Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 10 of 10 for “"Filamentous organisms"”.
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Causes and control of low F/M bulking in long sludge age nutrient removal activated sludge systems
… municipal sewage, is the prolific growth of :filamentous organisms (bulking), which inhibits the rate of sludge settling in the clarifier (secondary settling) stage of treatment and reduces plant throughput. To find the causes of :filament proliferation, a four-stage investigation was …
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A quantitative study of the relationships between morphology, physiology and geldanamycin synthesis in submerged cultures of Streptomyces hygroscopicus var. geldanus
… importance. However, most are produced by filamentous organisms which exhibit diverse growth patterns presenting challenges for industrial fermentation. There are many factors affecting secondary metabolite production which concomitantly impact on morphology, thus it is difficult to …
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The effect of a large anoxic mass fraction and concentrations of nitrate and nitrite in the primary anoxic zone on low f/m filament bulking in nutrient removal activated sludge systems
Filamentous bulking occurs when filamentous organisms are present in excessive numbers and extend from floes into the bulk solution. They interfere with the compaction and settling of the activated sludge either by producing a very diffuse floe structure or by causing bridging between floes. This …
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Modeling and microbiology of a New Zealand dairy industry activated sludge treatment plant : a thesis presented in partial fulfillment of the requirements for the degree of Master of [Technology in] Environmental Engineering at Massey University
… requires attention in the future. The dominant filamentous organisms in the sludge were identified as Type 0914, Type 0092, Nocardia pinensis, Nocardia amarae-like organisms, and Nostocoida limicola III. It was determined that these organisms were the major cause of the bulking and foaming …
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The effect of high temperatures (30 degrees Celsius) on biological nutrient removal performance
… was undertaken every four weeks to identify the filamentous organisms in the systems.
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The effect of temperature on denitrification kinetics and biological excess phosphorus removal in nutrient removal activated sludge systems in temperate climates (12°C - 20°C)
Filamentous bulking in nutrient (N & P) removal activated sludge systems is a problem of considerable magnitude - three quarters of 45 plants surveyed were found to have bulking sludges to the extent that sludge settleability (DSVI) was adversely affected. If filamentous organism proliferation …
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Operational parameters of the filamentous microbial process
… FAS process. Specifically: the settleability of filamentous sludge produced by the treatment system, the yield coefficient of the biological population, and the carbon to phosphorus ratio which limits organic removal efficiency. Findings of this study indicate that the sludges produced by the FAS …
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Physical and biological factors affecting oxygen transfer in the activated sludge wastewater treatment process
… (SV<sub>30</sub>), etc., does influence the OTE. Filamentous organisms increase the hydrodynamic radius of suspended particles, which dilates mixed liquor apparent viscosity (µ<sub>app</sub>) and impedes mass transfer. For example, an increase in the SFL from 3.8 x 10<sup>10</sup> to 2.7 x …
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The effect of the type, size, position and recycle ratio of the anoxic zone on low F/M filament bulking in nitrogen removal activated sludge systems
Filamentous bulking, which causes deterioration in sludge settleability has been shown, in two nation-wide surveys to be a problem of considerable proportions. Poor sludge settleability in the secondary clarifier limits the daily flow and load that can be treated in activated sludge wastewater …
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Factors affecting the growth of Nostocoida limicola II and other filamentous microorganisms in activated sludge systems
… responsible for the prolific growth of various filamentous microorganisms in the bulking activated sludge at the Hoechst Celanese wastewater treatment plant. First, futile attempts were made to isolate the filamentous bacterium, <i>Nostocoida limicola II</i>, from activated sludge for purposes …