Impact of Global Warming on Dissolved Oxygen and BOD Assimilative Capacity of the World’s Rivers: Modeling Analysis

For rivers and streams, the impact of rising water temperature on biochemical oxygen demand (BOD) assimilative capacity depends on the interplay of two independent factors: the waterbody’s dissolved oxygen (DO) saturation and its self-purification rate (i.e., the balance between BOD oxidation and reaeration). Although both processes increase with rising water temperatures, oxygen depletion due to BOD oxidation increases faster than reaeration. The net result is that rising temperatures will decrease the ability of the world’s natural waters to assimilate oxygen-demanding wastes beyond the damage due to reduced saturation alone. This effect should be worse for nitrogenous BOD than for carbonaceous BOD because of the former’s higher sensitivity to rising water temperatures. Focusing on streams and rivers, the classic Streeter–Phelps model was used to determine the magnitude of the maximum or “critical” DO deficit that can be calculated analytically as a function of the mixing-point BOD concentration, DO saturation, and the self-purification rate. The results indicate that high-velocity streams will be the most sensitive to rising temperatures. This is significant because such systems typically occur in mountainous regions where they are also subject to lower oxygen saturation due to decreased oxygen partial pressure. Further, they are dominated by salmonids and other cold-water fish that require higher oxygen levels than warm-water species. Due to their high reaeration rates, such systems typically exhibit high self-purification constants and consequently have higher assimilation capacities than slower moving lowland rivers. For slow-moving rivers, the total sustainable mixing-point concentration for CBOD is primarily dictated by saturation reductions. For faster flowing streams, the sensitivity of the total sustainable load is more equally dependent on temperature-induced reductions in both saturation and self-purification.

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Investigation of the Contribution of Natural Organic Runoff to Dissolved Oxygen Depletion in the Red Deer River

Water Quality Research Journal ◽

10.2166/wqrj.1979.007 ◽

1979 ◽

Vol 14 (1) ◽

pp. 71-88

Author(s):

S.E. Penttinen ◽

P.H. Bouthillier ◽

S.E. Hrudey

Keyword(s):

Dissolved Oxygen ◽

Red Deer ◽

Stream Water ◽

Oxygen Demand ◽

Oxygen Depletion ◽

Experimental Program ◽

Nitrogen Budgets ◽

Carbon And Nitrogen ◽

Tributary Stream ◽

Small Tributary

Abstract Studies on the chronic low dissolved oxygen problems encountered under winter ice in the Red Deer River have generally been unable to account for dissolved oxygen depletion in terms of known manmade inputs. An experimental program was developed to assess the possible nature and approximate bounds of oxygen demand due to natural organic runoff carried to the Red Deer River by a small tributary stream, the Blindman River. The study employed an electrolytic respirometer on stream water samples subjected to prior concentration by vacuum evaporation. Evaluation of carbon and nitrogen budgets in conjunction with the measured oxygen demand indicate that biochemical oxygen demand is originating with natural organic runoff in tributaries of the Red Deer River. The results provide a basis for estimation of the possible contribution to the observed oxygen demand in the Red Deer River originating from natural organic runoff.

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Considering the impact of intermittent discharges when modelling overflows

Water Science & Technology ◽

10.2166/wst.1998.0370 ◽

1998 ◽

Vol 38 (10) ◽

pp. 23-30

Author(s):

Sarah Jubb ◽

Philip Hulme ◽

Ian Guymer ◽

John Martin

Keyword(s):

Water Quality ◽

Dissolved Oxygen ◽

Preliminary Investigation ◽

Oxygen Demand ◽

Sediment Oxygen Demand ◽

Combined Sewer Overflows ◽

River Hydraulics ◽

Combined Sewer ◽

The Impact ◽

Curve Equation

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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A Niche Definition for Lake Trout (Salvelinus namaycush) and Its Use to Identify Populations at Risk

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-250 ◽

1994 ◽

Vol 51 (11) ◽

pp. 2513-2519 ◽

Cited By ~ 15

Author(s):

Phil A. Ryan ◽

Terry R. Marshall

Keyword(s):

Oxygen Content ◽

Lake Trout ◽

Cold Water ◽

Natural Populations ◽

Oxygen Demand ◽

Oxygen Depletion ◽

Salvelinus Namaycush ◽

Phosphorus Concentration ◽

Suitable Habitat ◽

Populations At Risk

Lake trout (Salvelinus namaycush) populations require cold water with high dissolved oxygen content for survival. We developed models that predict the availability of such habitat, using lake mean depth, which describes both the thermal regime and the initial oxygen reserves, and using a measure of primary productivity, which defines the subsequent oxygen demand of the sediments and water column. Measures of primary production include either phosphorus concentration, chlorophyll a concentration, or Secchi disk transparency. The models are presented as a series of seasonal oxygen depletion isopleths that predict the extent to which the oxygen content of thermally suitable habitat is lost during the period of thermal stratification. The presence or absence of native lake trout in lakes of northwestern Ontario superimposed on these graphs indicated that natural populations seldom occur in lakes in which the seasonal oxygen depletion exceeds 40%. This isopleth is a niche boundary in its representation of adverse temperature and oxygen conditions for lake trout. The delineation of this boundary permits the identification of lakes where lake trout populations could be seriously affected by cultural eutrophication, overfishing, or climate warming.

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Analysis of Leachate and Water Resource Quality Surrounding Municipal Solid Waste Landfill of Tamellast (Agadir, Morocco)

E3S Web of Conferences ◽

10.1051/e3sconf/202124002006 ◽

2021 ◽

Vol 240 ◽

pp. 02006

Author(s):

Saadia Asouam ◽

Farid Faik ◽

Zine El Abidine El Morjani

Keyword(s):

Electrical Conductivity ◽

Dissolved Oxygen ◽

Physicochemical Characterization ◽

Oxygen Demand ◽

Resource Quality ◽

Sodium Potassium ◽

Physico Chemical ◽

Dug Wells ◽

The Impact ◽

Surface And Groundwater

The aim of this work was to study the physicochemical characterization and heavy metal testing results carried out for leachate generated by the landfilling of household and similar waste in the Tamellast landfill of Agadir. The surface and groundwater resource (often used as drinking source) samples collected from Tamellast and different water sources wells surrounding the landfill were used to find out the impact of leachate percolation on surface and groundwater quality. The Physico-chemical parameters analyzed were, pH, Electrical Conductivity (EC), Dissolved oxygen, Sodium, Potassium, while biological parameters tested were Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), E.Coli and Coliform tot. The contamination was investigated by measuring the concentration of heavy metals (Pb, Zn, Cr, Ni, As, and Fe). The Electrical Conductivity (EC), COD, BOD, Sodium, Potassium, in leachate were found to be 13180 µs/cm, 3150 mgO2/l, 1000 mgO2/l, 2000 mg/L, and 10700 mg/L, respectively. The concentration in the surrounding dug wells varied from 8.33 – 9.13 mg/L for Dissolved Oxygen, 9.8 – 18 mg/L for potassium, 0.22 – 0.6 mg/L for Fe, and 0.012 – 0.1 mg/L for total Mn. The concentration of Mn, Fe, and other parameters decreased with increasing distance between the landfill and wells.

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Correcting a major error in assessing organic carbon pollution in natural waters

Science Advances ◽

10.1126/sciadv.abc7318 ◽

2021 ◽

Vol 7 (16) ◽

pp. eabc7318

Author(s):

Nianzhi Jiao ◽

Jihua Liu ◽

Bethanie Edwards ◽

Zongqing Lv ◽

Ruanhong Cai ◽

...

Keyword(s):

Organic Carbon ◽

Natural Waters ◽

Carbon Sink ◽

Scientific Information ◽

Experimental Studies ◽

Oxygen Demand ◽

Organic Pollution ◽

Oxygen Depletion ◽

Aquatic Environments ◽

Forested Areas

Microbial degradation of dissolved organic carbon (DOC) in aquatic environments can cause oxygen depletion, water acidification, and CO2 emissions. These problems are caused by labile DOC (LDOC) and not refractory DOC (RDOC) that resists degradation and is thus a carbon sink. For nearly a century, chemical oxygen demand (COD) has been widely used for assessment of organic pollution in aquatic systems. Here, we show through a multicountry survey and experimental studies that COD is not an appropriate proxy of microbial degradability of organic matter because it oxidizes both LDOC and RDOC, and the latter contributes up to 90% of DOC in high-latitude forested areas. Hence, COD measurements do not provide appropriate scientific information on organic pollution in natural waters and can mislead environmental policies. We propose the replacement of the COD method with an optode-based biological oxygen demand method to accurately and efficiently assess organic pollution in natural aquatic environments.

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Potential Viable Products Identified from Characterisation of Agricultural Slaughterhouse Rendering Wastewater

Water ◽

10.3390/w13030352 ◽

2021 ◽

Vol 13 (3) ◽

pp. 352

Author(s):

Brian Brennan ◽

Burcu Gunes ◽

Matthew R. Jacobs ◽

Jenny Lawler ◽

Fiona Regan

Keyword(s):

Dissolved Oxygen ◽

Chemical Oxygen Demand ◽

Total Nitrogen ◽

Environmental Sustainability ◽

Oxygen Demand ◽

Heat Processing ◽

Process Data ◽

Adequate Treatment ◽

Constant Flow Rate ◽

The Impact

The composition of challenging matrices must be fully understood in order to determine the impact of the matrix and to establish suitable treatment methods. Rendering condensate wastewater is a complex matrix which is understudied. It is produced when the vapour from rendering facilities (heat processing of slaughterhouse waste material) is cooled as a liquid for discharge. This study offers a full physicochemical characterisation of rendering condensate wastewater and its potential for valorisation via production of viable by-products. A study of seasonal variation of levels of dissolved oxygen, chemical oxygen demand, total nitrogen and ammonia was carried out on the wastewater. The results show that the wastewater was high strength all year-round, with a chemical oxygen demand of 10,813 ± 427 mg/L and high concentrations of total Kjeldahl nitrogen (1745 ± 90 mg/L), ammonia (887 ± 21 mg/L), crude protein (10,911 ± 563 mg/L), total phosphorous (51 ± 1 mg/L), fat and oil (11,363 ± 934 mg/L), total suspended solids (336 ± 73 mg/L) and total dissolved solids (4397 ± 405 mg/L). This characterisation demonstrates the requirement for adequate treatment of the condensate before releasing it to the environment. While there is a reasonably constant flow rate and dissolved oxygen level throughout the year, higher chemical oxygen demand, total nitrogen and ammonia levels were found in the warmer summer months. From this study, rendering condensate slaughterhouse wastewater is shown to have potential for production of marketable goods. These products may include ammonium sulphate fertilizer, protein supplements for animal feeds and recovery of acetic acid calcium hydroxyapatite, thus enhancing both the financial and environmental sustainability of slaughterhouse operations. This work demonstrates a valuable assessment of a complex wastewater, while taking advantage of on-site access to samples and process data to inform the potential for wastewater reuse.

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Modeling hypolimnetic dissolved oxygen depletion using monitoring data

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2019-0294 ◽

2020 ◽

Vol 77 (5) ◽

pp. 814-823 ◽

Cited By ~ 2

Author(s):

Lester L. Yuan ◽

John R. Jones

Keyword(s):

Dissolved Oxygen ◽

Chlorophyll Concentration ◽

Oxygen Demand ◽

Oxygen Depletion ◽

The United States ◽

Biological Communities ◽

Effective Strategies ◽

Organic Carbon Concentration ◽

Lakes And Reservoirs ◽

Oxygen Profiles

Eutrophication increases hypoxia in lakes and reservoirs, causing deleterious effects on biological communities. Quantitative models would help managers develop effective strategies to address hypoxia issues, but most existing models are limited in their applicability to lakes with temporally resolved dissolved oxygen data. We describe a hierarchical Bayesian model that predicts dissolved oxygen in lakes based on a mechanistic understanding of the factors that influence the development of hypoxia during summer stratification. These factors include the days elapsed since stratification, dissolved organic carbon concentration, lake depth, and chlorophyll concentration. We demonstrate that the model can be fit to two datasets: one in which temporally resolved dissolved oxygen profiles were collected from 20 lakes in a single state and one in which single profiles were collected from 381 lakes across the United States. Analyses of these two datasets yielded similar relationships between volumetric oxygen demand and chlorophyll concentration, suggesting that the model structure appropriately represented the effects of eutrophication on oxygen depletion. Combining both datasets in a single model further improved the precision of predictions.

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Limnological Comparisons of Threats to Aquatic Life Owing to Thermal Stratification in two Morphometrically Different Urban Shallow Lakes

Sustainability Agri Food and Environmental Research ◽

10.7770/safer-v2n1-art766 ◽

2014 ◽

Vol 2 (1) ◽

Author(s):

Nihar R. Samal ◽

Pankaj K. Roy ◽

Malabika B. Roy ◽

Asis Mazumdar Mazumdar

Keyword(s):

Organic Matter ◽

Dissolved Oxygen ◽

Shallow Lakes ◽

Thermal Stratification ◽

Oxygen Depletion ◽

Daily Basis ◽

Tropical Lakes ◽

Aquatic Life ◽

Delta Plain ◽

The Impact

A minimum value in the Dissolved Oxygen distribution of two shallow lakes namely, Rabindra Sarobar in south Kolkata and Subhas Sarobar in East Kolkata in the Gangetic Delta plain, has been observed to develop in the Hypolimnion during the stratified period. This minimum is usually explained by the accumulation of organic matter from the overlying layer of water. The introduction of organic matter from allochthonous and autochthonous sources is also a likely contributor to the accelerated oxygen depletion within Hypolimnion. The thermal stratification, in general, which occurs in these tropical lakes, is of direct relevance in maintaining the water quality standards, particularly for higher aquatic life. The present article attempts to investigate the possible depletion of hypolimnetic oxygen depletion as a result of the impact of thermal stratification. These investigations will be the basic guidelines for the fishermen and their livelihoods potentially depend upon the different varieties of fishing on daily basis. The massive summer fish kills in these lakes is a major devastating happenings that is reported by the fishermen and also it is well evident from our experimental observations. The comparison of the biodiversity of these two lakes is attempted in the present investigation. Key Words: Thermal stratification, Dissolved Oxygen, Tropical Shallow Lake, Hypolimnion, biodiversity

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The Effects of Effluent Discharged from Bottling Companies on Algal Composition in Kakuri Stream Kaduna, Nigeria

Nigerian Journal of Basic and Applied Sciences ◽

10.4314/njbas.v27i1.4 ◽

2020 ◽

Vol 27 (1) ◽

pp. 25-33

Author(s):

S.K. ◽

I.Y. Okpanachi

Keyword(s):

Dissolved Oxygen ◽

Dominant Species ◽

Soft Drink ◽

Oxygen Demand ◽

Organic Pollution ◽

Biological Oxygen Demand ◽

Wet Season ◽

Positive Correlation ◽

The Impact ◽

Algal Composition

This study determined the impact of soft drink effluent on algal composition in Kakuri stream, Kaduna South Local Government Area, Kaduna. Limnological studies of soft drink effluent were carried out for a period covering wet and dry seasons across three (3) sampling points code-named Stations A, B and C. Some physio-chemical parameters were analysed using standard methods. A total of 43 species were observed belonging to 5 families. Chlorophyceae and Cyanophyceae were the most abundant families across the three (3) stations. The total flora count was high during the dry season, 1965 cells than wet season, 1071 cells. The most dominant species were Euglena sp., Microcystis sp. and Oscillatoria sp. The pH of the three stations was more alkaline (pH 8.1) but reduces slightly at stations B and C during the months of May (pH 5.2) and August (pH 6.5). The biological oxygen demand (BOD) was relatively high across the stations, dissolved oxygen was generally low except for some months (December at station A and January at station B) that had its dissolved oxygen values above 5.00 mg/l. Euglenophyceae showed positive correlation to conductivity and BOD, Chlorophyceae was positively correlated with BOD, Cyanophyceae showed positive relationship with BOD and dissolved oxygen, Charophyceae was positively correlated with dissolved oxygen, Bacillariophyceae showed positive correlation with pH, temperature, phosphorus, BOD and dissolved oxygen. Effluent discharge and farmland run-off passed into the water body supports growth of dominant species indicating organic pollution, thus, poses a threat to the environment over a long period of time. Keywords: Algae, Effluent, Biological oxygen demand, Dissolved oxygen.

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