Water Recycling Home Page
Content Table
- Recycled Water as a Valuable Resource
- History and Development of Water Recycling
- Recycled Water Quality
- Regulating Water Recycling
- Treatment and Distribution of Recycled Water
- Beneficial Use of Recycled Water
- Water Recycling Showcase
- Water Recycling Planning and Economics
- Talking about Recycled Water
- Water Recycling Information and Resources
- General Articles
- Related Articles
- References
- Links
Recycled Water as a Valuable Resource
In many parts of the World, freshwater supplies are limited. Rainfall and river flows are often seasonal and intermittent. Growing water needs are causing increased competition for available supplies. In some regions, the amount of water available is being reduced by global warming and climate change.
Until recently, most of the water used for human activities was used once, then discharged back to the environment.
Water recycling – recovering used water and supplying it again for beneficial uses – allows greater human benefit to be obtained from available freshwater supplies. Water recycling conserves existing water resources and reduces the need for new freshwater supplies.
Recycled water is a valuable water resource.
History and Development of Water Recycling
A history of the development of water recycling can be found in Asano et al (2006).
Recycled Water Quality
Matching recycled water quality to beneficial uses requires an understanding of health and environmental requirements. Measures to ensure recycled water quality are determined firstly by treatment. The degree of treatment depends in part on the hydraulic and biochemical characters of the wastewater. The treatment process units used depend on the intended use of the recycled water. Overall recycled water outcomes may also be controlled by how recycled water is distributed and handled. Risk assessment and system management measures may improve outcomes. Water should be judged on its quality, not its history.
The Recycled Water Quality pages include information on:
· The Star Rating system for recycled water quality;
· Health and environment protection measures;
· Health studies and risk assessment.
Regulating Water Recycling
In most countries, the use of recycled water is subject to regulations and guidelines designed to protect public health and the environment. Some water recycling projects may require environmental assessment and regulatory authority approvals to ensure that public interests are addressed.
Treatment and Distribution of Recycled Water
When water is used for washing, cleaning and flushing, it picks up a wide range of substances. Wastewater from urban areas contains dirt and dissolved salts, minerals, chemicals and organic matter from human wastes, food wastes, cleaning products etc. Stormwater drainage from urban areas may also carry large amounts of dirt and dissolved substances from human activity. Runoff from farmland may contain wastes from animals, nutrients from fertilisers and chemicals from pesticides.
Before used water can be recycled for beneficial uses, it requires treatment to recover the water and separate out the solid and dissolved substances. The recovered water needs to be treated to a quality which is suitable for the intended uses. Recycled water needs to be “fit-for-purpose”.
The treatment processes required to produce recycled water commonly involve standard wastewater treatment process units followed by various advanced treatment process units to provide clarification, filtration, removal of organics, and disinfection.
Beneficial Use of Recycled Water
Beneficial uses of recycled water include:
· Residential, commercial and municipal uses,
· Industrial uses
· Agricultural uses
· Environmental and recreational uses
· Augmenting water supplies
Water Recycling Showcase
Case studies of successful water recycling projects will be added to the Water Recycling Showcase pages by the IWA Water Recycling Specialist Group.
Water Recycling Planning and Economics
The costs and benefits of water recycling projects should be evaluated against the costs of obtaining alternative freshwater supplies. The Water Recycling Planning and Economics pages include:
· discussion of economic evaluation approaches for water recycling projects;
· project funding mechanisms.
Talking about Recycled Water
Community understanding of water and environmental issues is increasing. There have been many cases where water recycling projects have been controversial but also many successful projects with strong public support. Considerable experience has been gained about the issues affecting community acceptance of water recycling and the conduct of community consultation and education programs. Information on these subjects can be found in the Talking about Recycled Water pages.
Water Recycling Information and Resources
The IWA and its Water Recycling Specialist Group aim to make water recycling information available through IWA WaterWiki and to provide linkages to other sources of water recycling information. The information posted by the Specialist Group can be found in the Information and Resources pages.
General Articles
Several authors have posted general articles about water reclamation, recycling and reuse.
Related Articles
History and Development of Water Recycling
General Articles on Water Recycling
References
Asano, T. et al (2007) Water reuse: issues, technologies and applications, McGraw-Hill New York, ISBN-13: 978-0-07-145927-3
Jiminez, B. & Asano, T. (2008) Water Reuse: An international survey of current practice, issues and needs, IWA Publishing, London, ISBN1843390892
Links
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