Overview of Subsurface Constructed Wetlands Application in Tropical Climates

Universal Journal of Environmental Research and Technology
All Rights Reserved Euresian Publications (c) 2011 eISSN 2249 0256
Available Online at: www.environmentaljournal.org
Volume1, Issue 2: 103-114






Open Access





Review Article

Overview of Subsurface Constructed Wetlands Application in Tropical Climates

1Siti Haryani Chek Rani, 1Mohd. Fadhil Md. Din, Mohd. 1Badruddin Mohd Yusof and
*2Shreeshivadasan Chelliapan

1Faculty of Civil Engineering, Universiti Teknologi Malaysia, 81310, Skudai, Johor Bahru, Malaysia.
2UTM Razak School of Engineering and Advanced Technology, Universiti Teknologi Malaysia (International
Campus), Jalan Semarak, 54100, Kuala Lumpur, Malaysia.

*Corresponding author: shreeshivadasan@ic.utm.my
Abstract:
Subsurface flow constructed wetlands (SFCW) have specific capacity to absorb and retain particulate
matters, nutrients and other pollutants which enters water bodies through surface runoff, domestic
wastewater, industrial wastewater and also from plantations. However, as the field becomes more relevant
towards sustainability environment, the SFCW study is often significant for developing countries with
tropical climates where the zones are warm and humid weather in all years. SFCW showed an increase rate
of contaminant up-take in warmer climates; therefore this treatment has been expected to operate more
efficiently in tropical regions. SFCW recent technologies are also excellent in the utilisation of natural
processes and the high process stability which contributing a high nutrient capturing capacity. Furthermore,
the systems are simple to construct and less expensive option than aquatic plant systems which is a benefit
in many developing countries. Accordingly, this paper highlights some SFCW applications on nutrients
capturing capabilities (nitrogen and phosphorus), general view on construction, operation and maintenance
of the SFCW and vegetation selection for start-up. In addition, application of different wastewater types
such as landfill leachate, domestic wastewater and industrial wastewater are also discussed in brief. Future
considerations in choosing appropriate technology aspect of wetlands applications such geographic
information system (GIS), compost material and bio-particle are highlighted.

Keyword: Bioparticle, Compost Material, Geographic Information System, Subsurface Flow Constructed
Wetlands, Tropical Climates

1.0 Introduction:

Constructed wetlands have been used widely for
basin or channels with some type of barrier to
the treatment of municipal, industrial and
prevent seepage, soil to support the roots of the
agricultural wastewater, as well as for urban storm
emergent vegetation, and water at a relatively
water. This is owing to their high nutrient
shallow depth flowing through the system. The
absorption capacity, simplicity, low construction,
water surface is exposed to the atmosphere, and
operation and maintenance costs, low energy
the intended flow path through the system is
demand, process stability, low excess sludge
horizontal.
production and potential for creating biodiversity

(Korkusuz et al., 2005). Properly designed and
The SF wetland consists of a basin with a barrier to
constructed man-made wetland ecosystems are
prevent seepage, but the bed contains a suitable
extremely efficient at utilizing and cleaning
depth of porous media. Rock or gravel is the most
nutrient-rich waters (Mitsch and Gosselink, 1993).
commonly used media types. The media support
Moreover, it has gained increasing acceptance for
the root structure of the emergent vegetation. The
many types of bioremediation, including mining
design of these systems assumes that the water
and agribusiness wastewater (Hammer, 1989; EPA,
level in the bed will remain below the top of the
1993; Reed et al., 1995).
rock or gravel media. The FWS systems have the

advantage of requiring less land area for
In general, there are two basic types of
wastewater treatment (Nelson et al., 2003).
constructed wetlands, the free water surface
Moreover, they have the ability to filter, absorb
(FWS) wetland and the subsurface flow (SF)
and retain particulate matters, nutrients or other
wetland (Figure 1). Both types utilize emergent
pollutants in wastewater. Table 1 illustrates the
aquatic vegetation and are similar in appearance
type of wetlands, vegetation types and water
to a marsh. The FWS wetland typically consists of a
column
contacts
in
constructed
wetlands.

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(a)
(b)

Figure 1: Type of Constructed Wetland (A) Free Water Surface (B) Subsurface Flow (Adapted from
Gearheart, 2006)

Table 1: Vegetation Type and Water Column Contact in Constructed Wetlands

Constructed Wetland Type
Type of Vegetation
Section in Contact with Water Column
Free water surface (FWS)
Emergent
Stem, limited leaf contact

Floating
Root zone, some stem / tubers

Submerged
Photosynthetic part, possibly root zone
Sub-surface flow (SSF)
Emergent
Rhizome and root zone

The subsurface flow constructed wetlands (SFCW)
contact between the water column and the
first emerged as a wastewater treatment
atmosphere. There is no opportunity for vermin to
technology in Western Europe based on research
breed, and the system is safer from a public health
by Seidel (1966) commencing in the 1960s and by
perspective. The system is particularly useful for
Kickuth (1977) in the late 1970s and early 1980s.
treating septic tank effluent or grey water, landfill
Early developmental work in the United States
leachate and other wastes that require removal of
commenced in the early 1980s with the research
high concentrations organic materials, suspended
of Wolverton et al. (1983) and Gersberg et al.
solids, nitrate, pathogens and other pollutants.
(1985). At present, a typical SFCW has been widely
The environment within the SFCW bed is mostly
applied in tropical climates such as in Thailand,
either anoxic or anaerobic. Oxygen is supplied by
India and Indonesia. However in Malaysia, the
the roots of the emergent plants and is used up in
application of SFCW has not been implemented
the biofilm growing directly on the roots and
since many research focuses into small scale
rhizomes, being unlikely to penetrate very far into
system (Katayon et al., 2008). Many countries in
the water column itself. SFCW systems are good
African continental which has tropical climates use
for nitrate removal (denitrification), but not for
constructed wetland for wastewater treatment
ammonia oxidation (nitrification), since oxygen
(e.g. Tanzania, Kenya, Malawi, Uganda, Zambia,
availability is the limiting step in nitrification.
Botswana, Zimbabwe). However, many of these
Generally, there are two types of SFCW systems:
systems have been performing below the required
horizontal flow SFCW and vertical flow SFCW. The
standards, due to lack of proper operation and
most common problem with horizontal flow is
maintenance (Kayombo et al., 1998). Constructed
blockage, particularly around the inlet zone,
wetlands have not yet received the deserved
leading either to short circuiting, surface flow or
attention as an alternative method for wastewater
both. This occurs because of poor hydraulic design,
treatment.
insufficient flow distribution at the inlet, and

inappropriate choice of porous media for the inlet
SFCW systems are most appropriate for treating
zone.
primary wastewater, because there is no direct

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Universal Journal of Environmental Research and Technology
2.0 Nutrient Capturing Capacity:
nitritation, nitrification and Anammox were
responsible for nitrogen removal in the subsurface
2.1 Nitrogen:
flow wetlands (Wendong and Jing, 2008).
The dominant forms of nitrogen (N) in wetlands

which are important to wastewater treatment
Completely autotrophic nitrogen-removal over
include organic nitrogen, ammonia, ammonium,
nitrite (CANON) is closely related to Anammox
nitrate, nitrite, and nitrogen gases. Inorganic forms
process in which ammonium is first partially
are essential to plant growth in aquatic systems
oxidized to nitrite, then transformed with
but if the amount limited it can affect plant
remaining
ammonium
into
dinitrogen
by
productivity. The nitrogen entering wetland
planctomycetelike
bacteria
(Guangzhi,
2007)
systems can be measured as organic nitrogen,
growing in anaerobic zones in treatment system.
ammonia, nitrate and nitrite. Ammonia is oxidized
Unlike the Anammox process, CANON can occur in
to nitrate by nitrifying bacteria in aerobic zones
a single stage aerobic system. Considering that
which typically occurs at the above soil level. The
wetland contains a network of intermeshing
oxygen required for nitrification is supplied by
aerobic, anoxic, and anaerobic zones within the
transmission from the atmosphere and leakage
same system, it provides an ideal habitat for the
from macrophyte roots. Organic N is mineralized
coexistence of different microbial communities.
to
ammonia
by
hydrolysis
and
bacteria
The stoichiometry of the CANON is given in
degradation. Nitrates are then converted to
equation 1.0 (Third et al., 2001). Since CANON
nitrogen gas (N2) and nitrous oxide (N2O) by
process could generates dinitrogen gas, the losses
denitrifying bacteria in anoxic and anaerobic zones
of total nitrogen is expected to occur in natural
(Koottatep, 2004) which usually occur in limited
process (Guangzhi, 2007).
oxygen supply. Nitrogen is also taken up by plants,

incorporated into the biomass and released back
.+

+
+
as organic nitrogen after decomposition. Other
removal mechanisms include volatilization and
+
...eq 1.0
adsorption. Typically, these mechanisms are

generally of less importance than nitrification -
However, many of the earliest SFCW were only
denitrification, but they can be seasonally
required to remove BOD and total suspended solid
important (Kadlec and Knight, 1996).
(TSS). In some cases, their permits have since been

revised to require the ammonia removal
In 1999, researchers at the Gist-Brocades in Delft,
(Koottatep and Polprasert, 1997). Many of these
The Netherlands discovered a new reaction to be
new systems also have ammonia limits depending
added in the nitrogen cycle that called Annamox
on receiving water requirements. The limiting
(anaerobic ammonia oxidation) Reaction. More
factor in ammonia removal via nitrification is
recently, Wendong and Jing (2009) found that
believed to be the availability of oxygen in the
integration of partial nitrification and anaerobic
media profile. Some study found that the excellent
ammonium oxidation (Annamox) in constructed
ammonia removal is based on plant roots (which
wetlands creates a sustainable design for nitrogen
typically abundance of oxygen) throughout the
removal. The previous observations of high
profile, and sufficient hydraulic retention time
ammonia removal in constructed wetlands under
(HRT) to complete the reactions (Konnerup et al.,
anaerobic and low-oxygen conditions were
2009; Brix et al., 2007). However, there is no
attributed to partial nitrification (conversion of
consensus on how much oxygen can be furnished
ammonium
to
nitrite,
or
nitritation)
and
by the vegetation in SFCW or on the oxygen
Anammox, in addition to nitrification and
transfer efficiency of various plant species. Suwasa
denitrification (Chiemchaisri et al., 2009; Wendong
et al. (2008a) demonstrated that the surface area
and Jing, 2009). Nitrifiers and Anammox bacteria
must be large enough to secure a sufficient oxygen
may be natural partners in many oxygen-limited
transfer to cover the need for microbial
situations (Schmidt et al., 2002). At the
degradation of organic matter and nitrification of
concentrations of dissolved oxygen in the
ammonium. They also found that the removal
subsurface
flow
wetlands,
nitritation
and
efficiencies of N decreased when the system
nitrification could take place in the bulk water,
operated with higher hydraulic loading rate (HLR)
while Anammox could occur in the deep layer of
(Suwasa et al., (2008b).
bio-films developed from gravel media in

wetlands. Ammonia that removed will be

converted to nitrite and nitrate. Mass balance

analysis for nitrate plus nitrite, confirms that
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Universal Journal of Environmental Research and Technology
2.2 Phosphorus:
3.0
Construction,
Operation
and
The removal of phosphorus is important since it is
Maintenance:
known to be major limiting nutrient for algae
3.1 Construction:
growth in freshwater ecosystems (Wetzel, 2001).
Construction of SFCW includes physical design,
Wetlands remove phosphorus through biological,
hydraulic design and physical construction of the
chemical and physical processes. Sediment burial
wetlands. Designing the wetlands is the critical
is considered to be the major long-term
phase of the implementation process. Because of
phosphorus storage in wetlands (Reddy et al.,
the nature of SFCW wetlands, errors made in the
1999). However, part of the sediment organic
early stages of construction become almost
phosphorus can be mineralized to dissolved
impossible and very expensive to correct after the
inorganic phosphorus, which can subsequently be
bed media is installed. As a result, a clear
partially released back to water (D'Angelo and
understanding and correct execution of the design
Reddy, 1994; McLatchey and Reddy, 1998).
documents are essential. Many texts and design

guidelines for SFCW have been published such as
The major processes responsible for phosphorus
USEPA, (2000), EC/EWPCA (1990); WPCF (1990);
removal in SFWC are typically by adsorption,
Reed et al. (1995); Kadlec and Knight (1996);
precipitation and plant up-take rates. The frequent
Campbell and Ogden (1999), however, there is no
filtration materials used in SFCW is gravel, which
guidelines
recorded
for
tropical
climates.
commonly good in absorption compared to the
Therefore, much misconception about their
plant roots (Vymazal, 2004). Phosphorus is an
application, design and performance has been
important nutrient required for plant growth and
occurs in the initial design of SFCW. The
is usually act as a limiting factor for vegetative
misconception that almost occurs is about the
productivity. Phosphorus is transformed in the
availability of oxygen in SFCW and the ability of
wetland by a complicated biogeochemical cycle.
SFCW to remove significant amounts of nitrogen.
Accordingly, most of the researcher claimed that

wetlands are not efficient in phosphorus reduction
Physical construction includes elevations and
(Kadlec and Knight, 1996). However, wetlands are
grading, liners, berms, vertical sidewalls, influent
not long-term removal solution for phosphorus as
and effluent piping, bed media placement and
compared to nitrogen. In the past, if the system
installation of control structures. The major
operate in a longer periods (maximum of 9 years)
consideration in the construction of wetlands is
the phosphorus removal will decrease over years
excavation and grading. The setting of the correct
probably because of limited sorption capacity. The
elevation of each basin, pipe and control structure
amount of phosphorus removed is not more than
is one of the most fundamental and critical aspect.
5% of the total removed phosphorus in the
The next major consideration is distribution piping
beginning of wetland operation. As the sorption
and effluent collection piping. For most SFCW, the
decreases over years and macrophyte biomass
drainage pipes are installed prior to placement of
increases simultaneously, the phosphorus bound
the various layers of bed media and the influent
in biomass becomes higher but it rarely exceeds
distribution piping is typically installed in top of the
the level of 20% of the total phosphorus removed
bed. Another aspect on wetlands construction is
(Binhe, 2008; Richardson and Qian, 1999).
selection of media type and size which is very

critical to the successful performance of the
Phosphorus removal in most constructed wetland
system. This is especially true for vertical flow of
systems is also not very effective because of the
SFCW, which rely on stacked layers of filter
limited contact between the contaminant in
materials that often, has to meet a quite tight
wastewater and the soil. Some experiment and
grain-size distribution (Kaldec and Wallace, 2009).
developmental work has been undertaken using
Unwashed crushed stone has been used on a large
expanded clay aggregates and the addition of iron
number of projects and washed stone or gravel is
and aluminium oxides. Some of these treatments
preferred.
Coarse
aggregates
for
concrete
are promisingly but the long-term expectations
construction are commonly available and would be
have not been observed so far (Vymazal, 2004).
suitable for construction of SFCW systems. The
Some systems uses sand instead of gravel to
recent trend toward the use of larger sizes of rock
increase the phosphorus retention capacity, but
is believed due to the impression created by the
selecting this media would reduce the hydraulic
surface flow conditions on many of the early
conductivity of sand compared to gravel (EPA,
systems. It was apparently thought that the
1993). Therefore, a wide land area is required in
surface flow was caused by clogging and that the
order to remove the phosphorus.
use of a coarser rock with larger void spaces and a
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Universal Journal of Environmental Research and Technology
higher hydraulic conductivity would overcome the
3.2 Operation and Maintenance:
problem. In most cases the problem has not been
SFCW have few operation and maintenance
overcome since the hydraulic gradient provided is
requirements,
but
maintenance
must
be
too small. The use of smaller rock sizes has a
performed
properly
to
ensure
system
number of advantages in that there is more
performance. Operation may entail alternating
surface area available on the media for treatment,
cells or adjusting water levels and harvesting
and the smaller void spaces are more compatible
vegetation. Some systems may have banks and
with development of the roots and rhizomes of the
berms that need to be maintained, and inlet and
vegetation, and the flow conditions should be
outlet
structures
that
should
be
cleaned
closer to laminar (EPA, 1993).
periodically.


3.2 Plants selection:
Water level and flow control are usually the only
One of the most important aspects of the start-up
operational variables that have a significant impact
of SFCW system is vegetation selection and
on a well designed constructed wetland's
establishment. The selection of plant species in
performance. Changes in water levels affect the
SFCW is often a product of cultural and regulatory
hydraulic residence time, atmospheric oxygen
constraints. In tropical countries, locally available
diffusion into the water phase, and plant cover.
species of Pragmites, Cyperus, Bulrush and Typha
Significant changes in water levels should be
have been the most common choice to date. Most
investigated immediately, as they may be due to
recently, Konnerup et al. (2009) successfully used
leaks, clogged outlets, breached berms, storm
Helicornia Psittacorum and Canna Generalis in
water drainage, or other causes (EPA, 2000).
order to increase the ecstatic value of wetlands

and to increase the local people's awareness of
Routine maintenance of the wetland vegetation is
wastewater treatment in Thailand. The selection of
not required for systems operating within their
a plant species is generally a function two factors
design parameters and with specific bottom-depth
which is the degree of rhizome spread and the
control of vegetation. Wetland plant communities
ability to achieve plant canopy and crowd out
are self-maintaining and will grow, die, and regrow
unwanted invasive species and another factor is to
each year. Plants will naturally spread to
develop more belowground root biomass and
unvegetated areas with suitable environments
depth of root penetration, which benefit
(e.g. depth within plant's range) and be displaced
wastewater treatment.
from areas that are environmentally stressful

(Merlin, 2002). The primary objective in vegetation
The most important functions of the plants are
management is to maintain the desired plant
related to their physical effects in the wetlands.
communities where they are intended to be within
The roots provide a huge surface area for attached
the wetland. This is achieved through consistent
microbial growth, and in temperate regions the
pre-treatment process operation, small, infrequent
plant litter provides an insulation layer against
changes in the water levels, and harvesting plants
frost during winter. Plants can also facilitate
when and where necessary. Where plant cover is
aerobic degradation by releasing oxygen to the
lacking, management activities to improve cover
rhizosphere, but oxygen release rates are difficult
may include water level adjustment, reduced
to quantify and the overall effect on pollutant
loadings, pesticide application, and replanting
removal is probably varying (Brix, 1990). Regarding
(EPA, 2000; Moore, 1999).
uptake of nitrogen (N) and phosphorus (P) many

studies in temperate climates have shown that the
4.0 Application of Different Wastewater
amount which can be removed by harvesting is
Types:
generally insignificant (Tanner, 2002). However, in
tropical climates where the plants grow faster and
4.1 Landfill Leachate:
throughout the year, the up-take of nutrients can
Landfill leachate is typically formed from
probably
contribute
to
significantly
higher
infiltration waters and the products of solid-waste
removals of nutrients as has been reported in
decomposition. Those contaminants leachate
several studies (Koottatep and Polprasert, 1997;
waters are a potential threat to surface and
Kantawanichkul et al., 2001; Kyambadde et al.,
subsurface receiving waters. New landfill leachate
2004). However, if the plants are not harvested
(<10 years) contains large amount of free volatile
the incorporated nutrients will be released again
fatty acid (VFA), resulting in high concentration of
during decomposition of the biomass.
chemical
oxygen
demand
(COD),
BOD,
ammoniacal-nitrogen (NH -
3 N) and alkalinity, a low
oxidation-reduction potential and black colour
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Universal Journal of Environmental Research and Technology
(Wang, 2004; Nazaitulshila, 2006). Therefore,
by high COD, low BOD, fairly high NH -
3 N and
biological processes are commonly employed for
alkalinity, low ratio of BOD/COD, a high oxidation-
new landfill leachate treatment to remove the
reduction potential and dark brown or yellow
volume of biodegradable organics. Old landfill
colour (Wang, 2004; Chew, 2006). Figure 2 show
leachate (>10 years) or biological treated new
typical landfill leachate characteristics over time
landfill leachate has a large percentage of
and Table 2 presents the typical concentration
recalcitrant organic molecules. It is characterized
ranges of chemical parameters in landfill leachate.




Figure 2: Typical Landfill Leachate Characteristics over Time (Adapted From Tchobanouglous Et Al., (1993)


Natural wetlands are often the recipients of landfill
Table 2: Typical Characteristics of Landfill
leachates because many landfills are adjacent to
Leachate in Thailand (Kjeldsen Et Al., 2002)
wetlands or partially fill them. However, previous

studies were investigated on different aspects of
Parameter Composition
constructed wetlands, including the effects of soil
composition and grain-size distribution, removal
pH
4.5-9.5
mechanisms, fate of pollutants, engineering
aspects and hydraulic distribution and flow. SFCW
TS
2,000-60,000
are the most used due to absence of odours and
TDS
1,000-20,000
mosquitoes, simple operation and maintenance,
COD
140-152,00
reliable operating conditions and a combination of
aerobic and anaerobic processes inside the
BOD5
20-57,700
system. This aerobic-anaerobic environment in
BOD
wetlands allows high removal rates of different
5/COD
0.02-0.87
organic compounds, pathogens and some low-
TKN
65-4,700
degradable matter. Lately, Yalcuk et al. (2009)
NH4-N
0.0-2,200
demonstrated that SFCW is the most excellent
Sulphide
n.d*
alternative treatment in leachate since vertical
systems performed better in ammonium removal
Mercury
0.2-50
whereas, the horizontal system was better for
Lead
0.01-5
organic removal.

Cadmium
0.0001-0.4
4.2 Domestic Wastewater:
Nickel
0.1-13
Domestic wastewater contains liquid and water
All values in mg/l except pH and BOD5/COD;
which carries waste from various types of
n.d* - not detected
components. It may be purely domestic in origin or

it may contain some industrial or agriculture
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Universal Journal of Environmental Research and Technology
wastewaters. In appearance, domestic wastewater
It is merely biodegradable and nontoxic, but has
is a grey turbid liquid which contains materials
high concentrations of BOD and SS. The
such as suspended solids (SS), biodegradable and
constituents of food wastewater are often
refractory organics, nutrients, inorganic matter
complex to predict due to the differences in BOD
and as well as microorganisms. The organic and
and pH, e.g. from vegetable, fruit, and meat
mineral matter constitutes about 0.1% of the
products and due to the seasonal nature of food
domestic wastewater and the other 99.9% is
processing and post harvesting. Processing food
mostly water (Metcalf and Eddy, 1991). Domestic
for sale produces wastes generated from cooking
wastewater in tropical climates country has a low
which are often rich in plant organic material and
organic content compared with typical sewage
may also contain salt, flavourings, colouring
(Giri et al., 2006). However, this is a fundamental
material and acids or alkali. Very significant
fact that seems not to have been fully appreciated
quantities of oil or fats may also be present.
by local engineers. Climatic conditions such as high
temperatures and heavy rainfall have resulted in a
Considering the quality of design and construction
further reduction in the organic content of the
of SFCW in tropical climates, not much information
wastewater. This is due to decomposition and
can be derived from this food- processing
dilution, and the fact that tendency to follow
wastewater. Horizontal SFCW were tested by
western-style wastewater treatment practices in
Vrhov et al. (1996) with a major concern of food
the urban areas can be determined (Giri et al.,
waste. The experiment was started with the
2006).
wastewater flows from the primary sedimentation

basin into the first bed due to gravity. The water
SFCW are gaining more popular because it is a low-
then flows under the surface of the substrate to
cost maintenance technology for on-site treatment
the end of the first bed and into the second bed.
of septic effluents. More recently, Konnerup et al.
At the end of the second bed, a drainage tube for
(2009) have tested on horizontal SFCW at the
the collection and outflow of purified water into
Asian Institute of Technology (AIT) campus in
the outlet sump is placed into a 1 m wide layer of
Bangkok, Thailand. A result of these investigations
rough stone. The pollution decreased with regard
indicates that the organic load, fecal coliform
to COD by 92%, BOD5 89%, orthophosphate 96%,
populations and the N and P concentrations of the
ammonium
86%
and
nitrate
65%.
The
septic water decreased considerably by passing
microbiological parameters indicated that the total
through the wetlands. Constructed wetlands can
number of coliform bacteria is reduced by 99% and
reduce BOD5 of septic water by 8090% which
the number of faecal streptococci by 98%.
provided for feasible disinfection by chlorination.

Reduction in populations of fecal coliforms varied
5.0 Technology in Wetlands Application:
but generally, populations were reduced by
5.1 Geographic Information System (GIS)
9099%. Chlorination further reduced populations
Application:
of fecal coliforms to less than 2 cfu/100 ml.
The importance of the wetland environmental
Constructed wetlands provided an effective
protection has been extensively recognized,
method for secondary treatment of on-site
computer technologies have been widely used in
domestic wastewater.
environmental protection, and a large number of

the wetland information systems have been
4.3 Industrial Wastewater:
developed. In the United State, almost every state
Industrial wastewater can be defined in category
has developed wetland information system. For
of food-processing wastewater, iron and steel
example, the University of Florida created the
industry, wood industry, pulp and paper industry,
Aquatic, Wetland and Invasive Plant Information
mines and quarries, complex organic chemicals
Retrieval System (APIRS), Texas created the Texas
industry
and
nuclear
industry.
Industrial
Wetland Information Network (WetNet) and
wastewater treatment covers processes of
California Resources Agency developed the
wastewater treatment to treat waters that have
California Wetlands Information System (CWIS).
been
contaminated
in
with
anthropogenic
Montanan wetlands committee initiated and
industrial or commercial activities prior to its
developed the Montanan Wetland Information
release into the environment. The wetland
System (Wang et al., 2005). Louisiana developed
application on food-processing wastewater is not
the wetland comeback Spatial Decision Support
popular yet in tropical country. Wastewaters
System (Lyon et al., 1995). At the same time, many
generated from food operations have typical
other
countries
developed
their
wetland
characteristics of common municipal wastewater.
information systems such as Turkey used ArcView
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Universal Journal of Environmental Research and Technology
GIS to create the Wetlands of Turkey Geographic
compost material compare with gravel base as a
Information System (TUSAP-GIS), India developed
filtering media in the SFCW. The average
the National Wetland Environmental Information
performance of the treatment for TSS exceeds
System (ENVIS), Canada created the Canadian
60.5% and 48.5% for compost based and gravel
Information System for the Environment (CISE)
based, respectively, for COD it exceed 52.5% and
and Six European countries (Greece, Germany,
47.5% and for BOD it exceeds 56% and 45% for
Sweden,
Rumania,
England,
and
Holland)
compost based and gravel based, respectively. This
developed Wetland Evaluation Decision Support
shows the removal performance of the compost
System (WEDSS) (Wang et al., 2005).
based system was good compared to gravel based

system.
In Malaysia, a research by Aminu, 2007 on Ramsar

Site involving Sungai Pulai in the state of Johor was
5.3 Bio-Particle Application:
done using the GIS application, with emphasis on
Bio-particle is considered as green technology and
sustainable
wetland
issues.
The
study
also recognized as environmental friendly process,
demonstrates that GIS can be an effective tool in
natural and reported as more economical method
preserving and monitoring green and open spaces
for
wastewater
processes.
Bio-particle
is
in an urban area. The study was approached from
developed recently similar with the trickling filter
the aspect of natural resources management and
technology which enables to treat low strength of
eco-tourism development potential using GIS. The
wastewater and high micronutrient contents. Bio-
GIS database components developed for the study
particle emphasizes on the use of indigenous/ bio-
include site and administrative boundaries,
augmentated microbes immobilized on bio-
physical and biophysical elements (flora and fauna
particle to enhance wastewater treatment in the
layers),
planning
and
legislative
elements,
biodegradation process. In principle, bio-particle
hydrology (water bodies, river reserve and river),
comprised of natural zeolite, slake lime and
environmental quality and resources, tourism
activated carbon immobilized with microbes.
(recreational activity, tourism facilities, and
Zeolite will absorb the organic substances and act
tourism resources), transportation (road and
as chemical filter which control cation such as
seaport), socio-economy and local community, and
sodium, potassium, barium and calcium and also
infrastructure and utility (electrical line reserve,
large molecule such as water, NH
2-
-
3, CO3 dan NO3 .
telecommunication, water supply, sewerage and
Besides act as chemical filter, zeolite can also act
waste disposal).
as ion exchange, censor, odour removal and gas

absorption. The slaked lime (Ca (OH) 2) is used to
5.2 Compost Material:
incerease the pH value and then removes the
Compost is a combination of food material and
impurities such as phosphorus and sulphate and
other organic material that is being decomposed
finally the activated carbon could adsorb colour
through aerobic decomposition into a rich black
and organic pollutants.
soil (Aslam et al., 2008). Compost soil is very rich
soil and used for many purposes. A few of the
Recently, Nadirah et al. (2008), applied the bio-
places that it is used are in gardens, landscaping,
particle onto bio-filter system as a filtering media
horticulture, and agriculture. The compost soil
to treat domestic wastewater and the result are as
itself is beneficial for the land in many ways,
shown in Table 3. Effectiveness of bio-particle to
including as a soil conditioner, a fertilizer to add
treat and improve the water quality is depends on
vital humus or humic acids, and as a natural
the selection of the support material capable of
pesticide for soil (EPA, 1997). In ecosystems,
maintaining a high amount of active biomass and a
compost soils are useful for erosion control, land
variety of microbial populations. The selection of
and stream reclamation, wetland construction,
useful microorganisms is also important to
and as landfill cover.
degrade or mineralize the pollutants. Types of
Amending wetland soils with compost in wetland
microorganism that can be used in treating
restoration projects is potentially a high value
wastewater
are
Pseudomonas
putida,
added to end use application for composted
Pseudomonas fluorescens, Xanthobacter sp, and
organic waste. Compost adds humus and nutrients
Rhodococcus rhodochrous.
that plants need to re-establishes themselves in
decimated areas. Compost with its high organic
Therefore, the combination of bio-particle and
contents, can absorb up to four time its weight in
subsurface flow constructed wetland is as an
water and can replace essential organic material in
alternative method since bio-particle has been
wetlands. Aslam
reported to effectively remove most of the
et al., (2008) used organic
recalcitrant compounds such as alkyl groups,
110
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Universal Journal of Environmental Research and Technology
benzene ring substances, sulphate, phosphate and
* It is likely that some oxygen is available from
nitrate and constructed wetlands have also been
the plant roots to support nitrification
proven to be an effective low cost treatment
reactions. Effective use of that oxygen source
system which utilizes the interactions of emergent
requires complete development of the root
plants and microorganisms in the removal of
zone in the bed profile and sufficient
wastewater pollutants. The used of bio-particle
detention time. Neither condition is present in
also seem can promise in reducing the space area
most operational SFCW systems. Further
and land acquisition.
research is necessary to optimize these
relationships.
Table 3: Experimental Result from a Biofilter
* Further research and a better understanding is
System (Nadirah, 2007)
primarily needed for nitrogen removal and

Parameters Before After
%
nitrogen transformations occurring in these
removal
SFCW systems especially the information in
pH
5.05
7.73
-
tropical climates which is very limited and
BOD
158
62
61
there is also some misconception on the
COD
334
10 l
97
oxygen available from the plants to support
Ammonia
1.694
0.230 86
nitrification reactions.
TSS
272.6
80
71
* The use of new technology and specialized
Turbidity
113
21
89
media in the SFCW to improved phosphorus
Oil and
214
100
53
removal
should
be
developed
and
Grease
demonstrated since phosphorus removal
Nitrate
0.4
0.2
50
always shows worse performance in the
Sulphate
1.8
0.0
100
removal.
Phosphate
0.316
1.970 -
* Although recent studies in the construction of
All values in mg/l except pH and Turbidity in FAU
SFCW indicate that the use of a coarser rock

with larger void spaces and a higher hydraulic
conductivity will contribute minimal clogging
6.0 Conclusions:
in the beds investigated, the effort needs to
Wetlands
for
wastewater
treatment
are
be continued to determine the long-term risks
deceptively simple. They have the complexity that
of clogging.
all ecological systems possess, and being a
* Operation and maintenance are the most
relatively new technology further research and
important aspect of treatment wetlands
development studies need to be conducted. For
operation. It is becoming apparent that SFCW
example, there is conflicting and limited data on
will require de-clogging one or more times
the impact of temperature which is not well
during a 20 year life span. Method for
understood, and wetland designers and engineers
removing solids are currently high needed.
have developed a number of conflicting formulas
* SFCW design can offer high performance
for determining size and hydraulics of constructed
levels for various types of wastewater.
wetlands in different climatic regimes. Therefore,
However, the response to complex organic
research is urgently needed to further advance
and inorganic compounds in industrial and
and understand the SFCW concept. Below are
domestic wastes needs more investigations.
suggested researches that have been discussed
* Further
researches
in
applying
new
which are high priority needed:
technology are needed to reduce the

wetlands area and land acquisition since most
* As reported in most of the study, the SFCW
of SFCW require large area and it is not
system does not establish reliable for treating
suitable for urban area.
wastewater
with
high
ammonium

concentration.
Most
operational
SFCW
References:
demonstrating successful ammonia removal at
long HRT, which usually takes more than six
1. Aminu, M. (2007): A geographic information
days. From the review, intermittent or batch
system (GIS) and multi-criteria analysis for
type flow to alternating beds might enhance
sustainable tourism planning. M.Sc Thesis,
the oxygen status and therefore, improve the
Universiti
Teknologi
Malaysia,
Skudai,
ammonia removal capability. Therefore, the
Malaysia.
approach should be tested and then
2. Aslam,
D.
N.,
Horwath,
W.
and
demonstrated if promising.
WanderGheynst, J.S. (2008): Comparison of
several maturity indicators for compost-
111
Siti Haryani Chek Rani et al.

---

Universal Journal of Environmental Research and Technology
amended soil. Waste Management, 8: 2070-
16. Guangzhi, S and Austin, D. (2007): Completely
2079.
autotrophic nitrogen-removal over nitrite in
3. Binhe, G. (2008): Phosphorus removal in small
lab-scale constructed wetlands: Evidence from
constructed
wetlands
dominated
by
a mass balance study. Chemosphere, 68:
submersed aquatic vegetation in South
1120-1128.
Florida, USA. Journal of Plant Ecology, 1:67-74.
17. Hammer, D.A. (ed.) (1989): Constructed
4. Brix, H. and Schierup, H.H. (1990): Soil
Wetlands
for
Wastewater
Treatment:
oxygenation in constructed reed beds: the
Municipal, Industrial and Agricultural. Lewis
role of macrophyte and soil atmosphere
Publishers, Chelsea, USA.
interface oxygen transport. In: Cooper, P.F.
18. Jetten, M.S.M. (2002): Aerobic and anaerobic
and Findlater, B.C. (Eds.). Constructed
ammonia oxidising bacteria-competitors or
Wetlands
in
Water
Pollution
Control.
natural? FEMS Microbiology Ecology, 39: 175-
Pergamon Press, London. 53-66.
181.
5. Brix, H., Koottatep, T. and Laugesen, C.H.
19. Kadlec, R.H. and Knight, R.L. (1996):
(2007): Wastewater treatment in tsunami
Treatment Wetlands. Lewis Publishers,
affected areas of Thailand by constructed
London.
wetlands. Water Science Technology, 56: 69-
20. Kaldec, R. H. and Wallace, S. C. (2009):
74.
Treatment Wetlands. (2nd Ed). CRC Press
6. Campbell, C.S. and Ogden M.H. (1999):
Publisher, USA.
Constructed wetlands in the sustainable
21. Kantawanichkul, S., Neamkam, P. and Shutes,
landscape. John Wiley and Sons, New York.
R.B.E. (2001): Nitrogen removal in a combined
7. Chew, A.L. (2006): Nutrient Removal From
system: vertical vegetated bed over horizontal
Leachate
Using
Horizontal
Subsurface
flow sand bed. Water Science Technology, 44:
Constructed Wetlands. M. Sc Thesis, Universiti
137- 142.
Teknologi Malaysia, Skudai, Malaysia.
22. Kantawanichkul, S., Neamkam, P. and Shutes,
8. Chiemchaisri, C., Chiemchaisri, W., Junsod, J.,
R.B.E. (2001): Nitrogen removal in a combined
Threedeach, S. and Wicranarachchi, P. N.
system: vertical vegetated bed over horizontal
(2009): Leachate treatment and greenhouse
flow sand bed. Water Science Technology, 44:
gas emission in subsurface horizontal flow
138-142.
constructed wetland. Bioresource Technology,
23. Katayon, S., Fiona, Z., Megat Mohd Noor M.J.,
100: 3808-3814.
Abdul Halim, G. and Ahmad, J. (2008):
9. D'Angelo, E.M. and Reddy, K.R. (1994):
Treatment of mild domestic wastewater using
Diagenesis of organic matter in a wetland
subsurface constructed wetlands in Malaysia.
receiving hypereutrophic lake water: II. Role
International
Journal
of
Environmental
of inorganic electron acceptors in nutrient
Studies, 65: 87 - 102.
release. Environmental Quality, 23: 937-943.
24. Kickuth,
R.
(1977):
Degradation
and
10. EC/EWPCA, (1990): European Design and
incorporation
of
nutrients
from
rural
Operations
Guidelines
for
Reed
Bed
wastewaters by plant rhizosphere under
Treatment Systems. Swindon, UK: WRc.
liminic conditions. In: Utilization of Manure by
11. EPA, (1993): Subsurface Flow Constructed
Land Spreading, Commission of the Europe
Wetlands for Wastewater Treatment: A
Communities, EUR 5672e, London, 335- 343.
Technology Assessment, U.S. EPA Office of
25. Kjeldsen, P., Barlaz, M.A., Rooker, A.P., Baun,
Water, EPA 832-R 93-008, Washington, D.C.
A., Ledin, A. and Christensen, T.H. (2002):
12. EPA, (1997): Compost - New Applications for
Present and long-term composition of MSW
an Age-Old Technology.
landfill leachate: a review. Critical Reviews on
13. Gearheart, R. A. (2006): Constructed Wetland
Environmental Science and Technology, 32:
for
Natural
Wastewater,
Southwest
297-336.
Hydrology, Humboldt State University, USA.
26. Konnerup, D., Koottatep, T. and Brix, H.
14. Gersberg, R.M., Elkins, B.V., Lyons, S.R. and
(2009): Treatment of domestic wastewater in
Goldman, C.R. (1985): Role of Aquatic Plants in
tropical subsurface flow constructed wetlands
Wastewater Treatment by Artificial Wetlands.
planted with Canna and Heliconia. Ecological
Water Research, 20: 363- 367.
Engineering, 35: 248-257.
15. Giri,
J.
Takeuchi,
H.
Ozaki,
(2006):
27. Koottatep, T. and Polprasert, C. (1997): Role of
Biodegradation of domestic wastewater under
plant uptake on nitrogen removal in
the simulated conditions of Thailand. Water
constructed wetlands located in the tropics,
and Environment Journal, 20: 169-176.
Water Science Technology, 36:1-8.
112
Siti Haryani Chek Rani et al.

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