The power point presentation is about constructed wetlands and wastewater treatment.

1. Credit Seminar
“CONSTRUCTED WETLANDS FOR WASTEWATER
TREATMENT”
Couse No. :- SWE 591
Course Instructor: Dr. K.G.Singh
Principal Scientist (SWE)
Presented by:- Aamir Ishaq Shah
Enrolment ID:- L-2019-AE-9-D
1

2. Water scarcity and the decline in water quality are two major issues we are facing today.
In India, only 23% of wastewater is being treated, mostly at primary level prior to
disposal (CPCB, 2015).
Punjab state has experienced a major problem of water crisis due to declining water
table and increasing surface/ ground water pollution.
Ludhiana district conveys 764 MLD of its industrial wastewater into Sutlej.
The wastewater if treated properly can serve as a major resource.
Introduction
2

3. Rising levels of wastewater has serious consequences.
Harmful effect on river and marine life
Lack of drinking water
Overabundance of certain harmful chemicals, some of which
are chronic
Adverse effect on groundwater
Soil pollution
Rise in chronic health conditions related to toxic chemicals
However, wastewater treatment is quite expensive.
A more sustainable solution to wastewater treatment
are the wetlands.
Need for Water Quality treatment?
3

4.  A wetland 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.
What is a Wetland???
Wetland
Natural
Constructed
4

5. 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.
The local village ponds are also an example of wetlands.
Our efforts can be aimed at either reviving the already available wetland or development
of constructed wetlands.
The Government of Punjab has launched a plan to revive dirty village ponds for fish
farming by adopting duckweed technology.
Around 20 systems have been implemented in rural Punjab so far (PSCST 2003; Ansal et
al. 2010), but no evaluation of the performance is available.
A water hyacinth pond is located close to a rural community in Naruana near Bathinda,
Punjab and receives 0.25 ML/D of domestic wastewater from the local households.
Natural Wetland
5

6.  Constructed wetlands (CWs) are engineered systems
designed and constructed to utilize the natural
functions of wetland vegetation (Kadlec and Knight,
1996).
 Constructed wetlands shallow (usually less than 1 m
deep) ponds or channels planted with aquatic
plants.
 One example of a CW as secondary treatment system
is located in Bhopal, Madhya Pradesh.
 It was evaluated after its implementation in 2003 by
Vipat et al. (2008) and treats 0.5 ML/D of
wastewater collected from the households of the
slum area where it is located.
Constructed wetlands
6

7. Constructed
Wetland
Surface
Flow
Sub Surface
Flow
Vertical Flow
Horizontal
Flow
TYPES
7

8. Basic design of constructed wetlands
0.1m stone
Rice Husk
0.7m
Different materials can be used. e.g. Phosphorus removal
construction material have been found to perform better
0.1m
Sand
A floating mat for supporting algae
1 m
Sampling pit
0.1m
3m
On repeat
Sampling
pit
8

9. Removal mechanism
 Organic matter : Aerobic microbial degradation
Anaerobic microbial degradation
 Suspended solids:
Sedimentation
Filtration
 Pathogens : Sedimentation
Filtration
Natural die-off
Predation
UV radiation
9

10. Removal mechanism
 Nitrogen : Nitrification and denitrification
Plant uptake
Matrix adsorption
 Phosphorus : Matrix absorption
Plant uptake
 Metals : Adsorption and cation exchange
Complexation
Precipitation
Plant uptake
Microbial oxidation/reduction 10

11. The use of plants to degrade a variety of pollutants present in wastewater.
 Heavy Metals
 Trace metals
 Nutrients
 Organics
 Pathogens
Diagram courtesy USEPA Office of Solid Waste
http://clu-in.org/download/citizens/citphyto.pdf
Phytoremediation
11

12. Water Hyacinths Eichhornia crassipes
Forage Kochia Kochia spp
Poplar Trees Populus spp
Willow Trees Salix spp
Alfalfa Medicago sativa
Cattail Typha latifolia
Coontail Ceratophyllum demersvm L
Bullrush Scirpus spp
Reed Phragmites spp.
American pondweed Potamogeton nodosus
Common Arrowhead Sagittaria latifolia
Various Plant Types
12

13. Advantages of constructed wetlands
Cheaper than Traditional Counterparts
Community Interaction
Prolonged Compensation via potential “products”
Wetlands can also provide wildlife habitat and be more aesthetically pleasing than
other water treatment options
Subsurface wetlands produce no biosolids or sludge that requires disposal
13

14. CWs have been mostly utilized to treat domestic recently, the application of CWs has been
increasingly extended to address other types of wastewaters including:-
Industrial wastewaters (Maine et al., 2007)
Agricultural wastewaters (He et al., 2006)
Lake waters (Martín et al., 2013)
Sludge treatment effluent (Kantawanichkul et al., 2003)
Stormwater runoff (Ávila et al., 2013)
Hospital wastewaters (Shrestha et al., 2001)
Winery wastewaters (Serrano et al., 2011)
Recent trends and applications
14

15. The Country's first constructed wetland. of 90m x 30m size. was installed at Sainik
School, Bhubaneshwar in the State of Orissa.
Two types of macrophytes, viz. Typha latifolia and Phragmites carea, were planted.
15
Constructed wetlands in India

16. The comparative study of nitrogen and phosphate removal from vegetated and
unvegetated constructed wetlands shows that the presence of plants makes a difference in
nutrient removal as shown in Table 2.
The nitrogen removal in the unvegetated wetland was 20 to 28% as compared to 66-73%
in the vegetated wetlands system. Similarly phosphate removal in vegetated system was
more than the unvegetated.
Role of vegetation
Type of Wetlands % Removal
Total Nitrogen Total Phosphate BOD
Vegetated 65-73 28-41 78-90
Unvegetated 20-27 12-17 58-68
Table 2. Removal of nitrogen, phosphate and BOD from vegetated and unvegetated wetlands
16

17. Case studies
S.no. Title Author and submission journal
01 Domestic wastewater treatment through constructed wetland in
India
A. S. Juwarkar et. al., (1995)
Water Sci. Tech.
02 Municipal wastewater treatment in horizontal and vertical flows
constructed wetlands
Sohair et. al., (2013)
Ecological Engineering
03 Industrial wastewater treatment in constructed wetlands packed
with construction materials and agricultural by-products
Saeed et. al., (2018)
Journal of cleaner production
04 Removal of dissolved metals in wetland columns filled with shell
grits and plant biomass
Firoozeh et. al., (2018)
Chemical Engineering Journal
05 Horizontal subsurface flow constructed wetlands as tertiary
treatment: Can they be an efficient barrier for microplastics
pollution?
Qintong Wang (2020)
Science of the Total Environment
17

18. Case Study-1
Domestic Wastewater Treatment Through Constructed Wetland in India
18

19. Study area
Figure I. Design of constructed wetland installed at Bhubanesbwar 19

20. • The mean concentration of nitrogen, phosphate and BOD in the inflow and the outflow
from the constructed wetlands which received primary treated wastewater at the rate 5
cm/day are presented in Table 1.
Results and discussion
20

21. Further, it was also observed that the removal efficiency of N was greater in the case of
Phragmites carca due to profuse growth as compared to Typha latifolia .
Removal of phosphate in the wetland was comparatively less than nitrogen and it
ranged from 23 to 48%.
The removal of nitrogen is mostly attributed to nitrification-denitrification followed by
plant removal.
Co-precipition of phosphate along with plant removal are considered to be the major
processes for phosphate removal.
Results and discussion
21

22. Phragmites carca was more efficient in N removal compared to Typha latifolia. Further,
it gets established quickly and grows profusely.
The constructed wetland seems to be a cost-effective alternative to conventional
treatment processes which involve huge energy and cost.
Being simple in installation and operation, a wetland system for wastewater treatment
can be adopted in small towns and villages.
Wetlands performance is affected by rainfall, temperature etc. Since it is not site
specific, the system can be implemented near the wastewater source.
Conclusions
22

23. Case Study-2
Industrial wastewater treatment in constructed wetlands packed with construction
materials and agricultural by-products
23

24. The study was carried in University of Asia Pacific, Dhaka, Bangladesh.
Shyampur industrial area of Dhaka city includes different industries such as steel
mills, paper and dyeing factories.
Wastewaters generated from these industries do not receive any treatment and are
discharged into river Buriganga through a common drainage outlet.
Collected wastewater was transported to the experimental site, and was stored in feed
tanks before being dosed into the experimental wetland systems.
Study area
24

25. Methodology
Figure 1 provides a schematic diagram of the experimental wetland units
Construction of the wetland systems
Construction materials i.e. recycled bricks (5.0-10.0 mm size) were employed as
the main media in VF and HF wetlands A1 and B1 respectively.
On the other hand, VF and HF wetlands A2 and B2 were packed with agricultural
by-products i.e. organic sugarcane bagasse.
All wetland units were planted with Canna indica and were waterlogged for eight
weeks to allow proper growth.
25

26. During experimental campaign wastewater was collected on a weekly basis from inlet
and outlet of each wetland unit.
The analyzed parameters included
• pH
• Dissolved oxygen (DO)
• Ammonium nitrogen (NH4-N)
• Nitrite nitrogen (NO2-N),
• Nitrate nitrogen (NO3-N)
• Total nitrogen (TN)
• Total phosphorus (TP)
• Sulfate (SO4 five days biochemical oxygen demand (BOD5)
• chemical oxygen demand (COD)
• Total suspended solids (TSS) and color compounds.
Methodology
26

27. Wastewater dosing
Collected mixed industrial wastewater was dosed into the experimental systems
between April - October, 2017.
During weeks 1-8 of experimental analyses campaign (non recirculation phase),
wastewater was dosed manually into VF wetlands A1 and A2 at loading rate 219.3
mm/d (across each VF system), two times a day, five days a week; time interval was
three hours between two dosing.
Effluents produced from such VF wetlands were again transferred into VF wetlands
(i.e. 100.0% recirculation rate); outputs of VF systems (after 100.0% recirculation)
were transferred into following HF systems (by gravity) producing final effluents.
Methodology
27

28. Results
Mean pollutant removal profiles across experimental VF and HF wetland systems have been presented in Table 1.
28

29. Results
Table 2. Mean pollutant concentration (mg/L) profiles across experimental wetland units.
29

30. Results
Mean input nitrogen, organics, solids and
phosphorus loadings were 3.7 g TN/m2 239 d,
43.5 g BOD/m2 d, 240.8 g COD/m2 d, 47.7 g
TSS/m2d and 1.0 g TP/m2d respectively
across the first stage of both hybrid wetland
trains.
Removal performances of the wetland units
under such loading rates have been presented
in Figure 2.
30

31. Nitrogen removal in constructed wetlands is often controlled by classical
denitrification route, where NO3-N is converted to N2 gas.
Table 1 and Figure 2 illustrate higher NO3-N and TN removals in VF wetland A2 (with
organic sugarcane media), when compared A1 system packed with recycled brick
materials.
Input COD/TN (of industrial wastewater) ratio values were substantial (i.e. 20.0-
247.0) to support denitrification in experimental wetlands, due to presence of
recalcitrant compounds.
Results
31

32. P removals were substantially higher in system A1-B1 packed with recycled brick
media.
P removals were higher in HF system B1; higher retention time (due to greater surface
area and porosity) allowed better mixing between wastewater and P adsorbing brick
substrate.
 In contrast, lack of P adsorbing contents in organic sugarcane bagasse media lowered P
removal performances across A2-B2 hybrid system.
Overall P removal percentage across system A1-B1 (that included recycled brick
materials) coincided within such reported values.
Results
32

33. Lower biodegradation ratio of the mixed industrial wastewater allowed physical
organics removal pathways in VF and HF wetlands of A1-B1 system, that were packed
with recycled brick materials.
On the other hand, microbial routes supported organics removals in wetland units of
A2-B2 system, due to C contents of the employed sugarcane bagasse material.
Higher porosity of recycled brick increased retention time and oxygen diffusion inside
the media, which improved nitrification in VF wetland A1.
Higher P removals were achieved across hybrid wetland system A1-B1, due to P
adsorption by the employed recycled brick materials.
Removal of SO4
2- was controlled by organic C availability in HF wetlands.
Hybrid wetland system A1-B1 achieved higher color removals; HF wetland unit B1 of
the hybrid train was more efficient in removing color compounds
Conclusions
33

34. Case Study-3
Removal of dissolved metals in wetland columns filled with shell grits and
plant biomass
34

35. In this study, a synthetic wastewater was prepared based on the characteristics of an
effluent at a coal mining site.
Measured amounts of Pb (CH3COO)2, MnCl2, FeSO4, CuSO4 and ZnSO4 powders, and
H2SO4 solution was added in a distillate water, to produce a synthetic wastewater with
target pollutant concentrations shown in Table 1.
Methodology
Theoretical concentration Reagent used Amount (g) per L
water
Cu 4 mg/L CuSO4(H2O)5 0.01572
Fe 200 mg/L FeSO4(H2O)4 0.80287
Mn 18 mg/L MnCl2(H2O)7 0.08262
Pb 2 mg/L Pb(CH3COO)2 0.00314
Zn 12 mg/L ZnSO4(H2O)7 0.05275
pH 2-3 H2SO4
35

36. Two lab-scale wetland systems (operated in parallel) were installed outdoors
(sheltered from rain).
The main spaces in the columns were filled with crushed sea shell grits (in system A)
or composted urban green waste (in B).
Mature plants of Typha domingensis were collected from a creek on James Cook
University’s Townsville campus and re-planted in these columns.
The Lab-scale Constructed Wetlands
Fig. 1. A schematic diagram of the hybrid wetland columns
36

37. The manual dosing was done four days per week (Monday–Thursday).
Water samples were collected on a weekly basis, every Thursday from the feed tank
and outlets of the vertical flow columns, and every Friday from the effluent tanks.
Immediately after collection, the samples were filtered through 0.45 μm syringe
filters.
The temperature, conductivity and pH values of the filtered samples were measured
System operation, sampling and analysis
37

38. Overall performance
A total of 40 water samples were collected and analysed.
Table 3 presents the average data from each treatment stage, and overall removal
percentages of dissolved metals.
Results
Table 3 Mean dissolved pollutant concentrations ( ± standard deviations) in the two lab-scale wetland systems
38

39. Pollutant mass removal rates
Results
39

40. Results
40

41. Lab-scale experiments demonstrated that wetland columns employing with crushed
shell grit media have significant capacity for removing dissolved metals from acidic
wastewater.
Over 99% percentage removals were obtained for Cu, Fe, Mn, Pb and Zn, under mass
loading rates of 0.223, 9.72, 1.038, 0.089 and 0.644 g/m3 d, respectively.
SEMEDS and IR analyses of the grits indicated slight changes of chemical
compositions, after the grits were used as wetland media.
Linear correlations between pH changes and percentage reductions of the dissolved
metals indicated that they were predominantly removed via abiotic routes
Conclusions
41

42. Case Study-4
Horizontal subsurface flow constructed wetlands as tertiary treatment: Can they
be an efficient barrier for microplastics pollution?
42

43. Aalbeke WWTP (Kortrijk, Belgium) was built in 1996 for serving a population of 450
population equivalents (P.E.).
The main units of this plant are a primary settler, two rotating biological contactor
(RBC) in series followed by a secondary settler, as secondary treatment, and a 500 m2
horizontal subsurface CW, as tertiary treatment.
The CW also functions as a storm water treatment unit, taking any flow higher than 3
Q14. It is filled with gravel (2.4 mm < 50% < 5.6 mm < 5.6 mm < 50% < 8.0 mm) and
planted with common reed.
Study area
43

44. Wastewater and macroinvertebrate sampling
Wastewater was collected from three different sites along the WWTP: raw wastewater in
the influent to the primary settler, effluent from the secondary settler and effluent from
the CW.
Six sampling campaigns were carried out in the following dates: Dec 17th (2018) and
Jan 22nd, Feb 14th, Oct 22nd, Nov 12th and Dec 4th (2019).
On the same dates, two substrate samples were also taken from the CW for collecting the
macroinvertebrates living in it.
The substrate sample was collected from the top 30 cm, which is the normal depth where
macroinvertebrates live.
Methodology
44

45. The beakers containing the residue collected from the sieves were put in the oven at
70 °C to dry up, higher temperature was avoided since the shape of plastics could
be affected by elevated temperature.
In order to speed up the digestion, the beakers were put back in the oven at 60 °C.
Once the digestion was completed and the solution dried out, a density separation
was conducted.
Extracting MPs from the water samples
45

46. Microplastics counting and characterization MPs retained on the filters were
examined under stereomicroscopes with augmentations between x14 and x70 (SZM
and SDZ-PL, Kyowa, Japan).
The microplastics were identified following the rules indicated by Hidalgo-Ruz et al.
(2012). During the filters examination, the hot needle test was also used to distinguish
between microplastics and organic matter (Witte et al., 2014).
The filters were read from left to right, then move down one row from right to left.
During the counting, MPs were classified into fibers, particles and films.
Statistical analyses were performed using SPSS software (SPSS® software).
Characterizing MPs
46

47. Wastewater MPs concentrations and removal efficiencies
MPs concentration was measured in different sites of the Aalbeke WWTP. The results
indicate a high variability in the influent to the WWTP, varying between 21.9 and
102.3 MPs/L (Fig. 1A and B).
The removal efficiency was, on average, 87% in the combined primary and secondary
treatment. The CW reduced the MPs concentration even more, with an average
efficiency of 88%, providing a great environmental benefit that adds to the already
known benefits of constructed wetlands.
The removal efficiency of the whole WWTP, from the influent to the final effluent,
was 98%. This is a value very similar to the TSS removal efficiency reported by the
Flemish Environmental Agency (see Section 2.1).
Based on these results the first hypothesis can be accepted: CW can efficiently reduce
the MPs coming from the secondary effluent, giving rise to a final effluent with a
significantly lower concentration.
The efficiency of the CW monitored in this study is within the range of other tertiary
treatments as in table.
Results and discussion
47

48. The concentrations are reduced along the treatment system and the range of variation is
narrowed, varying between 4.0 and 10.3 MPs/L after the rotating biological contactor
and secondary settler, and between 0.10 and 1.22 MPs/L in the final effluent, after the
CW, highlighting its buffering capacity (Fig. 1B).
Results and discussion
48

49. Another interesting aspect to know are the characteristics of the MPs present in the
wastewater, such as the size and shape distributions.
MPs in the medium size range (75–425 μm) were the most abundant, representing about
50% of the total MPs found in the samples.
The larger and smaller MPs had a similar abundance, around 25%. Therefore, the
second hypothesis of this study cannot be accepted: the particles in the effluent were not
significantly smaller than those in the influent.
Results and discussion
49

50. Overall, even though WWTPs provide high removal efficiencies, efforts should be
focused on reducing the contamination at the source, or even on methods that do not
wait until plastic has already become pollution (Leslie, 2019).
The control measures for reducing the MPs inputs to the wastewater can range from
simple gestures at home, like installing filters at the washing machine drain, to
government regulations (Correia Prata, 2018).
Results and discussion
50

51. Horizontal subsurface flow CWs efficiently reduce MPs concentration,
preventing them from entering vulnerable aquatic systems.
As tertiary treatment, CW is able to significantly reduce the MPs concentration
coming from the secondary treatment. The size and shape composition of the
MPs does not differ significantly from the influent to the effluent, so there is no
size or shape removed significantly more efficiently than others.
Fibers represent the most abundant shape both in water and macroinvertebrates,
so attention should be paid on reducing their contamination at source.
Macroinvertebrates ingest a non-negligible quantity of MPs, so they could play a
role in the MPs distribution inside constructed wetlands. The authors consider it
very interesting to further investigate this mobilization potential.
Conclusions
51

52. Municipal wastewater treatment in horizontal and vertical flows constructed
wetlands
Case Study-5
52

53. The two pilot plant units were designed, built and put into operation within the
vicinity of a wastewater treatment plant, North Giza governorate, Egypt. The pilots
were operated for three years and still running.
They were fed with settled real wastewater from the existing wastewater treatment
plant in the field using a submersible pump and through a PVC pipe.
Study area
53

54. Fig. 1 shows a schematic diagram of the two wetlands units.
Construction
54

55. Wastewater samples were collected on a weekly basis from the inlet and outlet of the
bed.
In addition, different parts of the plants were collected on a monthly basis for
analysis.
The samples were collected and analyzed for the duration of almost three years and
still running.
Sampling
55

56. Physico-chemical and biological analysis were carried out for raw and treated
wastewater.
The physico-chemical analysis covered: pH, chemical oxygen demand (COD) (total
COD and soluble COD) etc.
The biological parameters covered total coliform and fecal coliform.
Physico-chemical and biological analysis
56

57. Statistical analysis of the collected data was carried out using Microsoft Excel 2010
version. The percentage removal was calculated according to the following
equation:-
%R=
𝐶𝑖
∗𝑄𝑖 −(𝐶𝑒∗𝑄𝑒)
𝐶𝑖
∗𝑄𝑖
where Ci is the influent concentration in kg/m3; Ce the effluent concentration in kg/m3;
Qi the inflow in m3/day; and Qe is the outflow in m3/day.
Statistical analysis
57

58. Characterization of influent wastewater
The average characteristics of influent wastewater to the wetland are shown in Table 2.
Results and discussion
58

59. Reduction of COD and BOD
The COD and BOD concentrations in HFCW and VFCW effluents are shown in Fig. 2.
The results show that both pilot units are very efficient in the removal of pollutants in
terms of COD and BOD.
Results and discussion
Fig. 2. COD and BOD concentrations in influent and effluent of HFCW and VFCW. 59

60. Results and discussion
Fig. 3. TSS concentrations in influent and effluent of HFCW and VFCW.
60

61. Nitrogen transformation
The great variability in the TKN removal was observed along the monitoring period
(Fig. 5). The average TKN removal efficiencies throughout the study period were
60% for HFCW with a residual value of 6.5 mg/l, while it reached 62.5% in VFCW
with a residual value of 16 mg/l.
Results and discussion
Fig. 4. TKN concentrations in influent and effluent of HFCW and VFCW 61

62. Ammonia removal and nitrate transformation
The variation of nitrate-nitrogen concentrations during the study period is shown in Fig.
7.
Results and discussion
Fig. 4. Ammonia concentrations in influent and effluent of HFCW and VFCW.
62

63. Fig. 6. Nitrate-concentrations in influent and effluent of HFCW and VFCW
Results and discussion
63

64. • It is noticed that the plants in HFCW are taller than the plants in VFCW. This may be
attributed to the design of HFCW that allows continuous flow of wastewater under
the plant’s roots.
• Our results indicated that Cyperus was better than Canna and Phragmites in nitrogen
and phosphorus uptake in both basins as shown in Table 3. This may be attributed to
the fact that Cyperus was distributed more widely in the bed.
Results and discussion
Table 1 Plants heights in HFCW and VFCW during the study period. 64

65. Total phosphorous removal
The results obtained in Fig. 9 indicated that VFCW was more effective for phosphorus
removal than HFCW. The removal rate was 68% for VFCW, while in HFCW it reached
63%. VFCW provide more oxygenation than HFCW. Thus, the role of vegetation and
oxygen in P removal in VFCW is greater than HFCW.
Results and discussion
Fig. 8. Phosphate concentration in influent and effluent of HFCW and VFCW. 65

66. Reduction of bacterial indicators of pollution
The results depicted in Table 4 show that the VFCW was more effective for reducing
total coliform and fecal coliform than the HFCW.
Results and discussion
Table 2 Average concentration of pathogens in effluent wastewater.
66

67. In this study, assessment and evaluation of the performance of two large scales VFCW
and HFCW operated at the same conditions were carried out.
VFCW is recommended for wastewater treatment because of its smaller size, high
quality of treated effluent and less evapotranspiration rate.
Moreover, VFCW proved to be very promising technique for wastewater treatment not
only for COD, BOD and TSS reductions, but also for nitrification and pathogenic
removal.
The COD, BOD and TSS removal rates reached 92.9%, 93.6% and 94%, respectively.
Also, four logs of bacterial indicators were reduced in the treated effluent.
Conclusions
67

68. Overall conclusions
68

69. References
69

70. 70

71. Phytoconcentration Contaminant is concentrated in roots, stem and leaves
Phytodegradation Breakdown of the contaminant molecule by plant enzymes
which act as to help catalyze
Rhizosphere Biodegradation Plant roots release nutrients to microorganisms which are
active in biodegradation of the contaminant molecule
Volatilization Transpiration of organics through leaves of the plant
Stabilization Plant converts the contaminant into a form which is not
bioavailable, or the plant prevents the spreading of a
contaminant plume
Phytoremediation Processes
71

72. Water Hyacinths Eichhornia crassipes
Forage Kochia Kochia spp
Poplar Trees Populus spp
Willow Trees Salix spp
Alfalfa Medicago sativa
Cattail Typha latifolia
Coontail Ceratophyllum demersvm L
Bullrush Scirpus spp
Reed Phragmites spp.
American pondweed Potamogeton nodosus
Common Arrowhead Sagittaria latifolia
Various Plant Types
72

73. By various such process chemicals are considerably removed or settled and clean water
is drawn. These chemicals include Nitrogen, Ammonia, Phosphorous 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.
Constructed wetlands
73