Sediment Oxygen Demand and Pore Water Phosphate Flux: Measurement, Characterization, and Monitoring in Deer Creek Reservoir

This paper describes a preliminary investigation that identified factors important in the prediction of river water quality, especially regarding dissolved oxygen (DO) concentration. Intermittent discharges from combined sewer overflows (CSOs) within the sewerage, and overflows at water reclamation works (WRW) cause dynamic conditions with respect to both river hydraulics and water quality. The impact of such discharges has been investigated under both wet and dry weather flow conditions. Data collected from the River Maun, UK, has shown that an immediate, transient oxygen demand exists downstream of an outfall during storm conditions. The presence of a delayed oxygen demand has also been identified. With regard to modelling, initial investigations used a simplified channel and the Streeter-Phelps (1925) dissolved oxygen sag curve equation. Later, a model taking into account hydrodynamic, transport and dispersion processes was used. This suggested that processes other than water phase degradation of organic matter significantly affect the dissolved oxygen concentration downstream of the location of an intermittent discharge. It is proposed that the dynamic rate of reaeration and the sediment oxygen demand should be the focus of further investigation.

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Non-steady variations of SOD and phosphate release rate due to changes in the quality of the overlying water

Water Science & Technology ◽

10.2166/wst.2000.0390 ◽

2000 ◽

Vol 42 (3-4) ◽

pp. 265-272 ◽

Cited By ~ 7

Author(s):

T. Inoue ◽

Y. Nakamura ◽

Y. Adachi

Keyword(s):

Release Rate ◽

Oxygen Demand ◽

Phosphate Concentration ◽

Sediment Oxygen Demand ◽

Biochemical Reactions ◽

Overlying Water ◽

Phosphate Release ◽

Do Concentration ◽

The Difference

A dynamic model, which predicts non-steady variations in the sediment oxygen demand (SOD) and phosphate release rate, has been designed. This theoretical model consists of three diffusion equations with biochemical reactions for dissolved oxygen (DO), phosphate and ferrous iron. According to this model, step changes in the DO concentration and flow velocity produce drastic changes in the SOD and phosphate release rate within 10 minutes. The vigorous response of the SOD and phosphate release rate is caused by the difference in the time scale of diffusion in the water boundary layer and that of the biochemical reactions in the sediment. Secondly, a negative phosphate transfer from water to sediment can even occur under aerobic conditions. This is caused by the decrease in phosphate concentration in the aerobic layer due to adsorption.

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Geostatistical modeling of the spatial distribution of sediment oxygen demand within a Coastal Plain blackwater watershed

Geoderma ◽

10.1016/j.geoderma.2010.06.015 ◽

2010 ◽

Vol 159 (1-2) ◽

pp. 53-62 ◽

Cited By ~ 8

Author(s):

M. Jason Todd ◽

R. Richard Lowrance ◽

Pierre Goovaerts ◽

George Vellidis ◽

Catherine M. Pringle

Keyword(s):

Spatial Distribution ◽

Coastal Plain ◽

Oxygen Demand ◽

Sediment Oxygen Demand ◽

Geostatistical Modeling

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Experimental manipulations of the biomass of introduced carp (Cyprinus carpio) in billabongs. II. Impacts on benthic properties and processes1

Marine and Freshwater Research ◽

10.1071/mf97032 ◽

1997 ◽

Vol 48 (5) ◽

pp. 445 ◽

Cited By ~ 30

Author(s):

A. I. Robertson ◽

M. R. Healey ◽

A. J. King

Keyword(s):

Algal Biomass ◽

Solid Phase ◽

Negative Impact ◽

Oxygen Demand ◽

Sediment Oxygen Demand ◽

Sediment Surface ◽

Nutrient Concentrations ◽

Nutrient Ratios ◽

Biofilm Development ◽

The Impact

Two billabongs on the floodplain of the Murrumbidgee River, Australia, were partitioned in half with impermeable plastic barriers and the biomass of carp was manipulated to establish high- and low-carp biomass treatments in each billabong. Measurements of benthic variables (rates of particle settlement, biofilm development, sediment respiration, macrophyte detritus decomposition, sediment solid-phase nutrient concentrations and benthic algal biomass) were performed over four months from summer to winter 1995. Rates of particle settlement were greater in the high-carp treatment of each billabong throughout the experiment. High carp biomass had a negative impact on the autotrophic component of the biofilm developing on wood blocks placed at different heights above the sediment surface but the mechanism responsible differed between billabongs. Sediment oxygen demand became greater in the presence of a higher biomass of carp during the experiment but time courses differed between billabongs. Manipulations of carp biomass did not influence algal biomass on the sediment surface, the rate of decomposition of macrophyte detritus or sediment solid-phase nutrients or nutrient ratios. The impact of carp on benthic and surficial processes was significant but the mechanisms of change differed between billabongs.

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