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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.
221

Proměny Zahradního Města - Záběhlic očima starousedlíků / Changes of Zahradní Město - Záběhlice in lifestories of its natives

Kolářová, Dana January 2014 (has links)
The topic of this thesis is the way native inhabitants look at the changes of Zahradní Město and the old part of Záběhlice. It also describes its inhabitants' experience of these changes. The thesis employs the methodological approach of oral history, analyzing and interpreting interviews with people who were born or have spent the majority of their active life in that particular area. As a result, what comes to light is how much Zahradní Město and the old part of Záběhlice have changed over the last fifty years and, in a certain way, is changing still. It shows the evolution of a distant suburb as it came to be a part of the wider city centre of Prague, which faces typical urbanisation problems now. According to its inhabitants, Zahradní Město is best considered an independent part of Prague, even though it is officially "just" a part of Záběhlice. The mutual relationship of the inhabitants of Zahradní Město and the old part of Záběhlice is another topic of this thesis, as it tries to describe this relationship and find possible factors that have formed it. The thesis starts with an historical overview, following the way Prague was formed and divided regarding municipal administration. It then moves on to methodology, which describes the process of planning and the realization of the project...
222

Investigation of unknown groundwater flows to two leachate ponds at Hovgården / Undersökning av okända grundvattenflöden till lakdammar på Hovgården

Nordström, Katja January 2023 (has links)
The leaching of groundwater into two polishing ponds, the last step in the wastewater treatment process on Hovgarden waste facility, was examined. The focus of this study was to analyse the PFAS composition profile (fingerprint) to trace the leaching groundwater. PFASs are very persistent man-made substances, used invarious fields and have been linked to several health issues. Polishing pond data and groundwater data for ions and PFAS was collected, compiled with old data and surveyed, mainly by using principle component analysis (PCA). The results indicate that there is a water flow and a mass flow of ions to the ponds, and possibly also a flow of PFAS. The ponds appear to have a different composition, which possible could be the result of a mass flow, however the macro ion distributionis similar. Of the groundwater wells, data suggests that 18G09, P3 IN and P8 were most affected by the landfill. PFOA was the most detected PFAS, and the sampling points with the highest concentration of PFAS was 18G09, P3 IN and the first sampling point (R1) in the wastewater treatment plant. While no apparent correlation between the polishing ponds and groundwater wells were discovered,data suggest that the leaching may come from some of the wells more affected by the landfill.
223

Green Technologies and Sensor Networks for BMP Evaluation in Stormwater Retention Ponds and Wetlands.

Crawford, Anthony 01 January 2014 (has links)
The aim of this thesis is to examine and develop new techniques in stormwater Best Management Practices (BMP) for nutrient and erosion reduction and monitoring by incorporation of low impact green technologies and sensor networks. Previous research has found excessive nutrient loading of nitrogen and phosphorus species from urban stormwater runoff can lead to ecological degradation and eutrophication of receiving lakes and rivers (Fareed and Abid, 2005). In response, the Florida Department of Environmental Protection (FDEP) has set forth reduction goals as established in Total Maximum Daily Load (TMDL) reports to reduce nutrient loading and restore, or maintain, Florida water bodies to reasonable conditions. Often times current stormwater management practices are not sufficient to attain these goals and further improvements in system design are required. In order to reach these goals, affordable technologies designed for both nutrient reduction and monitoring of system performance to deepen and improve our understanding of stormwater processes are required. Firstly this thesis examines the performance of three types of continuous-cycle Media Bed Reactors (MBRs) using Bio-activated Adsorptive Media (BAM) for nutrient reduction in three retention ponds located throughout the Central Florida region. Chapter 2 examines the use of a Sloped and Horizontal MBRs arranged in a baffling configuration, whereas Chapter 3 examines the field performance of a Floating MBR arranged in an upflow configuration. Each MBR was analyzed for performance in reducing total phosphorus, soluble reactive phosphorus, total nitrogen, organic nitrogen, ammonia, nitrates + nitrites, turbidity and chlorophyll a species as measured from the influent to effluent ends of the MBR. The results of the experiments indicate that MBRs may be combined with retention ponds to provide "green technology" alternatives for inter-event treatment of nutrient species in urban stormwater runoff by use of recyclable sorption media and solar powered submersible pumps. Secondly the thesis focusses on three new devices for BMP monitoring which may be integrated into wireless networks, including a Groundwater Variable Probe (GVP) for velocity, hydraulic conductivity and dispersion measurements in a retention pond bank (Chapter 4), an affordable Wireless Automated Sampling Network (WASN) for sampling and analysis of nutrient flux gradients in retention ponds (Chapter 5), and finally an Arc-Type Automated Pulse Tracer Velocimeter (APTV) for low velocity and direction surface water measurements in retention ponds and constructed wetlands (Chapter 6). The GVP was integrated with other environmental sensing probes to create a remote sensing station, capable of real-time data analysis of sub-surface conditions including soil moisture, water table stage. Such abilities, when synced with user control capabilities, may help to increase methods of monitoring for applications including erosion control, bank stability predictions, monitoring of groundwater pollutant plume migration, and establishing hydraulic residence times through subsurface BMPs such as permeable reactive barriers. Advancement of this technology may be used by establishing additional sub-stations, thereby creating sensing networks covering broader areas on the kilometer scale. Two methods for velocity calculation were developed for the GVP for low flow (Pe < 0.2) and high flow (Pe > 0.6) conditions. The GVP was found to operate from a 26-505 cmd-1 range in the laboratory to within ±26% of expected velocities for high-flow conditions and effectively measure directional flow angles to within ±14° of expected. Hydraulic conductivity measurements made by the GVP were confirmed to within ±12% as compared to laboratory measurements. The GVP was found capable of measuring the dispersion coefficient in the laboratory, however turbulent interferences caused during injection was found to occur. Further advancement of the technology may be merited to improve dispersion coefficient measurements. Automated water sampling can provide valuable information of the spatial and temporal distribution of pollutant loading in surface water environments. This ability is expanded with the development of the WASN, providing an affordable, ease-of-use method compared to conventional automated water samplers currently on the market. The WASN was found to effectively operate by text activation via GSM cellular networks to an activation module. Propagation of the signal was distributed to collection units via XBee modules operating on point-to-point star communication using an IEEE 802.15.4 protocol. Signal communications effectively transmitted in the field during a storm event to within a range of 200 feet and collected 50 ±4 ml samples at synced timed increments. A tracer study confirmed that no mixing of samples occurs when a factor of safety of 2 is applied to flush times. This technology provides similar abilities to current market devices at down to 10% of the cost, thereby allowing much more sampling locations for a similar budget. The Arc-Type APTV is useful in establishing both low range horizontal velocity fields and expanding low range velocity measurements below detection ranges of mechanical velocity meters. Installation of a field station showed system functionality, which may be integrated with other environmental sensing probes for surface water testing. This may assist in nutrient distribution analysis and understanding the complex behavior of hydraulic retention times within wetland systems. The device was found to work effectively in both lab and field environments from a 0.02 – 5.0 cms-1 range and measure velocity within approximately ±10% of an acoustic Doppler velocimeter and within an average of ±10° of directional measurements. A drop in accuracy was measured for velocity ranges > 4.5 cms-1. The field station operated on 3G CDMA cellular network two-way communication by installation of a Raven cellular modem. Use of LoggerNet software allowed control and data acquisition from anywhere with an internet connection. This thesis also introduces brief discussions on expanding these "point" measurement technologies into sensing networks. Installation of sub-stations with communication protocols to one central master node station may broaden the sensing system into much larger kilometer-scale ranges, thus allowing large spatial analysis of environmental conditions. Such an integration into controllable sensing networks may help bridge the gap and add calibration and verification abilities between fine-resolution "point" measurements and large scale technologies such as Electrical Resistivity Tomography and satellite remote sensing. Furthermore, application of sensing networks may assist in calibration and verification of surface and groundwater models such as ModFlow, SVFlux and FEHM.
224

Chemophysical Characteristics And Application Of Biosorption Activated Media (bam) For Copper And Nutrient Removal In Stormwater Management

Jones, Jamie 01 January 2013 (has links)
For high groundwater table areas, stormwater wet detention ponds are utilized as the preferred stormwater management throughout the state of Florida. Previous research has found that accumulations of nutrients, algae, heavy metals, pesticides, chlorophyll a, fecal coliform bacteria and low concentrations of dissolved oxygen (DO) are common characteristics of stormwater wet detention ponds. Although these pollutant levels are not regulated within the ponds, states are required to compute the pollutant load reductions through total maximum daily load (TMDL) programs to meet the water quality requirements addressed by the Clean Water Act (CWA). In this study, field sampling data of stormwater ponds throughout Florida are presented to identify concentration levels of the main contaminants of concern in the discharge of wet detention ponds. Sampling was done to identify possible sources, in addition to possible removal mechanisms via the use of specific sorption media. Nutrients were found as a main problematic pollutant, of which orthophosphate, total phosphorus, ammonia, nitrate, and total nitrogen were targeted whereas heavy metals exhibited minor concerns. Accumulation of high nutrient concentrations may be mitigated by the adoption of best management practices (BMPs) utilizing biosorption activated media (BAM) to remove phosphorus and nitrogen species through physical, chemical, and biological processes. This study aims to increase overall scientific understanding of phosphorus removal dynamics in sorption media systems via Langmuir and Freundlich isotherms and column studies. The removal of phosphorus (P) was proven effective primarily through chemophysical processes. The maximum orthophosphate adsorption capacities were determined under varying conditions of the media within the columns, which were found up to 0.000534 mg-P adsorbed per gram BAM with influent concentrations of 1 mg∙L -1 orthophosphate in distilled water and 1 hour hydraulic residence time (HRT). When using iv spiked pond water under the same conditions, the adsorption capacity was increased about 30 times to 0.01507 mg-P∙g -1 BAM presumably due to the properties and concentrations of ions affecting the diffusion rate regulating the surface orthophosphate reactions. These equilibrium media uptake values (q) were used to calculate the life expectancies of the media under varying HRT and influent concentrations of treatment. Chemophysical and biological removal capabilities of the media for total nitrogen, ammonia, and nitrate were effective in columns using 1100 g of BAM. In flow-through column conditions, ammonia had a consistent ~95% removal while effluent nitrate concentrations were highly variable due to the simultaneous nitrificationdenitrification processes once an aerobic-anaerobic environment was established. Batch column experiments simulating no-flow conditions within a media bed reactor resulted in orthophosphate removals comparable with the continuous flow conditions, increased total phosphorus effluents indicative of chemical precipitation of orthophosphate, decreased ammonia removal, and increased nitrate removal. Due to a biofilm’s sensitivity to even low copper concentrations and accumulation in ponds, a copper sorption media mix of "green" materials was generated. Freundlich and Langmuir isotherm tests concluded a successful mix resulting in copper removal efficiencies up to 96%.
225

A Kinetics Study Of Selected Filtration Media For Nutrient Removal At Various Temperatures

Henderson, Elizabeth 01 January 2008 (has links)
In recent years the nutrient levels of the Upper Floridan aquifer have been increasing (USGS, 2008). An example of this is found in Ocala, Florida where Silver Springs nitrate concentrations have risen from 0.5 mg/L in the 1960 s to approximately 1.0 mg/L in 2003 (Phelps, 2004). Because stormwater is a contributor to surficial and groundwater aquifer recharge, there is an increasing need for methods that decrease nitrogen and phosphorus levels. A laboratory column study was conducted to simulate a retention pond with saturated soil conditions. The objectives of the column studies reported in this thesis were to investigate the capabilities of a natural soil and soil augmentations to remove nitrogen and phosphorus for a range of concentrations at three different temperatures. An analytical attempt to model the columns through low order reaction kinetics and derive the corresponding temperature conversion constant to relate the rate constants is also presented. The Media Mixes were selected through a process of research, preliminary batch testing and then implemented in column studies. Three columns measuring three feet in length and 6 inches outer diameter were packed with a control and two media mixes. Media Mix 1 consisted of 50% fine sand, 30% tire crumb, 20% sawdust by weight and Media Mix 2 consisted of 50% fine sand, 25% sawdust, 15% tire crumb, 10% limestone by weight. The control column was packed with natural soil from Hunter s Trace retention pond located in Ocala, Florida. The reaction rates for nitrate are best modeled as first order for Media Mix 1, and zero order for the Control and Media Mix 2. The reaction rates for orthophosphate are best modeled as zero order, second order and first order for the Control, Media Mix 1, and Media Mix 2 respectively. The best overall media for both nitrate and orthophosphate removal from this study would be Media Mix 1. Media Mix 2 does have the highest average orthophosphate removal of all the mixes for all of the temperatures; however Media Mix 1 outperforms Mix 2 for the other two temperatures. The best column for Nitrate removal is the Media Mix 1 column. The temperature conversion factors for nitrate were found to be 1.11, 1.1, and 1.01 for Media Mix 1, the Control and Media Mix 2 respectively. The temperature conversion factors for orthophosphate were found to be 1.02, 0.99, and 0.95. As well as temperature conversion factors, the activation energies and frequency factors for the Arrhenius Equation were investigated. Average values corresponding to each column, species, and temperature would be inaccurate due to the large variation in calculated values.
226

Dairy Manure Flushwater Treatment by Algae Raceway Ponds and Aerated Biofilm Reactors

Son, Darin 01 September 2020 (has links) (PDF)
Nitrogen removal technologies can help dairy industries meet their nutrient management needs. This thesis investigated two separate treatment technologies for total ammonia nitrogen (TAN) removal: algae raceway ponds and aerated biofilm reactors. Six 1000- liter algae raceway ponds and four 1000-liter tote tanks, each equipped with 10 sheets of nonwoven geotextile (i.e., thermally bonded or needle-punched) biofilm substrate, were used to treat the effluent from a flush dairy in central coastal California (TAN = 251 mg/L, cBOD5 = 204 mg/L). For the algae raceway ponds (TAN loading rate = 7 - 35 g/m³-day among 7-, 10- and 14-day hydraulic residence times (HRT)), first-order removal rate constants (k) were ~0.2 day⁻¹ in the summer and 0.1 - 0.2 day⁻¹ in the winter. Removal rate constants had no correlations (R² < 0.1) with water temperature, weak to moderate (for 7-day ponds, R² = 0.55) correlations with insolation and weak to no correlations with biomass (i.e. volatile solids) concentration. During the winter, low insolation likely inhibited algal photosynthesis and biological TAN treatment. Ponds with 7-day HRT had distinct absence of nitrate and nitrite compared to 10- and 14-day ponds. Net productivities were ~20 g/m²-day in summer and 9 – 11 g/m²-day in winter; gross productivities were 120 – 160 g/m²-day in summer and 77 – 150 g/m²-day in winter. Productivities had no correlations (R² < 0.1) with water temperature and weak to moderate correlations (for 14-day ponds, net productivity R² = 0.56, gross productivity R² = 0.83) with insolation. Analysis of organic compounds in pond effluent showed dissolved volatile solids (~2300 mg/L) were mostly non-biodegradable (~98% of soluble oxygen demand). Dissolved organic nitrogen concentrations in the pond effluent were ~35 mg/L. For the aerated biofilm reactors, tanks with needle-punched geotextiles had greater first- order TAN removal rate constants (0.69 day⁻¹) than tanks with thermally bonded geotextiles (0.23 day⁻¹) while operating in batch mode. Needle-punched geotextile reactor also accumulated sludge faster and had higher attached to water column biomass (i.e. volatile solids) ratios (~0.08 g VS/g VS) than thermally bonded geotextile reactor (~0.04 g VS/g VS). Among the four tanks, mass of attached biomass was 150 – 340 g per tank while mass of biomass in the water column was 3290 – 5430 g per tank. Comparing the two treatment technologies, aerated biofilm reactors (removal = 64 – 77%, k = 0.2 – 0.3 day⁻¹, removal rate = 36 – 43 g-N/m²-day, 16 – 19 g-N/m³-day) had more removal and faster removal rates per square meter of land footprint compared to the algae raceway ponds (removal = 38 – 77%, k = 0.1 – 0.2 day⁻¹, removal rate = 4 – 5 g- N/m²-day, 13 – 17 g-N/m³-day), likely due to direct application of aerators in the reactors.
227

Situation of wastewater treatment of natural rubber latex processing in the Southeastern region, Vietnam: Review paper

Nguyen, Nhu Hien, Luong, Thanh Thao 13 November 2012 (has links)
Rubber tree is one of the main plants which play an important role in the economy of Southeastern region, Vietnam. Approximately 90% of Vietnamese natural rubber latex is exported as raw products. The preliminary process of natural rubber latex discharges a large amount of wastewater to the environment. In Vietnam, there are many available technologies set up and operated for treatment wastewater of rubber latex processing. However, the effluent quality is still poor and the concentration of pollutants is higher than the required national technical regulation on the effluent of the natural rubber processing industry (QCVN 01:2008/BTNMT). Thus, this paper summarizes various technologies and methods currently applied for the treatment of latex processing wastewater in Vietnam. Additionally, the new effective methods being researched and applied in Thailand and Malaysia are also mentioned (countries with the highest production of natural rubber in the world). This paper also provides a screening of treatment technologies for reducing environmental pollution and contributing to high-quality effluent for meeting the required standard. / Cao su là một trong những cây trồng chính và đóng vai trò quan trọng trong nền kinh tế của miền Đông Nam Bộ, Việt Nam. Sản phẩm từ cây cao su thiên nhiên tại Việt Nam chủ yếu là xuất khẩu (khoảng 90%), tuy nhiên chỉ mới là dạng cao su thiên nhiên sơ chế. Quá trình sơ chế mủ cao su thiên nhiên thải bỏ một lượng lớn nước thải vào môi trường. Ở Việt Nam, hiện tại có rất nhiều công nghệ xử lý nước thải sơ chế mủ cao su đã được thiết lập và vận hành. Tuy nhiên, nồng độ ô nhiễm trong nước thải sau quá trình xử lý còn cao so với tiêu chuẩn yêu cầu (QCVN 01:2008/BTNMT). Vì vậy, bài báo này tóm tắt những công nghệ và phương pháp khác nhau được sử dụng để xử lý nước thải sơ chế mủ cao su tại Việt Nam gần đây. Thêm vào đó, những phương pháp mới và hiệu quả đang được nghiên cứu và áp dụng tại Malaysia và Thái Lan, những quốc gia có sản lượng sản xuất mủ cao su cao nhất trên thế giới cũng được giới thiệu. Bài báo này cũng cung cấp sự đa dạng của những phương pháp xử lý nhằm giảm thiểu ô nhiễm môi trường và góp phần đảm bảo chất lượng nước đầu ra đạt tiêu chuẩn cho phép.
228

Methane dynamics of a northern boreal beaver pond

Dove, Alice E. January 1995 (has links)
No description available.
229

INVENTORY OF STORMWATER MANAGEMENT PRACTICES IN THE CITY OF OXFORD, OHIO

Kitheka, Bernard M., Mr. 25 May 2010 (has links)
No description available.
230

Evaluation of the flue gas desulfurization mine seal and sedimentation pond at Broken Aro Mine Reclamation Site located in Coshocton County, Ohio

Thomas, Jed H. January 2001 (has links)
No description available.

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