This document discusses waste water purification using constructed wetlands. It begins by explaining that improper waste water disposal pollutes water bodies and harms organisms. Constructed wetlands are proposed as an effective tertiary treatment for domestic waste water. Constructed wetlands are artificial shallow wetland systems with plants that naturally treat waste water through processes like sedimentation, filtration, and microbial digestion. They have advantages over conventional treatment in being lower cost and more sustainable while effectively removing pollutants. The document outlines the types, processes, advantages and some challenges of constructed wetland waste water treatment.

1. WASTE WATER PURIFICATION USING
CNSTRUCTED WETLANDS
PRESENTED BY
AGLAIA

2. Introduction
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 The major environmental pollution is caused by improper disposal wastewater,
due to the outflow of effluents from various areas of sources.
 This pollution also interferes with the growth of organisms living in the water
bodies, thus retarding the natural purification process caused by such organisms.
 Hence treatment of this water becomes very necessary.
 Some of the suitable wastewater treatment processes for domestic wastewater
include biological treatment processes, such as activated sludge, trickling filter,
and rotating biological contractor systems.
 The treated wastewater from these types of wastewater treatment plants might
require further treatment with a tertiary treatment process, such as a constructed
wetland (CW), to improve the treated wastewater quality.

3. What is a wetland???
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 It is a land area that is saturated with water , either permanently or seasonally,
such that it takes on the characteristics of a distinct ecosystem .
 The primary factor that distinguishes wetlands from other land forms or water
bodies is the characteristic vegetation of aquatic plants , adapted to the unique
hydric soil.

4. Natural wetland
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 Natural wetland systems have often been described as the “earth’s kidneys”
because they filter pollutants from water that flows through on its way to
receiving lakes , streams and oceans.
Fig:1 Natural wetland
Source:http://i.livescience.com

5. What are constructed wetlands..?
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 They are small artificial wastewater treatment systems consisting of one or more
shallow treatment cells, with herbaceous vegetation that flourish in saturated or
flooded cells.
 They are usually more suitable to warmer climates.
 In these systems wastewater is treated by the processes of sedimentation,
filtration, digestion, oxidation, reduction, adsorption and precipitation.
 It generally consist of six chambers

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o Each chamber consists of four cells:
o Within each cell are water hyacinth plants
 They removes solids, dissolved solids, nutrients, and pathogens.
 Constructed wetlands are most economical as compared to conventional
treatment units which needs more energy for its process and this method require
cheaper materials.

7. 20 July 2019waste water purification using constructed wetlands7
Fig:2 constructed_wetland.jpg
Source:http://enacademic.com

8. 20 July 2019waste water purification using constructed wetlands8
Fig:3layout of an integrated constructed wetland.
Source:https://www.water.ie

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Constructed
wetlands
Sub Surface
flow
Vertical
Flow
Horizontal
Flow
Surface flow
Up Flow
Down Flow
Types of constructed wetlands

10. Processes in constructed wetlands
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 Wetland can effectively remove or convert large quantities of pollutants including organic matter,
suspended solids, metals and nutrients.
 The focus on wastewater treatment by constructed wetlands is to optimise the contact of microbial
species with substrate, the final objective being the bioconversion to carbon dioxide, biomass and water.
Wetlands are characterized by a range of properties that make them attractive for managing pollutants in
water (Bavor and Adcock, 1994). These properties include high plant productivity, large adsorptive
capacity of the sediments, high rates of oxidation by microflora associated with plant biomass, and a large
buffering capacity for nutrients and pollutants. 1. Biological processes: There are six major biological
reactions involved in the performance of constructed wetlands, including photosynthesis, respiration,
fermentation, nitrification, denitrification and microbial phosphorus removal (Mitchell, 1996b).
Photosynthesis is performed by wetland plants and algae, with the process adding carbon and oxygen to
the wetland. Both carbon and oxygen drive the nitrification process. Plants transfer oxygen to their roots,
where it passes to the root zones (rhizosphere). Respiration is the oxidation of organic carbon, and is
performed by all living organisms, leading to the formation of carbon dioxide and water. The common
microorganisms in the CW are bacteria, fungi, algae and protozoa. The maintenance of

11. Advantages
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 Long life and robustness
 Lower Cost
 Adaptability & Flexibility of treatment
 Simplicity and auto-organization
 Aesthetics
 Highly productive system and Water
saving
 No additional pollution nor chemical
products
 Protection of vital ecosystems such as
rivers, lakes, oceans, groundwater
sources and soils.
 High efficiency in Total Suspended
Solids removal

12. Challenges
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 Lack of Professionalism / Experience in constructing Wetlands.
 Local terrain not always possible
 Ignorance by public health officials and engineers
 Significantly longer design phase
 It requires agronomical knowledge in addition to standard plumbing
maintenance.

13. Conclusion
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 Constructed wetlands with horizontal subsurface flow have successfully been
used for treatment of domestic wastewater.

14. References
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 Almeida A., Catarino A., Ribeiro C., Carvalho F., Prazeres A.(2016). VFCW
applied to treatment of cheese whey wastewater pretreated by basic precipitation:
Influence of bed depth. 15th IWA International Conference on Wetland Systems
for Water Pollution Control, Gdańsk, Poland p. 28–38.
 Anastasiou n., Monou m., Mantzavinos d., Kassinos d. (2009). Monitoring of
the quality of winery influents/effluents and polishing of partially treated winery
flows by homogenous Fe(II) photooxidation. Desalination. Vol. 248. Iss. 2
 Berninger k., Koskiaho j., Tattari s. (2012). Constructed wetlands in Finish
agricultural environments: balancing between effective water protection, multi
functionallity and socio-economy. Journal of Water and Land Development. No.
17 p. 19–29. COOPER P. 2005.

15. 20 July 2019waste water purification using constructed wetlands15
 Davison l., Headley T., Pratt k. (2005). Aspects of design, structure,
performance and operation of reed beds – eight years experience in
northeastern New South Wales, Australia. Water Science and Technology. Vol.
51. Iss. 10 p. 129–138.
 Demirel B, Yenigum O, Onay T.T (2005). Anaerobic treatment of dairy
wastewater: A review. Process Biochemistry. Vol. 40. Iss. 8 p. 2583–2595.
 Fernandez B, Seijo I, Ruiz-Filippi G, Roca E., Tarenzi l., Lema J. (2007).
Characterization, management and treatment of wastewater from white wine
production. Water Science and Technology. Vol. 56. Iss. 2 p. 121– 128.

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 Gannoun H., Bouallagui H., Okbi A., Sayadi S., Hamdi M. (2009).
Mesophilic and thermophilic anaerobic digestion of biologically
pretreated abattoir wastewaters in an upflow anaerobic filter. Journal
of hazardous materials. Vol. 170. Iss. 1 p. 263–271.
 Grismer M E, Carr M.A, Shepherd H.L (2003). Evaluation of
constructed wetland treatment performance for winery wastewater.
Water environment research. Vol. 75. Iss. 5 p. 412–421.
 Hawkins W B., rodgers J.H, jr., dunn A.W., dorn P.B cano M.L.
(1997). Design and construction for aqueous transfers and
transformations of selected metals. Ecotoxicol. Environ. Saf. No. 36 p.
238–248

17. Thank you
For more…. Mail to aglaiaconnect2018@gmail.com