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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.

Biodegradation of toxic wastes by immobilized microorganisms

Livingston, Andrew Guy January 1989 (has links)
No description available.

The Extractive Membrane Bioreactor : flux enhancement and biofilm control

Strachan, Laura Fay January 1997 (has links)
No description available.

Assessing the resistance and bioremediation ability of selected bacterial and protozoan species to heavy metals in metal-rich industrial wastewater

Kamika, I, Momba, MNB 13 February 2013 (has links)
Heavy-metals exert considerable stress on the environment worldwide. This study assessed the resistance to and bioremediation of heavy-metals by selected protozoan and bacterial species in highly polluted industrial-wastewater. Specific variables (i.e. chemical oxygen demand, pH, dissolved oxygen) and the growth/dieoff- rates of test organisms were measured using standard methods. Heavy-metal removals were determined in biomass and supernatant by the Inductively Couple Plasma Optical Emission Spectrometer. A parallel experiment was performed with dead microbial cells to assess the biosorption ability of test isolates.

Impacts of industrial water composition on Salicornia in a hydroponic system

Schmitz, Erica Ann January 1900 (has links)
Master of Science / Department of Biological and Agricultural Engineering / Stacy L. Hutchinson / The energy sector needs to transition to renewable energy to provide energy and economic security in the future (Murray & King, 2012). Liquid biofuels are an important renewable fuel in this transition because they are the preferred renewable energy source in the transportation sector (Lange, 2007), and the only renewable energy alternative for the aviation industry [International Air Transport Association (IATA), 2015]. Biofuels produced from food crops (first-generation biofuels) are being produced at an industrial scale, but they create several environmental and social conflicts (Mohr & Raman, 2013). Currently, there is a demand for the next generation of biofuels to resolve the environmental and social conflicts associated with first-generation biofuels. Salicornia, a salt tolerant oil seed crop (Panta et al., 2014), is one feedstock that might be able to resolve some of those conflicts because it can be irrigated with saline water (Warshay et al., 2017). The ability of Salicornia to tolerate saline environments suggests that it might be able to be cultivated in a hydroponic system designed to treat industrial wastewater. A hydroponic system designed to treat industrial wastewater and produce Salicornia as a biofuel feedstock could prevent some of the detrimental effects of industrial sources of saline water on terrestrial and aquatic ecosystems (Gerhart et al., 2006), and produce a feedstock that resolves some of the issues with first-generation biofuels. The first step in the development of the proposed hydroponic system is to determine if Salicornia can be cultivated with industrial wastewater in a hydroponic system. Studies were conducted with two sources of industrial wastewater, Flue Gas Desulfurization (FGD) wastewater and Cooling Tower Blowdown Water (CTBW), to determine how the composition of water affects the germination, survivability, early seedling growth, and lignocellulosic composition of Salicornia. The composition of water was shown to have no effect on seed germination and visual signs of phytotoxicity. These studies found that full strength CTBW and 20% FGD wastewater could be used to cultivate Salicornia in a hydroponic system if nutrients are added. Full strength FGD wastewater was shown to have a negative impact on seedling growth. These studies also found that Salicornia is not a good lignocellulosic biofuel feedstock because of its low lignocellulosic composition (e.g. 14.9-9.1% glucan, 13.2-6.7% xylan, 5.2-2.4% arabinan, and 9.8-6.2% lignin). However, a large percentage of the extractives content is unidentified and could have a monetary value. Additional research is needed to determine if a hydroponic system that cultivates Salicornia is able to provide any water quality treatment.

Ceramic membrane nanofiltration for industrial wastewater treatment – a comparison with conventional polymer membranes & data-driven modeling of organic compounds removal

Agnihotri, Satyam January 2020 (has links)
Industrial wastewater treatment using conventional treatment technologies is becoming challenging day-by-day due to presence of ‘newer’ refractory compounds, lower treatment efficiencies and stricter environmental laws. Combination of conventional treatment techniques with modern treatment technologies like membrane filtration or advanced oxidation processes (AOPs) has shown promise in achieving high efficiencies. In this work we have worked towards development of a membrane nanofiltration unit to treat coagulation-flocculation pretreated IWW from a specialized treatment facility. More specifically, state-of-the-art TiO2 ceramic NF membranes with low molecular weight cut off (MWCO) (200, 450, 750, 8500 Da) purchased from Inopor Gmbh were tested on 6 different IWW samples due to their superior chemical stability, higher flux and high fouling resistance along with 3 commercial polymer NF membranes (NF90, NFX, NFS) for comparison purposes. Additionally, wastewater characterization dataset including composition analysis using Gas-chromatography Mass-spectroscopy (GC-MS) is leveraged to build data driven models for membrane performance prediction. ‘200 Da’ ceramic NF membrane was able to reject significant COD with an average rejection of 77% and 60% for two IWW samples with permeate flux between 5-15 LMH at 100-120 psi trans-membrane pressure (TMP). ‘200-Da’ membrane was also found to achieve more flux than ‘450 Da’ membrane while rejecting more COD at the same time. ‘200 Da’ membrane also showed lower flux decline than polymer membranes. Additionally, the ceramic NF membranes were found to be easily chemically cleanable restoring wastewater flux after fouling. Since polymer NF membranes were found to reject at higher COD rejection efficiencies (60-90%) and permeate flux, further improvement in ceramic membranes is needed to treat at higher efficiencies. 200 Da, NF90 and NFX membranes were found to be promising to reduce COD below target (600 mg/L) and should be studied further for this application. / Thesis / Master of Applied Science (MASc) / Conventional technologies for Industrial wastewater (IWW) treatment include biological treatment, coagulation, flocculation, adsorption and filtration. Many industries produce IWW with high concentration of biologically toxic organics ruling out the option of biological treatment. Moreover, with stricter regulatory laws in place for effluent discharge, adoption of new treatment technologies is needed. Nanofiltration (NF) is one such treatment technology that has seen a lot of growth in the past decade since its advent in 1980s. Polymer nanofiltration has been successfully used in applications such as dye removal in textile industry, as a pre-treatment method in desalination plants, for organic solvent nanofiltration in pharmaceutical industry and many more. More recent development of ceramic nanofiltration membranes has seen a lot of interest from researchers around the world due to their superior physical and chemical robustness, fouling resistant properties and higher permeability as compared to polymer NF membranes, though only a small amount of ceramic NF membranes are applied in industrial projects. To this end, we have conducted laboratory scale testing of 4 state of the art ceramic NF membranes on multiple real industrial wastewater samples collected from a specialized IWW treatment plant, along with 3 polymer NF membranes for comparison purposes. Additionally, a data-driven modeling approach leveraging the wastewater composition dataset is shown. The models can be used to predict % rejection of an unseen compound based on its chemical properties and provide insights into complex interactions between compounds and the membrane.

The interactions of toluic acid with indigenous microbial populations in a model Gravel Bed Hydroponic system

Fuller, Robert A. January 1996 (has links)
No description available.

Characteristics of a developing biofilm in a petrochemical wastewater treatment plant

Perera, Kuruppu Arachchige Kalyani, University of Western Sydney, College of Science, Technology and Environment, School of Science, Food and Horticulture January 2003 (has links)
A study was undertaken to investigate developing biofilms in a petrochemical wastewater treatment plant encompassing the architecture, microflora and the chemical nature of the matrix. Biofilms were developed on glass slides immersed in the activated sludge unit and analysed at known time intervals using a range of techniques. Initially, biofilms were investigated using conventional and emerging microscopic approaches to select a suitable technique. Scanning Confocal Laser Microscopy (SCLM) allowed visualisation of biofilms in situ with minimal background interference and non-destructive and optical sectioning which were amenable to quantitative computer-enhanced microscopy. SCLM was superior over Light microscopy and Scanning Electron Microscopy. This study demonstrated biofilm growth, presence of extracellular polymer substances (EPS) in early biofilms associated with cells and the development of porous nature of mature biofilms including channel-like structures. Overall new information has been obtained on developing biofilms in an Australian petrochemical wastewater treatment plant / Doctor of Philosophy (PhD) (Biological Sciences)

Development of an electrochemical primary treatment for hexahydro-1,3,5-trinitro-1,3,5-triazine laden wastewater

Johnson, Jared Lynn 08 August 2009 (has links)
This thesis explores the development of direct electrochemical reduction as a means of providing primary treatment of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in a manufacturing process waste stream. An industrial process wastewater laden with RDX was successfully treated in small batch reactors. Reaction kinetics were used to design a proof of concept bench scale flow reactor that utilized parallel packed electrode plates. Following successful testing of this reactor, a pilot scale packed electrode flow reactor was built. The reactor performance as a function of residence time was fit by a first order decay equation. Greater than 97% reduction of RDX in a process wastewater was observed at a reactor residence time of 27 minutes. The work presented herein was successful in creating an electrochemical treatment system capable of removing RDX from an industrial process waste stream with no chemical addition, and without creating an additional hazardous waste stream.

Performance Evaluation of Treating Optoelectronic Industrial Wastewaters by a Simultaneous Electrocoagulation/Electrofiltration Process Using Multi-Tubular TiO2/Al2O3 Composite Membranes

Yen, Chia-Heng 27 August 2008 (has links)
Water is essential for life as well as industrial growth. Therefore, this research is mainly to explore the treatment capacity of LCD (Liguid Crystal Display) industrial wastewater recycling by a simultaneous electrocoagulation/electrofiltration (EC/EF) process using laboratory-prepared multi-tubular TiO2/Al2O3 composite membranes. First, tubular membrane supports of Al2O3 were prepared by the extrusion method. Then the slip composed of nanoscale TiO2 (prepared by sol-gel process) was applied on the aforementioned tubular membrane supports by the dip-coating method, followed by sintering to obtain tubular TiO2/Al2O3 composite membranes. Then, two types of LCD industrial wastewaters (designated TFT-LCD wastewater and STN-LCD wastewater, respectively) from different LCD fabrication plants were treated by EC/EF process using TiO2/Al2O3 composite membranes. Moreover, the permeate qualities were evaluated under the recirculation-mode operation. In addition, the effects of different operating parameters (i.e., electric field strength, trans-membrane pressure, and crossflow velocity) on membrane flux and permeate quality were evaluated. Relations of the water quality and the different operation modes (i.e., the recirculation mode, flow-through mode, and secondary treatment mode) were also discussed. Finally, the effects of changing the backwash time and backwash cycle on membrane flux were investigated. In the recirculation mode, both kinds of wastewater achieved a satisfactory organics and anion removal. An average of about 90¢H of COD (Chemical Oxygen Demand) and TKN (Total Kjeldahl Nitrogen) could be removed. For anions (i.e., NO3¡Ð, NO2¡Ð, Cl¡Ð and SO42¡Ð), their removal efficiencies were all over 90%. Furthermore, TOC (Total Organic Carbon) and turbidity also had removal efficiencies of over 98%. When the operation mode was changed from the recirculation mode to flow-through mode, the changes of permeate quality were not obvious. But the cumulative quantity of permeate of the flow-through mode was greater than that of the recirculation mode. As for the experimental result of the secondary treatment mode, the permeate qualities were found to be improved. In this case, an average removal of over 95% of NO3¡Ð, NO2¡Ð, Cl¡Ð, and SO42¡Ð could be obtained. According to experimental results shown above, the treated water could be recycled and reused as the cooling tower make-up water if its pH and conductivity values were reduced. However, these problems could be easily resolved by proper adjustments of pH. Overall speaking, the tubular TiO2/Al2O3 composite membranes and simultaneous EC/EF treatment module employed in this work are capable of treating LCD industrial wastewater for the purpose of reclamation.

Study on Effective Adsorption Conditions for Perfluorinated Compounds (PFCs) Removal in Municipal and Industrial Wastewaters in Thailand and Japan / タイ王国および日本における下水および産業廃水中のペルフルオロ化合物類の効率的吸着条件に関する研究

Pattarawan Chularueangaksorn 24 September 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(地球環境学) / 甲第17932号 / 地環博第111号 / 新制||地環||22(附属図書館) / 30752 / 京都大学大学院地球環境学舎環境マネジメント専攻 / (主査)教授 藤井 滋穂, 教授 伊藤 禎彦, 准教授 田中 周平 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DFAM

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