope of Control =0.0005 mg/L-min Net SOD = 0.0065-0.0005 =0.0060= 0.006 * 1.44 * 240 =2.073 g/m2-day
Difficulties • Bed-sediment heterogeneities • Measurement errors • Possible disturbances during chamber placements • Sampling errors • Control chamber data fluctuations
Acknowledgements • Mr. James Harris, Utah Department of Water Quality • Mr. Carl Adam- Utah DWQ • Leland Myers- Great inspiration • The whole water quality personnel
Thank You!!! Questions???