Duckweed (L.gibba)-covered sewage lagoons (DSLs) are low cost treatment systems, especially suitable for warm climates, or in lands where there are warm seasons. This study attempts to assess DSL system as a new technology, contributing to the understanding of the different mechanisms in the system. Duckweed-covered sewage lagoons could either replace complete wastewater stabilization ponds (WSPs) or be introduced as a second stage in an integrated WSP-DSL treatment system, which could then be used for purifying municipal wastewater, achieving suitable effluent for reuse in agriculture. The duckweed harvested from DSL systems has, in itself, an intrinsic economic value.

Effective treatment of nitrogen containing wastewater is required to prevent eutrophication and groundwater pollution. This thesis shows that effective treatment may be combined with substantial nitrogen recovery in duckweed-based waste stabilization ponds.

The book aims to initiate a sustainable use of land and water resources in Central Asia by the transfer of scientific methods. It deals with the most advanced methods worldwide for better monitoring and management of water and land resources. We offer an array of methods of measuring, assessing, forecasting, utilizing and controling processes in agricultural landscapes. These are laboratory and field measurement methods, methods of resource evaluation, functional mapping and risk assessment, and remote sensing methods for monitoring and modeling large areas. The book contains methods and results of data analysis and ecosystem modeling, of bioremediation of soil and water, field monitoring of soils, and methods and technologies for optimizing land use systems as well. The chapter authors are inventors and advocators of novel transferrable methods. The book starts with an analysis of the current state of water and land resources. Finally concrete proposals for the applicability of novel methods are given.

Affordable and effective domestic wastewater treatment is a critical issue in public health and disease prevention around the world, particularly so in developing countries which often lack the financial and technical resources necessary for proper treatment facilities. This practical guide provides state-of-the-art coverage of methods for domestic wastewater treatment and provides a foundation to the practical design of wastewater treatment and re-use systems. The emphasis is on low-cost, low-energy, low-maintenance, high-performance 'natural' systems that contribute to environmental sustainability by producing effluents that can be safely and profitably used in agriculture for crop irrigation and/or in aquaculture, for fish and aquatic vegetable pond fertilization. Modern design methodologies, with worked design examples, are described for waste stabilization ponds, wastewater storage and treatment reservoirs; constructed wetlands, upflow anaerobic sludge blanket reactors, biofilters, aerated lagoons and oxidation ditches. This book is essential reading for engineers, academics and upper-level and graduate students in engineering, wastewater management and public health, and others interested in sustainable and cost-effective technologies for reducing wastewater-related diseases and environmental damage.

Water reuse management is one of the challenges all water scarce countries have to deal with in the coming decades. The present book highlights non-conventional solutions within the field of wastewater treatment and reuse predominantly for professionals and decision makers. It focuses on technologies which are reliable, sustainable, low cost and suitable for rural and sub urban areas. In addition, particularly innovative on-site concepts are presented.

Adopting a multi-disciplinary approach, Decentralised Sanitation and Reuse places public sanitation in a global context and provides a definitive discussion of current state-of-the-art sanitation technologies. It shows how these technologies can be implemented to integrate domestic waste and wastewater treatment in order to maximize resource recycling in domestic practice. Decentralised Sanitation and Reuse presents technical solutions for on-site collection and transport of concentrated waste streams, and focuses on the compromise between reliability and minimal water wastage. A whole range of available sustainable technologies, both low and high-tech, to treat concentrated (black water) and diluted (grey water) streams are addressed in detail from the fundamental scientific and engineering points of view. Sociological, economic and, particularly, environmental and public health aspects are essential issues within this book. The necessity of new infrastructure implementation and the resulting challenges for a good number of economic branches are illustrated with examples from architecture and town planning. Decentralised Sanitation and Reuse will be an invaluable resource for a wide academic and professional readership active in the fields of environmental protection and public sanitation. Contents The DESAR concept for environmental protection Waste and wastewater characteristics and its collection on the site Technological aspects of DESAR Environmental and public health aspects of DESAR Sociological and economic aspects of DESAR Architectural and urbanistic aspects of DESAR

With contributions from over 70 international experts, this reference provides comprehensive coverage of plant physiological stages and processes under both normal and stressful conditions. It emphasizes environmental factors, climatic changes, developmental stages, and growth regulators as well as linking plant and crop physiology to the production of food, feed, and medicinal compounds. Offering over 300 useful tables, equations, drawings, photographs, and micrographs, the book covers cellular and molecular aspects of plant and crop physiology, plant and crop physiological responses to heavy metal concentration and agrichemicals, computer modeling in plant physiology, and more.