wetlands could be joined to attain higher treatment results, but the HSSF-VSSF and
VSSF-HSSF constructed wetlands are the best public hybrid systems (Vymazal et al.
2007).
2.3 Application of Constructed Wetlands
Constructed wetlands (CWs) are solid biological methods used for different types of
wastewater treatment (Brix 1997). CWs have been used successfully for the management of general sewage, tannery wastewater, piggery manure, and fishpond
water. Constructed wetlands are mostly used for municipal wastewater and industrial
wastewater. The industrial wastewater needs to be analyzing carefully industrial
effluents because the water composition is highly variable and toxic. The use of
constructed wetlands for industrial wastewater has improved over the past decade
(Korkusuz 2005; Kadlec et al. 2000).
Constructed wetlands are nonnatural or man-made wetlands constructed for
treating wastewater of industries, municipalities, and stormwater runoff. Plants,
microbes, sunlight, and gravity are used to transform wastewater into reusable
water by effective design of constructive wetlands. Water is treated through physical, biological, chemical mechanisms by means of filtering, absorption, and decomposition. Sewage water can be converted into reusable water by constructed
wetlands and built green belts around the communities; there is no machinery, but
all the processes are run naturally, and if there is limited space for constructed
wetlands, then the new wetlands are integrated with old ones so this will be more
efficient and inexpensive (Wastewater Gardens International). Constructed wetlands
are not a new concept; it has been used from the last two decades for treating the
contaminated water and wastewater (Murray-Gulde et al. 2005; Maine et al. 2006;
Zhang et al. 2014).
The natural wetland concept is too much old; it has been used from millions of
years. Natural wetlands or volunteer wetlands are mostly associated with mining
(Beining and Otte 1996, 1997). Constructed wetlands in the past have been used for
different purposes such as rehabilitating areas where wetlands were formerly located
to treat wastewater (Hawkins et al. 1997). In recent years, concern has been focused
on the removal of toxic metals from wastewater (Horne 2000). Mostly the substrate
interactions eliminate maximum toxic metals from polluted water in constructed
wetlands (Walker and Hurl 2002). The stable or temporarily toxic situation in
wetland soil helps to generate an atmosphere for the restriction of toxic metals in
the extremely concentrated sulfite or metallic form (Gambrell 1994). Constructed
wetlands are effective, cost-efficient, and environmentally sound approach for
treating polluted water (Brix 1997; Stottmeister et al. 2003).
Arias and Brix (2003) classify constructed wetlands on the base of dominant plant
species: macrophytes floating leaf (e.g., Nymphaea alba, Potamogeton gramineus);
macrophytes submersed (e.g., Potamogeton crispus, Littorella uniflora); macrophytes floating (e.g., Lemna minor, Eichhornia crassipes); and macrophytes
emerged rooted (e.g., Phragmites australis, Typha latifolia).
6 Constructed Wetlands: A Clean-Green Technology for Degradation and. . .
133
VSSF-HSSF constructed wetlands are the best public hybrid systems (Vymazal et al.
2007).
2.3 Application of Constructed Wetlands
Constructed wetlands (CWs) are solid biological methods used for different types of
wastewater treatment (Brix 1997). CWs have been used successfully for the management of general sewage, tannery wastewater, piggery manure, and fishpond
water. Constructed wetlands are mostly used for municipal wastewater and industrial
wastewater. The industrial wastewater needs to be analyzing carefully industrial
effluents because the water composition is highly variable and toxic. The use of
constructed wetlands for industrial wastewater has improved over the past decade
(Korkusuz 2005; Kadlec et al. 2000).
Constructed wetlands are nonnatural or man-made wetlands constructed for
treating wastewater of industries, municipalities, and stormwater runoff. Plants,
microbes, sunlight, and gravity are used to transform wastewater into reusable
water by effective design of constructive wetlands. Water is treated through physical, biological, chemical mechanisms by means of filtering, absorption, and decomposition. Sewage water can be converted into reusable water by constructed
wetlands and built green belts around the communities; there is no machinery, but
all the processes are run naturally, and if there is limited space for constructed
wetlands, then the new wetlands are integrated with old ones so this will be more
efficient and inexpensive (Wastewater Gardens International). Constructed wetlands
are not a new concept; it has been used from the last two decades for treating the
contaminated water and wastewater (Murray-Gulde et al. 2005; Maine et al. 2006;
Zhang et al. 2014).
The natural wetland concept is too much old; it has been used from millions of
years. Natural wetlands or volunteer wetlands are mostly associated with mining
(Beining and Otte 1996, 1997). Constructed wetlands in the past have been used for
different purposes such as rehabilitating areas where wetlands were formerly located
to treat wastewater (Hawkins et al. 1997). In recent years, concern has been focused
on the removal of toxic metals from wastewater (Horne 2000). Mostly the substrate
interactions eliminate maximum toxic metals from polluted water in constructed
wetlands (Walker and Hurl 2002). The stable or temporarily toxic situation in
wetland soil helps to generate an atmosphere for the restriction of toxic metals in
the extremely concentrated sulfite or metallic form (Gambrell 1994). Constructed
wetlands are effective, cost-efficient, and environmentally sound approach for
treating polluted water (Brix 1997; Stottmeister et al. 2003).
Arias and Brix (2003) classify constructed wetlands on the base of dominant plant
species: macrophytes floating leaf (e.g., Nymphaea alba, Potamogeton gramineus);
macrophytes submersed (e.g., Potamogeton crispus, Littorella uniflora); macrophytes floating (e.g., Lemna minor, Eichhornia crassipes); and macrophytes
emerged rooted (e.g., Phragmites australis, Typha latifolia).
6 Constructed Wetlands: A Clean-Green Technology for Degradation and. . .
133