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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Stability Study of Wastewater During Storage at Three Different Temperatures Over a Three-Day Period

Kaskel, Parker 24 May 2022 (has links)
No description available.
282

Effect of Temperature on Biogas Production in Anaerobic Treatment of Domestic Wastewater UASB System in Hammarby Sjöstadsverk.

Zhao, Chengyuan January 2011 (has links)
The upflow anaerobic sludge blanket (UASB) reactor is widely used around the world to treat variety of domestic andindustrial wastewater with three main advantages: production of biogas as renewable energy, no need of support structure for development of microorganisms and high rate treatment efficiency with low rate of biomass production. This study evaluates the effect of temperature on biogas production and CODtotal removal in Line 4-UASB system treating domestic wastewater in Hammarby Sjöstadsverk. Eight parameters were examined including the following: Influent and effluent temperature, pH, influent CODtotal, influent rate, effluent CODtotal, volatile fatty acids, biogas production rate and methane concentration. There are eight set temperature and each is stabilized for seven days. The biogas production analysis is focus on UASB 1. Temperature rising from 19°C to 35°C achieves a general benefit result in methane yield rate and CODtotal removal efficiency. The best methane yield rate and CODtotal removal rate are 0.167l/gCODtotal and 56.84% respectively at highest working temperature 33.4°C with OLR 3.072gCODtotal/(l*day) and HRT 4.2h. / Den ökande energiförbrukningen i världen och utsläpp av växthusgaser (GHG) gör det nödvändigt att söka nya hållbara energikällor för att matcha efterfrågan på energi i framtiden. Rötningsteknik med organiskt avfall som förnybar energikälla, ger biogas som i genomsnitt består av 78% CH4, 22% av CO2och spår av H2S (<0.5%), är en idealisk kostnadseffektiv metod. Den Uppåt flödande anaeroba slambäddsreaktorn(UASB) med största fördelarna: biogasproduktion som förnybar energi, hög belastning och hög behandlingseffektivitet med låg produktion av biomassa, inget behov av stödstruktur för utveckling av mikroorganismer, är den viktigaste typen för anaerobt reningssystem. Det finns flera faktorer som påverkar UASB-reaktorns prestanda, såsom temperatur, pH, HRT, Uppåtriktat flödeshastighet, OLR, SRT och VFA. I denna studie är huvudsyftet att med fokus på utvärdering av temperaturpåverkan på biogasproduktion och CODtotal avlägsnat i UASB-systemet Linje 4 som behandlar hushållsspillvatten i Hammarby Sjöstadsverk. Analysen avbiogasproduktionen fokuserades på UASB reaktor 1. Åtta parametrar övervakades för att kontrollera skick inklusive inflöde och utflöde, temperatur, pH, CODtotal inflöde, strömningshastighet för inflöde, CODtotal utflöde, flyktiga fettsyror VFA, biogasproduktionstakt och metankoncentration. Försöken utfördes vid åtta inställda temperaturnivåer och varje nivå stabiliserades i sju dagar. pH och VFA-värde var stabilt under hela försöket. Resultatetvisar att temperaturen har en större inverkan på metanavkastningen och CODtotal avlägsnat än belastningen, OLR. Då temperaturen höjs från 19°C till 35°C erhålls en större metanavkastning och större CODtotal avlägsnat. Den största metanavkastningen och CODtotal avlägsnat är 0,167l/g CODtotal respektive 56.84% vid den högsta arbetstemperaturen 33.4°C med OLR 3.072g CODtotal/(l * dag) och HRT 4.2h. Energibalansen vid olika arbetstemperaturer visaratt det finns en stor skillnad i energibehov för uppvärmning och utbyte avenergi i form av biogas. För att minska klimatpåverkan och nå balans mellan input och output av energi måste energibehovet för uppvärmning reduceras. Energiåtervinning från utflöde till inflöde liksom drift av UASB vid låg temperatur är ämnen som kan studeras vid fortsatt arbete.
283

An Examination of Hepatitis A Virus on Working Surfaces in a Waste Water Treatment Plant

Coxe, Paul Cameron January 2018 (has links)
No description available.
284

Advanced Wastewater Recycling and Phosphorus Recovery using Membrane Bioreactor and Magnesium Carbonate-based Pellets

Eghombi, Elvis A. January 2020 (has links)
No description available.
285

Moving Towards Water Security: Mitigating Emerging Contaminants in Treated Wastewater for Sustainable Reuse

Augsburger, Nicolas 04 1900 (has links)
Continuous increases in the interest and implementation of wastewater reuse due to intensified water stress has escalated the concerns of emerging contaminants. Among emerging contaminants there are microbial (antibiotic resistance) and chemical (pharmaceuticals) elements which have been shown to survive wastewater treatment. This dissertation aims to mitigate emerging contaminants by means of understanding and/or developing the appropriate disinfection strategies, with the intention to provide knowledge that would facilitate towards safe and sustainable water reuse. The first part of this thesis explored microbial risk component of antibiotic resistance. Antibiotic resistance genes are abundant in treated wastewater, and only pose a risk if taken up by potential pathogens through natural transformation. Our results showed that solar irradiation can double natural transformation rates, mediated by reactive oxygen species generation, which led to upregulation in DNA repair and competence genes in Acinetobacter baylyi ADP1. Treatment with UV-C254 nm irradiation also resulted in upregulation in DNA repair genes, nevertheless we observed a decrease in natural transformation rates. These results imply that direct damage of antibiotic resistance genes (ARG) could inhibit their spread and therefore risk, despite other factors contributing to the contrary. The next chapter in this dissertation postulated that the UV/H2O2 combination would be ideal to treat microbial and chemical emerging contaminants in effluent generated from an anaerobic membrane bioreactor. We demonstrated that at an optimal UV intensity and H2O2 concentration, we were able to achieve a 2 and 6-log reduction of the two antibiotic resistance genes and bacteria and used in this study, respectively, and more than 90% removal of the three pharmaceutical compounds. These observations suggest that UV/H2O2 has great potential in treating effluent with high nitrogen concentrations, preserving the fertilization benefit of AnMBR effluent. Overall, this dissertation revealed the potential of UV-based treatments for treated wastewater intended for reuse. Post-membrane processes effluent allows one to deploy UV-C254 nm to selectively target DNA and therefore ARB and ARG that may be still present in the treated wastewater. At the same time, coupling chemical oxidants with UV-C (i.e., UV AOP) would further enhance the means to simultaneously oxidize and degrade potentially harmful chemical contaminants.
286

Production Of Fermentable Sugars And Lipids By Microalgae From Secondarily Treated Municipal Wastewater

Liu, Jen Chao 30 April 2011 (has links)
In this paper, replacing complete or partly of growth mediums with secondarily wastewater was studied. Lipid content of Neochloris oleoabundans grown in a 0.3 X SE medium and autoclaved secondarily treated wastewater mixture was 22.27 % (w/w). The maximum biomass concentration of N. oleoabundans grown in wastewater with no additional nutrients was 0.636 g/L with 33% (w/w) glucose. Two culture lines, MA, and NA were isolated within our laboratory and could grow in secondarily treated wastewater with no additional nutrients. The maximum biomass concentration of MA in batch culture was 0.860 g/L and the sum of glucose and xylose was 40% (w/w). The maximum biomass concentration of NA was 1.562 g/l and the sum of glucose and xylose was 33.8% (w/w). The maximum specific growth rates of NA and MA were determined to be 0.0566 and 0.0337 per hour.
287

Source Apportionment of Wastewater Using Bayesian Analysis of Fluorescence Spectroscopy

Blake, Daniel B. 10 July 2014 (has links) (PDF)
This research uses Bayesian analysis of fluorescence spectroscopy results to determine if wastewater from the Heber Valley Special Service District (HVSSD) lagoons in Midway, UT has seeped into the adjacent Provo River. This flow cannot be directly measured, but it is possible to use fluorescence spectroscopy to determine if there is seepage into the river.Fluorescence spectroscopy results of water samples obtained from HVSSD lagoons and from upstream and downstream in the Provo River were used to conduct this statistical analysis. The fluorescence 'fingerprints' for the upstream and lagoon samples were used to deconvolute the two sources in a downstream sample in a manner similar to the tools and methods discussed in the literature and used for source apportionment of air pollutants. The Bayesian statistical method employed presents a novel way of conducting source apportionment and identifying the existence of pollution.This research demonstrates that coupling fluorescence spectroscopy with Bayesian statistical methods allows researchers to determine the degree to which a water source has been contaminated by a pollution source. This research has applications in determining the affect sanitary wastewater lagoons and other lagoons have on an adjacent river due to groundwater seepage. The method used can be applied in scenarios where direct collection of hydrogeologic data is not possible. This research demonstrates that the Bayesian chemical mass balance model presented is a viable method of performing source apportionment.
288

Removal Of Refractory Tkn From An Effluent Wastewater Using Sodium Ferrate

Lettie, Lucia 01 January 2006 (has links)
This research addresses refractory forms of nitrogen that, even with advanced biological nitrification-denitrification systems are not removed completely from domestic wastewater. TKN (Total Kjeldahl Nitrogen), ammonia plus organic nitrogen, is one of the forms to measure the levels of nitrogen present in effluent wastewaters. Ferrate, a strong oxidant, was used for the treatment of these nitrogen forms with the objective of producing nitrogen compounds that can be removed by subsequent biological processes. Bench-scale experiments were performed on effluent samples taken prior to chlorination from an Orlando, FL wastewater treatment facility, using a biological nutrient removal process. The samples were treated with doses of ferrate ranging from 1 to 50 mg/L as FeO4–2 under unbuffered conditions. TKN removal as high as 70% and COD removal greater than 55% was observed. The TSS production after ferrate treatment was in a range of 12 to 200 mg/L for doses between 10 and 50 mg/L FeO4-2. After an optimum dose of ferrate was determined, three bench-scale reactors were operated under anoxic conditions for 10 to 12 days, two as duplicates containing the treated effluent and one as a control with untreated sample. Two different doses of ferrate were used as optimum dose for these experiments, 10 and 25 mg/L as FeO4-2. The purpose of these reactors was to determine the potential for biological removal of remaining nitrogen after ferrate oxidation of refractory nitrogen. Treated and raw samples were analyzed for Total Kjeldahl Nitrogen (TKN) (filtered and unfiltered), chemical oxygen demand (COD) (filtered and unfiltered), total suspended solids (TSS), nitrate (NO3-N), nitrite (NO2-N), and heterotrophic plate count (HPC). As a result, more than 70% of the soluble TKN was removed by chemical and biological oxidation for a sample treated with a dose of 25 mg/L FeO4-2, and less than 50% when treated with 10 mg/L FeO4-2. For the control samples run parallel to the ferrate treated samples, a maximum of 48% of soluble TKN and a minimum of 12% was removed. A three-log increase was observed in heterotrophic bacteria numbers for both doses during the operation of the reactors. Sodium ferrate was found to be an effective oxidant that can enhance the biodegradability of recalcitrant TKN present in municipal wastewaters. As mentioned before this research was develop using batch reactor units at bench-scale, therefore it is recommended to follow the investigation of the biodegradability of recalcitrant TKN of a ferrate treated sample under continuous flow conditions so that results can be extrapolated to a full-scale treatment facility.
289

A Risk-Based Approach for Examining Vertical Separation Distances in On-Site Wastewater Treatment Sytems

Janicek, Anthony M. 17 September 2010 (has links)
No description available.
290

Treating High Salt Content Wastewater with Sand Bioreactors

Conroy, Kristen Monica 26 October 2017 (has links)
No description available.

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