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Treating Wastewater with Vetiver Grass All-In-One Treatment and Reuse as Plant Biomass
Figure 1. Vetiveria zizianoides is the larger plant of the two pictured http://www.vetiver.com/g/galleries.htm
Alex Donaldson, Undergraduate
Lily Grimshaw, Undergraduate
December 2013
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Tables
Table 1. Influent Pond Water Characteristics
Table 2. Chemical contents in the aboveground tissue of different plant species in experiment 2
Table 3. Before and After Influent and Effluent Comparison
Table 4. Cost Comparison of Different Solutions
Table 5. Advantages and Disadvantages of Vetiver Treatment at a Glance
Figures
Figure 1. Vetiveria zizianoides is the larger plant of the two pictured
Figure 2. Applications of Vetiver grass biomass
Figure 3. From left to right, Vetiver planted on top of a landfill, hydroponic treatment, wetland
treatment
Figure 4. Nutrient N and P Removal over 1-16 Days of Treatment for each type of plant and a
control (CK)
Figure 5. Fresh and Dry Weight of Biomass for each Plant
Figure 6. Nutrient Uptake for each Plant
Figure 7. Layout of Toogoolawah Treatment Plant
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Introduction According to Dr. Tchobanoglous in his December 2013 Kappe lecture, the paradigm shift of 21st
century wastewater treatment is that wastewater is no longer a waste to be disposed of, but rather
it is a valuable resource of nutrients, energy, and water. While the majority of efforts focus on
individually extracting these resources with advanced and expensive technology, this paper will
focus on an alternative low-tech, low-cost, and highly sustainable solution that recovers
phosphorous, nitrogen, and even heavy metals in plant biomass. Figure 2 shows examples of
plant biomass applications such as animal feed, biofuel, and the raw material for handicrafts.
Figure 2. Applications of Vetiver grass biomass (L) http://vetivernetinternational.blogspot.com/2010/09/vetiver-for-cattle-feed.html
(M) http://www.teleservices.mu/index.php/front/rodrigues/articleLinks
(R) https://plus.google.com/photos/112053823950476566695/albums/5909108175367754065?banner=pwa
The Plant While there are several plants suitable for wastewater treatment, the application of Vetiveria
zizanioides (Vetiver), a perennial grass native to India, is the main focus of this paper. For
decades, Vetiver has been applied to agricultural areas all over the world in order to reduce run
off and erosion as well as stabilize slopes. In the last ten years, considerable research and
numerous projects have demonstrated the success of using Vetiver to treat various forms of
wastewater including landfill leachate, domestic sewerage, and industrial wastewater.
Successful treatment of wastewater depends on a number of factors starting with the plant.
Truong, Van and Pinners, in The Vetiver System, categorize these factors into three different
types of characteristics: Morphological, Physiological, and Ecological. Vetiver’s morphological
characteristics lend itself to use in wastewater treatment. Vetiver grass consists of a tall, stiff, and
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dense collection of stems rising up to 3 meters above the ground. This stem is coupled with a
finely sized and highly dense root system extending 3-4 meters below ground as shown in Figure
1. Both of these factors make Vetiver extremely resistant to erosion and highly tolerant of flow
conditions in wastewater treatment applications where the plant may be partially submerged.
Furthermore, Vetiver will respond to soil burial by growing new roots, making it ideal for
applications involving silt settlement. Physiologically, Vetiver is characterized as a hardy plant.
It is resistant to both drought and flood, as well as tolerant of a wide range of temperatures and
soil conditions including pH, alkalinity and other factors. Vetiver is also resistant to pesticides
and herbicides. Finally, Vetiver grass’ ecological characteristics are important to consider
regarding treatment application. The grass grows best when there is no shading, and can
contribute positively to erosion control and slope stability, acting as a nurse plant in areas where
soil has been disturbed. Furthermore, the USDA considers Vetiver grass to be non-invasive and
sterile. Vetiver grass’ adaptability ranges are listed in Appendix A.
Some specific traits of Vetiver grass are particularly applicable towards wastewater treatment.
Most notable, is Vetiver’s ability to uptake and remove nitrogen. In Australia, five hedgerows of
Vetiver were able to achieve a 99% reduction in total nitrogen when fed a sub-surface source of
septic tank effluent (Truong and Hart, 1991). Furthermore, Vetiver achieved 85% phosphorous
uptake which indicates that this method is at least partially effective in acting as a secondary
wastewater treatment system. Vetiver is also able to achieve some degree of filtration. Vetiver
roots grow in a thick and dense pattern with the average root diameter between .5 and 1 mm.
These characteristics put Vetiver root systems roughly on par with rapid sand depth filter
systems (.5mm effective particle size) (Stensel, 2013). Research in Australia by Truong et al.
(2008) demonstrated that a system of two Vetiver hedgerows was able to substantially reduce the
concentration of herbicides at an agricultural site. In addition to these treatment properties,
Vetiver roots were observed to act as a substitute disinfection process as well. Hart et al. (2003)
measured a reduction in E. Coli organisms present in a 20L sample of wastewater from
1600/100mL to 140/100mL over four days of treatment with no soil present. Lastly, Vetiver is
highly effective at creating an overall reduction in wastewater volume. This reduction is linked
to the high transpiration rate of Vetiver grass, which is 6.86 L/day under ideal conditions. This
water is either stored within the plant or evaporated. An overall reduction in wastewater is best
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for applications such as landfill leachate elimination, or the reduction of industrial effluent,
particularly in more remote areas. These characteristics of Vetiver Grass: Total P and Total N
reduction, filtration and disinfection in the roots, and overall reduction in the total volume of
wastewater, suggest a high potential for effective wastewater treatment.
Treatment Applications Plant treatment can be applied through several mediums including land, water, and wetland.
Land medium treatment involves using wastewater to irrigate land with plants or trees growing
on it. This method has been applied effectively at landfills and with small scale domestic sewage
treatment. Water medium treatment involves the use of floating beds of plants that can grow in
water. These beds are installed in ponds of water in need of treatment. Nutrients are assimilated
hydroponically through the plant’s root system (Zhao et al., 2012). Constructed wetland medium
treatment, as the name implies, runs influent wastewater through a wetland specifically designed
to encourage microbial activity along with plant nutrient uptake. The use of each medium
depends mainly on influent characteristics, climate, and land availability. Figure 3 shows
examples of each medium (land, water, and wetland) with Vetiver treatment.
Figure 3. From left to right, Vetiver planted on top of a landfill, hydroponic treatment, wetland treatment https://plus.google.com/photos/112053823950476566695/albums/5909108041704540833/5909108041301538018?banner=pwa&pid=590910804
1301538018&oid=112053823950476566695
Case Study: Hydroponic Treatment with Vetiver in China In Spring 2009, Zhao et al. conducted a comparison study involving the use of Vetiver and 5
other plant species capable of growing in floating beds in the hypereutrophic Haujiachi Pond in
Zeijiang University, Hangzhou, China. Motivation for this study is based on the prolific
eutrophication of inland water as result of the rapid growth and development of China over the
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last two decades. While constructed wetlands (CWs) were considered for treatment, CW large
land area requirements are limited by the high population density surrounding these areas of
extreme eutrophication. Floating plant treatment systems were considered in lieu of CWs due to
this limitation. The study also considered the additional benefit of contributing viable biomass
for energy and carbon dioxide sequestration (Zhao et al., 2012).
Two experiments were conducted. The first experiment evaluated each plants effect on water
quality. The second experiment harvested the biomass produced from each plant type and used
an Elemental Analyzer to determine leaf nitrogen, carbon, and sulfur content. Major mineral
nutrients in the biomass were also determined using other testing equipment. Influent wastewater
characteristics from the first experiment are included in Table 1. Twelve of each type of plant
were installed in a floating bed and a tank of diameter 50 cm and height of 60 cm filled with the
influent pond water. Water samples were taken from the upper, middle and lower portion of the
water column at 1, 6, 11, and 16 days.
Table 1. Influent Pond Water Characteristics
TN Ammonium-N NO2-N + NO3-N TP
8.12 ± 0.37 mg/L 2.28 ± 0.18 mg/L 4.07 ± 0.41 mg/L 2.28 ± 0.19 mg/L
The second experiment involved placing the floating beds on Huajiachi Pond for 5 months. The
area of the pond was 6000 m2 and the average water depth was 1.8 m. Plant seedlings were
arranged in a floating bed of four rows with 8 seedlings per row and fastened to a bamboo pillar
to prevent free movement of the floating bed. Plant samples were then harvested and analyzed in
the lab.
Nutrient removal for each plant from the first experiment is shown in figure 4. Vetiver and M.
sinensis anderss (Chinese Silvergrass) demonstrated the highest removal efficiencies for all
nutrients. From the data, the reduction of ammonium nitrogen is less than that of nitrite and
nitrate nitrogen. Plants uptake nitrogen in nitrate form, thus their ability to remove ammonium
nitrogen is limited by the rate of nitrification via nitrifying microbes.
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Figure 4. Nutrient N and P Removal over 1-16 Days of Treatment for each type of plant and a control
(CK)
Biomass analysis from experiment
2 are shown in Figures 4 and 5.
Vetiver (V.Z.) and M. sinensis
anderss (M.S.A.) have the highest
dry biomass as seen in Figure 4.
However, Figure 5 shows
variation in each plant’s ability to
uptake nutrients N, P, C, and S.
The four other types of plants
showed high N, P, and C content,
Figure 5. Fresh and Dry Weight of Biomass for each Plant
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but due to their low dry biomass production in Figure 4, their overall nutrient uptake in g/m2 is
reduced.
Figure 6. Nutrient Uptake for each Plant
Despite its secondary performance to Chinese Silvergrass, Vetiver offers additional value from a
bioenergy standpoint. Table 2 shows the high composition of carbohydrate in Vetiver (highest
crude fiber, neutral-detergent fiber, and acid-detergent fiber) making Vetiver ideal for
combustion (Zhao et al., 2012).
The results from this study draw several conclusions. Firstly, hydroponic treatment of polluted
water is not only viable, but it also effectively reduces nutrient levels to tolerable amounts as
seen in figure 4. Secondly, Vetiver and Chinese Silvergrass are ideal candidates for bioenergy
production based off their high chemical content and ability to utilize/grow on water surfaces as
opposed to dwindling land areas.
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Table 2. Chemical contents in the aboveground tissue of different plant species in experiment 2
Case Study: Tertiary Treatment with Vetiver in Australia In 2004, Ash & Truong created a report detailing the use of the Vetiver system to treat effluent in
Toogoolawah, South East Queensland, Australia. The local treatment plant had been operating
since 1971, using a relatively straightforward system where the influent was taken through
primary treatment and then released into a series of three retention ponds. These ponds were
designed to drain into a wetland area, where the effluent would eventually overflow into a local
creek.
The primary motivation for upgrading the plant to employ the Vetiver system was the loss of
permit. The effluent from the existing plant had concentration of nutrients remaining after
treatment. This, in turn, caused growth of algae in the ponds and increased the effluent pH from
7.5 to 9.2+. The permit for the operation of the treatment plant was threatened after Australian
environmental regulations were changed to require a maximum pH of 8.5 in treated effluent. A
new treatment process would need to be developed to reduce or eliminate the nutrient load in the
plant, removing the algae growth and returning the pH to acceptable levels for discharge into the
creek.
The treatment process chosen to be used in the Toogoolawah treatment plant was determined by
simulation to consist of two stages, both involving the use of Vetiver Grass. A plan view of the
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layout is shown in Figure 7.
The first stage involves
adding hydroponic Vetiver
floats to the existing ponds
in the treatment plant for
the purpose of pre-
treatment of the effluent
destined for the second
stage of Vetiver treatment.
21 floating platforms were
called for, each providing
roughly 6 square meters of
space for the grass to grow
and suspend its roots in the
pond water. The floating
Vetiver is supplemented by
Vetiver grown along the edges of the ponds, just above the water level. By employing this
method of pre-treatment, the models determined that approximately 1.5ha of land previously
thought required for the land-based Vetiver treatment could be eliminated. The Vetiver used in
this stage of the treatment process showed excellent growth, achieving a vertical height of 1.5m
in the first 5 months of operation. Furthermore, the growth has been substantial enough that the
plants from the floating pretreatment stage are used as the source of additional Vetiver grass for
the entire project. Overall, this pretreatment stage provides both treatment, and an element of
sustainability, eliminating the need for procurement and delivery of additional Vetiver grass.
The second stage is the main stage for the treatment process. It is fed by intermittent irrigation
from the pretreatment ponds. The wastewater flows across several rows of Vetiver grass, planted
at approximately 3m intervals. These rows form a curtain once the plants are fully matured. Two
separate areas are utilized to achieve a degree of redundancy, allowing for maintenance and other
work to be done on one area while the other is still treating wastewater. The systems are intended
to run on a 4-day cycle, where one day is an irrigation day and the other 3 are dry days. This
Figure 7. Layout of Toogoolawah Treatment Plant
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cycle has been implemented to accommodate the growth characteristics of Vetiver grass. It was
found that plants where the water was completely drained from the nearby area showed the best
growth, achieving heights of 1.5m and above. However, plants where the water was allowed to
linger displayed poor growth. This corroborates with the results from the first case study –
Vetiver performs best in land rather than in water.
Table 3. Before and After Influent and Effluent Comparison
Tests Plant Influent Previous Results
(Effluent: 2002-
2003)
New Results
(Effluent:
2004)
pH ( 6.5 to 8.5) 7.3 to 8.0 9.0 to 10.0 2.6 to 9.2
Dissolved Oxygen (2.0 minimum) 0 to 2 mg/L 12.5 to 20 mg/L 8.1 to 9.2 mg/L
5 Day BOD (20-40 mg/L max) 130 to 300 mg/L 29 to 70 mg/L 7 to 11 mg/L
Suspended Solids (30-60 mg/L max) 200 to 500 mg/L 45 to 140 mg/L 11 to 16 mg/L
Total Nitrogen
(6.0 mg/L max)
30 to 80 mg/L 13 to 20 mg/L 4.1 to 5.7 mg/L
Total Phosphorous
(3.0 mg/L max)
10 to 20 mg/L 4.6 to 8.8 mg/L 1.4 to 3.3 mg/L
Results from the implementation of the system are promising for the operators of the plants, and
are given in table 3. Adding the Vetiver grass system reduced the nutrient load significantly,
achieving the overall goal of the enhancement project at Toogoolawah wastewater treatment
plant. Successes of the system include reducing total nitrogen to >6mg/L from 13-20mg/L in the
old system’s effluent. Total phosphorus was also reduced from 4.6-8.8mg/L to <3.3mg/L. The
plant is now in compliance with the new license requirements, and with the exception of total P
in effluent, the plant is already compliant with the expected future limits with regards to
dissolved Nitrogen and Phosphorus.
There are some conclusions that can be drawn from the results of the report. The first conclusion
is that Vetiver grass wetland systems are a legitimate solution when an operator is faced with a
high nutrient load. The overall reduction in total Phosphorous and total Nitrogen have solved the
pH problem with the plant’s effluent.
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Furthermore, it showcases the fact that the
most expensive wastewater treatment solution is
not necessarily the best wastewater treatment
solution. Considering the alternatives
investigated by the plant operators and shown in
Table 4, the Vetiver grass wetlands system
implemented was able to achieve the desired
results for a fraction of the cost of other high-
technology solutions (Ash and Truong, 2004).
Operational and Design Issues The main operational and design issues associated with applying Vetiver treatment include
meeting wastewater flow demands while providing an adequate level of treatment, ensuring plant
survival, and optimizing nutrient uptake per unit area of grass. The easiest solution to providing
enough capacity for meeting wastewater flow demands is to increase land area use and
consequently, reduce the applied flow of wastewater and increase retention time. However, in
areas where land is limited such as the Chinese bioenergy study, planting Vetiver hydroponically
eliminates having to use any land at all (Zhao et al., 2012). In the case of treating leachate from a
landfill in Biloxi, Mississippi, the land available for Vetiver growth and leachate irrigation was
limited to the size of the landfill. With this limitation along with other factors that affect the
performance of Vetiver, an automated pretreatment system was installed in order to monitor and
respond to changes in leachate production, leachate quality, and weather conditions (Kenyon,
2012). This example shows that in conjunction with modern technology, treating wastewater
with Vetiver has tremendous potential for optimization and improvement in land use, overall
system control, and risk management.
Risk Associated with Treatment System In addition to managing influent wastewater variation and controlling effluent output (ensuring
that water quality standards are met), other concerns include the accumulation of hazardous
compounds in biomass. Especially with respect to mine tailing and landfill leachate treatment,
Solution
Considered
Projected Costs
Vetiver Grass
Wetlands
$200,000
Rock Filtration $250,000
Sand Filtration
(Alum Dosing)
$450,000
BNR Plant Upgrade $1,500,000
Table 4. Cost Comparison of Different Solutions
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Vetivers’ ability to uptake heavy metals may be of concern to either the animals or people who
eat/interact with its shoots. On discussing this possibility with Brad Granley, one of the engineers
working on the landfill leachate treatment system in Mississippi, he mentioned that most
research has shown that Vetiver accumulates heavy metals in its roots rather than leaves.
Minimizing surface interaction with heavy metals is key to reducing risk. In addition, Granley
mentioned that in his landfill project heavy metal concentrations were relatively low, not high
enough to be considered hazardous. Granley did mention that the soil, rather than the plant, is
more likely to absorb contamination of high enough concern (Granely, 2013). The results of long
term soil quality monitoring will be useful to see.
Another risk associated with Vetiver treatment is groundwater contamination. This risk applies
mostly to land treatment. However, consider that most of the water is being “reused” in the plant
itself, particularly with low volumes and hot climates, most of the water will evaporate or
infiltrate into the Vetiver root system where it is sucked up and transpired. The concept of using
up the water before it can infiltrate fully has led to the success of Vetiver latrines in Haiti, an
excellent example of a low volume and hot climate scenario. See Appendix B for a detailed
illustration of a Vetiver latrine. While there may be some risk involved, the cost of creating a
sealed impermeable barrier is not a viable solution for some parts of the world.
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Advantages and Disadvantages of Using Vetiver for Wastewater Treatment There are several factors to
consider when determining
whether the Vetiver system is
appropriate for treatment at a
given wastewater site. The main
points are listed at a glance in
table 5. Low-tech and low-cost
are the main advantages
associated with using Vetiver for
wastewater treatment.
Considering that beyond the
design, installation is comprised
of simply planting a grass in certain locations in land and wetland applications, and hydroponic
applications merely add construction of simple floats, it can be assumed that the labor skill
required is fairly low. This is an opportunity to save on costs as well as support a local workforce,
as there is no need to import a specialized group of technicians to work on-site and then return
home. Furthermore, Vetiver grass treatment systems are easily scaled down to small sizes for
small treatment systems. An application such as a single-home system or septic tank effluent
treatment is achievable with Vetiver grass without the need to pay a high premium for high
technology on a miniature scale. Finally, one advantage that Vetiver grass treatment systems
provide that should not be overlooked is the resource provided by harvesting the grass. This
grass can be used for a wide variety of applications, such as biomass for energy production or
fuel generation, or as feed for livestock or roofing.
There are shortcomings with Vetiver treatment systems, however. Most of these disadvantages
arise when the Vetiver systems is compared to large-scale wastewater treatment applications.
Under high flows the Vetiver system requires far more space. In metropolitan areas, large land
area is less available. The same is true for the amount of time that Vetiver needs to effectively
treat wastewater. Hydroponic applications need high retention times, and wetland systems
require special care so that short-circuiting does not occur. Lastly, another disadvantage that the
Advantages Disadvantages
• Low Cost
• Easy Implementation
• Easy Maintenance
• Aesthetically Pleasing
• Sustainable
• Economical at small
operation size
• Provides useful
resource
• Large land area
requirements
• Long detention times
required
• Downtime and drying
required in certain
treatment methods
• Waste accumulation
• Future fate of wastes
Table 5. Advantages and Disadvantages of Vetiver Treatment at a Glance
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Vetiver system poses when compared to traditional treatment comes when considering the fate of
hazardous wastes. Though Vetiver’s roots serve as an effective filtration system, unlike
traditional filtration, Vetiver is very difficult to backwash, scrub, or otherwise treat to remove the
buildup potential contaminants adsorbed and absorbed by the roots. This poses a problem when
pesticides, herbicides, heavy metals, or other toxic compounds are being retained underground
by Vetiver’s root system. Eventually, the operator of the plant may need to take action to reduce
the risk posed by the accumulation of these chemical compounds.
The Future of Vetiver The future scope, scale, and success of using Vetiver to treat wastewater will depend on a
number of factors, namely improvements to design and reliability, public acceptance, and further
research. Discussion of automated pre-treatment systems for the landfill leachate in Mississippi
demonstrates considerable potential for optimizing Vetiver’s unique plant characteristics to
uptake nutrients, metals, and water as well as reducing the risk of exceeding Vetiver’s capacity.
This kind of monitoring has also been successfully implemented with Poplar trees in the Pacific
Northwest. The Riverbend Landfill in McMinnville, Oregon deposited its leachate into a lined
storage lagoon with 7 million gallon capacity. In order to manage this build up of waste
efficiently, 35,000 trees were planted on a 17-acre field next to the lagoon. The trees were
sprayed with stored leachate dynamically, based on measuring soil moisture content with three
wells placed 8 feet deep in the ground (Licht and Isebrands, 2005). These optimization and risk
reducing improvements are the result of acquiring and processing more data. However, it is
important to note that one of the key aspects of using Vetiver for wastewater treatment is its
simplicity. This simplicity ensures relatively low costs of design, construction, and operation.
For large portions of the world, this simplicity and associated lower cost, is of far more value
than expensive alternatives. Keeping the cost low, while making improvements to system design
and reliability will be key for these localities. Where cost and lack of technical know-how is less
of an issue (e.g. the United States), more expensive effort may be taken to meet more stringent
water quality standards.
Public acceptance of Vetiver as a form of wastewater treatment will play the largest role in
places where very high standards for water quality are expected. The juxtaposition of nationwide
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implementation of large-scale mechanical wastewater treatment plants next to acres of trees or
Vetiver grass will look like nothing is actually being done to treat wastewater. Americans are
used to a particular image of what a wastewater treatment system looks like. If it doesn’t look
like a mechanical wastewater treatment plant, it must not be treating water effectively. While
great, even revolutionary, success has been shown in the landfill leachate treatment system in
Mississippi, it was a tremendous challenge convincing skeptical regulatory authorities (Kenyon,
2012). This project, and the enormous cost benefits associated with it, mark the beginning of
convincing both authorities and the public that phytoremediation, particularly with Vetiver grass,
is a viable wastewater treatment system.
While the results of successful projects are more convincing to the public than reading the results
of research in the field, further research is necessary to convince the engineers and regulatory
authorities that such projects can be successful. Research needed includes further optimization of
Vetiver’s ability to uptake nutrients, minimizing the sinusoidal effects of climate with seasons,
and investigating another possible advantageous functionality of Vetiver – disinfection. In their
report on the treatment of septic tank effluent in Australia, Hart et al. (2003) reported a decrease
in E. Coli organisms from over 1600 per 100mL to 140 after 4 days of treatment by Vetiver grass.
This was the result of hydroponic treatment with Vetiver. However, the authors also had
reservations about the resulting disinfection in the barrel, citing the time it took for analysis to
occur during the trial. In a different trial, mentioned by Ash and Truong (2004), flows passing
through five rows of Vetiver plants yielded a 95% reduction in fecal coliform indicators. While it
appears as though some forms of Vetiver grass treatment show great potential in their capability
to disinfect wastewater, conflicting reports indicate that additional studies may be required
before Vetiver grass can be relied on to be used specifically in a disinfectant role.
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Conclusion In summary, the Vetiver wastewater treatment system shows considerable promise when used
under the right circumstances. Currently, Vetiver is ideal in three cases for successful
performance. First, Vetiver grass treatment systems work best in tropical and subtropical
climates. The Vetiver plant itself thrives in full sun and warm growing conditions. Although it is
a hardy plant, capable of surviving many different adverse conditions as shown in Appendix A,
those considering the use of Vetiver should pay particular attention to the climate at the
treatment site. For example, if the site is in an area that is colder, instead of Vetiver it may be
best to explore other phytoremediation solutions, such as the use of Poplar trees (Licht and
Isebrands, 2005).
Secondly, land applications are most effective with low-flow wastewater. With high detention
times, Vetiver can be applied successfully to processing wastewater, particularly industrial
wastewater such as leachate from landfills or mine tailings. Most importantly is Vetiver grass’
ability to transpire great amounts of water into the atmosphere. This can reduce or completely
eliminate the amount of wastewater that reaches lakes, streams, and the groundwater table. This
can mean that effluent is completely contained in the treatment area, eliminating the possibility
of nutrients and pollutants to transport off-site.
Lastly, the Vetiver system thrives in decentralized (isolated) and developing areas. In these areas,
wastewater treatment ranges from ad-hoc systems such as septic tanks to a total lack of treatment
altogether. Vetiver systems can be applied to this entire range. For secondary treatment of septic
effluent, Vetiver is a viable solution (Ash and Truong, 2004). Furthermore, in developing areas,
low-tech solutions such as the Vetiver latrine may be ideal. Overall, the use of the Vetiver
wastewater water treatment system is a legitimate alternative to traditional wastewater treatment
in many areas around the world.
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Appendix A Adaptability Characteristics of Vetiver Grass in Australia (Truong et al., 2008) Condition Characteristic Australia Other Countries
Adverse Soil Conditions:
• Acidity (pH)
• Salinity (with 50% yield reduction)
• Salinity (Any survival)
• Aluminum Level
• Manganese Level
• Sodicity
• Magnesicity
• 3.3-9.5
• 17.5mS/cm
• 47.5mScm
• 68%-87%
• > 578 mg/kg
• 48% (exchange Na)
• 2400mg/kg
• 4.2-12.5
Fertilizer N & P (300kg/ha DAP) N & P (farm manure)
Heavy Metals:
• Arsenic
• Cadmium
• Copper
• Chromium
• Nickel
• Mercury
• Lead
• Selenium
• Zinc
(in mg/kg)
• 100 – 250
• 20
• 35 – 50
• 200 – 600
• 50 – 60
• > 6
• > 1500
• > 74
• > 750
Location: 15 degrees S to 37 degrees S 41 degrees N to 38 degrees S
Climate:
• Annual Rainfall (mm)
• Frost (low ground temp.)
• Heat wave
• Drought (no effective rain)
• 450 – 4000
• -11 degrees C
• 45 degrees C
• 15 months
• 250 – 5000
• -22 degrees C
• 55 degrees C
Palatability: Dairy cows, cattle, horse,
rabbits, sheep, kangaroo
Cows, cattle, goats, sheep, pigs,
carp
Nutritional Value: N = 11% , P = 0.17%, K =
2.2%
Crude Protein = 3.3%, Crude Fat
= 0.4%, Crude Fiber = 7.1%
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Appendix B – The Vetiver Latrine Concept
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References Ash, R., & Truong, P. (2004). The Use of Vetiver Grass for Sewerage Treatment. Presented at
the Sewage Management QEPA Conference, Cairns, Australia. Retrieved from
http://www.vetiver.org/AUS_ ekeshire01.pdf
Granley, B. (2013, December 7). Vetiver Phytoremediation of Landfill Leachate Discussion.
Hart, B., Cody, R., & Truong, P. (2003). Hydroponic Vetiver Treatment of Post Septic Tank
Effluent. Retrieved from http://www.vetiver.org/ICV3-Proceedings/AUS_hydroponic.pdf
Kenyon, T. (2012). Innovative Phytoremediation Process Utilizes Landfill Leachate as a
Resource in Lieu of Traditional Disposal as a Waste. American Academy of
Environmental Engineers and Scientists. Retrieved December 6, 2013, from
http://www.aaees.org/e3competition-winners-2012gp-smallprojects.php
Lee, O. (2013). The Vetiver Latrine. Presented at the Second Latin America International
Conference on the Vetiver System, Medillin, Colombia: The Vetiver Network
International. Retrieved from
http://www.vetiver.com/LAICV2F/2%20Environmental%20Protection/E5Lee_TE.pdf
Licht, L., & Isebrands, J. G. (2005). Linking phytoremediated pollutant removal to biomass
economic opportunities. Biomass and Bioenergy, 28(2), 203–218.
Stensel, D. (2013, December). Filtration.
Retreived from https://catalyst.uw.edu/workspace/stensel/40730/289680
Truong, P., Tan Van, T., & Pinners, E. (2008). The Vetiver System for Improving Water Quality
(1st ed.). The Vetiver Network International. Retrieved from
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