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.
Results
Showing 1 to 18 of 18 for “"anoxic/aerobic"”.
-
Measurement of ordinary heterotroph organism anoxic yield in anoxic-aerobic activated sludge systems
… heterotrophic organism (OHO) cell yield under anoxic conditions relative to its value under aerobic conditions for municipal sewage. In this regard, three primary objectives were identified: 1. Determine the ratio Y H,No: Y H,AE for real sewage in terms of electron acceptor (i.e. nitrate and …
-
The removal of nitrogen and phosphorus in anoxic-aerobic digestion of waste activated sludge from biological nutrient removal systems
… and pipe blockages. This investigation studies anoxic-aerobic digestion (aerobic digestion with intermittent aeration), as an alternative digestion of BNR WAS. Aerobic digestion is simple to operate – being an extension of the activated sludge process, requiring aeration and limited recycling. …
-
The effect of sludge age and aerobic sludge mass fraction on low F/M filament bulking in intermittent aeration nitrogen removal systems
… F /M filament proliferation - the presence of anoxic and aerobic zones, or, alternating anoxic-aerobic conditions in a system. It was also established that the presence or absence of readily biodegradable COD (RBCOD) or slowly biodegradable COD (SBCOD) were not deciding factors in their …
-
The Effectiveness of Multiple Redox Treatment Strategies on the Treatability of a High Strength Industrial Wastewater
… operated under alternating redox environments: anaerobic/aerobic (ANA), anoxic/aerobic (ANX), and aerobic was investigated. A synthetic wastewater was modeled after a wastewater from an existing chemical processing facility. The largest component, hydroxypivaldehyde, was unavailable for the use in …
-
The effect of nitrite and nitrate concentrations on low F/M filament bulking in nitrogen removal activated sludge systems
… This research also indicated that in fully aerobic systems low F/M bulking was ameliorated, but in intermittently aerated anoxic-aerobic systems low F/M filament bulking was promoted. The research presented in this thesis forms part of a follow-up bulking research program into low F/M …
-
Biological excess phosphorus removal in short sludge age activated sludge systems
… by operating a number of laboratory scale anaerobic/aerobic and anaerobic/anoxic/aerobic systems with varying sludge ages, anaerobic, anoxic and aerobic mass fractions, mixed liquor recycle ratios and COD loading rates.
-
Characterization of municipal waste waters
… have been developed, to progressively include aerobic COD removal and nitrification (Marais and Ekama, 1976; Dold et al., 1980), anoxic denitrification ( van Haandel et al., 1981; WRC, 1984; Henze et al., 1987; Dold et al., 1991) and anaerobic, anoxic, aerobic biological excess phosphorus …
-
Causes and control of low F/M bulking in long sludge age nutrient removal activated sludge systems
… when sludge is subjected to alternating anoxic-aerobic conditions with nitrite present. (3) A review of the biochemistry of respiration led to the formulation of a biochemical model for facultative organism respiration, an important aspect of which is a series of mechanisms that give rise …
-
Biological treatment schemes for preventing oxime inhibition of nitrification
… was to develop a single sludge multi-environment anoxic/aerobic biological treatment scheme that could achieve oxime degradation and nitrification in the same treatment process. Aerobic and anoxic batch experiments were initially performed to determine degrees of nitrification inhibition caused by …
-
The effect of fully anoxic conditions and frequency of exposure to anoxic and aerobic conditions on the growth of low F/M filaments in nitrogen remova
… 3 phases investigating (1) the effect of fully anoxic conditions and low nitrate concentrations during the anoxic phase of an intermittent aeration cycle on low F/M filament growth in continuously fed completely mixed single reactor systems receiving a synthetic sewage feed; (2) the effect of …
-
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)
… nutrient removing activated sludge plants. Anoxic-aerobic (AA) or low F/M filaments appear to proliferate in activated sludge plants that incorporate biological nitrogen removal. From earlier research, Casey et al. (1992a) showed that the cause for AA filament proliferation lay in the …
-
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
… control method was inclusion of either an anoxic or aerobic selector at the head of the wastewater treatment plant. Gabb et al (1989a) found that selectors did not control low F/M filament proliferation but that continuous aeration did. They concluded that the presence of anoxic and aerobic …
-
Study of population dynamics in a biological phosphorous removal wastewater treatment system
… ages. Each 8-hour cycle included an influent/anaerobic, anoxic, aerobic, and settling/effluent stage. Different feed mixtures of acetate, glucose, and nutrient broth were fed to the reactors. Chemical and physical parameters were tested during each stage of an 8-hour cycle weekly, in addition to …
-
Nutrient (Ammonium and Phosphate) Removal Using Aerobic Granulation at Pilot scale
This research investigated the causes of aerobic granulation inhibition and deterioration in nutrient removal performance of aerobic granular sludge (AGS) reactors at pilot scale. Identifying the underlying phenomena seems necessary to enhance predictability and reliability of this process under …
-
Development of a Dynamic Simulation Model for Equalization Tanks
… secondary settling tank, flotation unit, anoxic-aerobic digester), due to the less conservative design values that could be used as the variations of the influent were decreased. Despite this, a 13% overall increase in the footprint of the WRRF was observed due to the addition of the …
-
Development of a Dynamic Simulation Model for Equalization Tanks
… secondary settling tank, flotation unit, anoxic-aerobic digester), due to the less conservative design values that could be used as the variations of the influent were decreased. Despite this, a 13% overall increase in the footprint of the WRRF was observed due to the addition of the …
-
An Investigation of the Feasibility of Nitrification and Denitrification of a Complex Industrial Wastewater with High Seasonal Temperatures
… The four main treatment strategies tested were: aerobic/anoxic treatment of the final effluent of HRWTF at moderate temperatures (approximately 30oC); anaerobic/anoxic/aerobic (A2/O) treatment of the primary effluent of HRWTF at moderate temperatures; treatment of the effluent of one of the …
-
Comparing the Metcalf and Eddy and UCT steady state guidelines for sizing of biological nutrient removal activated sludge wastewater treatment plants
… but differ significantly in the sizing of the anoxic reactor to achieve a certain nitrate removal. The key findings are: (1) Both UCT and M&E guidelines close the COD and N flux balances within 1%. (2) For organics removal only, at the same SRT, sludge production and oxygen demand are about 5% …