Greywater is the waste water from baths, sinks, washing machines, and kitchen water. What makes up greywater is the fresh water, obtained from taps, mixed with cleaning detergents, washing powders, soaps, shampoos, fabric softeners and fat (to name a few) – basically, greywater is made up of everything one allows to pass through a drain after use of that product. A family of 4 will, on average, make use of between 300l and 400l of greywater in a single day. (Bekink, 2017)
The residues of greywater are diluted by the water content, but still possibly have the ability to negatively impact the environment due to their unnatural components such as Methylisothiazolinone, Cocamidopropyl betaine (Wikipedia, 17), Sodium Coco-sulphate (Humphries, 2016), Cocamidopropylamine Oxide (Info, 2016), Lavandula angustifolia (lavender) oil, Anthemis nobilis (chamomile) flower oil, Cocamidopropyl Betaine and Coco Amido Betaine1, Alcohol Ethoxylates (c12-14) Propoxylated (Tudons, 2014), Phenoxyethanol and Sodium Phenoxyethanol (Irish, 2017). Although organic residues are highly promoted and their use is encouraged over the use of inorganic compounds, these organic molecules do still form part of greywater and may negatively affect aquatic-plant life.
The hypothesis for this task is that greywater, specifically including contents of organic and inorganic detergents and residues, has a negative impact on the life of aquatic flora.
The hypothesis was chosen due to the fact that organic residues are highly promoted and their use is encouraged over the use of inorganic compounds, however, these organic molecules do still form part of greywater and may negatively affect aquatic-plant life. Greywater is made up of many different components and although many households do use only organic detergents and surfactants, many households use only inorganic detergents and surfactants and some use a variety of both organic and inorganic detergents and surfactants. Once released into the water pipes, the surfactants and detergents used by all households are, in fact, combined and are expelled as one mass group into the environment.
The hypothesis considers this fact and, therefore, does not only focus on the effects of only one type of surfactant or detergent (organic or inorganic) on aquatic-plant life
The aim for this task is to determine if greywater, specifically including contents of organic and inorganic detergents and residues, has a negative impact on aquatic-plant life.
Just as the hypothesis considers the fact that greywater is made up of many different components and although many households do use only organic detergents and surfactants, many households use only inorganic detergents and surfactants and some use a variety of both organic and inorganic detergents and surfactants and once released into the water pipes, the surfactants and detergents used by all households are, in fact, combined and are expelled as one mass group into the environment, the aim of the experiment considers this, too.
This research task for Life Sciences includes an experiment to test the effects of greywater on aquatic-plant life in comparison to the effects of clean water on aquatic-plant life. The experiment included was performed in an outdoor, sunny area from January 7th, 2018 to February 12th, 2018. The experiment results were obtained by testing four plants, two Nymphaea alba (water lily) and two Xerophyta viscose (monkey tail). One of each plant was placed into a large plastic planter filled with only clean water while the other two plants were placed into a large plastic planter filled with water taken directly from a sink filled with the water used to wash the dishes and from the washing machine that had just completed washing the clothes.
The experiment was performed to obtain primary information that can be used to validate whether or not greywater, specifically including contents of organic and inorganic detergents and residues, has a negative impact on the life of aquatic flora.
The significance of this topic is that underwater plant and animal life may be as harmed by organic detergents as they would by inorganic detergents because both form part of greywater. This experiment will research the effect of greywater on aquatic plant life in order to gain knowledge of the short and long-term effects of daily used water on underwater life.
Detergents are products used in the home for everyday cleaning purposes. They are composed of synthetic chemical compounds which, when expelled into natural environments, will have a negative impact on the aquatic life into which it is expelled. Detergents composed of phosphate can cause algae which utilise the oxygen to be used by other aquatic organisms; this will have a long-term effect of eutrophication . This is a problem because when the components are broken down into phosphorus and nitrogen, overgrowth of the algae plants will occur. Because of the extreme loss of oxygen, aquatic life begins to die. Another effect surfactants have on the environment is that they can deteriorate the outer protective layer of a fish in freshwater which will increase the probability of the fish of obtaining a disease.
Source 1 is valid because it gives a direct summary of the effects of detergents on plant life as well as on other effects they may have on animals and humans; and therefore, supports the hypothesis that greywater (including both inorganic and organic detergents) have a negative effect on the environment. The source refers to studies that have been made within recent years – and published between 2009 and 2017 – to support the reason of the source’s argument (that detergents negatively affect aquatic-plant life) and gives a direct reference to prove the mentioned studies have been made. The source is reliable because it contains more than one point of research and because the research involving experimentation was made at universities it can be recognized as independent and thorough. The article used is useful because it has a focal point of phosphate-containing detergents and the effects they have on the environment. Although it only deals with one type of detergent, the information supplied gives an understandable description of the impacts the detergent has of the environment which allows for insight of a specific type of detergent and allows for the ability to compare the mentioned detergent to other detergents. The limitations of this article include the fact that it focuses namely on phosphate-containing detergents and does not give insight of other detergent types and their environmental impacts which limits the ability of cross-referencing and comparison. The article will greatly contribute to the hypothesis because it gives information on a chemical that is found in greywater because it is used in detergents.
Detergents are a considered to be a large contributing factor of excessive water-plant growth, pollution of drinking water and for the disruption of plant life in the water of rivers, lakes and dams. In Europe, laws have been passed to ensure that all waste water is sterilised, foam-producing detergents are not used and products used as cleaning supplies are biodegradable. These laws protect the environment from potential harm and threats of detergents. For a product to be considered as biodegradable, it must deteriorate at 60% per 28 days in conditions where oxygen is obtainable. Per the source, these standards of measuring biodegradability are not ideal because this allows the detergent components to settle deeper within riverbeds and use more time to degrade without being accounted for. Although tests are made in a laboratory, where the requirement of the biodegradability of the product is to degrade fully, the conditions of the laboratory are not synchronous with that of the environment of the river, lake, or dam which therefore, may affect the results of the carried-out experiment. Phosphates are important in the development of many species and are essential for an organism’s life. Although they are non-toxic, overproduction of the element causes the deterioration of aquatic life within a certain region, as it decreases biodiversity.
Source 2 has a central focus on detergents being biodegradable in order to conserve aquatic life. It is valid because it was written in very recent years (between 2008 and 2016) and includes exact facts of how to determine a molecule’s biodegradability. The source discusses the potential dangers of non-biodegradable detergents and is not biased as it criticizes the fact that tests are made in an environment very different to that of actual natural conditions where the effects of the phosphates chemicals is pertinent. The source is viable to the hypothesis because it shows how the certain types of surfactants in greywater are accountable for their negative effects on plant life. The source can be considered reliable because of the evident knowledge that has been included; the text speaks of individual components of detergents (such as sulphide, phosphorus and nitrogen) and approximate percentages and the effects on the environment in which they habituate each compound has. This source is useful to the research task, as it provides a time frame for ideal biodegrading of detergents and allows room for comparison of detergents in experimenting and testing different types of detergents. The article is limiting because it does not provide South African statistics of what an ideal time frame for something to degrade is and does not give South African requirements of detergents and their biodegradability. This is a limitation to this study as the experiment will be conducted in a South African habitat.
Although commercial dishwashing detergent is considered a weaker threat to the environment than other detergents, its effect is still an issue. The compound in the detergent that poses the most threat to the environment is phosphate because it promotes the growth of algae, which if not controlled, can become overgrown. The overgrowth of algae will result in an equal depletion of oxygen within the water and will therefore decrease the biodiversity present in that region. It is therefore suggested, that in order to reduce phosphate concentrations in natural water, to use “homemade” dishwashing detergent that is composed of baking soda, borax and distilled white vinegar.
Source 3 is an article that deals, specifically, with dishwashing detergent. Because dish washing detergent is a contributing chemical to the make-up of greywater, this article is relevant. The source is valid because it is current and contains well known research. Although this research is well known because of the many other articles and media reviews focussed on the topic, the article lacks individual knowledge and research, in other words: it only has information that has been provided in other articles and does not refer to experiments made personally by the author and does not contain evidence to support its facts, which causes its reliability to be questioned. Source 3 is useful because it provides an alternative to using this detergent and allows for its research to be experimented. This source is limiting because it lacks experimentation and referenced research and only discusses the nature and effects of one detergent, namely dishwashing detergent.
Surfactants are a major component of detergents and have a negative effect on the environment when expelled into external habitats such as soil, water and sediment. Although they are commonly biodegradable, surfactants affect the environment more when untreated by treatment processes because their water solubility is low. Detergents and soaps are made up of anionic compounds and therefore are soluble and have cleaning properties. Many detergents consist of cationic compounds, which provide detergents with an antibacterial property; these detergents are considered the most obvious threat as they are fast-reacting in water and will therefore degrade aquatic plants at a rapid rate. A detergent can be considered amphoteric per its pH (a low pH is considered cationic and a high pH is considered anionic), but the class of these detergents have not undergone enough research to know their precise environmental effects. Non-ionic detergents do not dissociate in water and add to the solubility of the detergent. The concentrations of surfactants allowed in aquatic habitats are below the effective toxicity concentrations to aquatic life and the dilution of surface waters would too decrease toxic effects on aquatic organisms. Per an experiment made, diluted detergents had less of a negative effect on aquatic flora and suggested the idea that the effect of detergents on the environment could be decreased more with further research. As per further studies, incorporating invertebrates and vertebrates, surfactants and sodium silicate had a much greater effect on aquatic life than any other detergent component and it was the vertebrates that were most sensitive to the detergents than any other organism.
Source 4 is valid because it consists of many different references to experiments and many different access points of research. It explores the many different types of components of detergents and thoroughly explains the effects of each described detergent on various specific aquatic organisms that are not limited to aquatic flora, but also explore aquatic fauna. The source is reliable because it consists of many examples of cross-referencing and has numerous examples of experiments that were carried out and include the experiments’ statistics and conclusions. This source is useful because of the many different experiments and results provided, as well as the vast number of different components of detergents that were included in the writing of the source, which will assist in determining which detergents to use as control groups and which to use as experimental groups when carrying out an experiment for this research task. The limitations of this article are very few as it is not biased or focussed on only one compound, but a limitation is that the conclusions states that most of the points it attempts to support lack experimentation and crucial evidence and the source admits that “research is yet to be done” to confirm the negative effects of certain chemicals. Another limitation is that all results are from Croatia and that no other continental regions were used for experimental purposes and thus, only local detergents are assumed to be used in the mentioned experiments that compose Source 4, these detergents therefore, may have different concentrations of compounds to that of international detergents that were not included in experimentation. Although the source deals with mainly Croatian detergents acts as a limitation, it is also beneficial to the hypothesis because it allows for results beyond the South African local gridline. Source is highly valuable to the hypothesis, that greywater negatively affects the life of aquatic flora, because it states the unfavourable effects that individual components of detergents that make up greywater and is mentioned in the article has on various aquatic organisms.
Source 5 is a table showing the effects the compounds, of which make up a certain unnamed detergent, have on the environment. The compounds are named in the first column; the second column explains and provides a brief description of the health, environment and disclosure concerns of the compound named in the first column, and the third column provides a ranking of A to F that shows the negative effect the compounds, named in the first column, have on the environment (A being no effect and F being a very negative effect).
Methylisothiazolinone is a synthetic preservative and biocide used in both personal care products and used for industrial applications (such as the manufacture of paints and paper, and sanitizing). (Rohm, 2018) Methylisothiazolinone has the highest score in the table showing the affects the compounds certain detergents have on the environment, indicating that in this table, Methylisothiazolinone is the compound that has the most negative affect on the environment. Methylisothiazolinone is a high concern with reference to health, the environment and disclosure due to the compound expressing an acute aquatic toxicity and may cause skin irritation, allergies and skin damage to humans. If the dangers of Methylisothiazolinone are so high to humans, it can be assumed that the dangers to aquatic plant life are also high.
Cocamidopropyl betaine is a chemical compound found in various personal care products and surfactants. (Case, 2013) The compound causes detergents to create more foam when mixed with water and is rated with the letter “C” in the table showing the affects the compounds certain detergents have on the environment. This indicates that although Cocamidopropyl betaine does, in fact, have a negative effect on the environment, and human health, the negative effects of Cocamidopropyl betaine are not as high of a concern as the negative effects of Methylisothiazolinone. Cocamidopropyl betaine is a concern to health, disclosure and the environment due to the chronic and acute aquatic toxicity displayed in Cocamidopropyl betaine.
Sodium Coco-sulphate is a synthetic detergent that is, too, used in various personal care products and surfactants. (Humphries, Sodium Coco Sulfate – another synthetic detergent, 2018) according to the table showing the affects the compounds certain detergents have on the environment, Sodium Coco-sulphate has some health, environment and disclosure concerns due to the chronic and acute aquatic toxicity and the general systemic and humanly organ effects caused by Sodium Coco-sulphate; this, therefore, scores Sodium Coco-sulphate the letter “C” in the table showing the affects the compounds certain detergents have on the environment.
Lavandula angustifolia (lavender) oil is an essential oil that is antibacterial and antifungal. Lavandula angustifolia (lavender) oil contains lavender and flavouring and can be used as a preservative and an insect repellent. (A.E. Erland, 2015) In the table showing the affects the compounds certain detergents have on the environment, Lavandula angustifolia (lavender) oil is scored with the letter “C” and has some concern regarding skin irritation, allergies, cancer, respiratory effects, acute aquatic toxicity and general systemic effects.
Cocamidopropylamine Oxide is a cationic surfactant that is pH dependent and is used in baby shampoo and other bath products as a foaming and thickening agent. (Corperation, OXIDET® L-75 C, 2009) In the table showing the affects the compounds certain detergents have on the environment, Cocamidopropylamine Oxide is scored with the letter “C” and has some concern regarding respiratory effects.
Although PPG-4 LAURETH-5 (an emulsifier, moisturising agent and solubilizing surfactant (Chandler, 2018)), Anthemis nobilis (chamomile) flower oil (an ingredient that is included in the make-up of bath products, cleansing products, dentifrices, deodorants, makeup, fragrances, hair conditioners, hair bleaches, hair dyes and colours, permanent waves, shampoos, shaving products, suntan products and skin care products. (Council, 2016)) and Alcohol Ethoxylates (c12-14) Propoxylated (a low foaming, non-ionic surfactant mainly used in dishwashing (Corperation, FINDET® 1214N-1716H, 2015)) do not have any recorded data in the table showing the affects the compounds certain detergents have on the environment, PPG-4 LAURETH-5, Anthemis nobilis (chamomile) flower oil, and Alcohol Ethoxylates (c12-14) Propoxylated are all scored with the letter “C” showing that these chemical compounds have some effect on health, the environment and disclosure.
Phenoxyethanol and Sodium Phenoxyethanol are also in the table showing the affects the compounds certain detergents have on the environment but are scored with the letter “B”. This shows that these two chemicals have hardly any negative concerns regarding health, environment and disclosure.
Water is scored with the letter “A” in the table as this compound has no effect on the environment, health and disclosure.
This source is valid because it shows the reactions that certain organisms experience with certain products and how seriously those mentioned products effect the environment. It is not a very reliable source because it does not have any references or proof of experiments made to support its information but is useful because it provides products that can be used to test their effects on aquatic flora in an experiment and allows for the improvement of its facts and further research regarding its facts. Source 5 is very limiting because it provides no insight or evidence for each of the mentioned effects of the named products that contribute to the composition of detergents, and therefore greywater, and therefore has no proof or referencing to substantiate its provided information.
From the above resources, it is evident that most sources are valid and useful due to their referenced research and contribution to the research task at hand. Because not all the sources are reliable and because all do exhibit limitations, the experiment that is to be carried out must be thorough and should be performed using a large sample size in order to explore all possible aspects of the topic.
The conduction of an experiment is an essential asset to this research task due to the fact that very few local (South African) detergents were mentioned in the sources and that minimal visual images were formed for the fauna and flora that were used in experiments in the sources.
All sources have supplied a wide range of different compounds that will allow for a large amount of exploration in experimenting the effects of greywater on the life of aquatic flora. The sources have also allowed for further independent research to be made, because of its limitations, and for greater knowledge on the compounds one needs to consider when determining the classification of a detergent and how it should be handled in the environment. The sources, that have been provided in the appendix, showcase very similar facts, for example, nitrogen, present in natural water and obtain from detergents that were expelled through drains, causes the eutrophication of an aquatic environment due to the overgrowth of algae and loss of oxygen in the water. These similar facts that were mentioned support each other and support the hypothesis as it is seen that the various experiments made by a vast group of different people, all produced the same or similar results, and because this formed a large experimental and control group, experimental error will be extremely minimal.
Therefore, because all presented sources do mention at least one unfavourable consequence of the components that are part of the structure of greywater, the sources favour the hypothesis that greywater, including detergents, negatively impacts the life of aquatic flora.
“Greywater has a negative impact on aquatic plant-life and causes aquatic plants to die.” This hypothesis was experimented and the following results were obtained and recorded in a table and transferred into a graph. The level of browning was determined on a scale from 0 to 3, where 0 indicates that there was no physical change in the plant and 3 indicates that the plant had died.
As can be seen in the above table and graph, the monkey tail plant in both the greywater and in the clean water was the plant species that was affected at a faster rate due to the environmental conditions than the water lily.
It was found that as time passed, the water lily in the clean water remained in a very similar state to that of which it was in when originally placed into the clean water and only began to experience very little browning at the end of the third week. However, the water lily that was left to grow in the greywater, experienced some browning but was only noticeable after the second week. The monkey tail in the clean water was found to have endured slight browning by the end of the second week and endured more browning after the third week, after this, the level of browning increased only slightly. The monkey tail placed in the greywater was seen to have had slight browning by the end of week 1 and levels of browning increased rapidly until the end of the fourth week whereby the plant was grey-brown in colour and some of the leaves of the plant were no longer attached to the stem of the plant.
By recording results in a table and by making use of a photo diary, it was found that as time passed, the water lily in the clean water remained in a very similar state to that of which it was in when originally placed into the clean water and only began to experience very little browning at the end of the third week. However, the water lily that was left to grow in the greywater, experienced some browning but was only noticeable after the second week. The monkey tail in the clean water was found to have endured slight browning by the end of the second week and endured more browning after the third week, after this, the level of browning increased only slightly. The monkey tail placed in the greywater was seen to have had slight browning by the end of week 1 and levels of browning increased rapidly until the end of the fourth week whereby the plant was grey-brown in colour and some of the leaves of the plant were no longer attached to the stem of the plant.
It will therefore be concluded that greywater (composed of water directly taken from washed dishes and washed clothes) will cause the browning and death of water lilies and aquatic monkey tails.
In order to provide evidence to substantiate the accuracy of the hypothesis: “Greywater has a negative impact on aquatic plant-life and causes aquatic plants to die,” an experiment was carried out between January 7th, 2018 and February 12th, 2018. The experiment entailed two different aquatic plants, namely Nymphaea alba (water lily) and Xerophyta viscose (monkey tail), growing in two different environmental conditions each (one of each plant was placed in greywater and another of each plant was placed in clean water) and was each left to photosynthesize, grow, move, respire and excrete waste as it would in its natural habitat (a lake or river) for the duration of the experiment.
Any changes in the physiology of each of the plants was recorded weekly in a table and transferred into a graph in order to keep precise records of the plants’ weekly progress and development in accordance to the respective living conditions.
After the first week of the experiment was completed and the plants had been living in their respective living conditions for one full week, it was noticed that very few physical changes had occurred in any of the plants. The only plant that did showcase a very slight change in appearance was the Xerophyta viscose, which exerted slight browning of the leaves that were not fully covered by the greywater and was covered mostly by the fat and other residues of greywater.
At the end of the second week of the plants living in their opposing habitats, new results in the physical appearance of each plant was obtained. Although the Nymphaea alba left to grow in the clean water had not changed at all in physiology since the start of the experiment, the Nymphaea alba that was living in the greywater displayed slight yellowing at the edges of the one side of the plant and the Xerophyta viscose living in the clean water displayed the same physical features that the Xerophyta viscose living in the greywater had showcased at the end of the previous week: slight browning of the leaves that were not fully covered by the water and exposed to the surrounding air. The Xerophyta viscose living in the greywater, however, endured more browning of its leaves and looked as if it had a disease at the tip of its stalk and leaves exposed to the external air, as it had dark spots dispersed throughout the top part of the plant.
It was only after the third week that passed that the Nymphaea alba living in the clean habitat displayed any noticeable changes in its physiology. At the end of this week, the Nymphaea alba in the clean habitat demonstrated slight yellowing from the centre and a very thin line of yellow formed along the edge of the plant’s leaf. The Xerophyta viscose in the cleaner habitat seemed to follow the trend of the Xerophyta viscose in the dirtier habitat, but only a week after the Xerophyta viscose in the greywater endured the physical changes. At the end of this week, the Xerophyta viscose in the clean water endured more browning of its leaves but did not develop any spotting like that of the Xerophyta viscose in the greywater from week two. The Xerophyta viscose living in the greywater looked as if it had spread the spotting and browning from the previous week to approximately half of the plant. The Nymphaea alba that was living in the greywater presented a slightly more intense yellow-brown colour to its leaf and was missing a small piece of its edge that is assumed to have fallen into the water.
In the final week of the experiment, both Nymphaea albas living in the clean habitat and the greywater respectively, as well as the Xerophyta viscose in the pure habitat had expressed no noticeable physical changes since the previous week (the Nymphaea alba in the clean habitat demonstrated the same slight yellowing from the centre and a very thin line of yellow along the edge of the plant’s leaf as it had the previous week, but it had not intensified in any way, the Xerophyta viscose in the clean water did not express any more intense browning of its leaves and stem and the Nymphaea alba that was living in the greywater maintained its slightly more intense yellow-brown colour to its leaf and was missing a small piece of its edge that is assumed to have fallen into the water, but did not intensify in this feature.) The only plant that suffered more of a change in its physical features was the Xerophyta viscose in the greywater; it had dark spots that covered the whole plant, all its leaves had developed into a grey-brown colour and when the plant was picked up out of the water for further examination, the leaves deteriorated off of the stalk and the part of the stem that once held leaves was left bare.
From the retrieved results, it was noted that the rate of physical change of both the Nymphaea alba and the Xerophyta viscose that were living in the greywater was much faster than the rate of change of the Nymphaea alba and the Xerophyta viscose that were living in the pure water. This was particularly obvious in the Xerophyta viscose as all changes that were noted in the Xerophyta viscose living in fresh water had already been endured by the Xerophyta viscose in the greywater at the end of the previous week.
The results of the Nymphaea albas were less obvious than those of the Xerophyta viscose as the results were obtained at a much slower rate than those of the Xerophyta viscose. It is assumed that the greywater Nymphaea alba reacted at a much slower rate than the greywater Xerophyta viscose because the stem of the water lily is much thicker (and therefore stronger) than the stem of the monkey tail. The water lily was also put at an advantage at the beginning of the experiment as the water lily had to be planted in order to grow, whereas the monkey tail was left to float because this is the state in which it survives when in natural environments (river/lake/dam).
The Nymphaea alba and the Xerophyta viscose in their natural habitats grow from a seedling into large plants with their roots submerged into the soil. The plants can undergo both asexual and sexual reproduction and continuously grow and develop until damaged or dying due to natural or unnatural factors. The plants both have green stems and green leaves which float above the water surface. (Whittemore, 2010)
Greywater is the waste water from baths, sinks, washing machines, and kitchen water. What makes up greywater is the fresh water, obtained from taps, mixed with cleaning detergents, washing powders, soaps, shampoos, fabric softeners and fat (to name a few) – basically, greywater is made up of everything one allows to pass through a drain after use of that product. A family of 4 will, on average, make use of between 300l and 400l of greywater in a single day. (Bekink, 2017) The greywater used in the performed experiment was taken from the sink directly after washing dishes and from the washing machine after doing laundry. The grey water used in the experiment was therefore composed of fat from the dirty dishes, small food particles, dust, dirt, sweat, dead skin cells, washing powder, dishwashing liquid and fabric softener.
An issue, of which was only noticed at the end of the experimentation process, was that the aquatic plants used in the experiment (but not limited to these plants) had most likely already adapted to the living conditions in greywater. This was assumed when looking at possible locations that the purchased plants may have been extracted from. Results were very minimal because of the fact that before being extracted from their habitats, the Nymphaea alba and the Xerophyta viscose had possibly adapted to the constant increase of residue being added to their environment. This may have led the plants to being able to withstand the high concentration of greywater.
Another issue that was considered was that the actual concentration of greywater residue was inaccurate. Aquatic plants habit in large areas with large quantities of pure water (Miller, 2018). Although the concentration of greywater residue increases in the large water bodies in which these plants live every time a lavatory is flushed, a sink is unplugged or a washing machine empties, the concentration of pure water added to these large water bodies increases on a much higher factor every time it rains or fresh unused water is passed through a drain (Bekink, 2017).
A final problem that contributed to the experiment that was carried out, is that not enough time was allocated for the duration of the experiment as the estimated period for the collection of data was underestimated and because a plant’s life span is much longer than only one month, it is difficult to estimate how old the plants used were and if age was the cause of the rapid rate of deterioration that was seen in the plants in the greywater. The estimation of the time period need for the collecting of results of the experiment was also misjudged due to the fact that it was unknown whether or not the plants that were extracted from their natural habitats had been living in the same conditions as that of the greywater and the results that were obtained may have been obtained only because of the fact that the plants were already living in these conditions that were not optimal and the experiment only further increased the time that these plants were living in such conditions.
Although the results that are presented supported the hypothesis and substantiated that “greywater has a negative impact on the life of aquatic flora and causes aquatic plants to die” because the plants in the greywater deteriorated more than those in the pure water in the four-week experimental period, these results are inaccurate and imprecise due to the facts that these plants may already have adapted to the impure living conditions and therefore expressed minimal results (as seen in the Nymphaea alba in the greywater), the concentration of the greywater was much higher in the planters than it would be in a real-life habitat and therefore the plants would react at a much faster rate (as seen with the Xerophyta viscose in the greywater) and the age of the plants was unaccounted for and older plants would have died faster than those of a younger plant. Therefore, in order to have obtained fully reliable results, the exact concentration of residues in greywater, a larger sample size, the age of the plants and a greater time period would need to have been provided for this experiment and the obtained results are therefore inaccurate and inadequate for this research task.
Based on the information presented in Sources 1-5 of literature (Hill, C. (2017, June 13), Marghem, M.-C. (2016, January 12), Staff, G. L. (2009, October 12), Ivanković, T. (2009, July), Unknown. (2018, January 16)) and on the results obtained in the experiment that was made, it is clear that greywater, including components of organic and inorganic detergents, has a negative effect on the life of aquatic flora.
As previously mentioned, the sources provided had a great contribution to the research task as all the sources provided contained information that would be unobtainable by primary research alone. The information that was sourced provided research that was discovered in countries beyond the South African boarder and offered detailed analogy of specific detergent components (resulting to be greywater components) and their effects on aquatic flora. The results that are noted in the sources are mostly precise as the tests were completed in laboratories and were completed by highly qualified and experienced biologists and scientists.
The primary research, the experiment that was performed, presented results of which reinforced the hypothesis because the results of the experiment showed that after surviving in greywater for four weeks, the plants that were made to live in the extreme environment of purely greywater developed browning and the death of the plant. On the other side of the scale, the plants that habited in the pure water remained in a state of health and were both free of any signs or symptoms of a nearing death by the end of the fourth week. This therefore displayed that the effect that the greywater had on the plants, in comparison to the effects of pure water on the same types of plants, was negative and caused the death of the aquatic flora that was used as the experimental group.
Although the results that are presented supported the hypothesis and substantiated that “greywater has a negative impact on the life of aquatic flora and causes aquatic plants to die” because the plants in the greywater deteriorated more than those in the pure water in the four-week experimental period, these results are inaccurate and imprecise due to the facts that these plants may already have adapted to the impure living conditions and therefore expressed minimal results (as seen in the Nymphaea alba in the greywater), the concentration of the greywater was much higher in the planters than it would be in a real-life habitat and therefore the plants would react at a much faster rate (as seen with the Xerophyta viscose in the greywater) and the age of the plants was unaccounted for and older plants would have died faster than those of a younger plant.
If this topic were to be further research, it is recommended that an experiment is performed and repeated multiple times with various aquatic plant species. If more plant species are used in the experimental process, more accurate results would be easily obtained. In repeating the experiment at different times of the year and in different climates, one would be able to identify if the results obtained are purely obtained due to the concentration of chemicals in the water of which the plants being tested live, or if it is other factors, such as weather conditions, that affect the results that are obtained in the experimental procedure.
From the research that was obtained and from the experiment that was performed, it is therefore concluded that greywater is composed of many different compounds and ingredients that negatively affect the life of aquatic flora.