Short and long hydroperiod Everglades periphyton mats: Community characterization and experimental hydroperiod manipulation

Hydroperiod, or the distribution, duration and timing of flooding affects both plant and animal distributions. The Florida Everglades is currently undergoing restoration that will result in altered hydroperiods. This study was conducted in Everglades National Park to document the variability in periphyton community structure and function between long and short hydroperiod Everglades marshes. Periphyton is an important primary producer and important food resource in the Everglades. Periphyton is also involved in marl soil formation and nutrient cycling. Although periphyton is an important component of the Everglades landscape, little is known about periphyton structural-functional variation between hydroperiods. ^ For this study diatoms, as well as fresh algae slides of diatoms, cyanobacteria and green algae were identified and enumerated. Short verse long hydroperiod soil and water column nutrients were compared. Short and long hydroperiod algal periphyton mat productivity rates were compared using BOD incubations. Experimental manipulations were performed to determine the effects of desiccation duration and rewetting on periphyton productivity, community structure, and nutrient flux. ^ Variation in periphyton community structure was significantly greater between hydroperiods than within hydroperiods. Short and long hydroperiod periphyton mats have the same algal species, it is the distribution and abundance that varies between hydroperiods. Long hydroperiod mats have greater diatom abundance while short hydroperiod mats have greater relative filamentous cyanobacterial abundance. ^ Long hydroperiod mats had greater net primary production (npp) than short hydroperiod mats. Short hydroperiod mats respond to rewetting more rapidly than do long hydroperiod mats. Dry short hydroperiod mats became net primary producers within 24 hours of rehydration. Increasing desiccation duration led to greater cyanobacterial abundance in long hydroperiod mats and decreased diatom abundance in both long and short hydroperiod mats. ^

Effects of shading on calcareous benthic periphyton in a short-hydroperiod oligotrophic wetland (Everglades, FL, USA)

The effects of shade on benthic calcareous periphyton were tested in a short-hydroperiod oligotrophic subtropical wetland (freshwater Everglades). The experiment was a split-plot design set in three sites with similar environmental characteristics. At each site, eight randomly selected 1-m2 areas were isolated individually in a shade house, which did not spectrally change the incident irradiance but reduced it quantitatively by 0, 30, 50, 60, 70, 80, 90 and 98%. Periphyton mat was sampled monthly under each shade house for a 5 month period while the wetland was flooded. Periphyton was analyzed for thickness, DW, AFDW, chlorophyll a (chl a) and incubated in light and dark BOD bottles at five different irradiances to assess its photosynthesis–irradiance (PI) curve and respiration. The PI curves parameters P max, I k and eventually the photoinhibition slope (β) were determined following non-linear regression analyses. Taxonomic composition and total algal biovolume were determined at the end of the experiment. The periphyton composition did not change with shade but the PI curves were significantly affected by it. I k increased linearly with increasing percent irradiance transmittance (%IT = 1−%shade). P max could be fitted with a PI curve equation as it increased with %IT and leveled off after 10%IT. For each shade level, the PI curve was used to integrate daily photosynthesis for a day of average irradiance. The daily photosynthesis followed a PI curve equation with the same characteristics as P max vs. %IT. Thus, periphyton exhibited a high irradiance plasticity under 0–80% shade but could not keep up the same photosynthetic level at higher shade, causing a decrease in daily GPP at 98% shade levels. The plasticity was linked to an increase in the chl a content per cell in the 60–80% shade, while this increase was not observed at lower shade likely because it was too demanding energetically. Thus, chl a is not a good metric for periphyton biomass assessment across variously shaded habitats. It is also hypothesized that irradiance plasticity is linked to photosynthetic coupling between differently comprised algal layers arranged vertically within periphyton mats that have different PI curves.

Aplicação da oxidação eletroquímica no tratamento de efluentes contendo corantes reativos utilizando Ti/Pt e Ti/Pt-SnSb

The textile effluents are a complex mixture of many pollutants that contain high organic loads, severe color and toxic compounds. The high concentration of the textile effluent may cause increased chemical demand (COD) and biochemical (BOD) of oxygen, elevated temperature, acidity or alkalinity, causing damage and environmental problems. In addition to representing a serious threat to human health such effluent is also quite toxic to most aquatic organisms. And for this reason, one must meet the concentration limits for emission sources and sewage system. This study aimed to investigate the performance of electrochemical treatment of a textile effluent for the removal of color, turbidity, dissolved oxygen (DO) and dissolved organic matter by investigating the influence of experimental parameters such as the electrocatalyst materials (Ti/Pt and Ti/Pt-SnSb) and current density in order to compare their efficiency, energy consumption and cost. The dye Novacron Blue CD (NB) was employed in synthetic solution, while the dyes Remazol Yellow 3RS (RY 3RS) Remazol Red RR Gran (RR-RR Gran) and Navy Blue CL-R (NB CL-R) were used to generate simulated textile effluent laboratory. The results showed that the application of electrochemical oxidation process favors the elimination of color effectively independent the electrocatalytic material and current used, as well as treated effluent. However, the influence of electrocatalytic material was crucial to reduction of the organic matter in all cases.

Ajustes de coeficientes integrantes de processos físicos e bioquímicos na autedepuração em curso de água de médio porte

The mathematical modeling in the simulation of self-purification capacity in lotic environment is an important tool in the planning and management of hydric resources in hydrographic basin scale. It satisfactorily deals with the self-purification process when the coefficients of physical and biochemical processes are calibrated from monitorated water quality data, which was the main focus of this study. The present study was conducted to simulate the behavior of the parameters OD, BOD5, total phosphorus, E. coli, ammonia, nitrite, nitrate and the total metals cadmium, chromium, copper, lead and zinc in the Uberabinha’s lower course (with an approximate annual growth flow between 4-35 m3/s), in a stretch of 19 km downstream of the treated effluent release by the WWTP of the city. The modelings, on the present study, show the importance of constant water quality parameters monitoration over the water course, based on the comparison of the simulations from calibrated coefficients and coefficients obtained in the literature for the period of June until November 2015. After coefficients calibration, there were good adjustments between simulated and measured data for the parameters OD, BOD, Ptotal, ammonia and nitrate and unsatisfactory adjust for the parameters nitrite and E. coli. About the total metals, the adjustments were not satisfactory on the reservoir’s vicinity of the Small Hydropower Plant Martins, due the considerable increase of the bottom sediment in lentic region. The greatest scientific contribution of this study was to calibrate the decay coefficient K and the quantification of the release by the fund S of total metals in watercourse midsize WWTP pollutant load receptor, justified by the lack of studies in the literature about the subject. For the metals cadmium, chromium, copper, lead and zinc, the borderline for K and S calibrated were: 0.0 to 13.0 day-1 and 0.0 to 1.7 g/m3.day; 0.0 to 0.9 day-1 and 0.0 to 7.3 g/m3.day; 0.0 to 25.0 day-1 and 0.0 to 1.8 g/m3.day; 0.0 to 7.0 day-1 and 0.0 to 40.3 g/m3.day; 0.0 to 30.0 day-1 and 0.0 to 70.1 g/m3.day.

Reconstrucción mínimamente invasiva de la banda oblicua distal. Estudio anatómico

La radioulnar distal es una articulación diartrodial trocoide compuesta por la escotadura sigmoidea del radio y la cabeza ulnar. Su estabilidad depende de la integridad de diversas estructuras como son el complejo fibrocartílago triangular o CFCT, el músculo pronador cuadrado y el músculo extensor ulnar del carpo y la porción distal de la membrana interósea (MIO), fundamentalmente la banda oblicua distal, en los casos en los que se encuentra presente. La banda oblicua distal (BOD) es una estructura independiente de la porción membranosa distal de la membrana interósea la cual ha sido descrita en un 40% de los individuos. Se origina en 1/6 distal de la diáfisis ulnar y se inserta en el borde inferior de la escotadura sigmoidea. Algunas fibras se extienden más distalmente, pareciendo mantener continuidad con los ligamentos radioulnares dorsal y palmar, lo que ha hecho pensar en su función como estabilizador de la articulación radioulnar distal. A su vez, su inserción ulnar coincide con el eje de rotación del antebrazo, experimentando así pocos cambios durante la pronosupinación, comportándose de forma isométrica. El CFCT es el estabilizador primario de la articulación, y en situaciones normales la influencia de la porción distal de la membrana interósea es insustancial. Sin embargo, tras una lesión del fibrocartílago triangular o una resección de la cabeza ulnar, es cuando adquiere un papel fundamental...

Antropología de la Conservación en España. Balance y perspectivas

En este artículo presentamos un balance de la Antropología de la Conservación en el Estado español. Durante las últimas décadas, la protección de los espacios naturales ha aumentado de una manera exponencial en todo el mundo. A la vez que se extendía esta patrimonialización de la naturaleza, los trabajos etnográficos sobre las áreas protegidas han ido ganando terreno dentro de la disciplina y, en particular, en el campo de la Antropología Ambiental. La mencionada bibliografía ha puesto de relieve los múltiples aspectos derivados de las nuevas políticas territoriales de regulación, apropiación y mercantilización de la ‘naturaleza’. En este trabajo realizamos una revisión exhaustiva de la producción generada a raíz de este interés por las áreas protegidas en nuestro país subrayando sus principales aportaciones, características y debilidades. De este modo pretendemos reflexionar acerca de su continuidad, con el fin de evitar la mera reiteración y favorecer el avance en sus resultados.

Modelleren en formaliseren in de rekenwiskundeles

Lenferink, M. (2016).Modelleren en formaliseren in de rekenwiskundeles: Versterken van de kwaliteit van de rekenwiskunde-instructie door vakspecifieke feedback. Juli, 25, 2016, Heerlen, Nederland:Open Universiteit.

Ecosystem structure of Gomishan Wetland

Gomishan Wetland is situated in the extreme southern part of the eastern coast of Caspian Sea. It is connected to the Caspian Sea, so its hydrological features are directly generated from the sea. The whole wetland area (which also consists of the northern part of the wetland that is situated in Turkmenistan republic) is calculated with the aid of the Satellite Images for the years of 1977, 1987 and 1998 respectively 5070, 16320 and 29520 hectares. To have better ideas about food chains in the aquatic ecosystem, five permanent stations was appointed in different parts of the wetland. During one year field study, at the beginning of each month, physical, chemical and biological characteristics of the water and the sediment was surveyed and different specimens were gathered, fixed and took to the laboratories for the relevant analyses. The factors measured in water samples were mainly consist of turbidity, pH, EC, DO, BOD, PO4, NO3, alkalinity, Cl and hardness . The factors measured from sediment samples were the percentage of Sand, Very Fine Sand, Silt, Clay, K, P, N, and Organic Carbon. Biological examinations of the water has been consist of planktonic sample collections, determination, counting and analysis of both phyto and zoo planktons of the wetland. For example the zooplanktons of the Gomishan Wetland are determined in 15 groups, belonging to 5 phyla. The seasonal changes are recognized considerable. The least density of the zooplanktons is occurred in February. The density of most of the groups is seen from the beginning of the summer until the mid autumn. The annual mean density for any 15-zooplankton groups and also the minimum and maximum density with %95 confidences, for each of them, is calculated for the environment of all of the stations and also for the whole wetland. The spatial distribution of the individuals within the population of each of the groups is introduced, according to regular or contagious or random distribution. Diversity indices are calculated for the zooplanktons living in the environment of the stations. Comparison of the wetland, with the southeastern Caspian Sea, from the point of view of zooplankton density and diversity is also obtained. Benthos invertebrates in each station from sediment samples were also extracted. The specimens were colored by Rose Bengal solvent and then were determinate and counted, in separate groups of macro and meio benthos. Among the macro benthos, the highest density was seen in the species of Fyrgula caspia. After that, more density was seen respectively in Apra ovata, Cerastoderma sp., Balanus sp., Nerds divesicolarr, lifytilaster lineatus and Dreissena sp. Among the meio benthos, the most density was seen in Foraminifera and then respectively in Ostracoda, Nernatoda and Bivalve larvae. The indices of diversity and distribution are also calculated. As the birds in this lagoon are of prime importance, all mid winter waterfowl censuses available from recent 13 years are gathered and analysis. Also a whole year (12 times, each at the beginning of one month) waterfowl census was undertaken, throughout the wetland. According to this study, the Eastern Ecosystem of the wetland, is supporting the most population (%75) of the waterfowls, the Middle Open Water Ecosystem and the Western Reed bed Ecosystem, are supporting respectively %14 and %11 of the population. Four of the species are found in the global threatened red list, and the wintering population of the 20 species of the site, in some years, are observed more than %I of the global populations. The Waterfowl Species Diversity and Similarity Indices are given also.

Melhoria da qualidade de jerked beef pela substituição de nitrito de sódio por extratos naturais de própolis e erva mate como agente antioxidante

Jerked beef, an industrial meat product obtained from beef with the addition of sodium chloride and curing salts and subjected to a maturing and drying process is a typical Brazilian product which has been gradually discovered by the consumer. The replacement of synthetic antioxidants by natural substances with antioxidant potential due to possible side effects discovered by lab tests, consumer health, is being implemented by the meat industry. This study aimed to evaluate the lipid oxidation of jerked beef throughout the storage period by replacing the sodium nitrite by natural extracts of propolis and Yerba Mate. For jerked beef processing brisket was used as raw material processed in 6 different formulations: formulation 1 (control - in nature), formulation 2 (sodium nitrite - NO), formulation 3 (Yerba Mate - EM), formulation 4 (propolis extract - PRO), formulation 5 (sodium nitrite + Yerba Mate - MS + NO), formulation 6 (propolis extract + sodium nitrite - PRO + NO). The raw material was subjected to wet salting, dry salting (tombos), drying at 25°C, packaging and storage in BOD 25°C. Samples of each formulation were taken every 7 days for analysis of lipid oxidation by the TBARS method. In all formulations, were carried out analysis of chemical composition at time zero and sixty days of storage. The water activity analysis and color (L *, a *, b *) was monitored at time zero, thirty and sixty days of storage. The Salmonella spp count, Coliform bacteria, Termotolerant coliforms and coagulase positive staphylococci were taken at time zero and sixty days. The activity of natural antioxidants evaluated shows the decline of lipid oxidation up to 2.5 times compared with the product in natura and presented values with no significant differences between treatments NO and EM, confirming the potential in minimize lipid oxidation of Jerked beef throughout the 60 days of storage. The results also showed that yerba mate has a higher antioxidant capacity compared to the propolis except the PRO + NO formulation. When associated with yerba mate with sodium nitrate, TBARS values become close to values obtained only for the control samples with the addition of sodium nitrite. The proximal composition of the formulations remained within the standards required in the IN nº22/2000 for jerked beef. Samples that differ significantly at 5% are directly related to the established type of formulation. The count of microorganisms was within the standards of the DRC nº12/2001 required for matured meat products. The intensity of the red (a*) decreased with storage time and increase the intensity of yellow (b*) indicates a darkening of the product despite L* also have been increased. These results suggest that yerba mate is a good alternative to meat industry in reducing healing addition salts when associated with another antioxidant.

Reator de leito estruturado com recirculação submetido à aeração intermitente no tratamento de esgoto sanitário

The release of nitrogen compounds in water bodies can result in many environmental problems, so treat wastewater, such as sewage in order to remove not only organic matter but also nitrogen has been studied a few decades. From the above, the objective of this study was to evaluate the performance of a structured bed reactor, continuous flow, with recirculation, in removing organic matter and nitrogen present in wastewater under different cycles of intermittent aeration (AI) and to evaluate the influence of these cycles in the development of nitrifying bacteria (Oxidizing Bacteria Ammonia - BOA and Bacteria Oxidizing Nitrite - BON) and denitrifying (DESN) adhered (Support Material - MS) and suspension (Effluent - EF and sludge - LD). The reactor used has usable volume of 9.4 L. As support materials (MS) polyurethane foam was used, cut and fixed in PVC rods. 3 were worked aeration phases (AE) and non-aeration (AN) at different stage: Stage 1 (4 h EA / AN 2H); Stage 2 (2H EA / AN 1 h) and Phase 3 (2H EA / AN 2 h). During all hydraulic detention time phases was kept at 16 h and the effluent recirculated at a rate of 3 times the inflow. Were analyzed: pH, total alkalinity, temperature, chemical oxygen demand (COD), Biochemical Oxygen Demand (BOD), nitrogen Kjeldhl Total (NKT), ammonia-N-N-NH4+, nitrito-N-NO2+andnitrato-NO3-. The concentration of BOA, BON and DESN was determined using the number More Provável.gSSV-1 (NMP.gSSV-1). In phase 1 the percentage removal NTK N-NH4+ and NT was 76±10%, 70±21% and 67±10% respectively. In Phase 2 80±15% of removel NKT, 86±15% of N-NH4+ e 68±9% of removel NT e na Fase 3 de 58±20%, 72±28% and 41±6% of NKT, N-NH4+ of NT, respectively. The denitrification efficiency in stage 3 was over 70%, indicating that occurred in the reactor the process of simultaneous nitrification and denitrification (NDS). DQOT the removal percentages were 88 ± 4% in Phase 1, 94 ± 7 in Phase 2 and 90± 11% in Phase 3. The multivariate ANOVA applied to NMP.gSSV-1, it indicated that there was significant (F: 20,2, p <0,01) between the analyzed concentration of organisms AI in different cycles, but the differences between NMP.gSSV-1 depends not only isolated factors but of which means, and phase groups being analysis. From the results it is concluded that the working system is efficient in terms of nitrogen removal and organic matter, and that the stage with the highest availability of Dissolved Oxygen (DO) and C/N ratio (Step 2), was the one obtained the lower concentrations of organic matter effluents and N-NH4+. Hinted that there was a significant difference between the concentration (NMP.100mL-1) of the analyzed organizations (BOA, BON and DESN), but this difference does not depend on factors alone but of which means (MS, EF or LD), stages (1, 2 or 3) and groups (BOA, BON and DESN) is being considered.

A inserção da educação ambiental não formal no processo de implantação de saneamento ambiental na comunidade rural Colonia Mergulhão, São José dos Pinhais - PR

One of the biggest environmental problems of the population is the lack of sewage treatment, especially in rural communities and low-income. The development of technologies for efficient, low-cost sanitation need to be developed to meet the disadvantaged people of this basic service. This work was the implementation proposal of a technology called constructed wetlands, also known as Wastewater Treatment Plant for Roots Zone - ETEZR. The objective was to develop a non- formal environmental education proposal for redevelopment, using outreach methods for residents and deployment of this technology ETEZR in the rural community of Cologne Grebe in Sao Jose dos Pinhais - PR. With technical support from the Paranaense Technical Assistance and Rural Extension Institute -EMATER and the Federal Technological University of Paraná - UTFPR, 5 ETEZR were deployed in the colony through three theoretical and practical workshops, which involved total 67 people from the community 5 technicians EMATER and 13 of the Municipal Town Hall. Após4 months of implementation were carried out two collections of raw wastewater and treated to analyze physical, chemical and biological parameters. The results evaluated by chemical parameters BOD, COD, phosphorus, ammonia nitrogen comparing raw and treated sewage, demonstrate that ETEZR are effective in the treatment of sewage. 5 Seasons minimum and maximum efficiency between the basic parameters analyzed were 52.2 to 95.5% for BOD; 47 to 94.5% for COD; 21.5 to 96% phosphorus; 30-98% for ammonia nitrogen. Oils and greases, and a series of solid also achieved a significant reduction in their values when comparing the raw sewage and treated sewage, and biological parameters evaluated by means of coliforms showed a reduction of 80 to 99%. With the implementation of environmental education process aimed sanitation was possible to evaluate the perception of the population to accept the environmental sanitation technology using the ETEZR, understand the needs and sanitation concepts for the community. This research evaluated the development of the methodology applied by the non-formal environmental education in order to provide subsidies for rural sanitation plan process for the municipality.

Comunidade fitoplanctônica e qualidade da água da Lagoa do Jiqui, Parnamirim, RN

It is important to evaluate the quality of water for proper management of these resources, since the increase of environmental degradation and the multiple use of water resources are decreasing the quality of water consumed by living beings. The objective of this study was to characterize the phytoplankton community and its variations during periods of dray and rain in Jiqui Lake located in Parnamirim, RN. It was also aimed to analyze the physical and chemical factors of this environment, in order to contribute to the knowledge of water quality used for human consumption. The collection of water samples were carried out in September 2008 to August 2009. The collection of the phytoplankton community was carried out in four sampling sites (surface, bottom, margin of the lake without macrophytes and site dominated by macrophytes). Phytoplankton was collected using plankton net of 20m. The analysis of nutrients and identification of phytoplankton were performed in the laboratory. The results indicate that concentration of chlorophyll a was high in the bottom with mean value of 1.07 μgL-1 (SD ± 1.61). During the study period there was a dominance of the following species: Euglena gracilis, Trachelomonas sp, Cyclotellas sp, Gomphonema apuncto, Navicula cuspidata var. cuspidata, Navicula sp, Rhopalodia gibba. There was homogeneity between limnological values in the four study sites, with significant difference between the periods of drought and rain. The Jiqui Lake is considered oligotrophic due to its low concentrations of chlorophyll a, high transparency and low levels of nutrients. The values of BOD and chlorophyll a concentration remained below the permitted standards existing for freshwaters in Brazil, thus the water from Lake Jiqui is of good quality, suitable for human consumption.

Inibição de linhagens do complexo Fusarium Graminearum por compostos naturais e sintéticos

Quando produtos alimentícios e especiarias são contaminados por micotoxinas é quase impossível detoxificar utilizando processos usuais da indústria de alimentos ou durante o preparo doméstico. Por isso, controlar o crescimento do fungo e a produção de toxinas é uma demanda para garantir a segurança alimentar. Os agrotóxicos são rotineiramente utilizados como estratégia para proteger as plantas de doenças provocadas pela contaminação fúngica. No entanto, eles estão associados a efeitos adversos ao sistema nervoso central e periférico, têm ação imunodepressora e são cancerígenos. Em virtude disso, o objetivo deste trabalho foi estudar a inibição do desenvolvimento, do potencial toxigênico e da expressão gênica de linhagens do Complexo Fusarium graminearum por compostos naturais comparativamente aos fungicidas azoxistrobina e trifloxistrobina. Do farelo de arroz, foram extraídos o γ-orizanol e os ácidos fenólicos (EFF). Das sementes de nim foram extraídos os ácidos fenólicos (EFN), totalizando três extratos naturais. A capacidade antioxidante dos extratos foi verificada pelo consumo do radical livre DPPH• , capacidade de captura do radical ABTS●+, redução do ferro e inibição da oxidação enzimática. Os mecanismos de inibição de três linhagens de F. graminearum foram avaliados através da determinação de compostos estruturais (glicosamina e ergosterol) e da atividade de enzimas do metabolismo primário (α- amilase e proteases). Foram determinadas as micotoxinas de Fusarium: deoxinivalenol (DON), 15 acetildeoxinivalenol (15AcDON), 3 acetildeoxinivalenol (3AcDON), nivalenol (NIV) e zearalenona (ZEA). A expressão dos genes Tri1 e Tri5 foi determinada a fim de verificar se ocorria modificação da expressão gênica nas linhagens do Complexo F. graminearum ocasionada pela presença dos antifúngicos. O EFF apresenta atividade antioxidante destacada em relação aos demais extratos naturais para inibir a iniciação do processo, a propagação do radical livre e a catálise enzimática. A presença dos compostos naturais mostrou efeito promissor como antifúngico para as linhagens, sendo que a concentração necessária para inibir 50% do crescimento radial das colônias (MIC50) foi 0,9 g/kg para γ-orizanol; 0,032 g/kg para EFF e 0,037 g/kg para EFN, portanto, os extratos fenólicos são mais eficazes para inibição de F. graminearum do que o γ-orizanol. Os extratos naturais afetaram as atividades das enzimas α-amilase e proteases. Também ocorreu a redução da formação de componentes estruturais (glicosamina e ergosterol). Os extratos naturais se destacaram pela capacidade de inibição de micotoxinas produzidas pela biomassa fúngica, com destaque para o EFN sobre a produção de DON, 15AcDON, 3AcDON e ZEA. Sendo assim, é possível dizer que há uma relação direta entre a atividade antioxidante na inibição do fungo e na manifestação do seu potencial toxigênico. Além disso, esse estudo contribuiu com a elucidação do mecanismo de ação dos antifúngicos naturais estudados. Ocorre modificação na expressão gênica quando a linhagem é submetida ao tratamento com antifúngico, havendo uma relação direta entre a expressão do gene Tri5 e a produção de DON.

In situ characterization of sediment oxygen demand across the spectrum of non-resuspension to full resuspension with varying bed shear stress

Sediment oxygen demand (SOD) can be a significant oxygen sink in various types of water bodies, particularly slow-moving waters with substantial organic sediment accumulation. In most settings where SOD is a concern, the prevailing hydraulic conditions are such that the impact of sediment resuspension on SOD is not considered. However, in the case of Bubbly Creek in Chicago, Illinois, the prevailing slack water conditions are interrupted by infrequent intervals of very high flow rates associated with pumped combined sewer overflow (CSO) during intense hydrologic events. These events can cause resuspension of the highly organic, nutrient-rich bottom sediments, resulting in precipitous drawdown of dissolved oxygen (DO) in the water column. While many past studies have addressed the dependence of SOD on near-bed velocity and bed shear stress prior to the point of sediment resuspension, there has been limited research that has attempted to characterize the complex and dynamic phenomenon of resuspended-sediment oxygen demand. To address this issue, a new in situ experimental apparatus referred to as the U of I Hydrodynamic SOD Sampler was designed to achieve a broad range of velocities and associated bed shear stresses. This allowed SOD to be analyzed across the spectrum of no sediment resuspension associated with low velocity/ bed shear stress through full sediment resuspension associated with high velocity / bed shear stress. The current study split SOD into two separate components: (1) SODNR is the sediment oxygen demand associated with non-resuspension conditions and is a surface sink calculated using traditional methods to yield a value with units (g/m2/day); and (2) SODR is the oxygen demand associated with resuspension conditions, which is a volumetric sink most accurately characterized using non-traditional methods and units that reflect suspension in the water column (mg/L/day). In the case of resuspension, the suspended sediment concentration was analyzed as a function of bed shear stress, and a formulation was developed to characterize SODR as a function of suspended sediment concentration in a form similar to first-order biochemical oxygen demand (BOD) kinetics with Monod DO term. The results obtained are intended to be implemented into a numerical model containing hydrodynamic, sediment transport, and water quality components to yield oxygen demand varying in both space and time for specific flow events. Such implementation will allow evaluation of proposed Bubbly Creek water quality improvement alternatives which take into account the impact of SOD under various flow conditions. Although the findings were based on experiments specific to the conditions in Bubbly Creek, the techniques and formulations developed in this study should be applicable to similar sites.