Relevant bibliographies by topics / Internal loading of nitrogen and phosphorus

Academic literature on the topic 'Internal loading of nitrogen and phosphorus'

Author: Grafiati
Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Internal loading of nitrogen and phosphorus"

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Findlay, D. L., R. E. Hecky, L. L. Hendzel, M. P. Stainton, and G. W. Regehr. "Relationship Between N2-Fixation and Heterocyst Abundance and its Relevance to the Nitrogen Budget of Lake 227." Canadian Journal of Fisheries and Aquatic Sciences 51, no. 10 (October 1, 1994): 2254–66. http://dx.doi.org/10.1139/f94-229.

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A significant relationship between seasonal N2-fixation rate and heterocyst abundance has been found in Lake 227 and can be modelled to estimate areal rates of N2-fixation based on the known historical phytoplankton records. Experimental imposition of low nitrogen (N): phosphorus (P) loading ratios stimulated N,-fixation. The N:P molar ratio of the internal pool of nutrients oscillates around a mean of 30:1, despite experimental loading ratios that vary from 13:1 to 0. Maintenance of this internal nutrient mass ratio requires preferential regeneration of N through time at all loading rates. Heterocystous, cyanobacteria blooms are most predictable during imposition of a very low external loading N:P ratio and high P loading relative to natural sources. Knowledge of the internal loading N:P ratio and relative contribution of internal and external loadings are required for predicting blooms at intermediate external N:P loading rates. The internal N:P ratio has fluctuated within narrow limits over 25 yr of nearly constant P loading because of adjustments in N2-fixation, N sedimentation, and denitrification, which have counterbalanced changing experimental N loading regimes.
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Zhu, Yafei, Andrew McCowan, and Perran L. M. Cook. "Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon." Biogeosciences 14, no. 19 (October 6, 2017): 4423–33. http://dx.doi.org/10.5194/bg-14-4423-2017.

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Abstract. The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes) were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads), which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria). Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.
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Huang, Jian Jun, Yu Hong Li, and Ya Jie Gao. "Ferric Nitrate Suppresses Internal Phosphorus Loading in Municipal River." Advanced Materials Research 393-395 (November 2011): 1242–46. http://dx.doi.org/10.4028/www.scientific.net/amr.393-395.1242.

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The application of nitrate is an accepted procedure to manage eutrophication municipal rivers by controlling the phosphorus release from sediments into overlying water and offering electron acceptor for microorganism metabolism. In situ laboratory studies were carried out in simulated reactors to evaluate the potential of ferric nitrate for remediation municipal river sediment. Ferric nitrate could greatly improve the ability of bio-treatment properties for sediment. Two dose remediation experiment of ferric nitrate (70g and 35g per square meter) was carried out lasting 28 weeks. Observations showed that ferric nitrate could suppressed the release of phosphorus from the sediments. At the same time the TN concentration could reduce to common level compared to blank reactor by denitrification. As a whole the dose of 35g per square meter ferric nitrate is better. The results suggest that knowledge of a municipal river’s nitrogen budget may be a useful tool in the design of municipal river remediation efforts.
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White, Sarah A., Milton D. Taylor, Stewart L. Chandler, Ted Whitwell, and Stephen J. Klaine. "Remediation of Nitrogen and Phosphorus from Nursery Runoff during the Spring via Free Water Surface Constructed Wetlands." Journal of Environmental Horticulture 28, no. 4 (December 1, 2010): 209–17. http://dx.doi.org/10.24266/0738-2898-28.4.209.

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Abstract Agricultural operations face increasing pressure to remediate runoff to reduce deterioration of surface water quality. Some nursery operations use free water surface constructed wetland systems (CWSs) to remediate nutrient-rich runoff. Our objectives were twofold, first to examine the impact of two hydraulic retention times (HRT, 3.5 and 5.5 day) on CWS performance, and second to determine if increased nutrient loading from internal CWS and nursery sources during the spring contributed to nutrient export in excess of regulatory limits. We quantified nutrient loading and removal efficiency in a free water surface CWS from late winter through late spring over three years and monitored various water quality parameters. Total nitrogen in runoff was reduced from 20.6 ± 2.8 mg·liter−1 (ppm) to 4.1 ± 1.3 mg·liter−1 (ppm) nitrogen after CWS treatment. Phosphorus dynamics in the CWS were more variable and unlike nitrogen dynamics were not consistently influenced by water temperature and hydraulic loading rate. Phosphorus concentrations were reduced from 1.7 ± 0.8 mg·liter−1 (ppm) PO4-P in influent to 1.2 ± 0.6 mg·liter−1 (ppm) PO4-P in CWS effluent, but substantial variability existed among years in both phosphorus loading and removal rates. The CWS was able to efficiently remediate nitrogen even under high spring loading rates.
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Ding, Shiming, Musong Chen, Mengdan Gong, Xianfang Fan, Boqiang Qin, Hai Xu, ShuaiShuai Gao, Zengfeng Jin, Daniel C. W. Tsang, and Chaosheng Zhang. "Internal phosphorus loading from sediments causes seasonal nitrogen limitation for harmful algal blooms." Science of The Total Environment 625 (June 2018): 872–84. http://dx.doi.org/10.1016/j.scitotenv.2017.12.348.

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Buzzelli, C., Y. Wan, P. H. Doering, and J. N. Boyer. "Seasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USA." Biogeosciences Discussions 10, no. 2 (February 11, 2013): 2377–413. http://dx.doi.org/10.5194/bgd-10-2377-2013.

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Abstract. Interactions among watershed nutrient loading, circulation, and biogeochemical cycling determine the capacity of estuaries to accommodate introduced nutrients. Baseline quantification of loading, flushing time, export, and internal processes is essential to understand responses of sub-tropical estuaries to variable climate and nutrient loading. The goal of this study was to develop seasonal dissolved inorganic nitrogen (DIN) and phosphorus (DIP) budgets for the two estuaries in south Florida, the Caloosahatchee River Estuary (CRE) and the St. Lucie Estuary (SLE), from 2002–2008 spanning various climatic conditions. The Land Ocean Interactions in the Coastal Zone (LOICZ) Biogeochemical Model was used to generate water, salt, and (DIN and DIP) budgets. The predicted increase in internal DIN production for the CRE vs. the SLE was associated with increased external DIN loading. Water column DIN concentrations decreased and stabilized in both estuaries as flushing time increased to > 10 d. The CRE demonstrated heterotrophy or balanced metabolism across all seasonal budgets. Although the SLE was also sensitive to DIN loading, system autotrophy and net ecosystem metabolism increased with DIP loading to this estuary. This included a huge DIP consumption and bloom of a cyanobacterium (Microcystis aeruginosa) following hurricane-induced discharge in 2005. Additionally, while denitrification offered a loss pathway for inorganic nitrogen in the CRE, this potential was not evident for the smaller and more anthropogenically altered St. Lucie Estuary. Disparities between total and inorganic loading ratios suggested that management actions should examine the role of dissolved organic nitrogen (DON) in attempts to reduce both nitrogen and phosphorus inputs to the SLE. Establishment of quantitative loading limits for anthropogenically impacted estuaries requires an understanding of the inter-seasonal and inter-annual relationships for both N and P, circulation and flushing, variability in plankton community composition, and the dynamics of DON.
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Zhan, Ju Hong, Sha Deng, Zhao Xin Li, Yu Luo, Ting Ting Zhao, Hua Ying Liu, Xiao Li, and Xue Jun Pan. "The Effects of Estuary Dredging on Removing Nitrogen and Phosphorus in Dianchi Lake, China." Advanced Materials Research 518-523 (May 2012): 2895–99. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.2895.

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Sediment dredging is currently the most commonly selected option for getting rid of contaminated sediments. In this study, the effects of estuary dredging on removing nitrogen and phosphorus were investigated by comparing the different vertical nutrient content between the dredged and un-dredged areas in Dianchi Lake. The results showed that the contents of total nitrogen and total phosphorus in the un-dredged areas were relatively higher than that in dredged areas. Besides, the contents of bio-available nitrogen and phosphorus represented the similar results, only a few dredged spots showed a higher potential releasing capacity. Therefore, with the reduction of internal nutrient loading, it indicated that sediment dredging might be an effective and reliable way to improve such eutrophic lakes.
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Lee, Hye Won, Yong Seok Lee, Jonggun Kim, Kyoung Jae Lim, and Jung Hyun Choi. "Contribution of Internal Nutrients Loading on the Water Quality of a Reservoir." Water 11, no. 7 (July 9, 2019): 1409. http://dx.doi.org/10.3390/w11071409.

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Sediment plays an important role in the water quality of a lake by acting as both a nutrient source and sink. The amount of phosphorus and nitrogen in the water depends on the internal load from the sediment as well as the external load. To estimate the effects of sediment load on the water quality of a reservoir, we applied a three-dimensional hydrodynamic and transport model based on the benthic chamber experimental results at Euiam Lake, South Korea. As shown in the sensitivity analysis results, the eutrophication period could be significantly extended by a change of phosphorus flux rates from the sediments. The increased phosphorus flux from the sediments intensifies the algal growth of Euiam Lake, which could cause serious algal bloom during spring and fall. This study provides information on nutrient concentrations in the sediment of Euiam Lake, verifies the role of the sediment as a source or sink of nutrients, and evaluates the effect of sediment release of nutrients and contaminants on water quality. This research is a useful tool in determining the effects of internal load in lakes and establishing the operation guideline for sediment management in order to maintain feasible water quality for beneficial use.
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Lehman, John T. "Nuisance cyanobacteria in an urbanized impoundment: interacting internal phosphorus loading, nitrogen metabolism, and polymixis." Hydrobiologia 661, no. 1 (November 6, 2010): 277–87. http://dx.doi.org/10.1007/s10750-010-0535-x.

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Buzzelli, C., Y. Wan, P. H. Doering, and J. N. Boyer. "Seasonal dissolved inorganic nitrogen and phosphorus budgets for two sub-tropical estuaries in south Florida, USA." Biogeosciences 10, no. 10 (October 24, 2013): 6721–36. http://dx.doi.org/10.5194/bg-10-6721-2013.

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Abstract. Interactions among geomorphology, circulation, and biogeochemical cycling determine estuary responses to external nutrient loading. In order to better manage watershed nutrient inputs, the goal of this study was to develop seasonal dissolved inorganic nitrogen (DIN) and phosphorus (DIP) budgets for the two estuaries in south Florida, the Caloosahatchee River estuary (CRE) and the St. Lucie Estuary (SLE), from 2002 to 2008. The Land–Ocean Interactions in the Coastal Zone (LOICZ) approach was used to generate water, salt, and DIN and DIP budgets. Results suggested that internal DIN production increases with increased DIN loading to the CRE in the wet season. There were hydrodynamic effects as water column concentrations and ecosystem nutrient processing stabilized in both estuaries as flushing time increased to >10 d. The CRE demonstrated heterotrophy (net ecosystem metabolism or NEM < 0.0) across all wet and dry season budgets. While the SLE was sensitive to DIN loading, system autotrophy (NEM > 0.0) increased significantly with external DIP loading. This included DIP consumption and a bloom of a cyanobacterium (Microcystis aeruginosa) following hurricane-induced discharge to the SLE in 2005. Additionally, while denitrification provided a microbially-mediated N loss pathway for the CRE, this potential was not evident for the SLE where N2 fixation was favored. Disparities between total and inorganic loading ratios suggested that the role of dissolved organic nitrogen (DON) should be assessed for both estuaries. Nutrient budgets indicated that net internal production or consumption of DIN and DIP fluctuated with inter- and intra-annual variations in freshwater inflow, hydrodynamic flushing, and primary production. The results of this study should be included in watershed management plans in order to maintain favorable conditions of external loading relative to internal material cycling in both dry and wet seasons.
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Dissertations / Theses on the topic "Internal loading of nitrogen and phosphorus"

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Myers, Justin Adam. "Internal loading of nitrogen (N) and phosphorus (P), reduced N forms, and periodic mixing support cyanobacterial harmful algal blooms (HABs) in shallow, eutrophic Honeoye Lake (New York, USA)." Wright State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=wright1622556045440146.

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Spears, Bryan M. "Benthic-pelagic nutrient cycling in shallow lakes : investigating the functional role of benthic microalgae." Thesis, University of St Andrews, 2007. http://hdl.handle.net/10023/371.

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Microbes, living on the boundary between the sediment and the water-column in lakes, can play a pivotal role in governing the magnitude and frequency of nutrient cycling. The purpose of this research was to focus on the role of benthic microalgae in regulating such processes and to identify spatial and temporal characteristics in their function. Approaches included the quantification of sediment nutrient concentrations (particularly P fractionation), estimates of equilibrium phosphate concentrations (EPC0) (resuspended and undisturbed sediment estimates), and assessment of the benthic microalgal community composition, biostabilisation capacity, and its ability to regulate diffusive-nutrient flux. This thesis highlighted the importance of biological regulation of benthic/pelagic nutrient cycling, especially the role of benthic microautotrophs. Release sensitive sediment-P fractions were observed to be highly variable (both with depth and season) and correlated well with indicators of benthic photosynthesis (e.g. DO, chlorophyll, pH). Understanding the seasonality of whole-system P partitioning can enhance future lake management programmes. EPC0 estimates were significantly higher during undisturbed as opposed to disturbed sediment conditions. Epipelon constituted < 17 % of the total sediment chlorophyll signal and was highest in the clearer winter months and at intermediate depths at which a trade off between wind-induced habitat disturbance and light limitation existed. In intact core experiments, the benthic microalgal community significantly reduced the diffusive nutrient (especially PO₄-P and SiO₂) flux. NH₄ -N release was highest under light conditions at high temperatures. The mechanisms for regulation included direct uptake, photosynthetic oxygenation of the sediment surface, and regulation of nitrification/denitrification processes. Sediment stability increased with colloidal carbohydrate concentration (extruded by benthic microbes) at 4.1 m water-depth but not at 2.1 m overlying water depth, probably indicating the role of habitat disturbance in shallow areas acting to reduce epipelic production. Additionally, in an ecosystem comparison, the nature and extent of the biotic mediation of sediment stability varied between freshwater and estuarine ecosystems.
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Koski-Vähälä, Jukka. "Role of resuspension and silicate in internal phosphorus loading." Helsinki : University of Helsinki, 2001. http://ethesis.helsinki.fi/julkaisut/maa/limno/vk/koski-vahala/.

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Lappalainen, K. M. (K Matti). "Itämeren rehevöitymisen uudistettu diagnoosi ja paradigma." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526219417.

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Abstract The eutrophication of the Baltic Sea continues despite decrease of the external phosphorus load by as much as 80% of the target confirmed by HELCOM. The aim of this thesis is to investigate this paradox, critically evaluate previous explanations for the persistent eutrophication, and to introduce a new diagnosis and paradigm for the causes and processes behind eutrophication of the Baltic Sea. According to the current consensus, anthropogenic nutrient loading is nearly the sole cause of eutrophication and regular cyanobacterial blooms. However, this study shows that the areal phosphorus loading rate, when modeled properly, is surprisingly low, and unlikely to be the primary cause of eutrophication. Instead, the frequency of the salt water pulses has decreased dramatically during the past 40 years. This is the root cause of eutrophication, via the hyper-vicious cycle of the hypoxic and finally anoxic conditions of the deeps causing internal phosphorus loading, denitrification, and nitrogen and carbon fixation. Furthermore, this work confirms that nitrogen fixation increases in low nitrogen conditions, further increasing eutrophication and cyanobacterial blooms. Thus, the most effective way to break the cycle of eutrophication is to improve the oxygen conditions of the deeps, which really is impossible to achieve by decreasing external loading alone. A key result of this work is that natural processes, rather than human activity, plays a decisive role in the eutrophication process – a perspective that typically faces substantial resistance. This thesis discusses how sociological and political views have affected the scientific community and its pursuit to model the mechanisms of eutrophication of the Baltic Sea. In conclusion, this study leads to important novel insights by providing new models for calculating the external and internal phosphorus loads of the Baltic Sea, with results highlighting the importance of natural processes of internal loading from the anoxic deeps. Altogether, this thesis introduces a new a paradigm for eutrophication of the Baltic Sea
Tiivistelmä Itämeri rehevöityy edelleen, vaikka fosforikuormitusta on vähennetty 80 % tavoitellusta. On siis syytä tutkia miksi Itämeren tila ei ole parantunut. Syntyneen ristiriidan ratkaisemiseksi tarkoituksena on etsiä aiemmista tulkinnoista ristiriitoja, korjata ne ja uudistaa tietopohja uudeksi ja toimivammaksi paradigmaksi. Virhetulkintojen tunnistamiseen sovelletaan Popperin falsifikaatiomenettelyn periaatteita. Konsensuksen mukaan ihmisperäinen kuormitus on lähes yksinomainen syy (sinilevä)rehevyyteen. Kuitenkin Vollenweiderin mallin mukaan tehty, hydrologialla painotettu fosforin pintakuormitus on ollut 1970 - 1980-luvuilla vain lievää rehevyyttä edellyttävällä tasolla. Ulkoinen kuormitus ei siten voi olla suurin rehevyyden aiheuttaja. Sinilevärehevyyttä ylläpitävänä päätekijänä on syvävesiin happea tuovien suolavesipulssien toistuvuuden romahtaminen. Siitä syntyneet syvävesien ja -pohjien hapettomuudet aiheuttavat Gotlanninmeressä sekä sisäistä kuormitusta että lisärehevöittävää typen- ja hiilensidontaa. Yhdessä näitä prosesseja nimitetään nyt supernoidankehäksi. Johtopäätöksiä: • Ihmistieteelliset ja ympäristöpoliittiset näkemykset vaikuttavat luonnontieteellisiin tulkintoihin luultua enemmän. • Suolavesipulssien harventuminen on hapettomuus- ja rehevyyskierteen perussyy. • Syvänteiden hapettomuus on kaikkialle negatiivisesti säteilevä keskeistekijä. • Itämeren supernoidankehä on purettava saattamalla syvänteet hapellisiksi. • Hapellisuutta ei voida saada aikaan ulkoisen kuormituksen vähentämisellä. • Jäljelle jäävät siten teknologiset keinot, joista toteutuskelvollisimmalta näyttää Itämeren hapellisimman ja kylmimmän veden pumppaus 30 metrin syvyydestä syvänteisiin, mikä tehostaa myös pulssivesien virtausta syvänteiden pohjalle. Tämä väitöskirja sisältää viisi vallitsevasta paradigmasta poikkeavaa tulosta: 1. Itämerelle on kehitetty rehevyyden uusi diagnoosi ja paradigma, 2. Luonto dominoi Itämeren tilaa, ei ihminen, 3. Typensidonnalla on lisärehevöittävä mekanismi, 4. Itämerelle on kehitetty uusi fosforin sisäkuormituksen laskentamenetelmä, 5. Virtuaalisen fosforikuormituksen laskenta. Ilman Gotlanninmeren syvänteiden hapellisuutta Itämeri on tuomittu pysymään rehevyyden supernoidankehässä, ’kaksinkertaisessa takalukossa’
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Ding, Xue. "Characteristics and Applications of Cobalt-Based Phosphate Microelectrodes for Internal Phosphorus Loading." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1333652128.

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Gurr, Eric C. "PILOT STUDY OF NUTRIENT LOADING IN A WET DETENTION LAKE." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2189.

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Florida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean Water Act (CWA) in 1972 which set the framework for the water quality standards for the entire United States. As a result of the CWA many point sources were eliminated, but in the process it became apparent that nonpoint source loads represented even more of a threat. To further study the physical and chemical characteristics of urban runoff the Nationwide Urban Runoff Program (NURP) was established in 1978. This research lead to a series of management options, named Best Management Practices (BMPs) which proposed various structural and non-structural methods to reduce nutrient loads. But the research and data collection on the effectiveness of these systems to remove nutrients is in its infancy. The main objective of this study was to generate accurate and effective water quality and water quantity data that future stormwater management decisions can be based upon. More specific, this study established automatic monitoring sites throughout the City of Kissimmee, Florida to determine the pollutant loadings into the tributaries of Lake Tohopekaliga. These monitoring sites are located such that inflows from outside the city limits can be isolated and external pollutant loads quantified. Also, additional internal monitoring sites were established to determine the pollutant loads of internal sections of the city. Data from these internal monitoring sites will also be used to determine the variable pollutant removal efficiencies and hydraulic fluctuations of natural, irregular riverine systems. The secondary objective of this study was to perform a pilot study using the discrete grab samples in tandem with the continuous hydraulic and hydrologic data from the monitoring stations. An existing lake within the project limits was chosen for the pilot study area. Monitoring stations are located at the influent and effluent sections of the lake which provided data on the hydraulic and hydrologic parameters. The pilot study determined the nutrient loads to and from the lake and checked for any seasonal variations in pollutant loading or removal efficiencies. For the purpose of this pilot study, only total nitrogen and total phosphorous were examined for two monitoring sites. The nutrient removal efficiency was performed using both the event mean concentration method and the summation of loads method to check for seasonal variation. There were no storm event concentrations available for used in this analysis, however, there were 25 discrete grab samples collected on a bi-monthly basis over a twelve month period. This data was used with corresponding five-minute rainfall and flow data from both the inflow and outflow points. The results of this study did not reveal any seasonal variation in the nutrient concentrations either flowing into or out from the lake. Although there were some relatively lower values in late spring, the concentration levels of total nitrogen did not seem to vary significantly from its mean value of 0.90 mg/l throughout the year. The concentration levels of total phosphorus did range from 0.02 mg/l to 0.48 mg/l, but not in relation to either season or flow volume fluctuations. The lake showed no net removals of total nitrogen and was actually found to be releasing total phosphorus to the downstream receiving waters. The findings of this study are limited due to the fact that the period of pilot study was only for twelve months and there were no rainfall events used in the analysis. Rainfall events are typically high sources of nutrient loads to a lake. The lower efficiencies were probably due to missing the actual higher nutrient load concentrations during the rainfall event. However, even considering the lack of event data, the nutrient removal efficiency for the pond was still low. This analysis did serve well as a basis for performing future analysis once additional data, including rainfall events, has been collected.
M.S.C.E.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering MSCE
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Wilkes, Austin. "Phosphorus Mobility and Speciation Under Dynamic Redox Conditions in Shallow Eutrophic Freshwater Systems." ScholarWorks @ UVM, 2019. https://scholarworks.uvm.edu/graddis/1145.

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Internal loading of phosphorus (P) from lake sediments can delay the recovery of lakes from eutrophication for years to decades following decreases in external nutrient inputs. While internal P loading is a pervasive problem in freshwater systems, molecular speciation of P in benthic sediments of these systems remains poorly characterized. As different P species will exhibit different responses to changing sediment-water interface (SWI) geochemistry, quantifying P speciation in sediments is a critical step in understanding P dynamics in sediment-water systems. Here, various synchrotron-based techniques were employed to directly probe the bonding environments of P and iron (Fe) in natural and experimentally manipulated lake sediments in order to link chemical speciation to chemical behavior and to identify the geochemical drivers that mediate this linkage. We manipulated SWI redox conditions in mesocosm experiments to investigate the impacts of prolonged anoxia and redox oscillations on P mobility and speciation in sediments. Mesocosm experiments demonstrate that oscillating redox conditions near the SWI may drive accelerated P release from sediments relative to uninterrupted reducing conditions. Sediment P is found to be predominantly associated with Fe oxyhydroxides, calcium carbonate, and apatite minerals in three shallow hyper/eutrophic lakes in northern Vermont. In Missisquoi Bay and Lake Carmi, Fe redox cycling controls P mobility via precipitation and dissolution of Fe oxyhydroxides. In the hypereutrophic Shelburne Pond, the presence of Fe sulfides precludes redox-driven P cycling and P mobility is instead dominated by organic matter mineralization. Our results demonstrate that internal P loading can manifest differently in similar shallow lake systems due to differences in lake configuration, sediment P and Fe speciation, and organic content of sediments. This work demonstrates the potential utility, as well as the limitations, of P K- edge X-ray absorption near edge structure spectroscopy in determining sediment P speciation in freshwater lakes.
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Meert, Danielle. "Responses of a Louisiana oligohaline marsh plant community to nutrient loading and disturbance." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/890.

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Aboveground plant community dynamics in the oligohaline marsh at Big Branch Marsh National Wildlife Refuge, Louisiana, USA, were assessed in response to nutrient loading (3 N x 3 P treatments) and disturbance (both planned lethal disturbance and stochastic tropical storm/hurricane disturbance). Sampling was conducted seasonally from April 2004 to September 2006. Spartina patens and Schoenoplectus americanus are co-dominant plant species in this marsh. Low N-loading additions resulted in increased S. patens cover. However, increased N loading did not result in a shift in plant community composition despite S. americanus consistently having higher leaf tissue N than S. patens. Our results indicate that S. americanus may be more resilient than S. patens to disturbances that do not increase marsh surface elevation. Hurricane Katrina deposited significant amounts of sediment into remaining plots (August 29, 2005). By 2006, this disturbance resulted in a significant increase in both species richness and S. patens cover.
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Jidetorp, Frida. "Sjöars känslighet för klimatförändringar – vilka faktorer påverkar?" Thesis, Uppsala University, Department of Earth Sciences, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-88856.

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The Earths climate is changing at a higher rate, i.e between 1861 and 1994 the annual mean temperature in Scandinavia increased with 0,68º C and according to recent climate models the annual mean temperature is likely to rise with another 3º C during this century.

A warmer climate in many ways is associated with changing conditions for lake ecosystems. An expected higher water temperature and a stronger summer stratification of the water column increases the risk of anoxic conditions at the lake bottom. Thus anoxic conditions are likely to cause a phosphate leakage from the sediment, i.e. a higher internal loading of phosphate.

In this project, the extremely warm summer of 2002 has been used as an example for a possible scenario for a future climate. By comparing levels of phosphorus in the summer of 2002 with a ten-year median value, a phosphorus related sensitivity to climate change has been analyzed for 55 Swedish lakes. This sensitivity has then been related to several parameters of which in particular the lake morphometry and the land use in the catchment of the lake influenced the climatic sensitivity of the lake to climatic change.


Jordens klimat förändras i en allt snabbare takt. Mellan 1861 och 1994 steg årsmedeltemperaturen i Skandinavien med 0,68º C. Enligt aktuella klimatmodeller förväntas årsmedeltemperaturen i Skandinavien öka med ytterligare 3º C det närmaste seklet.

Ett varmare klimat innebär på flera sätt nya förutsättningar för ekosystemen. Genom höjda vattentemperaturer och en starkare stratifikation sommartid ökar risken för syrefria förhållanden i sjöar. Då sedimentet under syrefria förhållanden kan läcka fosfat innebär detta en ökad internbelastning av fosfor.

I detta projekt har den extremt varma sommaren 2002 använts som ett möjligt framtida klimat. Genom att jämföra fosforhalter sommaren 2002 med ett medianvärde för 10 år har den fosforrelaterade känsligheten för klimatförändringar kunnat analyseras för 55 svenska sjöar. Denna känslighet har sedan relaterats till diverse parametrar så som sjöns morfometri och avrinningsområdets sammansättning.

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Lynn, Thomas Joseph. "Evaluation and Modeling of Internal Water Storage Zone Performance in Denitrifying Bioretention Systems." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5260.

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Nitrate (NO3) loadings from stormwater runoff promote eutrophication in surface waters. Low Impact Development (LID) is a type of best management practice aimed at restoring the hydrologic function of watersheds and removing contaminants before they are discharged into ground and surface waters. Also known as rain gardens, a bioretention system is a LID technology that is capable of increasing infliltration, reducing runoff rates and removing pollutants. They can be planted with visually appealing vegetation, which plays a role in nutrient uptake. A modified bioretention system incorporates a submerged internal water storage zone (IWSZ) that includes an electron donor to support denitrification. Modified (or denitrifying) bioretention systems have been shown to be capable of converting NO3 in stormwater runoff to nitrogen gas through denitrification; however, design guidelines are lacking for these systems, particularly under Florida-specific hydrologic conditions. The experimental portion of this research investigated the performance of denitrifying bioretention systems with varying IWSZ medium types, IWSZ depths, hydraulic loading rates and antecedent dry conditions (ADCs). Microcosm studies were performed to compare denitrification rates using wood chips, gravel, sand, and mixtures of wood chips with sand or gravel media. The microcosm study revealed that carbon-containing media, acclimated media and lower initial dissolved oxygen concentrations will enhance NO3 removal rates. The gravel-wood medium was observed to have high NO3 removal rates and low final dissolved organic carbon concentrations compared to the other media types. The gravel-wood medium was selected for subsequent storm event and tracer studies, which incorporated three completely submerged columns with varying depths. Even though the columns were operated under equivalent detention times, greater NO3 removal efficiencies were observed in the taller compared to the shorter columns. Tracer studies revealed this phenomenon was attributed to the improved hydraulic performance in the taller compared to shorter columns. In addition, greater NO3 removal efficiencies were observed with an increase in ADCs, where ADCs were positively correlated with dissolved organic carbon concentrations. Data from the experimental portion of this study, additional hydraulic modeling development for the unsaturated layer and unsaturated layer data from other studies were combined to create nitrogen loading model for modified bioretention systems. The processes incorporated into the IWSZ model include denitrification, dispersion, organic media hydrolysis, oxygen inhibition, bio-available organic carbon limitation and Total Kjeldahl Nitrogen (TKN) leaching. For the hydraulic component, a unifying equation was developed to approximate unsaturated and saturated flow rates. The hydraulic modeling results indicate that during ADCs, greater storage capacities are available in taller compared to shorter IWSZs Data from another study was used to develop a pseudo-nitrification model for the unsaturated layer. A hypothetical case study was then conducted with SWMM-5 software to evaluate nitrogen loadings from various modified bioretention system designs that have equal IWSZ volumes. The results indicate that bioretention systems with taller IWSZs remove greater NO3 loadings, which was likely due to the greater hydraulic performance in the taller compared to shorter IWSZ designs. However, the systems with the shorter IWSZs removed greater TKN and total nitrogen loadings due to the larger unsaturated layer volumes in the shorter IWSZ designs.
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Books on the topic "Internal loading of nitrogen and phosphorus"

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James, William F. Internal phosphorus loading in Lake Pepin (Minnesota-Wisconsin). [Vicksburg, Miss: U.S. Army Engineer Waterways Experiment Station, 1995.

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Snyder, Daniel T. Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon. Portland, Ore: U.S. Dept. of the Interior, U.S. Geological Survey : Denver, CO : Branch of Information Services [distributor], 1997.

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Spears, Bryan, and Alan Steinman. Internal Phosphorus Loading in Lakes: Causes, Case Studies, and Management. Ross Publishing, Incorporated, J., 2019.

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Spears, Bryan, and Alan Steinman. Internal Phosphorus Loading in Lakes: Causes, Case Studies, and Management. Ross Publishing, Incorporated, J., 2020.

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Book chapters on the topic "Internal loading of nitrogen and phosphorus"

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Granéli, Wilhelm. "Internal phosphorus loading in Lake Ringsjön." In Nutrient Reduction and Biomanipulation as Tools to Improve Water Quality: The Lake Ringsjön Story, 19–26. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-017-2462-3_3.

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Søndergaard, Martin, Jens Peder Jensen, and Erik Jeppesen. "Internal phosphorus loading in shallow Danish lakes." In Shallow Lakes ’98, 145–52. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-017-2986-4_15.

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Pettersson, Kurt. "Mechanisms for internal loading of phosphorus in lakes." In Oceans, Rivers and Lakes: Energy and Substance Transfers at Interfaces, 21–25. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5266-2_2.

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Kowalczewska-Madura, Katarzyna, Renata Dondajewska, and Ryszard Gołdyn. "Internal Phosphorus Loading in Eutrophic Lakes in Western Poland." In Polish River Basins and Lakes – Part I, 277–303. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-12123-5_14.

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Wang, Shengrui, and Zhihao Wu. "The “Internal P-Loading” at SWI Assessed by DGT Technique." In DGT-based Measurement of Phosphorus in Sediment Microzones and Rhizospheres, 75–92. Singapore: Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-0721-7_4.

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Spears, B. M., L. Carvalho, R. Perkins, A. Kirika, and D. M. Paterson. "Long-term variation and regulation of internal phosphorus loading in Loch Leven." In Loch Leven: 40 years of scientific research, 23–33. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-4333-5_4.

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Dokulil, M. T., and A. Jagsch. "The effects of reduced phosphorus and nitrogen loading on phytoplankton in Mondsee, Austria." In The Dynamics and Use of Lacustrine Ecosystems, 389–94. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2745-5_40.

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Søndergaard, Martin, Peter Kristensen, and Erik Jeppesen. "Eight years of internal phosphorus loading and changes in the sediment phosphorus profile of Lake Søbygaard, Denmark." In Proceedings of the Third International Workshop on Phosphorus in Sediments, 345–56. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1598-8_43.

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van der Molen, Diederik T., and Paul C. M. Boers. "Influence of internal loading on phosphorus concentration in shallow lakes before and after reduction of the external loading." In Nutrient Dynamics and Biological Structure in Shallow Freshwater and Brackish Lakes, 379–89. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-017-2460-9_34.

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Quaak, Marinus, Joop van der Does, Paul Boers, and Jo van der Vlugt. "A new technique to reduce internal phosphorus loading by in-lake phosphate fixation in shallow lakes." In Proceedings of the Third International Workshop on Phosphorus in Sediments, 337–44. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1598-8_42.

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Conference papers on the topic "Internal loading of nitrogen and phosphorus"

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Magdum, Shubham Shankar, and Gopal M. Bhosale. "Studies on Application of Spent wash as a Nutrient for Agriculture waste Composting." In 7th GoGreen Summit 2021. Technoarete, 2021. http://dx.doi.org/10.36647/978-93-92106-02-6.14.

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Due to high organic loading rates, several chemicals in distillery spent wash have high B.O.D. and C.O.D. values. The cost of treating and disposing of spent wash is expensive. Hence Composting is one of the most effective methods for achieving this. Sugarcane farms agricultural waste is used as a raw material. The goal of this study is to figure out how to compost agricultural waste utilizing aerobic and windrow composting techniques. Pits should be 3m long, 1.5m wide and 1m high for aerobic composting, and 3m long, 1.5m wide, and 1.2m high for windrow composting (Composting, W.H.O Book). Turning should be done on the 5th, 17th, and 30th days of the interval for aerobic composting. For windrow composting, it should be provided after 2-4 weeks. To decompose the agricultural waste cow dung and spent wash were utilized as a media. The study research indicates that it should be cost-effective. The quality of nitrogen, phosphorus, potassium and the mass of carbon to nitrogen ratio (C/N ratio) were analyzed. The parametric values, such as nitrogen 0.8 percent, phosphorous 0.4 percent, potassium 0.4 percent, and C/N ratio = 20 to 30, are all within acceptable ranges, and the results show that the compost is ideal for plant growth.
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Jianjun Huang, Hongwei Zhang, Yu Tian, Nan Li, and Yuhong Li. "Alum control of internal phosphorus loading in a municipal river sediment." In 2010 2nd Conference on Environmental Science and Information Application Technology (ESIAT). IEEE, 2010. http://dx.doi.org/10.1109/esiat.2010.5568557.

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Selby, K., M. Urbanak, D. Colbourne, H. Leonhardt, P. Burnett, F. Machatschek, and S. Beviere. "Meeting the Lubrication Challenges of Heavy Duty Low Emission Diesel Engines." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63983.

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In recent years, legislative authorities in the US, Europe and Japan have steadily reduced engine exhaust emissions, i.e., carbon monoxide (CO), hydrocarbons (HC), sulphur, particulate matter (PM) and nitrogen oxides (NOx) to improve air quality. To meet these requirements engine manufacturers have had to make significant design changes and as a consequence new engine lubricant specifications from Industry bodies (ACEA, EMA, JAMA) and individual OEMs have had to be introduced to ensure adequate lubrication of these new engines. This has led to significant changes to heavy-duty diesel engine oil (HDDEO) oil formulation composition. Engine design modifications to increase fuel combustion efficiency such as increased peak cylinder pressure and increased fuel injection pressures have placed higher stress on piston rings and liners, bearings and valve train components [1], and improved oil consumption has meant longer oil residence time in the piston ring belt area. The practice of retarded fuel injection timing and exhaust gas recirculation (EGR) as measures to reduce NOx levels by reducing peak combustion temperature has had a considerable impact on lubricant performance. Retarded injection leads to higher soot levels which can cause valve train wear and piston ring liner wear and soot-induced thickening, whilst EGR leads to increased corrosive acids and wear in the combustion chamber. Currently in Europe, Euro 3 heavy-duty engines predominantly use retarded fuel injection as the primary NOx emission control strategy although there are cases where EGR is used. In the US, cooled EGR is used by most engine manufacturers to meet US 2002 emissions. HDDEO’s contain a combination of performance additives such as overbased metal detergents, dispersants, antiwear agents and antioxidants designed to provide wear protection, engine cleanliness, and control of soot contaminants and oxidation. Other additive components include selected viscosity index (VI) improvers and pour point depressants to provide necessary viscosity characteristics and shear stability, and also anti-foam agents for oil aeration control. To meet the increased demands from low emission engines, the chemical composition of the performance additives has been modified and levels increased. Current HDDEOs optimized to meet US and European specifications contain typically between 1.3 and 1.9%wt sulphated ash, 0.1–0.14%wt phosphorus and 0.3–1.1.wt sulphur. To meet the next generation emission standards, engines will require the use of exhaust after-treatment devices. In Europe, Euro 4 emission reductions for NOx and PM, scheduled for introduction in 2005, will require the use of either selective catalytic reduction, or the use of EGR in combination with a diesel particulate filter (DPF). To meet the US 2007 requirements, higher levels of EGR than currently used, in combination with DPFs, is envisaged by most engine builders. Exhaust after-treatment devices are already used extensively in some applications such as DPFs on city buses in Europe and the US. Further NOx restrictions are scheduled for Euro 5 in 2008 and USA in 2010. NOx absorber systems, although used in gasoline engines, are still under development for heavy-duty diesel engines and may be available for 2010. Some lubricant base oil and additive components from oil consumed in the combustion chamber are believed to adversely affect the performance of after-treatment devices. Ash material from metal detergents and zinc dithiophosphates (ZDTP) can build up in the channels within particulate filters causing blockage and potentially loss of engine power, leading to a need for frequent cleaning maintenance. The role of sulphur and phosphorus in additive components is less clear. Sulphur from fuel can either oxidize to sulphur dioxide and react through to sulphuric acid, which manifests itself as particulate, or can have a poisoning effect on the catalyst itself. However, the role of sulphur containing additives is yet to be established. Phosphorus from ZDTP antiwear components can lead to a phosphate layer being deposited on catalyst surfaces, which may impair efficiency. Concerns from OEMs regarding the possible effects of ash, sulphur and phosphorus has led to chemical limits being introduced in some new and upcoming engine oil specifications. The ACEA E6 sequence restricts sulphated ash to 1.0%wt max, phosphorus to 0.08%wt max and sulphur to 0.3%wt max, while the PC-10 category scheduled for 2007 will have maximum limits of 1.0%wt sulphated ash, 0.12%wt phosphorus and 0.4%wt sulphur. The resulting constraints on the use of conventional overbased metal detergent cleanliness additives and zinc dithiophosphate antiwear additives will necessitate alternative engine oil formulation technologies to be developed in order to maintain current performance levels. Indeed, performance requirements of engine oils are expected to become more demanding for the next generation engines where emissions are further restricted. If absorbers become a major route for NOx reduction, limits on sulphur and phosphorus are likely to be more restrictive. Oil formulations meeting ACEA E6 and PC-10 chemical limits have been assessed in several key critical lubricant specification tests, looking at valve train and piston ring/cylinder liner wear, corrosive wear in bearings, piston cleanliness and soot-induced viscosity control. It is demonstrated that it is possible to achieve MB 228.5 extended oil drain performance and API CI-4 wear, corrosion and piston cleanliness requirements for current US engines equipped with EGR [2], at a sulphated ash level of 1.0%wt, and phosphorus and sulphur levels, (0.05 and 0.17%wt, respectively), considerably lower than these chemical limits. This is achievable by the use of selected low sulphur detergents, optimized primary and secondary antioxidant systems and non-phosphorus containing, ashless supplementary antiwear additives blended in synthetic basestocks. Field trials in several city bus fleets have been conducted to assess engine oil performance and durability using one of these low sulphated ash, phosphorus and sulphur (SAPS) oil formulations and to examine lubricant effects on particulate filter performance. Engine oil durability testing was conducted in bus fleets in Germany and Switzerland. These trials, involving over 100 vehicles, cover a range of engine types, e.g., Daimler Chrysler and MAN Euro 1, 2 and 3 and different fuel types (low sulphur diesel, biodiesel, and compressed natural gas) in some MAN engines. The fleets are fitted with continuously regenerating particulate filters either from new or retrofitted. Oils were tested at standard and extended drain intervals (up to 60 000km). Used oil analysis for iron, copper, lead and aluminium with the low SAPS oil in these vehicles have shown low wear rates in all engine types and comparable with a higher 1.8% ash ACEA E4, E5 quality oil. Soot levels can vary considerably, but oil viscosity is maintained within viscosity grade, even at 8% soot loading. TBN depletion and TAN accumulation rates are low showing significant residual basicity reserve and control of acidic combustion and oxidation products. Buses in Stuttgart and Berlin have been used to investigate lubricant ash effects of engine oil on particulate filter durability. Exhaust back-pressure is routinely measured and DPF filters removed and cleaned when back pressure exceeds 100 mbar. Comparison of rate of back pressure build up as a function of vehicle distance shows reduced back pressure gradients for the low SAPS oil relative to the 1.8%wt ash oil in both engine types looked at. An average reduction in back pressure gradient of 40% was found in buses equipped with OM 906LA engines in Berlin and 25% with OM 457hLA engines at both locations. Examination of the ash content in DPFs has shown a 40% reduction in the quantity of ash with the low SAPS oil. This investigation shows that it is possible to meet current long oil drain requirements whilst meeting chemical limits for future lubricants and provide benefits in DPF durability.
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Jiang Jinyuan, Zhou Yuexi, Chai Yanli, Wang Haiyan, and Liu Hongliang. "Simultaneous biological removal of nitrogen and phosphorus in a novel internal-loop A/O/IAT-IAT process." In 2011 International Symposium on Water Resource and Environmental Protection (ISWREP). IEEE, 2011. http://dx.doi.org/10.1109/iswrep.2011.5893291.

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Offermanns, Stefan, Eberhard Roos, and Werner Stadtmu¨ller. "Structural Response of Thin-Walled Austenitic Pipes to Internal Gaseous Detonation Loading." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-63352.

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One of the main risks with the occurrence or by the use of hydrogen in oxygen-containing environment is the easy ignitability of the gas-mixture. An example of unwanted aggregations of such a gas-mixture is the generation of gaseous hydrogen and oxygen in safety-relevant piping of nuclear power plants due to radiolysis. Radiolysis is the dissociation of water under the influence of gamma and neutron radiation. Within the scope of a research project funded by the German Federal Ministry of Economics and Technology (BMWi), the assessment of incident situations with appearance and ignition of different amounts of radiolysis gas should be provided. Of central importance for the pipe behavior under detonative loading is the knowledge about the pressure-profile of the deflagration (subsonic combustion before entry of detonation) as well as the mechanisms of an acceleration of the deflagration up to the detonation, which starts as a so-called overdriven detonation in a volume of pre-compressed gas and then decays to the stable detonation. Furthermore pressure-profile and speed of the detonation wave are elementary pipe load parameters. Detonation tests and numerical evaluations were performed to simulate detonations of radiolysis gas in pipes with O.D. × t (outer diameter × wall thickness) = (114 × 6) mm made of austenitic steel under operating pressure of p0 = 7 MPa. For the consideration of mixtures of radiolysis gas and steam inside a piping the volume proportion in percent of oxyhydrogen (H2+ 1/2 O2) to nitrogen (N2) was varied. The influence of the overdriven detonation is essential for the deformation and rupture behavior of the pipe and depends strongly on the ratio of oxyhydrogen to nitrogen. Due to the high-rate response of the pipes to the detonation, multiple longitudinal cracks and fragmentation occurred in certain cases. For the evaluation of the fracture mechanisms accompanying metallographic investigations were performed. For the numerical investigations an appropriate material constitutive law was chosen in order to describe the material behavior including strain rate sensitivity and thermal softening at high deformations. Material parameters are obtained from small-size specimen tests. The material model includes necking and was validated by numerical simulations of tensile and compression tests. For the numerical simulation of gas detonations in pipes the full pressure profile including deflagration and overdriven detonation is of a central importance. In this publication pressure profiles were obtained by tests and calculations. The numerical simulations of detonations inside the pipes were verified by the detonation tests using results of optical deformation measurement.
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Chao, Tong Wa, and Joseph E. Shepherd. "Comparison of Fracture Response of Preflawed Tubes Under Internal Static and Detonation Loading." In ASME 2003 Pressure Vessels and Piping Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/pvp2003-1957.

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Fracture experiments were performed on thin-walled and preflawed aluminum 6061-T6 tubes. Flaws were machined as external axial surface notches. The tubes were 1) statically loaded with oil, 2) statically loaded with nitrogen, and 3) dynamically loaded with gaseous detonations traveling at 2.4 km/s. The experiments were controlled so that comparisons could be made on sets of specimens with the same material, tube and flaw geometry, nominal loading amplitude, and flange supports, with the only difference being the dynamics of the loading. It was found that there is a significant difference in crack propagation behavior for the three types of loading. In this paper, fracture behavior will be discussed along with the fluid dynamics involved. The tubes were also instrumented with pressure transducers, crack detection gages, and strain gages so that data on loading, crack propagating speeds, and strain history can be compared.
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Selim, M. Y. E., and S. M. S. Elfeky. "Effects of Diesel / Water Emulsion on Heat Flow and Thermal Loading in a Precombustion Chamber Diesel Engine." In ASME 2001 Internal Combustion Engine Division Spring Technical Conference. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/ices2001-126.

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Abstract An experimental investigation has been carried out to study the effects of using water / diesel emulsion fuel in an indirect injection diesel engine on the heat flux crossing liner and cylinder head, thermal loading and metal temperature distribution. A single cylinder precombustion chamber diesel engine has been used in the present work. The engine was instrumented for performance, metal temperature and heat flux measurements. The pure gas oil fuel and different ratios of water / diesel emulsion were used and their effects on the heat flux level and the injector tip temperature are studied. Two correlation were found for the heat flux crossing the liner and the cylinder head at various water / diesel emulsion ratios, fuelling rate and thermocouple probe locations. It was found that the addition of water to diesel fuel, to control the nitrogen oxides emissions, has great influence on reducing die heat flux, the metal temperatures and thermal loading of combustion chamber components.
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Domnin, Dmitry, Dmitry Domnin, Boris Chubarenko, Boris Chubarenko, Rene Capell, and Rene Capell. "MATHEMATICAL MODELING OF NUTRIENT LOADING FROM SMALL CATCHMENTS OF THE VISTULA LAGOON." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b93dfde6248.02952871.

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Vistula Lagoon as a part of the coastal zone translates nutrient load from catchment to the Baltic Sea. Catchments of the Primorskaya River (small settlements, mostly agricultural area, 120 km2) and Banówka-Mamonovka River (transboundary catchment between Russia and Poland, relatively big settlements, food production enterprises, agricultural activity, 490 km2) were selected as test ones for the Vistula Lagoon catchment (23 870 km2). Assessment of the retention of total nitrogen and phosphorus in the catchment and the transformation of nutrient load from anthropogenic sources while passing the catchment were studied by using open source numerical modeling tools. Initial data comprises the geomorphic characteristics, river net data, information on land use and nutrient point sources, time series of temperature, precipitation. Runoff was simulated by hydrological model HYPE considering the evaporation and infiltration into the soil. Retention and transport of nutrients were accessed using the model FyrisNP. Source apportionment was made for the nutrient load discharging from both catchments to the Vistula Lagoon. The greatest amount of nutrients in final discharge is coming from the arable land (50-80%), point sources constitute a smaller proportion (5-30%). The results will be used to obtain the first order approximation of the nutrient load from other small rivers of the Vistula Lagoon catchment and from the biggest river in the area, the Pregolya River (15 300 km2) by analogy.
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Domnin, Dmitry, Dmitry Domnin, Boris Chubarenko, Boris Chubarenko, Rene Capell, and Rene Capell. "MATHEMATICAL MODELING OF NUTRIENT LOADING FROM SMALL CATCHMENTS OF THE VISTULA LAGOON." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b431754b7a5.

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Vistula Lagoon as a part of the coastal zone translates nutrient load from catchment to the Baltic Sea. Catchments of the Primorskaya River (small settlements, mostly agricultural area, 120 km2) and Banówka-Mamonovka River (transboundary catchment between Russia and Poland, relatively big settlements, food production enterprises, agricultural activity, 490 km2) were selected as test ones for the Vistula Lagoon catchment (23 870 km2). Assessment of the retention of total nitrogen and phosphorus in the catchment and the transformation of nutrient load from anthropogenic sources while passing the catchment were studied by using open source numerical modeling tools. Initial data comprises the geomorphic characteristics, river net data, information on land use and nutrient point sources, time series of temperature, precipitation. Runoff was simulated by hydrological model HYPE considering the evaporation and infiltration into the soil. Retention and transport of nutrients were accessed using the model FyrisNP. Source apportionment was made for the nutrient load discharging from both catchments to the Vistula Lagoon. The greatest amount of nutrients in final discharge is coming from the arable land (50-80%), point sources constitute a smaller proportion (5-30%). The results will be used to obtain the first order approximation of the nutrient load from other small rivers of the Vistula Lagoon catchment and from the biggest river in the area, the Pregolya River (15 300 km2) by analogy.
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Twomey, Kelly M., Ashlynn S. Stillwell, and Michael E. Webber. "The Water Quality and Energy Impacts of Biofuels." In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90294.

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Concerns over rising fuel prices, national security, and the environment have led to the Energy Independence and Security Act (EISA) of 2007, which established a mandate for the production of at least 36 billion gallons of biofuels in 2022, up to 15 billion gallons of which can come from traditional first-generation biofuels sources such as corn starch-based ethanol. One consequence of ramped-up biofuels production is the risk of additional soil runoff. This runoff, potentially laden with nitrogen and phosphorus compounds from fertilizers, can detrimentally impact water quality. Consequently, the water treatment sector might require additional energy to remove increased quantities of sediment and run-off from nutrients and pesticides in degraded water bodies downstream of agricultural land. At the same time, the cumulative effects of increased eutrophication in the Mississippi and Atchafalaya River Basins have already negatively impacted much of the aquatic life in the Louisiana-Texas continental shelf. A recent report by U.S. Geological Survey measured nitrogen loading in the Mississippi River basin as high as 7,761 metric tons per day, the highest recorded loading in the past three decades, 52% of which is attributed to loading from corn and soybean crops. Massive algae blooms that thrive in nutrient-rich water deplete the water of oxygen when they die, creating a hypoxic region. This hypoxic region, which currently covers a region the size of New Jersey, is considered to be the second-largest dead zone in the world as of 2007. As a result, the Gulf Hypoxia Action Plan of 2008 was established to reduce nitrogen and phosphorous loading by 45% in order to shrink the hypoxic region to 5,000 square kilometers. Thus, at a time when water quality priorities aim to decrease nitrogen and phosphorous loading in waterways, legislative targets are seeking to increase corn starch-based ethanol production to 15 billion gallons a year, and thereby potentially increase nitrogen loading in this region by 10–34% due to runoff. Consequently, the energy intensity for water treatment may have a two-fold challenge. Because water and wastewater treatment is already responsible for 4% of the nation’s electricity consumption, putting more stringent demands on this sector could put upward pressure on energy consumption. This analysis quantifies the impact that the mandated increase in ethanol production might have on the energy required for water treatment in the United States. It reports results from a first-order top-level analysis of the energy impacts of ethanol. The results indicate that the increased production corn-starch based ethanol in the United States is not likely to increase the energy consumed during surface water treatment, but might cause significant increases in the energy consumed during groundwater treatment.
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Reports on the topic "Internal loading of nitrogen and phosphorus"

1

Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency lakes, Oregon. US Geological Survey, 1997. http://dx.doi.org/10.3133/wri974059.

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