effects of greywater on helianthus annuus growth nicole...
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Running Head: EFFECTS OF GREYWATER
Effects of Greywater on Helianthus Annuus Growth
Nicole Fleming and Mary McDonald
EDUC-4260
Matthew Roy
February 26, 2014
EFFECTS OF GREYWATER 2
Abstract
This paper is about the impacts of greywater on the growth of plants. The study looked
at the effects of four different types of greywater on the growth of Helianthus Annuus
(sunflower) plants. It studied the effects of laundry water, dish water, shower water, and a
mixture of the three on plant growth. This was done by allocating three Helianthus Annuus
plants for each type of water, watering them every day for a period of 29 days and measuring
them once a week. The study found that the mixture of the three types of greywater resulted in
the most growth. Following that it was shower, laundry and dish water in respective order
with the control having the least amount of growth. The higher amount of natural and some
artificial materials in the various grey waters enabled the plants to have higher levels of
growth.
Introduction
Greywater is composed of non-toilet wastewater that households produce, which can
include water from showers, sinks, and washing machines (Wiel-Shafran, Ronen, Weisbrod,
Adar & Gross, 2005). The use of said greywater for irrigation is becoming increasingly
common (Wiel-Shafran et al, 2005), especially for irrigation of household lawns and gardens
(Misra, Patel, & Baxi, 2010). According to current studies, the use of untreated greywater can
result in poor soil quality and can increase environmental pollution (Wiel-Shafran et al, 2005).
It is also considered hazardous for humans, as there is the potential for infection to occur
(Misra, 2010). The use of greywater for irrigation may reduce plant growth due high
concentrations of sodium, zinc and aluminium that is found in greywater (Misra, 2010);
therefore, it may not be considered a viable option for irrigation.
EFFECTS OF GREYWATER 3
The aim of this study was to gain an understanding of the impact of greywater on plant
growth, and to determine the applicability of using grey water for plant growth. The results
can be used to justify the use and application of greywater for sustaining plant growth in daily
life. Controlling the type of greywater given to each plant enabled the demonstration of which
source of liquid allows for the greatest amount of plant growth. Greywater can be collected in
a number of different ways. For this study, the greywater was collected by gather all liquid and
associated materials from each source, and then taking a sample of each source. Each sample
was used for the entire duration of the study. Greywater is apart of our daily lives, and the use
of greywater can help with the conservation of water. Research of this nature is important for
water conservation and environmental sustainability, as it demonstrates alternative methods
for watering plants, while still producing growth.
Hypothesis
If grey water is used to water the Helianthus Annuus seeds then there will be a
reduction in plant growth compared to the growth of the control plants.
Research Question
When comparing grey water sources, the dish water will produce the most growth.
This is due to the composition of the dish water, which is likely to include “bacteria, organic
matter, food particles, fat, oil, grease,” which positively affects plant growth (Jordan, 2006, p.
10). This positive plant growth will be due to more nutrients being available to the plant from
the greywater, outweighing the negative affects caused by soap and detergent residue.
The shower water will produce the second most growth, also due to the increase in
organic matter. The organic matter, which may include “bacteria, hair, organic material, [and]
EFFECTS OF GREYWATER 4
skin particles” (Jordan, 2006, p. 10), will be present in a smaller concentration than that of the
dish water, producing less growth than the plants watered with dish water.
The laundry water will produce the third most growth of the greywater sources, due to
the lack of organic matter in comparison to the other sources of greywater. Since laundry
water often contain detergents with bleach, the salinity and pH of this greywater source is
increased, which negatively affects the growth of plants (Jordan, 2006).
We believe that the mixed greywater will produce the least growth, due to higher
levels of soaps and detergents, which will negatively affect the growth of plants (Jordan,
2006). The presence of these soaps and detergents will outweigh the positive effects from the
organic matter presence, overall negatively effecting plant growth.
Due to the presence of detergents in all of the sources of greywater, all plants will have
less growth than that of the control.
Materials
• 460 milliliters of Tap water
• 460 milliliters of Laundry Water
• 460 milliliters of Dishwater
• 460 milliliters of Shower water
• Mixed water: 1:1:1 ratio of the various grey waters listed above
• 5 Helianthus Annuus seeds
• 15 planter pots
• 3.54 liters of Miracle Gro - Seed starting soil
• Tablespoon
• 4 containers for the water
EFFECTS OF GREYWATER 5
Method
This study was conducted over the period of 30 days. To begin, the 15 Helianthus
Annuus (herein referred to as sunflower) seeds, from the same package, were submerged in tap
water for a period of 24 hours prior to being planted. The seeds that were selected were of
similar size to attempt to control the starting conditions. When planting the seeds, 237 mL of
soil was placed in each of the 15 planter pots and a 12.5 mm hole was dug in each pot. A
sunflower seed was then placed in each hole and covered with soil. Each planter pot was had
30 milliliters (two tablespoons) of the appropriate water source poured directly over where the
seeds had been planted. There were three seeds planted in separate planter pots for each source
of water, therefore, there were:
o three seeds planted for tap water
o three seeds planted for laundry water
o three seeds planted for shower water
o three seeds planted for dish water
o three seeds planted for a mixture of the greywater
Each planter pot received 15 mL (one tablespoon) of the assigned water source daily, for 29
days. The plants were placed on a table where all of the plants would get the same amount of
sunlight. They were away from the heaters in the room and the room was kept at a constant
temperature of 18 degrees Celsius. All of the sources of grey water were obtained on the first
day of the experiment and used throughout the duration of the experiment. The laundry water
was collected when there was 150 mL of Sunlight Cold Water laundry detergent for 170 L.
There was 15 mL of dish soap in 20 L of dishwater. For the shower water 30 mL of soap and
shampoo combined was put into 80 L of shower water. Observations were made when growth
was first observed, and then were recorded weekly from the day of planting. Measurements
EFFECTS OF GREYWATER 6
were taken from the soil to the highest point on the plant, or the apex. If the plant was not able
to support itself, then it was lifted to the height it would naturally be standing if it were able to
support itself, and measurements were taken from the apex of that standing position.
Figure 1: Planting Arrangement of the Sunflower Seeds
Safety Considerations
When conducting this experiment, it is important to prevent any materials from being
ingested, inhaled, or contact with the eyes. This includes soils, and greywater sources. Due to
the composition of the soil and the greywater sources, ingestion, inhalation, or contact with the
eyes could result in irritation. To prevent this, wear safety goggles and proceed with caution
when handling soils and greywater. If ingestion, inhalation, or contact with the eyes occurs,
follow appropriate warnings on containers of soils, soaps, and detergents.
EFFECTS OF GREYWATER 7
Results
December 1st was the first day that we saw growth.
Chart 1. The Comparison of the Effects of Different Types of Grey Water on Plant Growth
Chart 2. Control Plant Growth
0
10
20
30
40
50
60
70
80
90
1 7 14 21 30
Plant Growth (mm)
Day
Tallest Plant Growth for the Various Types of Grey Water Sources
Control Plant Growth
Dishwater Plant Growth
Shower Water Plant Growth
Laundry Water Plant Growth
Mixed Grey Water Plant Growth
0
10
20
30
40
50
60
70
80
90
1 7 14 21 30
Plant Growth (mm)
Day
Sun<lower Plant Growth For the Control
Plant 1
Plant 2
Plant 3
EFFECTS OF GREYWATER 8
Chart 3. Dish Water Plant Growth
Chart 4. Shower Water Plant Growth
0 10 20 30 40 50 60 70 80 90
1 7 14 21 30
Plant Growth (mm)
Days
Sun<lower Plant Growth For Dishwater
Plant 1
Plant 2
Plant 3
0 10 20 30 40 50 60 70 80 90
1 7 14 21 30
Plant Growth (mm)
Days
Sun<lower Plant Growth for Shower Water
Plant 1
Plant 2
Plant 3
EFFECTS OF GREYWATER 9
Chart 5. Laundry Water Plant Growth
Chart 6. Mixed Grey Water Plant Growth
As demonstrated in the results above, the mixed greywater had the largest amount of
plant growth. The next source of greywater that had a large amount of plant growth was the
shower water, followed by laundry water, dishwater, and finally the control plant. The three
plants for each source of water had similar results and were consistent with the overall
comparison of plant growth between the various sources of greywater.
0 10 20 30 40 50 60 70 80 90
1 7 14 21 30
Plant Growth (mm)
Day
Sun<lower Plant Growth For Laundry Water
Plant 1
Plant 2
Plant 3
0 10 20 30 40 50 60 70 80 90
1 7 14 21 30
Plant Growth (mm)
Day
Sun<lower Plant Growth For Mixed Water
Plant 1
Plant 2
Plant 3
EFFECTS OF GREYWATER 10
Discussion
There was a large amount of plant growth in the mixture of the three types of
greywater (refer to Chart 6), potentially due to the idea that there were the most amounts of
potential nutrients to optimize the amount of plant growth. Within the laundry machine, there
are materials like “dirt, lint, oil, grease, organic material, sodium, nitrates, and phosphates,
bleach, increase the salinity and pH ” (Jordan, 2006, p.10). The natural ingredients like skin
and other organic materials in addition to the nitrates and phosphates all give the plants more
nutrients to help increase the amount of growth (Jordan, 2006). In our laundry water, we did
not use bleach or a detergent containing bleach, therefore, our grey water contained fewer
materials than listed above. Due to the nature of laundry water and from our research, we
speculate that there would be organic matter, dirt, lint, grease, nitrates, and phosphates; all of
which give the plants more nutrients and assist in growth, compared to the control (refer to
Chart 1).
In dish water there is likely to be “bacteria, organic matter, food particles, fat, oil,
grease, soap, and detergent residue,” which affects plant growth (Jordan, 2006, p. 10).
Although there is some organic matter, which will increase the amount of plant growth for
these plants, the soaps and detergent residues have chemicals that reduce the amount of plant
growth (Jordan, 2006). Food particles, oil, and grease could be observed in the dish water that
was collected, leading us to believe that there was also bacteria and other organic matter; as
well as the soap and detergent residue. Each of those components would affect plant growth
compared to the control (refer to Chart 1 and Chart 3). Unlike what we additionally believed,
the dish water did not have a lot of plant growth, presumably due to the high concentrations of
soaps, detergent, and grease, which negatively affects plant growth.
EFFECTS OF GREYWATER 11
For shower water, there is usually “bacteria, hair, organic material, skin particles, lint,
oil, grease, soap, and detergent residue” (Jordan, 2006, p.10). Just like with the dish water,
some of the organic matter will help increase the growth of the plants (Jordan, 2006), while
other components of the grey water will hinder growth. The shampoos, soaps, and
conditioners that are part of the shower water contain more chemicals such as bleaches,
sodium and chloride, which are very harmful to sunflower plants (Jordan, 2006; Wang et. al,
2012). Within our sources of greywater, the make-up positively affected the growth of the
plants, resulting in more growth than the control (refer to Chart 1 and Chart 4), potentially due
to the low concentrations of soaps in comparison to the concentration of organic materials,
such as the ones listed above.
The mixed source of greywater had the most growth (refer to Chart 1 and Chart 6). It is
believed that this growth was due to a higher concentration of organic material from the
combination of the sources of greywater, which allowed for the increased plant growth. It is
also believed, due to the increased plant growth that this source had a lower concentration of
soaps and detergents, which resulted in less inhibition of plant growth.
With an increase in ratio of water to soaps, detergents, shampoos and other chemical
products used for cleaning, there was a decrease in the potential chemicals in the sources used
to irrigate the plants. The increase of these chemicals, such as sodium, decreased the amount
of water being absorbed by the plants (Jordan, 2006). Chemicals like sodium also decrease the
amount of discolouring and burning of the leaves (Jordan, 2006). Although we did not find
this happening to any of our plants, as they were all green and standing upright, it would be
good to look at what point this would happen.
EFFECTS OF GREYWATER 12
Errors
This study encountered some experimental errors, which may have influenced our
results. There could have been some human error, which would include incorrect measurement
of the amount of soil added initially, and the amount of liquids given to each plant. This could
have been due to sloppiness or spilling of materials during measurement and transfer from the
source to the plant. When collecting the sources of greywater, improper collection techniques
may have affected the composition of the greywater sources and ultimately affected the
growth of the plants. This could include the improper cleaning of holding containers or
measurement equipment, which could have contaminated the greywater sources and/or the
plants. During observation and recording, poor recording could have occurred from a variation
of eye level when reading the measurement. This would result in improper measurements
being taken, altering the results. Taking precautions to be aware of human errors and being
precautious during steps will assist in minimizing human errors. These precautions can include
accurate measurements of materials by using proper and specific measuring tools, measuring
results from eye level, and not rushing through steps.
Experimental errors could have also occurred, which would also alter the results. The
location of the plants within the set-up of the experiment would influence the conditions,
which the plants were under. Movement and rotation of plants could have assisted in
minimizing this effect. Another error is the differentiation of seeds, due to natural differences,
which results in different abilities of growth and successful maturation. During measurement
and transfer of greywater from source to plant, evaporation of the liquid may have occurred
due to natural environmental effects on the liquids. This evaporation alters the amount of
liquid being given to the plants, influencing the results. Awareness of experimental error can
allow for a more accurate interpretation of the results.
EFFECTS OF GREYWATER 13
Conclusion
All of our plants had growth, suggesting that each mixture of grey water had natural
and organic matter, which assisted in growth; rather than harmful chemicals that would hinder
growth. Our results did not support our hypothesis. The control, in fact, had the least amount
of growth when we predicted that the control would have the greatest amount of growth. We
also thought that the sunflower seeds watered with the mixed grey water would produce the
least amount of growth; instead they had the greatest amount of growth. Our other prediction
was that the shower water would produce the greatest amount of growth, and it showed the
second greatest amount of growth. Although our hypothesis was disproved, we were pleased
with our results; which support the use of grey water for watering household plants.
It is difficult to determine how successful future uses of grey water use for watering
household plants will be, because the concentration of grey water will change from household
to household. By using watered down greywater or organic soaps, there would be an increase
in plant growth, as there would be a further reduction in the amount of harmful chemicals
(Jordan, 2006). Since the concentrations that were used for this study may not be the same
concentrations used in homes, the results will vary in different situations. We suggest watering
down grey water to decrease the concentration of potential harmful chemicals, and increase
the potential for growth. Overall, this study found that using grey water to irrigate household
plants is a viable option for reducing water consumption, while still having positive plant
growth.
EFFECTS OF GREYWATER 14
References
Jordan, A. (2006). Overview of greywater management Health considerations. World Health
Organization. Retrieven Jan 11th, 2014 from, http://applications.emro.who.int/
dsaf/dsa1203.pdf
Misra, R. K., Patel, J. H., & Baxi, V. R. (2010). Reuse potential of laundry greywater for
irrigation based on growth, water and nutrient use of tomato. J. Hydrol., 386(1-4), 95-
102.
Planet Ark. (2007). Grey Water. Retrieved Jan 10th, 2014 from, http://products.planet
ark.org/documents/doc-163-greywater-information-guide.pdf
Wang, J., Bai, Z., Yang, P., (2012). Sodic Soil Properties and Sunflower Growth as Affected
by the Byproducts of Flue Gas Desulfurization. PLoS ONE 7(12): e52437. doi:
10.1371/journal.pone.0052437
Wiel-Shefran, A., Ronen, Z., Weisbrod, N., Adar, E., & Gross, A. (2005). Potential changes in
soil properties following irrigation with surfactant-rich greywater. Ecological
Engineering, 26, 348-354.
EFFECTS OF GREYWATER 15
APPENDIX 1
Day Control
Plant
Growth
(mm) 5
Dishwater
Plant Growth
(mm) 4
Shower
water Plant
growth
(mm) 2
Laundry
Water Plant
growth
(mm) 3
Mixed Grey
Water Plant
Growth
(mm) 1
1 -
Nov. 25th,
2013
0 0 0 0 0
7 -
Dec. 1st,
2013
10 0 35 30 40
14 -
Dec. 8,
2013
15 12 49 45 55
21 -
Dec. 15th,
2013
27 26 56 50 68
30 -
Dec.22nd
2013
39 41 70 64 80
Table 1. Tallest Plant Growth for the Various Types of Water Sources
EFFECTS OF GREYWATER 16
Day Plant 1 ( mm) Plant 2 ( mm) Plant 3 (mm)
1 -
Nov. 25th, 2013
0 0 0
7 -
Dec. 1st, 2013
7 10 8
14 -
Dec. 8, 2013
15 12 13
21 -
Dec. 15th,
2013
21 20 27
30 -
Dec.22nd
2013
35 30 39
Table 2. Plant Growth For the Control
EFFECTS OF GREYWATER 17
Day Plant 1 ( mm) Plant 2 ( mm) Plant 3 (mm)
1 -
Nov. 25th, 2013
0 0 0
7 -
Dec. 1st, 2013
0 0 0
14 -
Dec. 8, 2013
12 6 10
21 -
Dec. 15th,
2013
18 16 26
30 -
Dec.22nd
2013
31 29 41
Table 3. Dishwater Plant Growth
EFFECTS OF GREYWATER 18
Day Plant 1 ( mm) Plant 2 ( mm) Plant 3 (mm)
1 -
Nov. 25th, 2013
0 0 0
7 -
Dec. 1st, 2013
35 20 26
14 -
Dec. 8, 2013
49 37 41
21 -
Dec. 15th,
2013
56 50 52
30 -
Dec.22nd
2013
70 59 61
Table 4. Shower Water Plant Growth
EFFECTS OF GREYWATER 19
Day Plant 1 ( mm) Plant 2 ( mm) Plant 3 (mm)
1 -
Nov. 25th, 2013
0 0 0
7 -
Dec. 1st, 2013
15 30 24
14 -
Dec. 8, 2013
27 45 39
21 -
Dec. 15th,
2013
36 50 46
30 -
Dec.22nd
2013
49 64 58
Table 5. Laundry Water Plant Growth
EFFECTS OF GREYWATER 20
Day Plant 1 ( mm) Plant 2 ( mm) Plant 3 (mm)
1 -
Nov. 25th, 2013
0
0 0
7 -
Dec. 1st, 2013
40 27 34
14 -
Dec. 8, 2013
55 42 48
21 -
Dec. 15th,
2013
68 51 64
30 -
Dec.22nd
2013
80 65 72
Table 6. Mixed Grey Water Plant Growth