Energy Conservation In Municipal Wastewater Treatment

Special Offer: Cao Ye Shi Author Set - Buy all three books together and save a total £76! Mass Flow and Energy Efficiency of Municipal Wastewater Treatment Plants presents the results of a series of studies that examined the mass flow and balance, and energy efficiency, of municipal wastewater treatment plants; it offers a vision of the future for municipal wastewater treatment plants. These studies were undertaken as part of the R & D program of the Public Utilities Board (PUB), Singapore. The book covers the latest practical and academic developments and provides: a detailed picture of the mass flow and transfer of Chemical Oxygen Demand (COD), solids, nitrogen and phosphorus and energy efficiency in a large municipal wastewater treatment plants in Singapore. The results are compared with the Strass wastewater treatment plant, Austria, which reaches energy self-sufficiency, and the approaches for improvement are proposed. a description of the biological conversions and mass flow and energy recovery in an up-flow anaerobic sludge blanket reactor - activated sludge process (UASB-ASP) - and compares this to the conventional activated sludge process. a comprehensive and critical review of the current state of the art of energy efficiency of municipal wastewater treatment plants including benchmarks, best available technologies and practices in energy saving and recovery, institution policies, and road maps to high energy recovery and high efficiency plants. a vision of future wastewater treatment plants including the major challenges of the paradigm shift from waste removal to resource recovery, technologies and processes to be studied, integrated sanitation system and management and policies. Mass Flow and Energy Efficiency of Municipal Wastewater Treatment Plants is a valuable reference on energy and sustainable management of municipal wastewater treatment plants, and will be especially useful for process and design researchers in wastewater research institutions, engineers, consultants and managers in water companies and water utilities, as well as students and academic staff in civil/sanitation/environment departments in universities.

Providing wastewater and drinking water service to citizens requires energy—and a lot of it. The twin problems of steadily rising energy costs and climate change have therefore made the issue of energy management one of the most salient issues facing wastewater and water utilities today. Energy management is also at the heart of efforts across the entire sector to ensure that utility operations are sustainable in the future. More and more utilities are realizing that a systematic approach for managing the full range of energy challenges they face is the best way to ensure that these issues are addressed on an ongoing basis in order to reduce climate impacts, save money, and remain sustainable. Working closely with a number of utilities and others, the Office of Water at the U.S. Environmental Protection Agency (EPA) is proactively addressing this issue by developing this Energy Management Guidebook for Wastewater and Water Utilities that provides a systematic approach to reducing energy consumption and energy cost. This Guidebook was specifically written to provide water and wastewater utility managers with a step-by-step method, based on a Plan-Do-Check-Act management system approach, to identify, implement, measure, and improve energy efficiency and renewable opportunities at their utilities.

The principle of the conventional activated sludge (CAS) for municipal wastewater treatment is primarily based on biological oxidation by which organic matters are converted to biomass and carbon dioxide. After more than 100 years’ successful application, the CAS process is receiving increasing critiques on its high energy consumption and excessive sludge generation. Currently, almost all municipal wastewater treatment plants with the CAS as a core process are being operated in an energy-negative fashion. To tackle such challenging situations, there is a need to re-examine the present wastewater treatment philosophy by developing and adopting novel process configurations and emerging technologies. The solutions going forward should rely on the ways to improve direct energy recovery from wastewater, while minimizing in-plant energy consumption. This book begins with a critical overview of the energy situation and challenges in current municipal wastewater treatment plants, showing the necessity of the paradigm shift from removal to recovery in terms of energy and resource. As such, the concept of A-B process is discussed in detail in the book. It appears that various A-B process configurations are able to provide possible engineering solutions in which A-stage is primarily designed for COD capture with the aim for direct anaerobic treatment without producing excessive biosludge, while B-stage is designated for nitrogen removal. Making the wastewater treatment energy self-sustainable is obviously of global significance and eventually may become a game changer for the global market of the municipal wastewater reclamation technology. The principal audiences include practitioners, professionals, university researchers, undergraduate and postgraduate students who are interested and specialized in municipal wastewater treatment and process design, environmental engineering, and environmental biotechnology.

Quantities of all forms of energy consumed for collection and treatment of municipal wastewater are estimated. Heat energy is equated to electrical energy by a conversion factor of 10,500 Btu/kwh. Total energy consumption, expressed as kwh/mg of wastewater treated, ranges from 2300-3700 kwh/mg. Energy used for construction of the treatment plant and the sewerage system represents 35-55% of the total energy consumed. The remainder used for plant operation is predominately (65-75%) electrical energy. The use of high efficiency aeration devices combined with good maintenance practices appears to offer the best opportunity for conservation of energy within the plant. Recovery of energy from the sludge produced at the plant can be accomplished by anaerobically digesting the sludge and using the digester gas as fuel for internal combustion engines. In large plants, when the sludge is sufficiently dewatered, it is also possible to recover energy by incinerating the dewatered sludge with production of steam in a waste heat boiler. The steam can then be used within the plant or expanded through a steam turbine to produce mechanical or electrical energy.

As part of the GWRC project titled Energy Efficiency in the Water Industry: A Compendium of Best Practices and Case Studies, WERF has developed this report summarizing existing information on well-established energy optimization/energy recovery best practices, as well as documenting a series of case studies of novel (yet full-scale proven) technologies/practices in wastewater treatment in primarily North America.