What is free water surface wetland?
What is free water surface wetland?
DESCRIPTION. Free water surface (FWS) wetlands are defined as wetland systems where the water surface is exposed to the atmosphere. Most natural wetlands are FWS systems, including bogs (primary vegetation mosses), swamps (primary vegetation trees), and marshes (primary vegetation grasses and emergent macrophytes.)
How do you measure a constructed wetland?
Constructed Wetland Cell Lengths to width ratios are 2:1 (or less). For example, a two bedroom home would require 300 square feet of wetland area with dimensions of 25 by 12 feet. A constructed wetland cell for a three bedroom home may have dimensions of 30 by 15 feet.
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.
What is constructed wetland system?
A constructed wetland is an organic wastewater treatment system that mimics and improves the effectiveness of the processes that help to purify water similar to naturally occurring wetlands.
How effective are constructed wetlands?
If properly built, maintained and operated, constructed wetlands can effectively remove many pollutants associated with municipal and industrial wastewater and stormwater. Such systems are especially efficient at removing contaminants such as BOD, suspended solids, nitrogen, phosphorus, hydrocarbons, and even metals.
What are the free water surface and subsurface constructed wetlands?
A free-water surface constructed wetland (also called free water surface, FWS) is a series of flooded planted channels or basins. It aims to replicate the naturally occurring processes of a natural wetland, marsh or swamp.
How can we use wetlands to treat sewage?
What are the limitations of constructed wetlands?
The main disadvantages associated with the (SF) constructed wetland are: 1. The large land area required 2. The unpleasant odor that can be associated with certain types of effluent being treated.
What is a vertical flow constructed wetland?
A vertical flow constructed wetland is a planted filter bed that is drained at the bottom. Wastewater is poured or dosed onto the surface from above using a mechanical dosing system. The water flows vertically down through the filter matrix to the bottom of the basin where it is collected in a drainage pipe.
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 is the main purpose of constructed wetlands?
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 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.
What are constructed wetlands used for?
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 are the components of a constructed wetland?
What is the purpose of a constructed wetland?
How does a constructed wetland work?
How do constructed wetlands work? Wastewater flows through a pipe from a septic tank or other type of primary wastewater treatment system into the constructed wetland. Wastewater can either flow on top of the existing soil (surface) or through a porous medium such as gravel (subsurface).
What is a free water surface constructed wetland?
A free-water surface constructed wetland aims to replicate the naturally occurring processes of a natural wetland, marsh or swamp. As water slowly flows through the wetland, particles settle, pathogens are destroyed, and organisms and plants utilize the nutrients.
What is FWS constructed wetland analysis?
The analysis employs models for FWS constructed wetland design, considering simultaneously the removal requirements and the hydraulics of the system. On the basis of these models, a step-by-step methodology is developed outlining the design procedure for new and performance evaluation for existing FWS constructed wetland systems.
Is there an optimal design for constructed wetland systems?
Thus, optimal design of constructed wetland systems has not yet been determined. However, in order to take advantage of [43,44] models and ease complexity of computation, [24] presented a simplified approach for the design and sizing of FWS constructed wetlands using the two equations.
How to construct a water level structure for a wetland?
situations and the objectives of the wetland (Figure 8, 9, 10, 11). The water level structure should be constructed in a weir or embankment. The embankment needs to be constructed with an impervious core to reduce seepage and to ensure stability.