What are wetland based sewage treatment systems?
What are wetland based sewage treatment systems?
Constructed wetlands are treatment systems that use natural processes involving wetland vegetation, soils, and their associated microbial assemblages to improve water quality.
What types of wastewater Do constructed wetlands treat?
Constructed wetlands can be used to treat raw sewage, storm water, agricultural and industrial effluent. Constructed wetlands mimic the functions of natural wetlands to capture stormwater, reduce nutrient loads, and create diverse wildlife habitat.
What are the three main types of constructed wetlands?
The three types of constructed wetlands discussed in this chapter are: 1) horizontal subsurface flow constructed wetlands, 2) horizontal free water surface flow constructed wetlands, and 3) vertical flow constructed wetlands. Constructed wetlands have been used to treat both centralized and on-site wastewater.
How do constructed treatment wetlands work?
Constructed wetlands are designed and built similar to natural wetlands to treat wastewater. They consist of a shallow depression in the ground with a level bottom. The flow is controlled in constructed wetlands so the water is spread evenly among the wetland plants.
What is a constructed wetland system?
Constructed wetlands are usually made up of a primary settlement tank where wastewater from the community is collected and from that, several ponds follow which are planted with wetland plants including reeds, rushes and sedges.
What are the disadvantages of constructed wetlands?
Disadvantages of constructed wetlands include high land area requirements (depending on the design, they may require a relatively large land area compared to a conventional facility), the need for a preliminary treatment before the wastewaters treated by the system (normally they do not used to treat raw wastewaters).
What are the components of constructed wetland?
Usually, the constructed wetland has three primary components: an impermeable layer (generally clay), a gravel layer that provides a substrate (i.e., an area that provides nutrients and support) for the root zone, and an above-surface vegetation zone.
Are constructed wetlands expensive?
Constructed wetlands are finding increasing uses communities because they cost less than conventional wastewater treatment plants. Also they readily can be accommodated in these areas, which have the land such systems require.
What is the main purpose of constructed wetlands?
A constructed wetland is used to recreate the treatment processes that occur in natural wetlands. Natural wetlands generally have visible water in the system. (NOTE: Natural wetlands are not to be used to treat wastewater. Constructed wetlands are sized and designed specifically to treat wastewater.)
What is the role of macrophytes in constructed treatment wetlands?
The structure of the Macrophytes role in constructed treatment wetlands macrospore system is dependent on the plant species and the conditions of growth, and can be very effective in channelling water through a bed of soil (Beven and Germann, 1982).
What are macrophytes and why are they important?
The macrophytes stabilise the surface of the beds, provide good conditions for pbysical filtration, prevent vertical flow systems from clogging, insulate against frost during winter, and provide a huge surface area for attached microbial growth.
What are the large aquatic plants growing in wetlands called?
The larger aquatic plants growing in wetlands are usually called macrophytes. These include aquatic vascular plants, aquatic mosses and some larger algae. The presence or absence of aquatic macrophytes is one of the characteristics used to define wetlands, and as such macrophytes are an indispensable component of these ecosystems.
What is a wetland?
Wetlands refer to a wide range of wet areas surrounded by land that are saturated with water (Brix, 1994).