Small Decentralized Wastewater Management Systems

Decentralized Wastewater Management presents a comprehensive approach to the design of both conventional and innovative systems for the treatment and disposal of wastewater or the reuse of treaded effluent. Smaller treatment plants, which are the concern of most new engineers, are the primary focus of this important book.

This text presents a design of alternative collection systems, both conventional and experimental, for the treatment and disposal of the treated effluent. The book focuses particularly on smaller treatment plans and individual decentralized systems.

In December 2002, a group of specialists on water resources from the United States and Iran met in Tunis, Tunisia, for an interacademy workshop on water resources management, conservation, and recycling. This was the fourth interacademy workshop on a variety of topics held in 2002, the first year of such workshops. Tunis was selected as the location for the workshop because the Tunisian experience in addressing water conservation issues was of interest to the participants from both the United States and Iran. This report includes the agenda for the workshop, all of the papers that were presented, and the list of site visits.

Less expensive and more environmentally appropriate than conventional engineering approaches, constructed ecosystems are a promising technology for environmental problem solving. Undergraduates, graduate students, and working professionals need an introductory text that details the biology and ecology of this rapidly developing discipline, known as

"This manual contains overview information on treatment technologies, installation practices, and past performance."--Introduction.

Centralized wastewater treatment, widely practiced in developed areas, involves transporting wastewater from large urban or industrial areas to a large capacity plant using a single network of sewers. Alternatively, the concept of wastewater collection, treatment and reuse at or near its point of generation is called decentralized wastewater treatment. Smaller decentralized plants with energy-efficient reclaimed water pumping, modularization of expansion and minimum capital investment can meet the increasing need for reclamation and wastewater management accessibility in rapidly developing regions Decentralized treatment can improve access to wastewater infrastructure in developing regions and improve energy-efficiency in reclamation in many rapidly growing developed regions. They can also replace land-intensive and inefficient treatment systems such as septic tanks and leach fields for remote, residential communities. They can reduce the strain on existing central facilities and can be an alternative to expensive collection system upgrades. We demonstrated the applicability of decentralized treatment to two examples in India and an example in Los Angeles. It is important to study the optimization and implications of decentralization. We formulated design and optimization methodology subject to user-defined constraints for a decentralized configuration of several treatment plants and collection networks. In this dissertation we developed an algorithm, using a constrained multi-objective optimization method (Genetic Algorithm), to obtain feasible decentralized configurations with minimum cost and energy. The applications of this methodology include obtaining the optimal solution for a given scenario, comparing alternative solutions devised by the user, and analyzing capacity expansion. Enabling easier reclamation and a more widespread access to wastewater collection and treatment are the chief motivation behind this study.

In many countries, a rapidly upcoming demand for decentralised wastewater treatment systems (DEWATS) and a demand for efficient community-based sanitation (CBS) can be observed. DEWATS is designed to be an element of a comprehensive strategy for city-wide planning and sustainable infrastructure development. In this book, not only are the technical requirements for the efficient treatment of wastewater at a given location explained, but the specific socio-economic conditions and steps for community action planning are also taken into consideration.

Around 2004, members of governmental and nongovernmental organizations, science institutes, and private companies throughout India began brainstorming and then experimenting with small-scale treatment systems that could produce usable water from wastewater. Through detailed case studies, Microbial Machines describes how residents, workers, and scientists interact with technology, science, and engineering during the processes of treatment and reuse. Using a human-machine-microbe framework, Kelly Alley explores the ways that people's sensory perceptions of water--including disgust--are dynamic and how people use machines and microbes to digest wastewater. A better understanding of how the human and nonhuman interact in these processes will enable people to generate more effective methods for treating and reusing wastewater. While decentralized wastewater treatment systems may not be a perfect solution, they alleviate resource stress in regions that are particularly hard hit by climate change. These case studies have broad relevance for solving similar problems in many other places around the world.