Download or read book Characterization of Acid Phase Anaerobic Digestion of Municipal Sludges to Improve Biological Nutrient Removal Processes written by Antonio Albornoz and published by . This book was released on 2017 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Enhanced biological phosphorus removal (EBPR) can improve the balance sheet for waste water treatment plants. However, for phosphate accumulating organisms (PAOs) to work efficiently, there needs to be a readily biodegradable carbon source as their substrate for growth. Side stream hydrolysis and acid-phase fermentation of the sludge can generate readily available carbon in the form of volatile fatty acids (VFAs). The VFAs are subsequently consumed by PAOs to support the phosphorus removal process. Phosphorus is then recovered from the waste activated sludge using various dewatering and sorting methods. This study evaluated modeling of side-stream acid-phase digestion of primary sludge to support consistent production of VFAs and thereby stabilize and optimize phosphorus removal processes. In this regard, hydrolysis processes were focused on since they are typically the rate-limiting step in anaerobic digestion. It was found that the literature fails to provide consistent information to aid in the modeling of this process, particularly with regards to the values of the hydrolysis rate constants and the sensitivity of these constants to environmental factors such as temperature, pH, and sludge composition. An experimental set up consisting of three semi-batch reactors provided data that was subsequently employed in the model evaluation. The reactors were fed with either primary sludge (PS), waste activated sludge (WAS), or a mixture of both (mixed liquor (ML)). The ML set up received 62% PS and 38% WAS by volume. The reactors were fed with sludge from the Elmira WWTP and were operated at an SRT of 6 days. Water quality parameters such as pH, NH3, COD, SS, TKN, VFA, PO4 were monitored using standard analytical methods. It was found that adding WAS to PS increased the hydrolysis of PS solids by 19% based on VFA produced by influent Total COD. BioWin model simulations employed this data to calibrate a baseline model that described the observed VFA production. It was found that traditional anaerobic hydrolysis rate expressions could not describe all data sets consistently. In an effort to improve the universality of the hydrolysis expression, two extensions for the model were considered. The product inhibition extension considered reduced hydrolysis at high VFA concentrations. This model performed well but improved with the second extension regarding enzyme concentration. It was found that including the effect of hydrolytic enzymes in the model can improve the ability of the model to predict results and it is suggested that the follow up research expands in this area to consider more specific enzymes.

Download or read book Effect of Acid and Base Pretreatment on the Anaerobic Digestion of Excess Municipal Sludge written by and published by . This book was released on 2005 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The treatment and disposal of sewage sludge is a growing problem worldwide due to the continuing increase in sludge production from biological wastewater treatment plants and recent stringent regulations regarding sludge treatment and disposal. To date, the primary disposal methods for the excess sludge produced are landfilling, incineration and application in agricultural or forestland [1]. The high water content of the sludge makes incineration expensive and faces restrictions on disposal in modern landfills due to the tendency to reduce the amount of organic matter applied. Agricultural use seems to be the best options but several constraints exist due to health related problems such as odors, heavy metals content or pathogens and hazardous compounds that may be present in the sludge preventing their use in farming [2]. In this context, anaerobic sludge digestion represents a good sludge treatment alternative, decreasing the amount of solids present in the sludge with consequent reductions in disposal cost. Furthermore, we have to consider the advantage represented by energy recovery in the form of methane production that can be utilized as an energy source at the facility [3]. The present research project evaluates the combined use of hydrochloric acid (HCl) and sodium hydroxide (NaOH) for sludge chemical pretreatment to improve the performance of anaerobic digestion by extending the effectiveness of solids hydrolysis which is considered the rate-limiting step in the process [4]. The effect of temperature and the length of pre-treatment were initially evaluated to optimize the pretreatment process prior to use of any anaerobic treatment. Once the results of this experiment are analyzed, the performance of anaerobic digestion with chemical pretreatment using different combinations of primary and waste activated sludge pretreatment with either acid or base was studied. Two different SRTs for anaerobic digestion, 10 and 20 days, were investigated using duplicate reactors for each condition. Two reactors (number 1 and 6), used as control, were fed with a mixture of untreated primary and waste activated sludge in a mass ratio 1:1 with a combined VSS concentration around 30 g/l. Two reactors (number 2 and 4) were fed with a mixture of primary sludge pretreated with HCl and activated sludge pretreated with NaOH. The last two reactors (number 3 and 5) were fed with a mixture of primary sludge treated with NaOH and activated sludge treated with HCl. The same primary and waste activated sludge mass ratio as the one used to feed the control reactors were maintained in the four reactors fed with the chemically pretreated sludge. Monitored parameters were: TSS, VSS, total and soluble COD, Total Kjheldahl Nitrogen (TKN), Ammonia, Volatile Fatty Acids (VFA), pH, Phosphates, metals concentration, fecal coliforms concentration and gas production and composition. As expected, the results showed that 20 days SRT provided higher VSS and COD removal than 10 days SRT for all the three configurations evaluated. For both SRTs, the mixture of primary sludge treated with NaOH and activated sludge treated with HCl resulted in higher VSS and COD removal. VSS removal averaged from 37.2% in reactor 1 and 38.6% in reactor 6 for the 10 days SRT. Increasing the SRT to 20 days led to 46.6% and 44% VSS removal for reactor 1 and 6, respectively. Reactors 2 and 4 led to an overall average VSS removal of 44% for the 10 days SRT experiment which increased to around 50% in both reactors during the 20 days SRT experiment. For both SRTs, reactors 3 and 5 provided the highest average solids reduction with values around 46% for 10 days treatment and close to 53% for 20 days SRT (Chapter 7.2.1). It has to be considered that, in terms of maximum solids destruction, for the 10 days SRT experiment, a highest solids removal value of 47.8% was achieved in reactor 3 while 56.7% removal was obtained in reactor 5 when the SRT increased to 20 days. A similar trend was obtained when the COD removal has been considered. The two control reactors, 1 and 6, averaged from the 37.2% and 38.1% removal for the 10 days SRT experiment to values around 45% when the SRT was increased to 20 days. An overall average COD removal of 44.5 and 43.2% was achieved in reactors 2 and 4, respectively, for the 10 days SRT experiment and increased to around 47% in both reactors when the SRT was increased to 20 days. For both SRTs, reactors 3 and 5 provided the highest average COD removal with values around 45% for 10 days treatment experiment and close to 51% for 20 days SRT. For both retention times, all reactors exhibited good reproducibility in the replicates. Volatile fatty acids (VFAs) concentration was very low for both 10 and 20 days SRT in all reactors and weekly gas analysis exhibited a methane content of approximately 65%, meaning good overall performance of anaerobic digestion. The research proposed showed that anaerobic sludge digestion can be successfully used as sludge treatment alternative to reduce the amount of solids present in the sludge, with consequent reductions in disposal costs. Furthermore, compared with other sludge pretreatment options, the combined use of strong acid and strong base as chemical sludge pretreatment resulted in a good balance between solids reduction, process stability and cost reduction.

Download or read book Secondary Settling Tanks written by G. A. Ekama and published by International Water Assn. This book was released on 1997-01-01 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: The secondary settling tank (SST) plays a major ro

Download or read book Biomethanization of the Organic Fraction of Municipal Solid Wastes written by J. Mata-Alvarez and published by IWA Publishing. This book was released on 2002-08-31 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomethanization of the Organic Fraction of Municipal Solid Wastes is a comprehensive introduction to both the fundamentals and the more practical aspects of the anaerobic digestion of organic solid wastes, particularly those derived from households, that is, the organic fraction of municipal solid wastes (OFMSW). It can be used as a textbook for specialized courses and also as a guide for practitioners. In the first part, the book covers the relevant aspects of anaerobic digestion (AD) of organic wastes. The fundamentals and kinetic aspects of AD are reviewed with particular emphasis on the aspects related to solid wastes. This introduction is necessary to have a comprehensive view of the AD process and to understand the practical principles as well as the origin of possible problems arising from the management of the process. Chapter 2 emphasizes the role of kinetics in designing the reactor, paying special attention to existing models, particularly the dynamic ones. Through this introduction, it is intended to facilitate the technology transfer from laboratory or pilot plant experiences to full-scale process, in order to implement improvements in current digesters. Laboratory methods are described for the analysis and optimization of reactor performance, such as methanogenic activity tests or experimental evaluation of the biodegradation kinetics of solid organic waste. The different reaction patterns applied to industrial reactors are outlined. Industrial reactors are classified in accordance with the system they use, pointing out advantages and limitations. Co-digestion, enabling the co-treatment of organic wastes of different origin in a more economically feasible way, is described in detail. Examples of co-digestion are given, with OFMSW as a base-substrate. Finally, full-scale co-digestion plants are discussed. Various types (mechanical, biological, physico-chemical) of pre-treatment to increase the biodegradability, and thus the yields of the process, are reviewed in detail. The use of the fermentation products of anaerobic digesters for biological nutrient removal processes in wastewater treatment plants is described. This constitutes an example of integrated waste management, a field in which both economic and technical advances can be achieved. Balances are given to justify the approach, and a full-scale case study is presented. The important topic of economics and the ecological advantages of the process are emphasized. The use of compost, the integration with composting technology, and advantages over other technologies are detailed in the framework of an environmental impact assessment of biowaste treatment. Finally, the anaerobic digestion of MSW in landfills is reviewed in detail, with emphasis on landfill process enhancement and strategies for its application.

Download or read book Acidogenic Anaerobic Digestion of Primary Sludge as a Supplement in Biological Nutrient Removal written by Supawadee Sinnaraprasat and published by . This book was released on 2002 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Design Manual written by and published by . This book was released on 1987 with total page 132 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 1991 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biological Wastewater Treatment written by Mogens Henze and published by IWA Publishing (International Water Assoc). This book was released on 1881 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: For information on the online course in Biological Wastewater Treatment from UNESCO-IHE, visit: http://www.iwapublishing.co.uk/books/biological-wastewater-treatment-online-course-principles-modeling-and-design Over the past twenty years, the knowledge and understanding of wastewater treatment have advanced extensively and moved away from empirically-based approaches to a first principles approach embracing chemistry, microbiology, physical and bioprocess engineering, and mathematics. Many of these advances have matured to the degree that they have been codified into mathematical models for simulation with computers. For a new generation of young scientists and engineers entering the wastewater treatment profession, the quantity, complexity and diversity of these new developments can be overwhelming, particularly in developing countries where access is not readily available to advanced level tertiary education courses in wastewater treatment. Biological Wastewater Treatment addresses this deficiency. It assembles and integrates the postgraduate course material of a dozen or so professors from research groups around the world that have made significant contributions to the advances in wastewater treatment. The book forms part of an internet-based curriculum in biological wastewater treatment which also includes: Summarized lecture handouts of the topics covered in book Filmed lectures by the author professors Tutorial exercises for students self-learning Upon completion of this curriculum the modern approach of modelling and simulation to wastewater treatment plant design and operation, be it activated sludge, biological nitrogen and phosphorus removal, secondary settling tanks or biofilm systems, can be embraced with deeper insight, advanced knowledge and greater confidence.

Download or read book Anaerobic Digestion Process Stability and the Extension of the ADM1 for Municipal Sludge Co Digested with Bakery Waste written by Morris Elya Demitry and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainty about anaerobic digestion process stability is the main issue preventing more widespread use of the process as a source of energy recovery in wastewater treatment facilities. The overall objective of this research was to study the feasibility of enhancing biogas production inside wastewater facilities using co-digestion of municipal sludge with bakery waste. Another objective was to improve the stability index and a mathematical model that can be useful tools to predict the process stability of municipal sludge digestion alone, and when it is mixed with bakery waste, as a substrate for microorganisms. Experiments were conducted in three phases. In phase 1, a full-scale anaerobic digester at Central Weber Sewer Improvement District, Ogden, UT, receiving a mixture of primary and secondary sludge, was monitored for one hundred days. Chemical oxygen demand (COD), and volatile solids (VS) mass balances were conducted to evaluate the stability of the digester and its capability of producing methane gas. The COD mass balance accounted for nearly 90% of the methane gas produced while the VS mass balance showed that 91% of the organic matter removed resulted in biogas formation. Other parameters monitored included: pH, alkalinity, VFA, and propionic acid. The values of these parameters showed that the digester was running under stable steady state conditions. At mesophilic temperature, the stability index was determined and equal to 0.40 L (CH4)/ g(Î4VS) In phase 2, the feasibility of adding BW to MS was tested in batch reactors scale. The biogas production was enhanced and the digester was stable until the range of 37- 40% of BW to 63-60% of MS. The ADM1 coefficients were modified to accurately predict the digester performance. The modified model outputs (pH, VFA, and methane) were within acceptable ranges when compared with the observed data from the batch reactors. In phase 3, the feasibility of MS and BW were tested using an Induced Bed Reactor (IBR) with a 50:50% ratio of MS:BW (COD basis). The process was stable during different hydraulic retention times and the ADM1 was modified to predict the stability of the process in the IBR.

Download or read book Handbook of Environmental Materials Management written by Chaudhery Mustansar Hussain and published by Springer. This book was released on 2019-06-03 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference work analyzes and assesses global environmental management techniques for environmental materials with a focus on their performance and economic benefits, proposing eco-friendly solutions and designating policies that will sustain the environment for future generations. It addresses management of environmental materials as not only a complex anthropogenic problem, but also as an expensive problem that needs to be managed sustainably. Simultaneously, it considers the environmental and economic benefits involved in the high levels of investment and operation costs required to develop effective materials collection and management systems in modern society.

Download or read book Sludge Treatment and Disposal written by Cleverson Vitorio Andreoli and published by IWA Publishing. This book was released on 2007-03-30 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sludge Treatment and Disposal is the sixth volume in the series Biological Wastewater Treatment. The book covers in a clear and informative way the sludge characteristics, production, treatment (thickening, dewatering, stabilisation, pathogens removal) and disposal (land application for agricultural purposes, sanitary landfills, landfarming and other methods). Environmental and public health issues are also fully described. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 1: Waste Stabilisation Ponds; Volume 2: Basic Principles of Wastewater Treatment; Volume 3: Waste Stabilization Ponds; Volume 4: Anaerobic Reactors; Volume 5: Activated Sludge and Aerobic Biofilm Reactors

Download or read book Sludge Reduction Technologies in Wastewater Treatment Plants written by Paola Foladori and published by IWA Publishing. This book was released on 2010-07-31 with total page 381 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sludge Reduction Technologies in Wastewater Treatment Plants is a review of the sludge reduction techniques integrated in wastewater treatment plants with detailed chapters on the most promising and most widespread techniques. The aim of the book is to update the international community on the current status of knowledge and techniques in the field of sludge reduction. It will provide a comprehensive understanding of the following issues in sludge reduction: principles of sludge reduction techniques; process configurations; potential performance; advantages and drawbacks; economics and energy consumption. This book will be essential reading for managers and technical staff of wastewater treatment plants as well as graduate students and post-graduate specialists.

Download or read book Wastewater Sludge Processing written by Izrail S. Turovskiy and published by John Wiley & Sons. This book was released on 2006-08-08 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reap the benefits of sludge The processing of wastewater sludge for use or disposal has been a continuing challenge for municipal agencies. Yet, whensludge is properly processed, the resulting nutrient-rich product--biosolids--can be a valuable resource for agriculture and other uses. Wastewater Sludge Processing brings together a wide body of knowledge from the field to examine how to effectively process sludge to reap its benefits, yet protect public health. Presented in a format useful as both a reference for practicing environmental engineers and a textbook for graduatestudents, this book discusses unit operations used for processing sludge and the available methods for final disposition of the processed product. Topics discussed include sludge quantities and characteristics, thickening and dewatering, aerobicand anaerobic digestion, alkaline stabilization, composting, thermal drying and incineration, energy consumption, and the beneficial use of biosolids. COMPREHENSIVE IN ITS COVERAGE, THE TEXT: * Describes new and emerging technologies as well as international methods * Compares different types of sludge processing methods * Explains both municipal and industrial treatment technologies Written by authors with decades of experience in the field, Wastewater Sludge Processing is an invaluable tool for anyone planning, designing, and implementing municipal wastewater sludge management projects.

Download or read book Handbook of Water and Wastewater Microbiology written by Duncan Mara and published by Elsevier. This book was released on 2003-08-07 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Access to safe water is a fundamental human need and therefore a basic human right" --Kofi Annan, United Nations Secretary General Edited by two world-renowned scientists in the field, The Handbook of Water and Wastewater Microbiology provides a definitive and comprehensive coverage of water and wastewater microbiology. With contributions from experts from around the world, this book gives a global perspective on the important issues faced in the provision of safe drinking water, the problems of dealing with aquatic pollution and the processes involved in wastewater management. Starting with an introductory chapter of basic microbiological principles, The Handbook of Water and Wastewater Microbiology develops these principles further, ensuring that this is the essential text for process engineers with little microbiological experience and specialist microbiologists alike. Comprehensive selection of reviews dealing with drinking water and aquatic pollution Provides an understading of basic microbiology and how it is applied to engineering process solutions Suitable for all levels of knowledge in microbiology -from those with no background to specialists who require the depth of information

Download or read book Anaerobic Reactors written by Carlos Augustos de Lemos Chernicharo and published by IWA Publishing. This book was released on 2007-03-30 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anaerobic Reactors is the forth volume in the series Biological Wastewater Treatment. The fundamentals of anaerobic treatment are presented in detail, including its applicability, microbiology, biochemistry and main reactor configurations. Two reactor types are analysed in more detail, namely anaerobic filters and especially UASB (upflow anaerobic sludge blanket) reactors. Particular attention is also devoted to the post-treatment of the effluents from the anaerobic reactors. The book presents in a clear and informative way the main concepts, working principles, expected removal efficiencies, design criteria, design examples, construction aspects and operational guidelines for anaerobic reactors. About the series: The series is based on a highly acclaimed set of best selling textbooks. This international version is comprised by six textbooks giving a state-of-the-art presentation of the science and technology of biological wastewater treatment. Other titles in the series are: Volume 1: Waste Stabilisation Ponds; Volume 2: Basic Principles of Wastewater Treatment; Volume 3: Waste Stabilization Ponds; Volume 5: Activated Sludge and Aerobic Biofilm Reactors; Volume 6: Sludge Treatment and Disposal

Download or read book Biological Nutrient Removal from Municipal Sewage Using Acti zyme written by Musaida Mercy Manyuchi and published by . This book was released on 2016 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bioaugmentation with Sidestream Granular Sludge for Nitrification in Activated Sludge Wastewater Treatment written by John Andrews Carter and published by . This book was released on 2020 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stricter effluent permits and growing metropolitan areas have contributed to a move towards the intensification of biological treatment processes for water resource recovery facilities (WRRFs). Process intensification with aerobic granular sludge (AGS) has the potential to increase the treatment capacity of WRRFs and enable or increase biological nutrient removal without increasing footprint. Growth of AGS in continuous flow activated sludge (CFAS) facilities has yet to be fully realized, despite the success of AGS wastewater treatment in sequencing batch reactors (SBRs). Sidestream growth and bioaugmentation of AGS aim to take advantage of the selection pressures for growth of granular sludge in SBRs to increase the treatment and nutrient removal capacity of a CFAS system. A sidestream SBR fed acetate and anaerobic digestion centrate diluted with final effluent was used to grow AGS enriched with ammonia oxidizing bacteria (AOB) and polyphosphate accumulating organisms (PAOs) to evaluate the effect of sidestream AGS bioaugmentation on a low solids retention time (SRT) non-nitrifying CFAS system in a pilot plant study. The CFAS system had a hydraulic separator unit for the purpose of uncoupling the SRTs of granular and flocculent sludge to enhance the impact of bioaugmentation. The sidestream SBR was operated for a 6.5-month period at an NH3-N loading of 0.31 ± 0.04 g/L-d, an SRT of 25-30 days, and a mixed liquor suspended solids (MLSS) concentration between 8.6 and 14.4 g/L. The sidestream NH3-N loading averaged 21% of the mainstream NH3-N loading, to represent a typical proportion for full-scale treatment systems with anaerobic sludge digestion. Specific nitrification rates (SNRs) varied between 1.2 and 1.4 mg NH3-N/g VSS-hr. A low DO:NH3-N concentration ratio of 0.06 mg/mg or less during the aeration phase resulted in suppression of nitrite oxidizing bacteria (NOB) growth and thus shortcut nitrogen removal with over 89% simultaneous nitrification/denitrification. NOB suppression was evident because of an effluent NO2-:/NO3-N ratio of greater than 1.0 and a qPCR AOB to NOB ratio of between 3 and 4. A high COD:N removed ratio of 6.0 – 7.0 resulted in PAOs to be in the granule outer aerobic layers besides the inner core to thus compete with AOBs for space and dissolved oxygen, which would limit AOB activity causing a lower SNR than expected based on prior operation with the same reactor. The mainstream pilot was seeded with return activated sludge from a local WRRF and operated at two different time periods: Phase 1 and Phase 2. Phase 1 provided initial operating experience for the CFAS system but was shut down for pilot plant repairs and modifications before bioaugmentation could be started. Phase 2 lasted 56 days with 3 operating conditions: 1) 16 days for baseline flocculent sludge operation, 2) a spike of sidestream AGS and operation for 20 days, and 3) 20 days with continual sidestream bioaugmentation. After bioaugmentation the separator only captured 40-50% of the granular sludge, which limited the fraction of granules in the MLSS from 17.1 to 40.5%, the granular to floc SRT ratio to an average of 1.5, and the nitrification efficiency to increase by 20 to 30%.