11 |
The Organizational Improvement of the Village Creek Wastewater Treatment Plant in Fort Worth, Texas, 1969-1988: a Case Study of Forces Responsible for Organizational ChangeAkidi, Innocent O. (Innocent Okechuknu) 05 1900 (has links)
This study documents that external and internal forces were causes of change at VCWTP. External forces caused. Fort Worth to reorganize and introduce new management at VCWTP after 1982. These improvements led to VCWTP being selected best managed wastewater treatment plant in the nation by EPA in 1988. This study first analyzes external and internal forces responsible for changes at VCWTP. A history of plant operations also is reviewed. Personnel interviews were conducted of perceptions of employees. Finally, statistics obtained of the plant operation from 1969 to 1988 are compared with personal interviews. Five forces effect change at VCWTP; population, regulatory requirements, political conflicts, an organizational and managerial factors. Turnaround occurred as external and internal corrections were made.
|
12 |
Sources, Transport, Measurement and Impact of Nano and Microplastics in Urban WatershedsBirch, Quinn T. January 2019 (has links)
No description available.
|
13 |
XENOKAT – Biofilter für Xenobiotika in der Ressource WasserWerner, Anett, Bley, Thomas, Wick, Justus, Hauser, Ralf January 2016 (has links)
Aus der Einleitung:
"Xenobiotika werden durch den Menschen in die Stoffkreisläufe der Natur eingebracht, sie sind dort ursprünglich nicht anzutreffen. Dazu zählen auch Medikamente, die der menschliche Körper in kurzer Zeit wieder ausscheidet ohne diese abzubauen. Die bestehenden Abwasserreinigungsanlagen sind derzeit nicht in der Lage diese Frachten vollständig zu eliminieren, sodass sie unweigerlich in die Umwelt gelangen und dort undefiniert Einfluss nehmen. Xenobiotika können bereits in den großen Wasserreservoirs der Erde detektiert werden, die Prognose für die nächsten Jahre zeigt eine 30% Steigerung der Emissionen auf. In Deutschland gelangen z.B. jährlich 63 Tonnen des Schmerzmittels Diclofenac in die Flüsse (Bundesumweltamt 2014). Der Mensch hinterlässt regelrechte anthropogene Fußabdrücke, bestehend aus Schmerzmitteln, Antibiotika und Hormonen. Die problematischen Emissionen einiger Xenobiotika treten anhand von Folgeerscheinungen weltweit immer gravierender zutage (Bundesumweltamt 2014). So müssen das globale Artensterben (Geier in Indien), die Verweiblichung von Tierpopulationen in aquatischen Systemen und Krebserkrankungen mit partiell hohen Xenobiotika-Belastungen in der Umwelt in Zusammenhang gebracht werden. Die Entfernung von Xenobiotika insbesondere aus den Wasserkreisläufen stellt eine große ökonomische als auch ökologische Herausforderung zum Schutz der Lebensräume dar. ..."
|
14 |
The Microbial Community Composition of Cincinnati Wastewater Treatment Plants and Eutrophic Freshwater LakesIcardi, Keely Marie 10 January 2019 (has links)
No description available.
|
15 |
Method Development for the Synthesis of Anaerobic Digester Biogas with the Laboratory EnvironmentFreitas, Andrew Daniel Sanchez 12 February 2015 (has links)
Biogas, a gaseous mixture produced during decomposition of organic matter, is a renewable, easily generated and common byproduct of anaerobic digestion at wastewater treatment plants (WWTP), landfills and agricultural operations. There is growing interest in researching and utilizing the energy potential associated with its combustion. Siloxanes, a family of volatile organic silicon compounds, pose large impediments to biogas usage due to the formation and precipitation of silicon dioxide within combustion devices. Removal of siloxanes prior to combustion is therefore a growing endeavor. Research was performed to synthesize a representative gas stream produced from anaerobic digesters within WWTP. Methane, carbon dioxide and hydrogen sulfide were combined with humidity and gaseous siloxane in levels characteristically seen exiting anaerobic digesters. A methanol impinger train was utilized to sample the biogas composite. Gas chromatography-mass spectrometry (GC-MS) was used to determine gas-phase siloxane concentrations in the gas stream effluent for the purposes of confirming the generation of a consistent and reproducible biogas stream. / Master of Science
|
16 |
Svenska avloppsreningsverks arbete kring läkemedelsrening : Drivkrafter, utmaningar och skillnader mellan kommunerLindqvist, Frida January 2017 (has links)
Det senaste årtiondet har man uppmärksammat läkemedelsrester i den akvatiska miljön. Kommunala avloppsreningsverk är en av de viktigaste källorna till detta. Denna rapport behandlar frågan om att bygga ut avloppsreningsverk med teknik för att reducera läkemedel från kommunalt avloppsvatten. En telefonenkät har genomförts med personal på kommunala avloppsreningsverk. Med hjälp av den försöker rapporten sammanfatta läget för läkemedelsrening i svenska kommuner, hur långt man har kommit, vilka drivkrafter som kan stimulera arbetet och utmaningar som kan komma med det. Rapporten försöker också identifiera skillnader mellan kommuner som kan avgöra om man jobbar för att införa läkemedelsrening. Undersökningen visar att majoriteten av svenska kommuner ännu inte har börjat jobba med frågan; de som har börjat är främst stora kommuner. De flesta har dock hört talas om minst en reningsteknik för läkemedelsrening. I små kommuner är ekonomi och brist på kunskap en framtida utmaning. För de flesta kommuner skulle lagstiftning och lokala politiska beslut vara de viktigaste drivkrafterna för att börja jobba med frågan. Ungefär hälften av kommunerna uppgav att de trodde man skulle börja jobba med frågan inom 15 år. / Pharmaceutical residues in the aquatic environment has been a growing concern in the last decade, and municipal wastewater treatment plants (WWTPs) are an important source of pharmaceuticals to the aquatic environment. This paper treats the question of upgrading public WWTPs with technology for reducing pharmaceutical residues in wastewater. By means of a telephone survey directed at personnel at municipal WWTPs, this report tries to conclude the position of Swedish municipalities; what work has already been done in this area, what possible motives might propel upgrading WWTPs, and challenges that might follow with it. The report also investigates whether there are any differences between municipalities that might determine whether a municipality has engaged in this area. The investigation shows that the majority of Swedish municipalities has not yet started working towards upgrading WWTPs. Those that have are mainly large municipalities. However most have heard of treatment techniques. For small municipalities economy and a lack of knowledge pose a future challenge. For most of the municipalities, legislation and local political decisions would be the most important drives towards upgrading WWTPs. About half of the municipalities in the survey thought that they might start working towards upgrading WWTPs within 15 years.
|
17 |
Nitrous oxide and nitrate in the Grand River, Ontario: Sources, production pathways and predictabilityRosamond, Madeline Simone 13 December 2014 (has links)
The increased use of synthetic nitrogen fertilizers since the early 1900s has resulted in greater food production but also problems with nitrogen pollution in freshwaters. Nitrate (NO3-) is a common pollutant in rivers and groundwater in agricultural watersheds; the drinking water limit in Canada is 10 mg N/L. Microbial processing of NO3- and ammonium (NH4+) can produce nitrous oxide (N2O), a potent greenhouse gas responsible for about 5% of the greenhouse effect. Rivers provide a complex environment, where a variety of redox conditions, available substrates and microbial populations can co-exist on small spatial and temporal scales. Therefore, many questions remain about N cycling in river environments.
N2O is produced during anoxic microbial NO3- or NO2- reduction to N2 (denitrification) and oxic microbial NH4+ oxidation to NO3- (nitrification). A significant portion (~25%) of global anthropogenic N2O is produced in rivers and estuaries, but mechanisms are not clear and predictability is poor. The United Nations Intergovernmental Panel on Climate Change (IPCC) provides default equations for calculating N2O emission estimates, in which annual NO3- loading to rivers is positively linearly related to N2O emissions. However, it is unclear how sound these linear relationships are and if measured N2O emissions are similar to IPCC estimates.
The Grand River watershed is the largest in southern Ontario. Nutrient discharge to the Grand River is high due to extensive agriculture and high urban populations. The river often has a hypoxic water column due to high community respiration in summer. However, although nitrogen pollution is significant, N cycling is not well understood in the river. This thesis shows that NO3- and NH4+ do not typically change on the diel scale, with the exception of two sites downstream of wastewater treatment plants (WWTPs). However, N2O concentration changes dramatically. N2O concentrations are higher at night and lower during the day for most sites, but are reversed at very low-nutrient sites. N2O is therefore a sensitive indicator of changes in N cycling that may not be evident from NO3- and NH4+ concentrations or stable isotope ratios. Additionally, this work shows the importance of having a sampling design that captures diel variability in N2O.
Previous work in rivers and streams worldwide focused on the appropriate N2O:NO3- ratio used to predict N2O emissions. In contrast, this thesis shows that there is a significant but very weak relationship between instantaneous N2O emissions and NO3- concentrations. However, there is a much stronger negative exponential relationship between DO and N2O. Annual N2O emissions tripled between 2006 and 2007 but NO3- masses in the river were only 10% higher, likely because river levels were lower and anoxia more prevalent in 2007. This research suggests that the IPCC needs a new conceptual model for N2O-NO3- relationships in rivers.
N2O is produced in rivers, partially due to microbial processing of NO3- and NH4+ from WWTP effluent. However, WWTP effluent may also include dissolved N2O and CH4 but this previously had not been directly quantified. It was also unclear if stable isotopic ratios of NH4+, NO3-, N2O and CH4 in WWTP effluent were distinct from river sources and could be used for effluent tracing. N2O emissions from three WWTPs in the Grand River Watershed were measured over 24 hours in summer and winter. N2O emissions were similar to direct emissions from WWTPs but CH4 emissions were about an order of magnitude lower than direct WWTP emissions. This is a previously-ignored source of N2O and CH4 to the atmosphere. While stable isotopic ranges of NO3- and NH4+ were not always distinct from river sources, ??15N-N2O, ??18O-N2O and ??13C-CH4 were distinct, making them potentially useful tracers of WWTP effluent in rivers.
N2O isotopic signatures may help determine production and removal processes in rivers, but isotopic effects of the major production pathway, denitrification, have not been characterized for river sediments. This was addressed by preparing anoxic laboratory incubations of river sediment from two sites (non-urban and urban) in the Grand River and measuring stable isotopic effects of N2O production via denitrification. Stable isotopic fractionations were similar to published values but, surprisingly, strongly negatively correlated to production rate, even though NO3- substrate was plentiful. This novel finding suggests that N2O reduction resulting in isotopic effects is more prevalent in high-substrate systems than previously thought, and that N2O reduction may be inhibited by high NO3- or NO2- or by lags in N2O reductase activity in high N2O-production incubations. This could explain why N2O emissions from the Grand River are lower than predicted by IPCC equations, which assume that N2O:(N2O+N2) ratios produced by denitrification are constant.
Concern about NO3- export to freshwater lakes and to oceans is growing, but the role of large, eutrophic rivers in removing watershed NO3- loading via denitrification and biotic assimilation is not clear. To understand how much NO3- the Grand River receives, and how much it removes annually, a NO3- isotope mass balance for the Grand River was created. The river denitrified between 0.5% and 17% of incoming NO3-, less than the 50% suggested by the IPCC. This is surprising, as the river is well mixed, has moderate to high NO3- concentrations, experiences hypoxia (promoting denitrification), and has extensive biomass (biofilm and macrophytes) that assimilate N. However, the river???s short residence time (~3 days not counting reservoirs), organic carbon-poor sediment and mineralization of organic matter could contribute to low denitrification rates. These findings suggest that denitrification rates in rivers worldwide could be lower than previously estimated.
Although error was high, most ??15N-NO3- values for losses were in the expected range for denitrification and most ??15N-NO3- values for gains were within ranges from tributaries, WWTP effluent and groundwater measured in the watershed. The model suggests that 68% to 83% of N loads to the watershed are lost before entering the Grand River, and 13% is exported to Lake Erie, leaving 5 to 19% lost in the Grand River from a combination of denitrification, assimilation and storage. These findings suggest that large rivers are much less efficient in denitrification than other locations in watersheds such as small streams, ponds, groundwater and riparian zones. They also indicate that agricultural NO3- loading is much higher than WWTP effluent, suggesting that N management strategies should focus on agricultural runoff and groundwater.
Given that N2O:NO3- relationships are weak and non-linear in the Grand River, a new conceptual model for N2O:NO3- relationships is presented. First, the Grand River dataset was supplemented with data from high-oxygen streams in southern Ontario. Regression tree analysis shows a weak relationship between NO3- and N2O in these streams with no other factors (temperature, DO, NH4+, TP, DOC, etc.) improving fit. A conceptual model was then created, which posits that N2O emission variability (between and within sites) increases with NO3- concentration when NO3- concentrations are above the threshold for NO3- limitation. The global dataset does not dispute this model, though a NO3- threshold was not clear. The lack of sites with both high NO3- and high N2O may indicate a paucity of research on eutrophic sites. Alternatively, high NO3- may indicate oxic conditions (i.e. little to no denitrification to remove it) which are incompatible with very high N2O emissions. In this case, the conceptual model can be modified such that N2O variability decreases when NO3- > ~ 4 mg N/L. The work also shows that low DO consistently results in high N2O emissions but high temperatures result in a very large range of N2O emissions. This approach allows N2O emissions, which have very high variability and are difficult to predict, to be constrained to likely ranges.
|
18 |
VA-bolags kommunikationsstrategier för att reducera oönskade utsläpp i avloppsnätet från hushållStröm, Nikolina January 2018 (has links)
p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px Helvetica} For a long time there has been a problem with unwanted emissions to sanitary systems that causes problems in pipelines, pump stations and in wastewater treatment plants and also adversely affect the quality of the sludge. The wastewater contains for example: sanitary products, hair, grease, pharmaceutical residues etc. also the purification of the wastewater requires large investments. The aim of this study was to investigate the wastewater treatment plants (WWTP) communication methods to reduce the emissions from households to wastewater treatment plants. The study was made by a literature review and an interview survey involving four WWTP: Stockholm vatten och avfall AB, Kalmar vatten AB, Vatten & Miljö i Väst AB and Laholmsbuktens VA. WWTP use several different communication methods such as websites, social media, study visits and campaigns. Because of limited time and lack of resources the WWTPs have difficulty in fulfilling the purposes of their interventions. It also depends on that the interventions are not evaluated or monitored enough. It shows in the interviews that the WWTP are not working actively with best practice and also that there is no legal requirement for WWTPs to inform households about sewage rules and requirements. WWTPs need to create better structures to their interventions and they also need to evaluate and follow up ALL interventions to make progress in the future. The study also consider that a plan for best practice need to be developed and stricter regulations which also households may be sanctioned if they violate. / Det har länge funnits ett problem med oönskade utsläpp i avlopp som orsakar problem i ledningsnät, pumpstationer och reningsverk samt påverkar slamkvaliteten negativt. Dagens sanitetssystem har begränsad kapacitet för att kunna hantera dessa föroreningar och samtidigt även bidra till att sluta kretsloppen. Det finns en del okända risker för miljön med innehållet i avloppsvattnet. Exempelvis på oönskade utsläpp i avloppsvatten är bl.a. tops, hår, hygienartiklar, fett, kemikalier, läkemedelsrester m.m. Reningsprocesserna för utsläppen kräver omfattande ekonomiska satsningar samt stora energi- och kemikaliekostnader. Vad gör egentligen VAbolagen idag för att minska på dessa utsläpp? Syftet med studien är att undersöka VA-bolags kommunikationsmetoder för att minska utsläppen från hushåll till avloppsreningsverken. Frågorna som ställs är följande: - Vilka kommunikationsvägar finns och används för att förmedla information från VAbolagen till anslutna hushåll? - Hur arbetar VA-bolag med kampanjer samt huruvida mäts effektiviteten av kampanjer? - Finns det best practice hos VA-bolagen? Studien bestod av en litteratursammanställning samt en intervjuundersökning där fyra VAbolag medverkade: Stockholms vatten och avfall AB, Kalmar vatten AB, Vatten & Miljö i Väst AB samt Laholmsbuktens VA. Syftet var att ta reda på hur de arbetar med miljökommunikation samt vilka kommunikationsmetoder de använder för att nå ut med information till anslutna hushåll och privatpersoner. I resultatet framkommer att HUR- och VAD- frågorna ligger till grund för miljökommunikation, samt att kommunikation kräver att fem punkter används för att budskap ska nå fram: vad, var, vem, hur och varför. För att skapa ett logiskt upplägg och skapa en helhet för en process bör arbetet läggas upp m.h.a. tre punkter: nulägesbeskrivning, framtidsvision samt en handlingsplan. VA-bolagen använder sig av flera olika kommunikationsvägar som ex. webbaserad hemsida, broschyrer, sociala medier, studiebesök, utskick samt kampanjer. På grund av tidsbrist och bristen på resurser lyckas inte kampanjer fylla de syften de är menade att nå. Det beror även på att kampanjerna inte utvärderas eller följs upp i tillräckligt stor utsträckning. VA bolagen anser att riktade mindre kampanjer och utskick mot rätt målgrupp är av de bättre kommunikationsmetoderna. Däremot framkommer det även att VA-bolagen inte aktivt arbetar med best practice samt att det inte finns något lagligt krav på att VA-bolagen måste informera sina användare om de regler och krav som finns. De slutsatser som kan dras är att VA-bolagen behöver skapa bättre strukturer i sina kampanjer samt att de måste utvärdera och följa upp alla insatser för att kunna göra framsteg i kommande insatser. Ett upplägg för best practice behöver tas fram för att VA-bolagen ständigt ska kunna utvecklas och hela tiden kunna jobba utefter de bästa metoderna för tillfället, utefter de resurser som tillhandahålls. Studien förordar även skärpta regelverk där inte bara verksamheter utan även hushållen kan drabbas och sanktioneras vid upptäckt av regelbrott.
|
19 |
ObservaÃÃes Sobre o FitoplÃncton de Lagoas de EstabilizaÃÃo e AvaliaÃÃo de RemoÃÃo Algal Via FlotaÃÃo com Ar Dissolvido / Observations on phytoplankton of Stabilization Ponds and Evaluation of Algal Removal Via Dissolved Air FlotationExpedito RÃmulo Amado de Oliveira 08 May 2013 (has links)
nÃo hà / A composiÃÃo, variaÃÃo semanal, e avaliaÃÃo de remoÃÃo de biomassa fitoplanctÃnica por FlotaÃÃo com Ar Dissolvido de um sistema de lagoas de estabilizaÃÃo da EstaÃÃo de Tratamento de Esgoto de Aquiraz â CE foi estudada durante o perÃodo de maio a dezembro de 2011. Analisando-se dados de eficiÃncia de remoÃÃo de SÃlidos, DQO, DBO, Turbidez, Coliformes e densidade de organismos. Qualitativamente o fitoplÃncton apresentou-se composto por 36 tÃxons especÃficos, distribuÃdos por 14 clorofÃceas, 11 euglenofÃceas, 7 cianobactÃrias, 2 bacilariofÃceas, uma criptofÃcea e apenas uma clamidofÃcea. Apesar do nÃmero de espÃcies de algas verdes, o destaque em densidadade e frequÃncia foi de Planktotrhix agardhii, espÃcie conhecida como produtora de toxinas, dominando durante todo o perÃodo estudado. Esta espÃcie foi suplantada em pouquÃssimas semanas por algas verdes cocÃides. Ocorreu decrÃscimo do nÃmero de classes entre as lagoas ao longo da pesquisa com reduÃÃo e piora da riqueza de espÃcies entre as lagoas, culminando com a concentraÃÃo de mais de 90% da composiÃÃo dos organismos pertencentes a uma Ãnica espÃcie de cianobactÃria. Cyanophyceae foram encontradas com mÃdias de 7,9x105 a 1,6 x 106 org./mL. Os resultados sÃo preocupantes no que tange à potencialidade tÃxica da espÃcie dominante e que à lanÃada no Rio Pacoti alÃm de as lagoas se comportarem como estoque de hormogÃnios e replicaÃÃo desses organismos para o ambiente. Nos ensaios de remoÃÃo, o efluente da Lagoa de MaturaÃÃo B possuÃa 5,7 x 104 ind/mL, 132 NTU de turbidez, 4,8x103 NMP de E. coli. Os testes de flotaÃÃo com ar dissolvido mostram-se promissores. ApÃs flotaÃÃo, caÃram para 291,4 org/L, 2,7 NTU, 102NMP de E. Coli/100mL. A menor eficiÃncia foi de DBO, alcanÃando mÃdias de 73%. A DQO foi removida em 80%. A flotaÃÃo teve que ser auxiliada por coagulantes. Foi removido 98% dos organismos fitoplanctÃnicos, 98,8% de coliformes e 98% da turbidez. E. coli foi reduzida em duas unidades logarÃtmicas, resultando em <600 NMP/100mL. A baixa concentraÃÃo bacteriana permite indicar, apÃs desinfecÃÃo simples, o reÃso para fins de irrigaÃÃo urbana, lavagem de automÃveis e outros usos de contato humano restrito. / The composition, weekly change, and evaluation of removal of phytoplankton biomass by Dissolved Air Flotation with a system of stabilization ponds Station Wastewater Treatment Aquiraz - EC was studied during the period from May to December 2011. Analyzing data removal efficiency of solids, COD, BOD, Turbidity, Coliform and density of organisms. Qualitatively the phytoplankton is composed of 36 specific taxa spread over 14 green algae, 11 euglenoids, 7 cyanobacteria, 2 bacilariofÃceas, 1 criptofÃcea and only one clamidofÃcea. Although the number of species of green algae, the highlight densidadade and frequency was Planktotrhix agardhii, species known as producing toxins, dominating throughout the study period. This species has been supplanted in a very few weeks a coccoid green algae. Decrease occurred in the number of classes among the ponds along the survey reduction and worsening of species richness among lakes, culminating with the concentration of more than 90% of the composition of organisms belonging to a single species of cyanobacteria. Cyanophyceae were found with averages of 7.9 x105 to 1.6 x 106 org./mL. The results are worrying regarding the toxic potential of the dominant species and is thrown into the River Pacoti plus ponds behave like stock hormogon and replication of these organisms to the environment. In tests of removal, effluent Maturation Pond had 5.7 x 104 ind / mL, 132 NTU turbidity, 4,8 x103 NMP E. coli. The flotation tests with dissolved air show to be promising. After flotation, fell to 291,4 org/L, 2.7 NTU, 102 NMP E. Coli/100mL. The lowest efficiency of BOD, reaching averages of 73%. The COD was removed at 80%. Flotation had to be helped by coagulants. Was removed 98% of the phytoplanktonic organisms, 98.8% of fecal and 98% turbidity. E. coli was reduced by two logarithmic units, resulting in <600 NMP/100mL. The low bacterial concentration allows state after simple disinfection, reuse for irrigation, urban car washing and other uses of human contact restricted.
|
20 |
ANALYSIS, OCCURRENCE, FATE AND TREATABILITY OF N-NITROSAMINES AND THEIR FORMATION POTENTIAL IN WASTEWATER TREATMENT PLANTS / 下水処理場におけるN-ニトロソアミン類と生成能の分析、存在実態、挙動および処理性能に関する研究Yoon, Suchul 26 September 2011 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第16387号 / 工博第3468号 / 新制||工||1524(附属図書館) / 29018 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 清水 芳久, 教授 伊藤 禎彦 / 学位規則第4条第1項該当
|
Page generated in 0.1344 seconds