Modelling of sediment oxygen demand and organic flux for a pulsed sediment organic load

2006 ◽  
Vol 54 (11-12) ◽  
pp. 85-92 ◽  
Author(s):  
Y.X. Wang ◽  
X.Y. Li ◽  
J.H.W. Lee
Keyword(s):  
Surface Waters ◽  
Laboratory Experiments ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Organic Load ◽  
Organic Input ◽  
Fish Food ◽  
Organic Sediment ◽  
Diagenetic Reactions

Biodegradation of organic matter in the sediment affects both the level of dissolved oxygen (DO) in the overlaying water and material flux into the water body. In the present study, a mathematical model was developed to describe the DO dynamics and related organic transformation in the sediment after a pulsed load of rich organic, sediment. The model includes DO diffusion at the sediment–water interface and inside the sediment, diagenetic reactions of particulate organic to soluble organic, substances, biodegradation of soluble organic, and related DO consumption. The model can simulate sediment oxygen demand (SOD) in a dynamic system after a sudden organic load on the sediment and the flux of both biodegradable and non-biodegradable organic can be predicted. In addition, laboratory experiments were conducted using SOD chambers to investigate the SOD dynamics and sediment material fluxes. The sediment of the batch SOD tests was loaded with fish food at various rates for the sudden organic input. Numerical simulations for SOD and organic fluxes compared well with the experimental measurements. The results demonstrate that the model can be used to predict the effect of sediment pollutants on the water quality of surface waters.

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

2000 ◽  
Vol 42 (3-4) ◽  
pp. 265-272 ◽  
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.

Fecal and Coliform Levels as Indicative Factors in Deterioration of the Water Quality of

2014 ◽  
Vol 10 (1) ◽  
Author(s):  
EUKENE OPORTO BENSIG ◽  
MARY JOYCE L. FLORES ◽  
FLEURDELIZ F. MAGLANGIT
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Physicochemical Parameters ◽  
Oxygen Demand ◽  
Aquatic Ecology ◽  
Total Dissolved Solids ◽  
Biological Oxygen Demand ◽  
Indicator Bacteria ◽  
The Difference

The use of surface waters such as rivers for domestic, agricultural andindustrial purposes have made them vulnerable to pollution leading to impairedwater quality. The water quality of Lahug River in Cebu City was evaluated usingcoliforms as indicators, in relation with physicochemical parameters such as biological oxygen demand (BOD), conductivity, dissolved oxygen (DO), nitrate,pH, phosphate, salinity, temperature, total dissolved solids (TDS) and totalsuspended solids (TSS). Sampling was done once a month from November 2011to April 2012 in three stations covering the upstream, midstream and downstream.The multiple tube fermentation technique was used for the analysis of coliforms.The level of these indicator bacteria increased from the upstream towards thelower reaches of the river especially in the months of February to April; however,the difference in values across time was not significant. This implies that therewas a continuous fecal pollution in the river. There were no statistically significantcorrelations between FCs and TCs with the physicochemical parameters. Anegative relationship was observed among FCs and TCs with pH, TSS, DOand nitrate (p>0.05). These results suggest the presence of sewage and organicpollutants in the river.Keywords: Aquatic Ecology, water quality, coliform, physicochemical parameters,experimental design, Philippines

scholarly journals A reactivity continuum of particulate organic matter in a global ocean biogeochemical model

2016 ◽  
Author(s):  
Olivier Aumont ◽  
Marco van Hulten ◽  
Matthieu Roy-Barman ◽  
Jean-Claude Dutay ◽  
Christian Ethé ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Critical Role ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Global Ocean ◽  
Biogeochemical Model ◽  
Mesopelagic Zone ◽  
Ocean Biogeochemical Model ◽  
The Impact ◽  
Reactivity Continuum

Abstract. The marine biological carbon pump is dominated by the vertical transfer of Particulate Organic Carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which such as iron are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. Yet, this variable reactivity of POC has never been extensively considered, especially in modeling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical Reactivity Continuum Model proposed by (Boudreau and Ruddick, 1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean’s interior by one to two orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of two, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macro-nutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: Vertical gradients in Fe are milder in the upper ocean which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.

Quality Issues Regarding the Watercourses from Middle Basin of Jiu River

2017 ◽  
Vol 68 (1) ◽  
pp. 72-76
Author(s):  
Daniela Cirtina ◽  
Camelia Capatina
Keyword(s):  
Dissolved Oxygen ◽  
River Basin ◽  
Total Phosphorus ◽  
Surface Waters ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Chloride Content ◽  
Quality Issues

The study aims to characterize the quality of surface waters in the middle of the river basin Jiu by monitoring physicochemical indicators of their quality, in 2013-2015. In this regard, the pH, dissolved oxygen (DO), biochemical oxygen demand (BOD5) of nitrate (NO3-), nitrite (NO2-), ammonium (NH4+), total phosphorus (Ptotal), chlorides and sulphates from water have been determined. Water of Jiu River and its tributaries of Gorj county have been monitored on representative sections for the evolution of their quality. It was found that the water from natural reservoirs monitored shows an evolution in the limits permitted by the regulations in force except biochemical oxygen demand and nitrites indicators for river Jiu and Tismana and nitrate and chloride content for Gilort River.

scholarly journals Spatial analysis of water quality of the Karra River, Hetauda, Nepal

2016 ◽  
Vol 8 (1) ◽  
pp. 58-65
Author(s):  
Sadhana Pradhanang
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Surface Waters ◽  
Industrial Wastewater ◽  
Good Condition ◽  
Oxygen Demand ◽  
Industrial Effluents ◽  
Physico Chemical ◽  
Water Region

The assessment of water quality of Karra River in Hetauda, Nepal was carried out by determining the changes in the concentration levels of eight physico-chemical parameters (pH, Electric conductivity (EC), bicarbonate, dissolved oxygen (DO), silica, chemical oxygen demand (COD), phosphate and nitrate). The samples were collected from upstream, industrial belt and downstream of the Karra River. The Karra River is the dumping ground for industrial effluents of Hetauda industrial district (HID). On analysis, the concentrations of most of the physico-chemicals parameters were found to be above the prescribed limits for industrial wastewater into inland surface waters. Dissolved Oxygen was found to be in the range of 0.49- 8.47 mg/L while COD, nitrate and phosphate were recorded in the range of 8.3-367 mg/L, 0.35- 78.22 mg/L and 0.01-1.64 mg/L, respectively. Concentrations of most of these parameters were within the prescribed limits in the samples collected from upstream and downstream, revealing the river still in good condition at these points indicating less human interference at the head water region and good self-purification capacity at downstream. However the concentrations of the pollutants’ parameters are higher at the sample points just after effluent discharge.Journal of Hydrology and Meteorology, Vol. 8(1) p.58-65

scholarly journals Investigation of the water quality of daily used surface-sources for drinking and irrigation by the population of Segou in the center of Mali

2018 ◽  
Vol 17 (2) ◽  
pp. 338-349
Author(s):  
Amadou Toure ◽  
Duan Wenbiao ◽  
Zakaria Keita ◽  
Abdramane Dembele
Keyword(s):  
Surface Waters ◽  
Fecal Coliform ◽  
Oxygen Demand ◽  
Field Analysis ◽  
Source Surface ◽  
The Public ◽  
Quality Of Water ◽  
State Of Water ◽  
Organoleptic Parameters

AbstractThis study evaluates the quality and pollution status of source surface waters in Segou, Mali. The nature, sources, and extent of pollution of Comatex Stream, Cerfitex Pond, and Sonikoura River were studied for a period of twelve months (July 2016–June 2017). Analysis included 209 water samples collected from eleven different locations in the study area. Laboratory and field analysis were realized using the standard methods and concerned eleven parameters including four physicals, six chemicals and one bacteriological. Also, organoleptic parameters were observed. Most of the average values of parameters addressing the quality of water were significantly higher (P < 0.05) in both the stream and river compared to the pond. Fecal coliform counts (FCC) were not in significant correlation with the temperature; pH and turbidity; but had a significant and positive correlation (P < 0.05) with conductivity: total dissolved solids (TDS); total suspended solids (TSS); Cl−; PO4−P; NO3−N and 5-day biochemical oxygen demand (BOD5). Analysis of samples revealed a level of FCC that is above the permissible limit for both drinking water and of fresh vegetable irrigation water. In all, there is a pressing need to inform the public about the state of water bodies and the application of relevant laws regarding the proper treatment of sewage before it is discharged into surface water.

scholarly journals Pollution mapping in the urban segment of a tropical river: is water quality index (WQI) enough for a nutrient-polluted river?

2019 ◽  
Vol 9 (8) ◽  
Author(s):  
Kashifa Iqbal ◽  
Shamshad Ahmad ◽  
Venkatesh Dutta
Keyword(s):  
Water Quality ◽  
Biochemical Oxygen Demand ◽  
Water Quality Index ◽  
Quality Index ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Tropical Rivers ◽  
Polluted River ◽  
Gomti River

Abstract Most of the tropical rivers of the world are being affected by multiple sources of pollution. The intensity of pollution is much bigger in the urban stretches due to discharge of untreated or partially treated sewage. A rapid and cost-effective tool is required for identification of water quality problems and their spatial variation for determining the main pollution sources and to detect relationships between various parameters. For this study, Gomti River, a major tributary of River Ganges, India, was considered which has gained substantial attention because of increasing anthropogenic pollution loads that has badly affected its water quality and ecosystem functions. The urban segment is polluted with organic substances, nutrients and heavy metals. The study provides an overview of the quality of water in the Gomti River through water quality index (WQI) and multivariate statistical techniques to check if WQI is enough for a nutrient-polluted river in the urban stretch. The study suggests that periodic monitoring and the water quality index development are not enough as it does not incorporate all the aspect of a rivers water quality. The separate assessment of nitrogenous biochemical oxygen demand, carbonaceous biochemical oxygen demand, sediment oxygen demand and the nitrification inhibition aspects are required to be integrated when developing a WQI. Present study illustrates that water quality of Gomti River has gradually worsened from upstream and downstream to middle stretch. The middle stretch was found to be most polluted as the major drains are concentrated within this stretch. Principal component analysis/factor analysis (PCA/FA) helped in obtaining and recognizing the factors/sources accountable for river water quality differences in the study area. The findings are useful for the decisions regarding water quality management and this can also be applied for speedy and low-cost assessment of water quality of the polluted urban stretch of other tropical rivers for better environmental management and planning perspective.

Can macrobenthic communities be used in the assessment of environmental quality of fish earthen ponds?

2009 ◽  
Vol 90 (1) ◽  
pp. 135-144 ◽  
Author(s):  
Susana Carvalho ◽  
Marisa Barata ◽  
Fábio Pereira ◽  
Pedro Pousão-Ferreira ◽  
Luís Cancela da Fonseca ◽  
...  
Keyword(s):  
Environmental Quality ◽  
Production Cycle ◽  
Fish Production ◽  
Fish Ponds ◽  
Organic Input ◽  
Fish Food ◽  
Macrobenthic Communities ◽  
Ria Formosa ◽  
Earthen Ponds

The present study was undertaken in order to analyse whether macrobenthic communities can or not be used in monitoring programmes of the environmental quality of fish ponds. Functional community analysis and biotic metrics were analysed aiming at the assessment of their effectiveness in discriminating potential impacts of fish production in these systems. The macrofaunal patterns in earthen fish ponds of the Ria Formosa lagoon showed to be influenced by the input of fish food during the production cycle and by changes in abiotic parameters caused by seasonality and fish production. Polychaetes were generally dominant considering the number of taxa and abundance. The trophic functional analysis of the benthic communities showed that the deposit-feeding functional group dominated in both areas of the ponds but within water entrance areas there was an increase of suspension-feeding, carnivory and herbivory feeding modes. The presence of less trophically mixed communities within feeding areas may be related to the relative high disturbance levels of these areas. From the biotic indicators that show a differential response to organic input in fish earthen ponds, the abundance of Capitella spp. as well as the diversity (Shannon–Wiener and Margalef species richness), evenness (Pielou) and AMBI indices seem to be the best indicators to be used in monitoring studies in similar systems. Managers should pay particular attention when Capitella spp. taxa are observed within the feeding areas. Nevertheless, manipulative experiments are needed in order to test the dominance levels of Capitella spp. and the values of those indices that are of concern.

scholarly journals Variable reactivity of particulate organic matter in a global ocean biogeochemical model

2017 ◽  
Vol 14 (9) ◽  
pp. 2321-2341 ◽  
Author(s):  
Olivier Aumont ◽  
Marco van Hulten ◽  
Matthieu Roy-Barman ◽  
Jean-Claude Dutay ◽  
Christian Éthé ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Critical Role ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Global Ocean ◽  
Biogeochemical Model ◽  
Mesopelagic Zone ◽  
Modelling Studies ◽  
Ocean Biogeochemical Model ◽  
The Impact

Abstract. The marine biological carbon pump is dominated by the vertical transfer of particulate organic carbon (POC) from the surface ocean to its interior. The efficiency of this transfer plays an important role in controlling the amount of atmospheric carbon that is sequestered in the ocean. Furthermore, the abundance and composition of POC is critical for the removal of numerous trace elements by scavenging, a number of which, such as iron, are essential for the growth of marine organisms, including phytoplankton. Observations and laboratory experiments have shown that POC is composed of numerous organic compounds that can have very different reactivities. However, this variable reactivity of POC has never been extensively considered, especially in modelling studies. Here, we introduced in the global ocean biogeochemical model NEMO-PISCES a description of the variable composition of POC based on the theoretical reactivity continuum model proposed by Boudreau and Ruddick (1991). Our model experiments show that accounting for a variable lability of POC increases POC concentrations in the ocean's interior by 1 to 2 orders of magnitude. This increase is mainly the consequence of a better preservation of small particles that sink slowly from the surface. Comparison with observations is significantly improved both in abundance and in size distribution. Furthermore, the amount of carbon that reaches the sediments is increased by more than a factor of 2, which is in better agreement with global estimates of the sediment oxygen demand. The impact on the major macronutrients (nitrate and phosphate) remains modest. However, iron (Fe) distribution is strongly altered, especially in the upper mesopelagic zone as a result of more intense scavenging: vertical gradients in Fe are milder in the upper ocean, which appears to be closer to observations. Thus, our study shows that the variable lability of POC can play a critical role in the marine biogeochemical cycles which advocates for more dedicated in situ and laboratory experiments.

scholarly journals Study on the Assessment of the Oxygen Regime and the Nutrients Content of Some Water Streams in Gorj County

2020 ◽  
Vol 71 (2) ◽  
pp. 315-323
Author(s):  
Daniela Cirtina ◽  
Maria Nicoleta Mihut
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Oxygen Demand ◽  
Organic Pollution ◽  
Environmental Legislation ◽  
Oxygen Regime ◽  
Ammonium N ◽  
Nitrite Content ◽  
Hydrographic Network

The study aims to characterize the quality of some representative surface waters of Gorj county�s hydrographic network by assessing the oxygen regime, namely the dissolved oxygen content (DO), the chemical oxygen demand (COD-Cr), the biochemical consumption of oxygen BOD5) and nutrients measured by ammonium (N-NH4+), nitrites (N-NO2-), nitrates (N-NO3-), total nitrogen, soluble orthophosphates (P-PO43-) and total phosphorus during 2016-2018. In order to carry out the study, representative sections of the Jiu, Motru and Jilt rivers were monitored in areas considered vulnerable to nutrient and organic pollution. The results regarding water quality from the monitored natural receptors generally showed an evolution within the limits allowed by the environmental legislation, except for the nitrite content that was exceeded for all three monitored rivers. Also, the values of the COD-Cr and BOD5 indicators have been exceeded in some Jiu and Jilt river monitoring sections. Consequently, there is a need to monitor the mentioned parameters.

Sign in / Sign up

Export Citation Format

Share Document