<br>
{{procontable | pro=
- High reduction of BOD, suspended solids and pathogens <br>- Ability to nitrify due to good oxygen transfer <br>- Does not have the mosquito problems of the [[Free-Water Surface Constructed Wetland]]. <br> - Less clogging than in a [[Horizontal Subsurface Flow Constructed Wetland|Horizontal Flow Constructed Wetland]]. <br> - Requires less space than a Free-Water Surface Constructed or Horizontal Flow Wetland. <br> - High reduction in BOD, suspended solids and pathogens. <br> - Construction can provide short-term employment to local labourers.Low operating costs
| con=
- Constant source of electrical energy required. <br> - Not all parts Requires expert design and materials may be available locally. construction, particularly, the dosing system <br> - Requires expert design and supervision. more frequent maintenance than a Horizontal Subsurface Flow Constructed Wetland <br> - Moderate capital cost depending on land, liner, etc.; low operating costs. A constant source of electrical energy may be required <br> - Pre-treatment is required Long startup time to prevent clogging. work at full capacity <br> - Dosing system requires more complex engineering.Not all parts and materials may be locally available
}}
===AdequacyAppropriateness===The vertical flow constructed wetland is a good treatment for communities that have primary treatment (e.g., Septic Tanks, S.9), but are looking to achieve a higher quality effluent. Because of the mechanical dosing system, this technology is most appropriate where trained maintenance staff, constant power supply, and spare parts are available. Since vertical flow constructed wetlands are able to nitrify, they can be an appropriate technology in the treatment process for wastewater with high ammonium concentrations. Vertical flow constructed wetlands are best suited to warm climates, but can be designed to tolerate some freezing and periods of low biological activity.
Clogging ===Health Aspects/Acceptance=== Pathogen removal is a common problemaccomplished by natural decay, predation by higher organisms, and filtration. The risk of mosquito breeding is low since there is no standing water. Therefore, the influent The system is generally aesthetic and can be integrated into wild areas or parklands. Care should be well settled taken to ensure that people do not come in contact with primary treatment before flowing into the wetland. This technology is not appropriate for untreated domestic wastewater (i.e. blackwater)influent because of the risk of infection.
This is a good treatment for communities that have primary treatment (e.g. [[Septic Tank|Septic Tanks]] or [[Waste Stabilization Pond|WSPs]] but are looking to achieve a higher quality effluent. This is a good option where land is cheap and available, although the wetland will require maintenance for the duration of its life. There are many complex processes at work, and accordingly, there is a significant reduction in BOD, solids and pathogens. In many cases, the effluent will be adequate for discharge without further treatment. Because of the mechanical dosing system, this technology is most appropriate for communities with trained maintenance staff, constant power supply, and spare parts. Vertical Flow Constructed Wetlands are best suited to warm climates but can be designed to tolerate some freezing and periods of low biological activity. ===Health Aspects/AcceptanceOperation & Maintenance=== The risk of mosquito breeding During the first growing season, it is low since there is no standing water. The system is generally aesthetic and important to remove weeds that can be integrated into wild areas or parklandscompete with the planted wetland vegetation. Care Distribution pipes should be taken cleaned once a year to ensure remove sludge and biofilm that people do not come in contact with might block the influent because of the risk of infectionholes. ===Maintenance=== With time, the gravel will become clogged with by accumulated solids and bacterial film. The Resting intervals may restore the hydraulic conductivity of the bed. If this does not help, the accumulated material may have has to be removed and clogged parts of the filter material replaced every 8 to 15 or more years. Maintenance activities should focus on ensuring that primary treatment effectively lowers organics and is effective at reducing the concentration of solids concentrations in the wastewater before entering it enters the wetland. Testing may be required to determine Maintenanceshould also ensure that trees do not grow in the area as the suitability of locally available plants with roots can harm the specific wastewater. The vertical system requires more maintenance and technical expertise than other wetland technologiesliner.
===References===
* CritesBrix, RH. and TchobanoglousArias, GC. A. (19982005). [httpThe Use of Vertical Flow Constructed Wetlands for on-Site Treatment of DomesticWastewater://booksNew Danish Guidelines.google.com/books/about/Small_and_decentralized_wastewater_manag.html?id=yx9SAAAAMAAJ Small and Decentralized Wastewater Management Systems]. WCB and McGrawEcological Engineering 25 (5): 491-Hill, New York, USA. pp 599–609. Comprehensive summary chapter including solved problems500.
* MaraCrites, DDR. and Tchobanoglous, G. (20031998). [http://wwwSmall and Decentralized Wastewater Management Systems.pseau.orgWCB/outils/ouvrages/earthscan_ltd_domestic_wastewater_treatment_in_developing_countries_2003.pdf Domestic wastewater treatment in developing countries]. LondonMcGraw- Hill, EarthscanNew York, US. pp 85–187.599-609. (Comprehensive summary chapter including solved problems)
* Poh-EngKadlec, LR. H. and PolprasertWallace, CS. D. (19982009). [http://books.google.com/books/about/Constructed_Wetland_for_Wastewater_Treat.html?id=uo5vNAAACAAJ Constructed Treatment Wetlands for Wastewater Treatment and Resource Recovery], 2nd Ed. Environmental Sanitation Information CenterCRC Press, AITTaylor & Francis Group, BangkokBoca Raton, ThailandUS.
* Polprasert, CUN-HABITAT (2008)., et alConstructed Wetlands Manual. (2001)UN-HABITAT Water for Asian Cities Programme. Wastewater Treatment IIKathmandu, Natural Systems for Wastewater ManagementNP. Lecture Notes:Available at: [http://www. IHE Delft, The Netherlandsunhabitat. Chapter 6org unhabitat.org]
* Reed, SCU.S. EPA (19932000). [http:Constructed Wetlands Treatment of Municipal Wastewaters. EPA/625/R-99/water010. U.epaS. Environmental Protection Agency, Washington, D.gov/type/wetlands/restore/upload/2003_07_01_wetlands_pdf_subC.pdf Subsurface Flow Constructed Wetlands For Wastewater Treatment, A Technology Assessment]US. United States :Available at: [http://www.epa.gov Environmental Protection Agencyepa.gov], USA. Comprehensive design manual.
===Acknowledgements===
{{:Acknowledgements Sanitation}}
