Changes

sys2=[[Blackwater Treatment System with Infiltration|56]]|sys3=[[Blackwater Treatment System with SewerageEffluent Transport|67]]|sys4=[[Blackwater Transport to (Semi-) Centralized Treatment System|78]]| sys5=[[Sewerage System with Urine Diversion|89]]|

Output1=- Biomass |Output2= | Output3= | Output4= | Output5=

Water hyacinths are perennial, freshwater, aquatic macrophytes that grow especially fast in wastewater. The plants can grow large: between 0.5 to 1.2m 2 m from top to bottom. The long roots provide a fixed medium for bacteria which in turn degrade the organics in the water passing by.

Duckweed is a fast growing, high protein plant that can be used fresh or dried as a food for fish or poultry. It is also tolerant of a variety of conditions and can significantly remove significant quantities of nutrients from wastewater. ===Design Considerations=== Locally appropriate plants can be selected depending on their availability and the characteristics of the wastewater. To provide extra oxygen to a floating plant technology, the water can be mechanically aerated but at the cost of increased power and machinery. Aerated ponds can withstand higher loads and can be built with smaller footprints. Non-aerated ponds should not be too deep otherwise there will be insufficient contact between the bacteria-harbouring roots and the wastewater.

- Water hyacinth grows rapidly and is attractive. <br> - High reduction of BOD Potential for local job creation and solids; low reduction of pathogens. income generation <br> - Low to moderate Relatively low capital costcosts; operating cost costs can be offset by revenue. <br> - Potential for local job creation High reduction of BOD and income generation. solids; low reduction of pathogens <br> - Can be built and maintained with locally available materials. | con=- Can become an invasive species if released into natural environments. <br> - Requires a large land (pond) area.<br>}} ===Adequacy=== The technology can achieve high removal rates of both BOD and suspended solids, although pathogen removal is not substantial. Harvested hyacinths can be used as a source of fibre for rope, textiles, baskets, etc. Depending on the income generated, the technology can be cost neutral. Duckweed can be used as the sole food source to some herbivorous fish. This technology is only appropriate for warm or tropical climates with no freezing temperatures, and preferably with high rainfall and minimal evaporation. Different, locally appropriate - Some plants can be selected depending on availability and the wastewater type. Trained staff is required for the constant operation and maintenance of the pond.become invasive species if released into natural environments

===Health Aspects/AcceptanceAppropriateness===A floating plant pond is only appropriate when there is a sufficient amount of land (or pre-existing pond). It is appropriate for warm or tropical climates with no freezing temperatures, and preferably with high rainfall and minimal evaporation. The technology can achieve high removal rates of both BOD and suspended solids, although pathogen removal is not substantial.

Water hyacinth has attractiveHarvested hyacinths can be used as a source of fibre for rope, textiles, baskets, lavender flowersetc. A well designed and maintained system Depending on the income generated, the technology can add value and interest to otherwise barren landbe cost neutral. Adequate signage and fencing should Duckweed can be used to prevent people and animals from coming in contact with as the watersole food source for some herbivorous fish.

===MaintenanceHealth Aspects/Acceptance===Water hyacinth has attractive, lavender flowers. A well designed and maintained system can add value and interest to otherwise barren land. Adequate signage and fencing should be used to prevent people and animals from coming in contact with the water. Workers should wear appropriate protective clothing. WHO guidelines on wastewater and excreta use in aquaculture should be consulted for detailed information and specific guidance.

===Operation & Maintenance=== Floating plants require constant harvesting. The harvested biomass can be used for small artisanal businesses, or it can be composted. Mosquito problems can develop when the plants are not regularly harvested regularly. Depending on the amount of solids entering, that enter the pond , it must be desludged periodicallyde-sludged. Trained staff is required to constantly operate and maintain it.

* Abbasi, SA. (1987). Aquatic plant based water treatment systems in Asia. pp 175–198, In: [http://publichealth.sdsu.edu/publications/gersberg722.pdf Aquatic Plants for Water Treatment and Resource Recovery], K.R. Reddy and W.H. Smith (eds.), Magnolia Publishing Inc., Orlando, Florida. * Bagnall, LO., Schertz, CE. and Dubbe, DR. (1987). Harvesting and handling of biomass. pp. 599–619, In: [http://publichealth.sdsu.edu/publications/gersberg722.pdf Aquatic Plants for Water Treatment and Resource Recovery], K.R. Reddy and W.H. Smith (eds.), Magnolia Publishing Inc., Orlando, Florida. * Crites, R. and Tchobanoglous, G. (1998). [http://books.google.com/books/about/Small_and_decentralized_wastewater_manag.html?id=yx9SAAAAMAAJ Small and Decentralized Wastewater Management Systems]. WCB and /McGraw-Hill, New York, USA, US. pp 609–627. 609-627. (Comprehensive summary chapter including solved problems. * Gerba, CP., et al. (1995). Water-Quality Study of Graywater Treatment Systems. Water Resources Bulletin 31(1): 109–116. * Iqbal, S. (1999). [http://www.eawag.ch/forschung/sandec/publikationen/wra/dl/duckweed.pdf Duckweed Aquaculture-. Potentials, Possibilities and Limitations for Combined Wastewater Treatment and Animal Feed Production in Developing Countries]. Eawag (Department Sandec), Dübendorf, SwitzerlandCH.:Available at: [http://www.sandec.ch sandec.ch]

* McDonald, RDR. D. and Wolverton, BCB. C. (1980). [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19860066307_1986066307.pdf Comparative study Study of wastewater lagoon Wastewater Lagoon with and without water hyacinth]Water Hyacinth. Economic Botany: 34 (2): 101–110101-110.

* PolprasertReddy, CK.R. and Smith, et alW. H. (Eds. ) (20011987). Wastewater Aquatic Plants for Water Treatment IIand Resource Recovery. Magnolia Publishing Inc., Orlando, Natural Systems for Wastewater Management. IHEFL, Delft. (Comprehensive Design Manual: see Chapter 4 – Water Hyacinth PondsUS.)

* RoseSkillicorn, GDP., Spira, W. and Journey, W. (19991993). Duckweed Aquaculture. A New Aquatic Farming System for Developing Countries. The World Bank, Washington, D.C., US. (Comprehensive manual):Available at: [http://wwwdocuments.pseauworldbank.org/outilscurated/ouvragesen/crdi_community_based_technologies_for_domestic_wastewater_treatment_and_reuse_options_for_urban_agriculture_1999home documents.pdf Community-Based Technologies for Domestic Wastewater Treatment and Reuse: options for urban agriculture]worldbank. [http:org/curated/en/idrinfo.idrc.ca IDRC, Ottawahome].

* Skillicorn, WU., Journey, K. and Spira, PS. EPA (19931988). [http://infohouseDesign Manual.p2ricConstructed Wetlands and Aquatic Plant Systems for Municipal Water Treatment.orgEPA/ref625/091-88/08875022. U.htm Duckweed aquaculture: A new aquatic farming system for developing countries]S. World BankEnvironmental Protection Agency, WashingtonCincinnati, DCOH, US.:Available at: [http://www. Comprehensive manualepa.gov epa.gov]

* US Environmental Protection Agency WHO (19882006). Guidelines for the Safe Use of Wastewater, Excreta and Greywater. Volume 3: Wastewater and Excreta Use in Aquaculture. World Health Organization, Geneva, CH.:Available at: [http://waterwww.epawho.gov/type/wetlands/upload/designint who.pdf Design Manual: Constructed Wetlands and Aquatic Plant Systems for Municipal Wastewater Treatmentint]. USEPA, Cincinnati, Ohio.