Download or read book Dynamics of Nitrification in the Activated Sludge Process written by Richard Alan Poduska and published by . This book was released on 1974 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Nitrification in the Activated Sludge Process written by Harendra M. Mehta and published by . This book was released on with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Dynamics of Nitrification in the Activated Sludge Process written by Richard Alan Poduska and published by . This book was released on 1974 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Temperature on the Dynamics of Nitrification in the Activated Sludge Process written by Keith Edward Israel and published by . This book was released on 1977 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book OPERATIONAL ESTIMATION AND PREDICTION OF NITRIFICATION DYNAMICS IN THE ACTIVATED SLUDGE PROCESS written by M. B. Beck and published by . This book was released on 1982 with total page 17 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 A Dynamic Model of Nitrification for the Activated Sludge Process written by Richard Alan Poduska and published by . This book was released on 1973 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Dynamic Model of Nitrification denitrification in the Activated Sludge System with Powdered Activated Carbon written by Jong Soull Lee and published by . This book was released on 1977 with total page 458 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 Aerobic Granular Sludge written by S. Bathe and published by IWA Publishing. This book was released on 2005-03-31 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerobic Granular Sludge has recently received growing attention by researchers and technology developers, worldwide. Laboratory studies and preliminary field tests led to the conclusion that granular activated sludge can be readily established and profitably used in activated sludge plants, provided 'correct' process conditions are chosen. But what makes process conditions 'correct'? And what makes granules different from activated sludge flocs? Answers to these question are offered in Aerobic Granular Sludge. Major topics covered in this book include: Reasons and mechanism of aerobic granule formation Structure of the microbial population of aerobic granules Role, composition and physical properties of EPS Diffuse limitation and microbial activity within granules Physio-chemical characteristics Operation and application of granule reactors Scale-up aspects of granular sludge reactors, and case studies Aerobic Granular Sludge provides up-to-date information about a rapidly emerging new technology of biological treatment.
Download or read book Dynamics and Control of the Activated Sludge Process written by Paul Bishop and published by CRC Press. This book was released on 1992-04-24 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Verifiability of the Activated Sludge System Dynamics written by and published by . This book was released on 1993 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Intensifying Activated Sludge Using Media Supported Biofilms written by Dwight Houweling and published by CRC Press. This book was released on 2019-08-16 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Intensifying Activated Sludge Using Media-Supported Biofilms will be of interest to practicing wastewater treatment process designers, along with those seeking more compact and energy-efficient wastewater treatment options. The advantages of Moving Bed Biological Reactor (MBBR)-based hybrid processes are now well-established in practice, leading to their increased use in the field. Membrane Aerated Biofilm Reactor (MABR)-based hybrid processes are much newer and offer further systematic process and energy advantages. This book examines the evolution of hybrid technologies as well as the potential for continued improvement of biological wastewater treatment techniques. Features: Reviews current approaches for intensifying biological wastewater treatment processes and their mechanistic bases. Examines hybrid suspended growth/biofilm-based wastewater treatment processes, including the newly-developed MABR-based processes, and their unique dynamic performance characteristics. Presents a novel method for characterizing the performance and process intensification advantages of hybrid processes. Provides guidance for simulating the performance of hybrid processes, including oxygen transfer in MABR hybrid processes.
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 Reexamining the Engineered Nitrogen Cycle written by George Fraser Wells and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Biological wastewater treatment is a multi-billion dollar industry--the largest application of biotechnology in the world. Nitrification systems in these wastewater treatment plants are critically important barriers to nitrogen pollution, thereby protecting natural systems from ammonium toxicity, excess emissions of the potent greenhouse gas nitrous oxide, nitrogenous oxygen demand, and N-stimulated eutrophication. Despite the environmental and economic importance of these processes, surprisingly little is known about the nature of the key biocatalysts (microbial communities) within nitrifying wastewater treatment bioreactors. The body of research presented in this dissertation targets three knowledge gaps in the microbial ecology of biological nutrient removal systems: microbial community dynamics and associated deterministic drivers; microbial diversity--namely, the 'core' and 'dispensable' microbiome in activated sludge and the relative importance therein of different groupings of ammonia-oxidizing microorganisms to nitrogen transformations; and the importance of microbial immigration in structuring engineered microbial communities. In Chapter 2, I investigate the diversity, population dynamics, and relative importance of two key types of microorganisms in nitrogen removal processes--ammonia-oxidizing bacteria (AOB) and newly-discovered ammonia-oxidizing archaea (AOA)--in a one-year time series of weekly activated sludge samples from a nitrifying wastewater treatment plant in California. I demonstrate that AOB predominate by 3 orders of magnitude over AOA in this system--an important result, given recent reports of natural environments dominated by AOA, and the first quantitative comparison of AOA and AOB in activated sludge. Moreover, my results reveal a predominance in the AOB community of a novel Nitrosomonas-like lineage and strong associations between AOB community dynamics and temperature, dissolved oxygen, influent nitrite concentrations, and primary influent chromium concentrations. In Chapter 3, I employ molecular fingerprinting analyses (T-RFLP) to characterize overall bacterial dynamics in activated sludge over the same one-year time period and to test a fundamental prediction of macroecological theory--the "Species-Time Curve"--In engineered microbial systems. My results reveal surprisingly strong long-term temporal dynamics in the activated sludge bacterial assemblage during a period of stable performance, with a gradual succession away from initial conditions likely linked to variations in dissolved oxygen, temperature, influent silver, biomass levels, and influent nitrite concentrations. I also provide significant support for a power-law taxa-time relationship (TTR) in activated sludge systems, as predicted by macroecological theory, with a power-law exponent (w=0.209) well in-line with those observed in macrobial systems. In Chapter 4, I detail an astonishingly high reservoir of overall microbial phylogenetic and functional diversity and unexpectedly large community dynamics in activated sludge via application of cutting-edge phylogenetic (PhyloChip) and functional gene (GeoChip) microarrays. While nearly 2,500 distinct microbial taxa distributed throughout 48 bacterial and archaeal phyla were observed in 12 monthly samples from a full-scale wastewater treatment bioreactor, the set of taxa that were present in all samples--the "core" microbiome--was limited to ~700 taxa. Dynamics in the ~1800 taxa present in only a subset of samples--the "dispensable" microbiome--were significantly associated with temperature and influent nitrite. Of 10,267 unique functional genes in 266 gene families that showed statistically significant hybridization signals to our functional gene microarray platform, only 66 unique functional genes were detected in all samples. In contrast, representatives from 63% of detected functional gene families were present in all samples. This core functional gene set encoded for resistance to several metals, specific organic degradation functions, cellulose degradation, nitrification, denitrification, and, surprisingly, sulfate reduction and methanogenesis. This first examination of the core and dispensable microbiome in an activated sludge bioreactor suggests that activated sludge microbial communities are functionally and phylogenetically highly diverse, but that only a fraction of this diversity constitutes a true core microbiome. In Chapter 5, I resolve a puzzling connection in Chapters 2-4 between microbial community dynamics and small levels of nitrite in the bioreactor influent by demonstrating intra-plant microbial immigration between coupled process units at a full-scale wastewater treatment plant. I provide converging lines of retrospective and prospective evidence that these microbial immigrants may be significant drivers of microbial community dynamics in engineered systems. Quantitative PCR (qPCR) analyses demonstrated accumulation of AOB in a BOD--removal trickling filter and significant immigration to a downstream activated sludge bioreactor. T-RFLP analyses corroborated by clone libraries showed that Nitrosomonas europaea dominated the trickling filter, while a 'Nitrosomonas-like' lineage dominated in activated sludge. N. europaea was previously shown to predominate in activated sludge during elevated bioreactor influent NO2- events, strongly suggesting that activated sludge AOB community dynamics are driven in part by immigration via sloughing from the upstream trickling filter. High-density phylogenetic microarray (PhyloChip) analyses revealed an overabundance of methanogens in the trickling filter relative to the activated sludge bioreactor and demonstrated transport of a diverse heterotrophic assemblage to the activated sludge via the trickling filter effluent. Our results indicate that immigration may play an unexpectedly significant role in the microbial community assembly process in activated sludge bioreactors, with potentially profound implications for design and operation of this widely-used, environmentally and economically important technology. Taken together, my research suggests the utility of coupling fundamental microbial ecology research to bioprocess engineering. I anticipate that, in the long term, the results of my work on bioreactor microbial ecology will lay the framework for enhanced "microbial resource management" strategies for wastewater treatment bioreactors, a critically important application of environmental biotechnology.
Download or read book Mathematical Modelling and Computer Simulation of Activated Sludge Systems written by Jacek Makinia and published by IWA Publishing. This book was released on 2020-03-02 with total page 682 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical Modelling and Computer Simulation of Activated Sludge Systems – Second Edition provides, from the process engineering perspective, a comprehensive and up-to-date overview regarding various aspects of the mechanistic (“white box”) modelling and simulation of advanced activated sludge systems performing biological nutrient removal. In the new edition of the book, a special focus is given to nitrogen removal and the latest developments in modelling the innovative nitrogen removal processes. Furthermore, a new section on micropollutant removal has been added. The focus of modelling has been shifting in the last years to models that can describe the performance of a whole plant (plant-wide modelling). The expanded part of this new edition introduces models describing the most important processes interrelated with the mainstream activated sludge systems as well as models describing the energy balance, operating costs and environmental impact. The complex process evaluation, including minimization of energy consumption and carbon footprint, is in line with the present and future wastewater treatment goals. By combining a general introduction and a textbook, this book serves both intermediate and more experienced model users, both researchers and practitioners, as a comprehensive guide to modelling and simulation studies. The book can be used as a supplemental material at graduate and post-graduate levels of wastewater engineering/modelling courses.
Download or read book Dynamics and Control of Wastewater Systems Second Edition written by Michae Barnett and published by CRC Press. This book was released on 1998-07-20 with total page 358 pages. Available in PDF, EPUB and Kindle. Book excerpt: FROM THE PREFACE Dynamic modeling, computer simulation, and modern control systems are valuable tools for use in both the design and operation of dynamic systems. From the "tools" point of view, this book is designed to show practicing engineers how to develop models capable of describing dynamic behavior and how to "solve" these models using computer simulation. The basic principles of process control are also presented so that the effects of different control systems on dynamic behavior can be established by computer simulation.
