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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.
351

A Review of Reclaimed Water for Irrigation Use in an Urban Watershed

Rivera, Anamarie Elizabeth 04 November 2016 (has links)
It is well established that converting wastewater, a point-source of pollution, into reclaimed water makes management of nutrients more difficult. Not all service lines measure the volume of reclaimed water used by a customer, and frequently there are no restrictions on the amount of reclaimed water that is used. Nutrients applied in excess have the potential to runoff or leach through soils and contaminate surface and groundwater resources. This research attempted to determine if corresponding surface water quality monitoring sites in reclaimed service areas reflect elevated total nitrogen (TN) and total phosphorous (TP) concentrations. The Joe’s Creek Watershed in Pinellas County, FL is a highly urbanized watershed with one wastewater plant providing tertiary treatment for reclaimed water (Pinellas County Utilities Dept.) and another wastewater plant providing secondary treatment (City of St. Petersburg Water Resources Dept.). This research reviewed concentrations of TN and TP in the reclaimed water effluent for each wastewater treatment plant and at four tributary sites in the Joe’s Creek Watershed. One tributary site, Bonn Creek, is in the tertiary treated service area, another tributary site, Miles Creek, is in the secondary treated service area, and a third tributary, Joe’s Creek, provides two control sites which are both outside of reclaimed service areas. Based on the results of comparisons and statistical analyses of the 6-year period, the TN and TP concentrations of reclaimed water from the City of St. Pete Wastewater Treatment Plant (WWTP) far exceed those of the Pinellas County WWTP. The TN concentration in the reclaimed effluent from St. Pete was nine times higher than that of Pinellas County. The TP concentration was almost five times higher at St. Pete than Pinellas County. The sites within reclaimed service areas had higher concentrations of TN and TP when compared to the control sites for the same period. Miles Creek recorded the highest mean concentrations of TN and TP of the four monitoring sites. Bonn Creek recorded the second highest mean concentrations of TN and TP. Rainfall data were reviewed and results show that several monitoring dates for Miles Creek and Bonn Creek had elevated TN and TP concentrations which coincided with periods of rainfall deficit. These and other results of this research indicate a need to reconsider minimum wastewater treatment levels in urban environments in an effort to reduce nutrient pollution, as well as a need to expand watering restrictions and enforcement, and expand education of consumers about reclaimed water.
352

Tratamento de águas oleosas com alto grau de emulsificação e presença de sólidos de baixa densidade utilizando fad

Santana, Renata Kelly de Lima 20 November 2017 (has links)
Submitted by Biblioteca Central (biblioteca@unicap.br) on 2018-11-20T18:51:24Z No. of bitstreams: 2 renata_kelly_lima_santana.pdf: 1101025 bytes, checksum: a6b7adb81731f8710c249fee6ad58062 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-11-20T18:51:24Z (GMT). No. of bitstreams: 2 renata_kelly_lima_santana.pdf: 1101025 bytes, checksum: a6b7adb81731f8710c249fee6ad58062 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-11-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / A methodology was developed for the treatment of an effluent from the metalworking industry composed of water, cutting fluid and graphite. The recovery of components from an effluent from the machining process becomes complex due to the coexistence of solids such as graphite, mixed with a water-oil emulsion. Due to the use of graphite in very small particles and emulsified in water with the aid of an emulsifier, distributing in both phases (aqueous and organic), making the treatment process difficult. In general, treating such an effluent requires, in the preliminary step, the breaking of the emulsion so that the graphite dispersed in the liquid medium is recovered. The treatment was initially performed in a prototype phase separation in laboratory scale, counting on recirculation tanks, pumps, hydrocyclones and continuous decanter. In an initial stage the effluent was acidified by the addition of sulfuric acid PA as a way of breaking the solid-liquid emulsion. Subsequently, the solid phase was reered with the aid of a hydrocyclone, resulting in an overflow of the equipment of a mixture of water and residual oil. The mixture of part of the water and the water-cutting fluid, after acid destabilization of the emulsion, was separated into the continuous decanter, giving rise to a stream of cutting fluid and an aqueous phase containing residual oil, contaminated by about 130 ppm Of organic phase. The aqueous phase was then subjected to a dissolved air flotation (FAD) process, aided by a demulsifying biosurfactant in a FAD prototype, also on a laboratory scale. In order to define adequate conditions to obtain an aqueous phase with contamination level that allowed its return to the process, the operational conditions of application of the FAD technique were determined with the aid of an experimental design of the type rotational central compost (CDCR). At the end of the aqueous phase recovery process, a residual oil content of 12% was obtained, below that required by the Brazilian environmental regulatory agency (CONAMA) for discharge in water bodies, which is 20 ppm. The recoveries of graphite and cutting fluid are suggested studies for the next works. / Foi desenvolvida uma metodologia para tratamento de um efluente da indústria metalmecânica composto de água, fluido de corte e grafite. A recuperação de componentes de um efluente do processo de usinagem torna-se complexa devido à coexistência de sólidos como o grafite, misturado a uma emulsão do tipo água-óleo. Devido ao uso do grafite em partículas muito pequenas e emulsionado em água com auxílio de um emulsificante, distribuindo-se em ambas as fases (aquosa e orgânica), dificultando o processo de tratamento. De modo geral o tratamento de um efluente desse tipo exige, na etapa preliminar, a quebra da emulsão para que seja recuperado o grafite disperso no meio líquido. O tratamento foi inicialmente realizado em um protótipo de separação de fases em escala de laboratório, contando com tanques de recirculação, bombas, hidrociclones e decantador contínuo. Numa etapa inicial o efluente foi acidificado através da adição de ácido sulfúrico PA como forma de quebrar a emulsão sólido-líquido. Posteriormente, foi recuperada a fase sólida com auxílio de um hidrociclone, dando origem a uma descarga pelo overflow do equipamento de uma mistura de água e óleo de corte residual. A mistura de parte da água e do água-fluido de corte, após a desestabilização ácida da emulsão, foi separada no decantador contínuo, dando origem a uma corrente de fluido de corte e uma fase aquosa contendo óleo residual, contaminada por cerca de 130 ppm de fase orgânica. A fase aquosa foi então submetida a um processo de flotação por ar dissolvido (FAD), auxiliada por biossurfactante desemulsificante em um protótipo FAD, também em escala de laboratório. Para definir condições adequadas à obtenção de uma fase aquosa com nível de contaminação que permitisse seu retorno ao processo, as condições operacionais de aplicação da técnica de FAD foram determinadas com auxílio de um planejamento experimental do tipo Delineamento Compost Central Rotacional (DCCR). Ao final do processo de recuperação da fase aquosa foi obtido um teor óleo residual de 12 %, abaixo do exigido pelo órgão brasileiro de regulamentação ambiental (CONAMA) para descarte em corpos hídricos, que é de 20 ppm. As recuperações do grafite e do fluido de corte são estudos sugeridos para os próximos trabalhos.
353

Návrh využití šedých vod v plaveckém areálu Kraví hora s ohledem na dostavbu wellness centra / Proposal for the use of gray water in the swimming area "Kraví hora" with a view to completion of the wellness center

Běloušková, Pavla January 2013 (has links)
Greywater is the leftover water from baths, showers, hand basins and washing machines only, what implies that it is free of faeces and urine. Greywater can be recycled as processing water (whitewater) for toilet and/or urinal flushing or landscape irrigation. Energy recovery from greywater looks also very promising. The subject of this thesis is short research on the issue of the use of greywater in the first part, the following chapter provides examples of the use of greywater in practice. Practical part of thesis provides suggestion of use of greywater and their heat potential in swimming area Kraví hora with regard to completion of wellness centre. This part also includes economical analysis of suggested recycling.
354

Fireproofing the Lawn: Reclaimed Water and Polybrominated Diphenyl Ethers in Tampa Bay

Davis, Ryan C 30 October 2009 (has links)
Reclaimed water has increased in popularity as a means to recycle water and thus decrease the amount of wasteful water use. This process is widely used in Tampa Bay for watering of lawns. This increase in popularity and use has raised questions as to what contaminants are in the reclaimed water. The purpose of this study was to analyze reclaimed water for contaminants believed to be detrimental to health and conduct interviews to ascertain perceptions of risk in the local population. As water reuse grows in popularity further research will need to be conducted to address potential human health concerns. This research shows that there are potential health concerns related to reclaimed water when we use dioxin as a surrogate compound. Additionally, the research shows that local governments aren't doing enough to communicate information to local communities. Any policy that moves forward in regards to supplementing drinking water with reclaimed water must incorporate local communities in the decision making process. Decisions made in the absence of information can be misguiding and the first feedback of these decisions is felt by local communities. With their input in the beginning, throughout the decision making process, and during the evaluation period, new information will be generated. The incorporation of the community in the decision making process will make the reclaimed for drinking water initiative, more successful.
355

Identifying Untapped Potential: A Geospatial Analysis of Florida and California’s 2009 Recycled Water Production

Archer, Jana E., Luffman, Ingrid, Joyner, T. Andrew, Nandi, A. 01 June 2019 (has links)
Increased water demand attributed to population expansion and reduced freshwater availability caused by saltwater intrusion and drought, may lead to water shortages. These may be addressed, in part, by use of recycled water. Spatial patterns of recycled water use in Florida and California during 2009 were analyzed to detect gaps in distribution and identify potential areas for expansion. Databases of recycled water products and distribution centers for both states were developed by combining the 2008 Clean Water Needs Survey database with Florida’s 2009 Reuse Inventory and California’s 2009 Recycling Survey, respectively. Florida had over twice the number of distribution centers (n 1/4 426) than California (n 1/4 228) and produced a larger volume of recycled water (674.85 vs. 597.48 mgd (3.78 mL/d1/4 1 mgd), respectively). Kernel Density Estimation shows the majority of distribution in central Florida (Orlando and Tampa), California’s Central Valley region (Fresno and Bakersfield), and around major cities in California. Areas for growth were identified in the panhandle and southern regions of Florida, and northern, southwestern, and coastal California. Recycled water is an essential component of integrated water management and broader adoption of recycled water will increase water conservation in water-stressed coastal communities by allocating the recycled water for purposes that once used potable freshwater.
356

Process Integration: Unifying Concepts, Industrial Applications and Software Implementation

Mann, James Gainey 29 October 1999 (has links)
This dissertation is a complete unifying approach to the fundamentals, industrial applications and software implementation of an important branch of process-engineering principles and practice, called process integration. The latter refers to the system-oriented, thermodynamically-based and integrated approaches to the analysis, synthesis and retrofit of process plants, focusing on integrating the use of materials and energy, and minimizing the generation of emissions and wastes. This work extends process integration to include applications for industrial water reuse and wastewater minimization and presents previous developments in a unified manner. The basic ideas of process integration are: (1) to consider first the big picture by looking at the entire manufacturing process as an integrated system; (2) to apply process-engineering principles to key process steps to establish a priori targets for the use of materials and energy, and for the generation of emissions and wastes; and (3) to finalize the details of the process design and retrofit later to support the integrated view, particularly in meeting the established targets. Pinch technology is a set of primarily graphical tools for analyzing a process plant's potential for energy conservation, emission reduction and waste minimization. Here, we identify targets for the minimum consumption of heating and cooling utilities, mass-separating agents, freshwater consumption, wastewater generation and effluent treatment and propose economical grassroots designs and retrofit projects to meet these goals. An emerging alternative approach to pinch technology, especially when analyzing complex water-using operations and effluent-treatment systems, is mathematical optimization. We solve nonlinear programming problems for simple water-using operations through readily available commercial software. However, more complex, nonconvex problems require sophisticated reformulation techniques to guarantee optimality and are the subject of continuing academic and commercial development. This work develops the principles and practice of an environmentally significant breakthrough of process integration, called water-pinch technology. The new technology enables the practicing engineers to maximize water reuse, reduce wastewater generation, and minimize effluent treatment through pinch technology and mathematical optimization. It applies the technology in an industrial water-reuse demonstration project in a petrochemical complex in Taiwan, increasing the average water reuse (and thus reducing the wastewater treatment) in the five manufacturing facilities from 18.6% to 37%. This dissertation presents complete conceptual and software developments to unify the known branches of process integration, such as heat and mass integration, and wastewater minimization, and explores new frontiers of applications to greatly simplify the tools of process integration for practicing engineers. / Ph. D.
357

Fabrication of Lab-Scale Polymeric and Silicon Dioxide Nanoparticle-Enabled Thin Film Composite Reverse Osmosis Membranes for Potable Reuse Applications

Dinh, Timothy J 01 August 2022 (has links) (PDF)
Reverse osmosis (RO) is widely used for water reclamation and is one of the most feasible technologies for addressing water scarcity around the world. RO membrane fabrication procedures are continually being optimized and modified to enhance the treatment performance and efficacy of the RO process. A review of the existing literature published on membrane fabrication revealed that a detailed and reproducible methodology consistent among prior studies was not available. Therefore, the primary objective of this study was to utilize techniques from prior research to develop a reliable lab-scale membrane fabrication process for studying the potable reuse applications of TFC RO membranes. Phase inversion was used to create a polysulfone (PSF) support layer on a non-woven fabric sheet. Then, the process of interfacial polymerization (IP) between amine and acyl chloride monomers was utilized to form a highly selective and ultrathin polyamide (PA) layer on the PSF support surface. The resulting membrane composition and performance was dependent on a wide range of parameters during the fabrication process. The optimal support materials, reactant types and concentration, and reaction conditions were determined through trial and error. The best performing membranes utilized N-methyl-2-pyrrolidone (NMP) as the solvent, Novatexx-2471 non-woven fabric for mechanical support, and 15 wt% PSF concentration for phase inversion. The optimal immersion duration was five minutes for the aqueous amine monomer solution during the IP process. The flux for membrane triplicates was 20.2  3.6 liters per square meter per hour (LMH) while the salt rejection was 96.8  2.0%. The relatively low standard deviation for flux and salt rejection indicates that the fabrication method developed herein is consistent. A commercial Dow Filmtec BW30 flat sheet PA-TFC RO membrane was tested for comparison and exhibited a flux of 44.9 LMH and a salt rejection of 98.5%. Thus, the membranes developed in this study achieved salt rejection on par with commercial membranes but exhibited a flux that was significantly lower. Furthermore, this study investigated modifications to the traditional TFC membrane using engineered silica nanomaterials with the goal of enhancing the membrane flux while maintaining high salt rejection. Two types of nonporous silicon dioxide nanoparticles (SDNPs), non-functionalized and amine functionalized, were dispersed in the aqueous and organic IP solutions. Ultrasonication of the non-functionalized SDNPs in the aqueous solution was observed to produce the most stable dispersion. Compared to the unmodified TFC membranes, the average flux of the SDNP-modified (TFC-NP) RO membrane triplicates was higher at 25.4  2.0 LMH with 0.1% (w/v) SDNPs incorporated in the PA layer. The salt rejection was lowered to 92.3  0.1% for the TFC-NP membranes. In addition, the membranes fabricated in this study were characterized using scanning electron microscopy (SEM), Fourier Transport Infrared Spectroscopy (FTIR), atomic force microscopy (AFM), and goniometry measurements. SEM images showed that the TFC-NP membranes contained larger spaces between ridges and valleys of the PA pore structure. FTIR confirmed the PA layer formation on the membranes fabricated herein but a spectral peak from the SDNPs was not observed for the TFC-NP membranes. AFM measurements indicated an increase in surface roughness of the modified membranes, likely because of the incorporation of SDNPs. The surface of TFC-NP membranes was found to be more hydrophilic than the unmodified TFC membranes based on contact angle measurements. Further optimization of the fabrication method developed herein is warranted before pursuing additional RO research topics, such as the disinfection byproduct precursor removal of TFC membranes.
358

Anaerobic/aerobic degradation of a textile dye wastewater

Loyd, Chapman Kemper 04 August 2009 (has links)
Consumer demands have led to the development of new, more stable textile dyes. These dyes, many of the azo type, are often incompletely degraded/removed in wastewater treatment plants, leading to the discharge of highly colored effluents to rivers and streams. Concerns by downstream users of that water have led to enactment of effluent color and toxicity standards for plants that treat textile dye wastewater. Both anaerobic and aerobic biological degradation of azo dyes have been reported in the literature; the rate and extent of degradation is often quite dye-specific. This research utilized laboratory-scale reactors to investigate the effectiveness of those treatments, both singly and in combination, on two azo dye wastewaters: a textile dyeing and finishing process water and a municipal wastewater consisting predominately of textile dyeing and finishing mill effluents. / Master of Science
359

Drivers and Barriers to Circular Water Economy Implementation in Ohio

Hull, MacKenzie S. January 2022 (has links)
No description available.
360

Wash Water Quality Characterization from Transportation Maintenance Facilities in Ohio During Winter Operations

Sullivan, Sarah E. 17 September 2014 (has links)
No description available.

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