Download or read book A Study of Nitrate Respiration in the Activated Sludge Process written by Carl Beer and published by . This book was released on 1980 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Nitrate Respiration in the Activated Sludge Process written by Carl Beer and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of Nitrate Versus Oxygen Respiration in the Activated Sludge Process written by Samuel Alan McClintock and published by . This book was released on 1986 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study of Nitrate Respiration in the Activated Sludge Process written by U.S. Environmental Protection Agency and published by BiblioGov. This book was released on 2013-11 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Environmental Protection Agency (EPA) was introduced on December 2, 1970 by President Richard Nixon. The agency is charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress. The EPA's struggle to protect health and the environment is seen through each of its official publications. These publications outline new policies, detail problems with enforcing laws, document the need for new legislation, and describe new tactics to use to solve these issues. This collection of publications ranges from historic documents to reports released in the new millennium, and features works like: Bicycle for a Better Environment, Health Effects of Increasing Sulfur Oxides Emissions Draft, and Women and Environmental Health.
Download or read book A Study of Nitrate Respiration in the Activated Sludge Process written by Carl Beer and published by . This book was released on 1980 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrification and Denitrification in the Activated Sludge Process written by Michael H. Gerardi and published by John Wiley & Sons. This book was released on 2002-01-09 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrification and Denitrification in the Activated Sludge Process, the first in a series on the microbiology of wastewater treatment, comprises the critical topics of cost-effective operation, permit compliance, process control, and troubleshooting in wastewater treatment plants. Avoiding the technical jargon, chemical equations, and kinetics that typically accompany such texts, Nitrification and Denitrification in the Activated Sludge Process directly addresses plant operators and technicians, providing necessary information for understanding the microbiology and biological conditions that occur in the treatment process. Of special interest to wastewater treatment plant operators are the bacteria that degrade nitrogenous wastes–the nitrifying bacteria–and the bacteria that degrade carbonaceous wastes–the cBOD-removing bacteria. Both groups of bacteria need to be routinely monitored and operational conditions favorably adjusted to ensure desired nitrification. Each chapter in this groundbreaking study offers a better understanding of the importance of nitrification and denitrification and the bacteria involved in these crucial processes. Chapters include: Organotrophs The Wastewater Nitrogen Cycle Nitrite Ion Accumulation Dissolved Oxygen Denitrifying Bacteria Gaseous End Products Free Molecular Oxygen The Occurrence of Denitrification
Download or read book Process Design of Single sludge Activated Sludge Systems Using Nitrate Respiration written by Carl Beer and published by . This book was released on 1977 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrification and Denitrification in the Activated Sludge Process written by Michael H. Gerardi and published by John Wiley & Sons. This book was released on 2003-03-19 with total page 207 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrification and Denitrification in the Activated Sludge Process, the first in a series on the microbiology of wastewater treatment, comprises the critical topics of cost-effective operation, permit compliance, process control, and troubleshooting in wastewater treatment plants. Avoiding the technical jargon, chemical equations, and kinetics that typically accompany such texts, Nitrification and Denitrification in the Activated Sludge Process directly addresses plant operators and technicians, providing necessary information for understanding the microbiology and biological conditions that occur in the treatment process. Of special interest to wastewater treatment plant operators are the bacteria that degrade nitrogenous wastes–the nitrifying bacteria–and the bacteria that degrade carbonaceous wastes–the cBOD-removing bacteria. Both groups of bacteria need to be routinely monitored and operational conditions favorably adjusted to ensure desired nitrification. Each chapter in this groundbreaking study offers a better understanding of the importance of nitrification and denitrification and the bacteria involved in these crucial processes. Chapters include: Organotrophs The Wastewater Nitrogen Cycle Nitrite Ion Accumulation Dissolved Oxygen Denitrifying Bacteria Gaseous End Products Free Molecular Oxygen The Occurrence of Denitrification
Download or read book The Microbiology of Activated Sludge written by Robert J. Seviour and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 433 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has been a long time in preparation. Initially it grew out of our frustrating attempts over the past ten years to identify the filamentous bacteria seen in large numbers in most activated sludge plants, and the realization that we know very little about them and the other microbial populations in these systems. Unfortunately this book does not provide many answers to the problems these filamentous bacteria can cause, but we hope it might encourage microbiologists and engineers to communi cate more with each other and to spend some time trying to understand the tax onomy, ecology and physiology of activated sludge microbes. It is now very timely, for example, to try to provide these filamentous bacteria with proper taxonomically valid names and to determine their correct place in bacterial classifications. This book is not meant to compete directly with the books by Gray (1989, 1990) nor the excellent manual published by Jenkins and coworkers (1993b), which has been invaluable to us and others trying to identify filamentous bacteria. Wanner's book (1994a) also provides an excellent account of the problems of bulking and foaming caused by filamentous bacteria. These publications and others by Eikelboom's group have made an enormous contribution to the study of filamentous bacteria, and will con tinue to do so.
Download or read book A Study of the Regulation of Denitrification in Activated Sludge Using an Enzyme Assay written by Thomas J. Simpkin and published by . This book was released on 1986 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nitrate Versus Oxygen Respiration in an Activated Sludge Sequencing Batch Reactor written by Yeou-Fen Chiang Yu and published by . This book was released on 1990 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Endogenous Or Sequestered Carbon for Denitrification in a Sequencing Batch Reactor Activated Sludge System written by A. Gary Meyer and published by . This book was released on 1987 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding of Nitrifying and Denitrifying Bacterial Population Dynamics in an Activated Sludge Process written by Tongzhou Wang and published by . This book was released on 2014 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen removal from wastewater has been an important objective in treatment since the 1960s and is one of the most important biological processes used. The progression of knowledge has evolved in stages moving from simple stoichiometric equations into the modern activated sludge models of today. These models use surrogates such as volatile solids for biomass and outcome parameters such as nitrate and nitrite in the secondary effluent to simulate biological activity. Thus, even the most complex models fail to capture the cyclical nature of bacterial abundance and the operating parameters which drive these cycles in full-scale plants. Better understanding of microbial communities has been attempted through the application of florescent in situ hybridization (FISH), which has determined the presence of specific organisms and the distributions of nitrifying and denitrifying populations within a single grab sample. New techniques such as quantitative polymerase chain reaction (qPCR) allowed the identification and quantification of nitrifying and denitrifying bacterial populations over time in full- scale plants. This has permitted the determination of relationships between organisms and operating parameters, which is missing from the majority of earlier microbial studies of wastewater treatment processes.Intense monitoring of bacterial populations involved in nitrification and denitrification was used in this dissertation to identify and illustrate how application of these molecular tools can be used improve plant performance. The overall findings of this study showed that plant performance should be optimized seasonally for maximum nitrification and to maximize denitrification anoxic dissolved oxygen needs to be carefully monitored during the winter and spring to prevent excess oxygen from inhibiting denitrification activity. Furthermore, this study suggests that consortia of bacterial groups carried out denitrification and no one single group could be identified which represented more than 50% of the population. This latter finding suggests that interactions, of what might otherwise be considered as minor groups, become important in understanding overall influences on the denitrification process. This was shown by the inhibition of the abundance of denitrifying bacteria through the production of nitrite by a bulking organism (Thiothrix Eikelboomii ).In the first study, we determined the nitrifying populations (ammonia oxidizing bacteria, Nitrobacter spp. and Nitrospira spp.) and the total bacterial population were most affected by five of the major physicochemical parameters. Water temperature, nitrite produced, nitrate produced, solids retention time, and pH were found to be the major physicochemical parameters controlling these bacterial dynamics. Two clusters in Principal Component 1(PC1) reflected a seasonality shift at 26.9°C. Temperature was found to be the parameter most directly affecting all bacterial populations in the warmer seasons (July-December), while nitrite produced and pH showed direct negative impacts on the bacterial populations in the cooler seasons (January-June) in the principal component analysis plot. PC1 and PC2 together accounted for 59.8% of the total variance, and the first six Principal Components accounted for 90.2% of total variance. Nitrifying and total bacterial abundance were strictly dependent on temperature in the summer time and inhibited by pH and nitrite in the winter season. This study found SRT needs to be extended by approximately 3.6 days to achieve optimum nitrification and the reduction of the ammonia-oxidizing bacteria: nitrite-oxidizing bacteria ratio of 9.5:1 to 2:1, because the SRT is too short for the Nitrobacter spp. and Nitrospira spp. growth rates.In the second study, two major denitrifying microbial groups, Thauera-like bacteria and Zoogloea-Methyloversatilis-like bacteria, which accounted for 34% on average of the total bacterial community measured using quantitative PCR (qPCR), were investigated in relation to the denitrification ability in a full scale plant. In this study of 11-months in warm wastewater (23-28.6 °C), dissolved oxygen (DO) in the anoxic zone was the most important parameter that determined denitrification efficiency when the temperature was below 27°C. Zoogloea-Methyloversatilis -like bacteria correlated significantly with denitrification ( r= 0.52, p
Download or read book Stabilization of Thickened activated Sludge Through the Anoxic aerobic Digestion Process written by Ming Ying Tan and published by . This book was released on 2002 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerobic digestion is widely used to treat waste-activated sludge and thickened sludge from wastewater treatment plant due to its shorter retention time and achieving the same efficiency in solids volume reduction compared to anaerobic digestion. However, the supernatant and filtrate from the aerobic digestion system contain high concentration of suspended solids. The nitrogen which had been embedded in sludge is solubilized to form ammonical and nitric nitrogen which in turn tranferred to the liqour and cause the increase of nitrogen loading in sewage treatment plant. In this study, anoxic-aerobic digestion is applied to remove both the mixed-liquor volatile suspended solids (MLVSS) and soluble nitrogen simultaneously. The objective of the study are to investigate and evaluate the removal efficiency of both MLVSS and soluble nitrogen by anoxic-aerobic digestion and compared to the aerobic control digesters, with and without lime control. By applying anoxic-acrobic, a comparable MLVSS was gained to aerobic digestion. 66.12% and 63.00% of MLVSS destruction was found in both anoxic-aerobic digesters, with and without methanol addition respectively. Aerobic with lime control tended to have the greatest solids reduction, which was 66.30%. Percent MLVSS reduction in aerobic control digester was 60.76%, the lowest among the digester. There was no unfavorable condition in anoxic-aerobic digesters due to the well maintenance of alkalinity and mixed-liquor pH levels naturally. The endogenous decay coeeficient were found 0.0581 day-1 and 0.0548 day-1 in anoxic-aerobic digester with and without methanol addition respectively, similar rate with lime control digester of 0.0584 day-1 in decay coeffiecient. Nitrate generated in situ due to nitrification was utilized through endogenous nitrate respiration (ENR) during anoxic periods. Thus, reduced nitrates levels in the supernatant in anoxic-aerobic digesters. In this study, it showed that anoxic-aerobic digestion yielded comparable percent solids reduction, despite less energy consumption. It maintained neutral mixed-liquor pH levels without any chemical or lime control. In addition, significant removal of soluble nitrogen and reduced in phosphorus released were realized.
Download or read book Volatile Fatty Acid Effects on Nitrite Removal and Nitrate Formation During Activated Sludge Treatment written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Reaction sequences of nitrifying and denitrifying bacteria are widely used to eliminate nitrogenous compounds from wastewater. During nutrification, ammonia is oxidized to nitrite by autotrophic ammonia oxidizing bacteria and nitrite is further oxidized to nitrate by nitrite oxidizers. Subsequently, nitrate or nitrite is reduced by denitrifying bacteria to gaseous nitrogen compounds. It is common knowledge that nitrification is an aerobic process and denitrification an anaerobic process. However, recent research has shown that denitrification can occur under aerobic conditions in pure cultures. Volatile fatty acids (VFAs), produced during anaerobic treatment processes, can affect both nitrite oxidation and aerobic denitrification. VFAs were shown to reduce nitrate formation via nitrite oxidation in activated sludge systems and to simulate aerobic denitrification in pure cultures. Nitrite removal inhibition by VFAs observed in activated sludge systems may be due to the level of aerobic denitrification which occurs. Investigation of this possibility can provide a new insight for the removal of nitrogen from wastewater and possibly reduce the chemical and energy demand for nitrogen treatment. The overall goal of this research was to demonstrate that nitrification and denitrification could occur in the same reactor under aerobic conditions in the presence of VFAs. The impact of VFAs on nitrite removal and nitrate formation in activated sludge systems was studied in batch and CSTR experiments. The experimental work included measurements of nitrite removal, nitrate formation and CO2 fixation in the absence and presence of VFAs. In addition, molecular tools were applied to examine changes in microbial population density when the population was exposed to VFAs. Production of N2O and activity of periplasmic nitrate reductase enzyme (NAP) which catalyses the first step of aerobic denitrification were also analyzed. Nitrite removal and nitrate formation rates were reduced in the presence of VFA's in batch experiments. Nitrate formation rate was reduced to a greater extent (74%) than nitrite removal rate (35%) indicating that products other than nitrate were formed during nitrite oxidation. The addition of VFAs into an activated sludge CSTR treating municipal wastewater resulted in a rapid decrease in nitrate formation rate (> 70% reduction); however, nitrite removal was not reduced. No nitrogen was discharged in the effluent of the CSTR indicating that nitrogenous compounds were completely removed from the wastewater. In contrast, VFAs were not found to impact carbon dioxide fixation efficiency in either batch or CSTR experiments although it is generally believed to be limited by the availability of energy derived from nitrite oxidation.
Download or read book Operating the Activated Sludge Process to Decrease Cell Yield Without Increasing Oxygen Consumption written by Westley Kyung Choon Chun and published by . This book was released on 1988 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1990 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt:
