DUAL WATER DISTILLATION UNIT:

Transcription

1 DUAL WATER DISTILLATION UNIT: A DESIGN SOLUTION FOR BENDEE DOWNS: A COMMMUNITY WITH LIMITED & UNSUITABLE WATER. D4.5 Juan Su Joseph Indaimo Ali Darabi GolshaniDDD4.5 Paul Gauci Paul Gauci Rachel Massie Rachel Massie Heasam Odoh Heasam Odoh Steve Vajas JULY 2010

2 Executive Summary There is an insufficient supply of clean drinking water for the proposed expansion of the rural community at Bendee Downs. The proposal to solve this problem is the Dual Water Distillation (DWD) unit which is an innovative, cost effective and efficient method of purifying contaminated bore water. However, the unit s operation is diverse and can be used to purify any source of contaminated water with a purified water output of 12L per unit. The unit is affordable to the community and once bought has a low maintenance cost and is expected to last years. The first installed unit will cost approximately $1800 and each additional unit only $300 as there is no need to install additional storage tanks. The two stakeholders are the Bendee Downs community and the future ecotourists. The proposed design delivers a constant, sustainable supply of drinking water to both stakeholders. The unit effectively captures and purifies enough water for the existing Kooma community and can be expanded for the anticipated population growth. This added benefit makes the DWD unit superior to other water units on the market. This design has two functions, one of which is a method of evaporating and condensing water and a second function of capturing rain water before it reaches the ground, both happen simultaneously. This is beneficial since there is significant rainfall in this region through the wet season and sufficient amounts during the dry seasons. The rainwater captured is pure and can be stored immediately without treatment for human consumption. This is an added benefit for maximising water storage. Distillation efficiency of the unit is 35% which is considerably greater compared to the 15% of other units of similar distilling purposes. The tank that stores the purified water is located above ground and below the single unit (refer to figure 4.2). This feature of the design reduces the area used, respecting 2

3 the owners of the land. Surrounding the purified water tank is a Mud brick wall which serves two purposes. Firstly, to support the distillation tray and secondly to insulate the water in the tanks from the temperature extremes experienced at Bendee Downs. The design brief is a completely environmentally friendly solution. The design uses solar energy to evaporate and collect quality drinking water from a contaminated water source. No additional energy is required thus, removing the need for additional water pumps to transport water from the contaminated water storage tank to the DWD unit. This contributes to the design being a pollutant free solution. All materials integrated into the system are recyclable and reusable after the life span of the Unit. The DWD design incorporates easy assembly, maintenance and usage to assist the Bendee Downs community. With simple steps, along with visual images the Kooma community will be able to construct multiple Dual Water Units with ease. No harsh chemicals are required for cleaning of the Unit which minimises the cost that is associated with other distillation units of the market. Basic cleaning utensils allow for continued motivation of the community to clean the DWD Unit. Materials used in the design will be bought in bulk to reduce cost and allow for multiple units to be constructed on site when necessary. Since they are all lightweight and concise, transportation and storage will be effortless. The abundance of stock will allow for quick repair of damaged units minimising downtime. Incorporation of this unit into the Kooma tribe will provide the opportunity to grow and enhance their vision of an Eco-tourism industry. The DWD unit has the ideal option of increasing the water catchment area and purified water output by connected units in series in the same location (refer to section 4.2). This benefit will provide sufficient water supply for fluctuating numbers of Eco-tourists and the pre existent residents. 3

4 In summary, the design incorporates the highest priority of Bendee Down s needs; a source to produce clean, drinkable water, a source to capture and store rainwater, a means to raise the health standards of the Kooma community and allowing for the expansion and growing number of eco-tourists capable of visiting the region. The design is cost affordable and an effective way to produce and store water from various supplies whilst utilising space. The versatile and long life of the unit exceeds other competitive designs, making it the ideal solution. 4

5 Team Reflection When reflecting upon the past events that have occurred throughout the construction of our report it is evident that we have gained a better understanding of the definition of an engineer and more importantly working in groups as engineers. When we first started the EWB challenge each member had their individual perceptions about engineering, but it was certain that none of us were expecting that in first year engineering, we would be involved in providing solutions to real life situations. The sheer gravity of the concept that our group could help those in need of clean water, especially those in our own Australian country, motivated us as team to produce a design of practical quality. Despite the inexperience, we all started with regards to report writing and the general design process; we believe our final product of the following report and the foundations of our design are of a competitive standard. This is not to say that we didn t have challenging times along the way. Considering that we were only a four person team and the work load was the same as other groups that had up to six members, we are proud of our efforts. Our assigned roles were testing on our time management skills and required extensive efforts to complete our sections successfully and on time, especially under the new conditions associated with engineering. However, throughout the course, all of us accomplished the roles to a high and team accepted level. Our team consisted of both male and female participants. Overall there was no gender bias and we all were respectful of each person s opinions and suggestions. As a group we now better understand the process of design within the world of engineering and feel equipped to tackle other design criteria. Together we have equally combined our new and innovative engineering minds to create a water distillation unit that has been modified to meet the needs of the Kooma Community. On the completion of our design concept and report we believe we have emerged with a better understanding of what an engineer may be involved in outside of University. We understand the purpose of the EWB challenge to be an effective means of creating a foundation to real life applications of engineering and we are thankful for this opportunity. 5

6 CONTENTS 1.0 Bendee Downs and the Water Problem General Overview The Current Water Situation Bendee Downs Cultural Concerns The Stakeholders Benefiting Eco-tourism Maximising the Climatic Conditions Water Contamination and Prevention Deep Bores Shallow Bores Rainwater Preventing Greater Contamination Conceptual Design of the Distillation Unit Basic Outline of the Single Unit Functions of the Single Unit Unit Size and Dimensions Detailed Design of the Unit Multi-purpose Benefits Multiple Unit Setup Unit Features Materials Metals Non-metals Structural Life Expectancy

7 4.6 Units Efficiency Implementation of the Unit Cost Breakdown Detailed Construction and Instillation Maintenance and Cleaning Programs Testing for Impurities Appropriate Cleaning Styles Limitations of Implementation Technical Environmental References...56 Appendix A: Technical Mind Maps...60 Appendix B: Technical Assumptions...62 Appendix C: Process of Design...63 Appendix D: Graphical Design of Unit...64 Appendix E: Water Output Data Table and Efficiency Formula...65 Appendix F: Presenting to Kooma Tribe...66 Appendix G: Design Options Matrix...67 Appendix H: Alternative Options

8 List of Tables and Figures: Table 1.1. Climate Statistics for Australian Locations...16 Figure 2.1. Major prevention flow diagram...19 Figure 3.1. CSIRO Australia Design Concept (Practical Answers: Solar Distillation)...21 Figure 3.2. Abstract of the CSIRO design...21 Figure 3.3. Process of Water Distillation...22 Figure 3.4. Visual Steps to obtaining clean bore water using the unit...24 Figure 3.5. Front and Back Dimensions...26 Figure 3.6. Side Dimensions...26 Figure 4.1 Multiple unit setup: Nine Units connected Figure 4.2. Underside of Multiple Units: Less tanks Figure 4.3. Outside gutters...30 Figure 4.4. Screen grate...30 Figure 4.5. Black silicone base...30 Figure 4.6. Glass Hinges...31 Figure 4.7. Overflow Outlet...31 Figure 4.8. Dripper system...31 Figure 4.9. Distilled Water Tank...32 Figure Equipment for making mud bricks...36 Figure Mud bricks...37 Graph Life expectancy of unit materials...38 Table 5.1. Cost of materials and other related items...42 Figure 5.1. Materials and tools used Figure 5.2. Dimension of aluminium sheet...44 Figure 5.3. Cutting the aluminium sheet...44 Figure 5.4. Finished cutting product...45 Figure 5.5. Bending of the sides...45 Figure 5.6. Riveter for the aluminium

9 Figure 5.7. Silicone gun on edges...46 Figure 5.8. Silicone gun on the inside gutters...46 Figure 5.9. PVC central support for glass...47 Figure Gutters for outside of unit...47 Figure Glass added to the top of the unit...48 Figure Finished construction of the single unit...49 Figure 6.1. Process of microbiological removal...50 Figure 6.2. Summary for testing...52 Figure ph scale values (Vintage direct)

10 1.0 Bendee Downs and the Water Problem 1.1 General Overview Bendee Downs is a rural community in South-West Queensland. They are an aboriginal community and are aiming to increase ecotourism in their area. Water distillation is a significant factor for the stakeholders, the local Kooma Aboriginal Tribe and the future tourists. It is also critical for the ecotourism faculty and the local community, since pure drinking water is essential for life. The proposed idea for water distillation is a water still that will use sunlight to purify bore water whilst collecting rain. The water still is a cheap and practical idea that can be used in rural areas to sustain clean drinking water and hence, ideal for the Bendee Downs community. Bendee Downs is a remote community and it is hard to transport many materials to the site. Being a remote community it is difficult for access to the site and any suggested design should be able to be assembled at the site. Currently the sites only source of water is from a deep bore water system which pumps water to the surface. The quality of this bore water can be improved to decrease the health risk from drinking the water. It is culturally unacceptable to use water from the river which flows through sacred land and hence, the idea of using the water from the river can be neglected. The disadvantages of providing a water supply are influenced by the Aboriginal culture. The tribe will meet in large groups spontaneously and it is essential that this design can distil and collect enough water to accommodate for the large groups. Therefore, included in the design are storage tanks to hold enough clean water for these spontaneous events. Incorporated in the water still idea is the ability to catch rain water. This will be stored in a storage tank and can be used for multi purposes such as watering crop, drinking water for animals and for cooking purposes. This also accommodates for the lack of water 10

11 distilled in the wet season due to lower solar radiation exposure thus, the rain water collected can be used for drinking water during this time. The design process involved defining the most appropriate water needs for the Kooma community whilst being cost efficient, easy assembly and incorporating ecotourism. The Kooma tribe will not be receiving sufficient government funding and therefore, it was decided that the water still should be of low cost. This is achieved by using cost efficient, reliable and supportive materials to help maximise the effectiveness of the unit whilst minimising cost. The materials chosen are easy to transport to Bendee Downs and can be easily assembled by the Kooma tribe, which is a fundamental requirement of the EWB challenge. This is achieved as in theory they are two dimensional sheets that once assembled form a three dimensional water still. The tanks that store the water can be assembled at the site and hence, make the transportation of the materials easy and affordable. The design solution takes into account ecotourism by providing sufficient pure water supplies for the developing tourism faculty of Bendee Downs. Therefore our main priorities for the community of Bendee Downs include: Distilling bore water for the community to consume. Capturing rainwater to supplement the water consumed and store as a backup supply. Removing all microbiological matter and harmful additives in the water. Creating a simple yet effective design that can be constructed by the Kooma Tribe with simple and easy to use tools. Designing an eco-friendly solutions in which all materials and waste can be recycled, reused or added back to the natural environment. In essence, this dual purpose water still will meet the requirements of being environmentally friendly, User friendly whilst maximising the water supply in both the wet and dry seasons experienced at Bendee Downs and is respectful to the Aboriginal Dreamtime culture. 11

12 1.2 The Current Water Situation The current situation at Bendee Downs shows that there is a need for a sustainable supply and backup of water for both the permanent resistants and the future tourists. The current source of drinking water comes from the Hurray Sandstone Formation (EWB Challenge Bendee Downs 2010), which is a deep bore system at around 550m deep (refer to section 2.1.). The continued use of this system can be neglected due to the fact that is may become culturally unacceptable to drink the same water as the Kooma s ancestors, the hairless ones (EWB Challenge Bendee Downs 2010) once did. At the site there is currently a shallow bore water system that s main function is for agricultural purposes. This shallow system presents some difficulties in straight drinking (refer to section 2.2.) as it has impurities that would cause health problems. This bore system can be utilised by the proposed design solution, purifying the water to a drinkable status and allowing a more sustainable source of water. If the bore system happens to dry out and the bore water storage tank runs dry, then the shallow surface water can be used as a supplement, as mention in the EWB design brief (EWB Challenge Bendee Downs 2010). The Nebine Creek contains a large supply of water that could be considered for distillation because it is so readily available, however as stated by the EWB design brief, a key design consideration includes protecting cultural sites of the Nebine Creek. (EWB Challenge Bendee Downs 2010). The distillation of the creek was therefore disregarded, as to accommodate for the values set by the Kooma people. Although this is the case, if in dire need of water to be distilled and with the consent of the Kooma people, the creek water could be used. There are multiple water sources available for the Kooma people to take advantage of, but with cultural traditions and values, only the purification of agricultural and shallow surface water will be considered. This agricultural water is able to be pumped to the surface and distilled for consumption. 12

13 1.3 Bendee Downs Cultural Concerns The Hurray formation which is currently a source of bore water for the area was created and used over a century ago by the former land occupants also known as the Hairless ones. Many factors concerning culture are to be considered when finding a location to assemble the dual water system. It is important that we do not build and store on any sites labelled as sacred by the Kooma tribe, as they have a deep sense of connection with the land and its history. Thus, the aim is to provide an area that produces clean drinking water for the community whilst complying with unit specifications, without offending and disrupting their way of life. It is a known fact that the Kooma community meet spontaneously in large groups at Bendee Downs for various festivals. This was a greatly considered factor when defining the purpose of the unit. Installation of unit will require on site assembly by the local community with the assistance of the designers. Firstly, permission to enter into Bendee downs will need to come from a respected person in the tribe. Once there, visitors must be accompanied at all times by an Elder of the Aboriginal community where possible or by an Aboriginal community member (Mayrah Yarraga n.da, 1). Out of general politeness, utter care should be taken to not litter as this is also disrespectful to the land, ancestors and culture. As a result care has been taken to ensure the dual water system unit has minimal waste and potentially reusable materials. According to Mayrah Yarraga (n.db), Under Customary laws, particular sites do not allow the visitation of boys and girls. If permission were to be required, the organisation speaking on behalf of the tribe would be the ones to do so. This is an important factor if the designers there to accompany the builders are considered to be young (1). 1.4 The Stakeholders The stakeholders of the EWB challenge are the people and organisations to which the design solution is centred around. These groups are the ones that will benefit from the 13

14 proposed solution, with all details, decisions and assumptions made to accommodate the needs and wants of the Kooma community and what they are striving to achieve. The first major stakeholder of this task is the community of Bendee Downs or the Kooma people. These people are the ones that want a proposed solution for the site to which the design must cater around the traditions passed down through generations and respect the culture present. The EWB challenge document states that a sustainable source of water is required with the potential for increased people visiting and living on the site (EWB Challenge Bendee Downs 2010), allowing a design to be formed around this request. The proposed design solution of a dual water system which purifies bore water and collects rainwater will account for this want by the community, giving them a sustainable source of drinkable water all year round. The second and equally important stakeholder for the task is the eco-tourists. These are the people that will bring the community a source of income, by coming to stay at the community and allowing traditions and culture to be explored. The proposed design solution of water distillation will account for this group of stakeholders, by allowing fresh water to be supplied and stored all year round for a vast amount of people. By increasing the surface area of the unit, more people can visit as there will be no shortage of water. Water is essential for life and eco-tourists are essential for bendee downs, hence the more water, the more eco-tourists and income for the community. All stakeholders are accounted for in the design of the task and are considered as the guiding principles to be followed in subsequent research and production. 1.5 Benefiting Eco-tourism Bendee Downs being a rural community does not have the chance to support or gain many tourists. Through other EWB designs, the construction of tourist attractions are possible, with the main emphasis being on eco-tourism. This will allow the community to have ongoing guests that stay at the site for periods of time, or see the return of the family 14

15 clans back to the area. To support this growing and fluctuation number of people, the essentials for life are needed. Water is the main essential for human survival, and currently the water situation at Bendee Downs can be improved to support the growing number of people. This can be done through the dual water system, which can be refined to account for changes in population. With emphasis on community growth, the only way it can be done is if water is readily available and there is always a steady supply of drinkable, clean water. The design proposed does not bring tourists to the area, but is the base for it to be possible for tourists to come. Without the supply of water, there would be no chance to accommodate eco-tourists and would leave Bendee Downs without a continued and reliable source of income with little chance to share traditions and culture with others or allow the clan families to return home. By storing water in tanks at the site, emergency supplies will also be available and in turn can allow for tourists to stay for longer periods of time. 1.6 Maximising the Climatic Conditions There is no weather station in Bendee Downs and the closets weather station is at Bollon. Table 1.1 shows the climatic details of Bollon. Since, no further information is available of the location of Bendee Downs, this is the most reliable source and it can be assumed that there is some consistency between the climate of Bollon and the climate of Bendee Downs. Bollon is only 80km from Bendee Downs and dramatic difference in climatic features is unlikely. By observing the table of Bollon it can be noted that they receive a steady rate of rainfall all year round which is important for the water still as part of the function will be collecting rain water. Another notable feature is of course a relatively high temperature all year around which will help in the water distillation process as it can provide more energy and increase the rate at which the water is distilled. Also by looking at the table it is noted that Bollon rarely receives overcast and most days the sun is shining with little clouds covering it. This will again support that the water still will be effective since there is no 15

16 clouds minimizing the rays from the sun. The table also shows that this is a collection of data from decades and it can be assumed that the tables are accurate and precise. Table 1.1 Climate Statistics for Australian Locations Statistics Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual Years Temperature Mean maximum temperature 2010 ( C) Mean minimum temperature 2010 ( C) Rainfall Mean rainfall (mm) Decile 5 (median) rainfall 2010 (mm) Mean number of days of rain 1 mm Other daily elements Mean number of clear days Mean number of cloudy days

17 2.0 Water Contamination and Prevention 2.1 Deep Bores One of the major sources of water to Bendee Downs is the bore water that originates from the Great Artesian Basin (GAB). The GAB is considered to be a deep confined aquifer as it is located well below 20 meters of the Earth s surface. Specific to Bendee Downs is a 550m bore water supplement known as the Hurray Sandstone Formation (EWB Challenge Bendee Downs 2010a). Isolation from surface contaminants protects the water from manifesting microorganisms, thus the Hurray formation contains low concentrations of harmful pathogens. Unfortunately, earthly minerals and elements such as Magnesium and Calcium are also present with generally higher concentrations in aquifers due to their deep underground location (Health department 2008a, 1). These metals are not dangerous and are easily absorbed by the human body. However, other metals and minerals that exist in low concentrations (but still higher than the World Health Organisation regulation amounts) such as aluminium, barium, cadmium, chromium, lead, manganese, sodium, zinc, Arsenic, manganese, fluoride, iron and nickel ions presents a risk if consumed. Water from the GAB and more specifically the Hurray formation must be purified of the unaccepted and unhealthy amounts of metals if intended for human consumption, of which the unit is capable of doing. 2.2 Shallow Bores The use of shallow bores without distillation is highly discouraged. Due to their close proximity to the Earth s surface, these water catchments are the first to be filled by penetrated rain and are easily susceptible to human contamination if water is initially in contact with waste present at ground level. One of the most commonly known strains of bacteria present in sewage contaminated water is Escherichia coli also known as E.coli which can cause major sickness to those who consume it. If natural water storage systems are subject to any faeces or fertiliser, the concentrations of nitrates and nitrites will be 17

18 greater which decreases its useability and distillation is required if intended for consumption. Fortunately the usage of fertilisers at Bendee downs is minimal to nonexistent due to the limited agriculture need thus in considering future Ecotourism, agriculture will be a primary. Bendee Downs has a waste management plant on the outskirts of the central living quarters. Human waste is pumped down into an underground septic tank, mixed together and channelled by underground pipes to a vast grassed open paddock where it is further sterilised (Engineers Without Borders 2010). Rain water will inevitably be in contact with the effluent and from that point on will be contaminated with dangerous microorganisms. Since all underground water systems are connected, penetration of the contaminated water will place the entire shallow aquifer in jeopardy. 2.3 Rainwater Due to the remote location of Bendee downs and its isolation to any polluting industries, collected rain water will not contain high levels of chemicals. The amount of air polluting contaminants discharged by the Kooma Community can be considered to have negligible impact disabling the ability to produce acid rain. As such, the population required to contribute large amounts of air contaminants is not there. The dual water system endeavours to collect rainwater before it comes in contact with the Earth s surface. Therefore no contact with human or animal waste will occur resulting in another pure, available drinking water supply. 2.4 Preventing Greater Contamination According to the ADWG (2004): The greatest risk to consumers of drinking water is pathogenic microorganisms. Protection of water sources and treatment are of paramount importance and must never be compromised... prevention of contamination provides greater surety than removal of contaminants by treatment, so the most effective 18

19 barrier is protection of source water to the maximum degree practical. (Government of Western Australia 2009, 5). Figure 2.1. Major prevention flow diagram The open air human waste treatment plant at Bendee Downs collects effluent in a partial dip in the grassland so surface water does not flow in any one direction and in particular, towards any bore water pumps. The Government of Western Australia (2010a) suggests that other substances such as scrap metals, pesticides, waste oils, tyres, batteries, chemical waste and their containers should be disposed of at approved off site facilities when referring to private bore water usage in rural areas. In considering the future 19

20 expansion of the ecotourism industry and the food supply required to support the general increase in consuming occupants agriculture may need to be an area worth considering. If the bore water pumps for both the Wyandra and Hurray Formations do not comply with the minimum requirements, local drilling contractors will need to be contacted to rectify these problematic issues. With minimal access to the actual specifications of the bore water pumps, we need to consider if they are ventilated or not. Ventilation is considered to be any opening the pump has to the atmosphere. 20

21 3.0 Conceptual Design of the Distillation Unit 3.1 Basic Outline of the Single Unit The base outline of the unit is an abstract of the CSIRO design (Practical Answers: Solar Distillation 2009) from which many modifications and additions have been made to suit the Bendee Downs climate and needs, as well as considering limitations of cost and construction ability. Bendee Downs has limited knowledge of the use of many constructional devices; hence the design has been kept as simple as possible to comply by these standards. The features have been designed to maximum efficiency and water output, whilst other ideas are mentioned that the Kooma tribe can consider. Figure 3.1. CSIRO Australia Design Concept (Practical Answers: Solar Distillation) Figure 3.2. Abstract of the CSIRO design. 21

22 3.2 Function of the Single Unit The dual water system is a relatively simple and easy system to follow when considering how it functions and what is involved in the process of the distillation. Figure 4.5 below shows the basics to how the water is distilled and the function of the major elements of the unit. Figure 3.3. Process of Water Distillation. The following are the steps to obtaining clean bore water and rainwater using the unit. 1. Existing pump pumps the bore water straight into the bore storage tank from a dual connection connected to the pipe coming off the pump. This bore water is stored in the tank to be added to the unit. All though bore water is used; in theory any water can be used. 22

23 2. This bore water then flows into the unit once the open tap is turned on. A pump is not needed to do this as the tank is at a higher potential, allowing gravity to push it through the black reticulation pipe. 3. The black reticulation pipe runs through the back of the unit, with multiple dripper holes along its length. This allows the water to be constantly dripping into the tank, at a level to ensure the amount of water being distilled equals the amount of bore water to replace it. This keeps the water level as the recommended height of 2-5cm. 4. Once the bore water is in the unit, it is constantly being heated from solar radiation emitted from the sun. This energy is absorbed by the black base of the unit, in turn heating the water. Once particles of the water have sufficient energy, they are able to break free of the solution as pure water molecules. 5. These water molecules rise to the roof and condense due to the energy being exchanged to the glass. This pure liquid water then runs down the slanted glass and collects in the gutter on the inside. 6. This gutter causes the water to flow down into the collection pipe and then flow further into the pure water collection tank. This tank is located under the unit to reduce the overall area of the system and the water is stored in the tank for drinking. 7. Rainwater to supplement the bore water distillation in the winter months is collected when it rains on the unit. The large surface area of the unit catches this water. 8. The water flows down the roof of the unit and into the side gutters where from there it flows to one end and collects at the fly screen filtration point. 9. Once filtered, the rainwater flows down a pipe and into the rainwater collection tank. This tank is one the outside of the unit and can be used as drinking water for the fluctuating number of eco-tourists. 23

24 Figure 3.4. Visual Steps to obtaining clean bore water using the unit. (1) (2) (3) (4) (6) (5) (8) (9) 24

25 3.3 Unit Size and Dimensions The single unit is the foundation of the overall design. The dimensions of this single unit account for many factors in the running, construction and efficiency of the water distillation and hence the dimensions were based around these conditions. The main dimensions of the unit are the rectangular prism shape for the unclean bore water waiting to be distilled. These dimensions account for the maximum amount of water being held per unit. The length of the base is 2.0m long, the width is 1.5m and the height is 0.30m. This gives the unit a large base area with a minimal height, allowing it to be more stable, with less chance of falling over. The water level in the unit will be at 0.02m to 0.05m with the max being 5cm to allow for a greater efficiency. The glass roof on top of the unit will be on a slant to allow for water to be collected in gutters inside on the sides. To account for the slant, the glass will be 0.10m higher in the middle than on the sides with one end being to 0.095m to cause the distilled water to flow to one end. This makes the maximum height of the unit at 0.40m high, allowing it be at a height from which it can be cleaned with ease. The gutters on the inside of the unit will be 0.10m wide, allowing for the distilled water to be caught with minimal loss back into the bore water. These will run the full length of the unit. The gutters on the outside of the unit will be 0.7m high and follow around the edge of the unit at 0.14m away. These distances allow for maximum rainfall to be caught without lowering the output efficiency of the solar still by area. They also allow for a high capacity of rainwater collection if the pipes cannot cope at the time. The dripper system will sit at 5-10cm above the water, to minimise splash when dripping and be of a diameter of 1-2cm, the pipes diameter collecting the water will be at 5-10cm to allow for easy flow of water and the unit itself will sit at 1.50m above the ground, letting it be in full sun view without any shadows over it. Extended dimensions for aspects of the unit are showing in figure 4.3 and Figure 4.4 below. 25

26 Figure 3.5. Front and Back Dimensions Figure 3.6. Side Dimensions 26

27 4.0 Detailed Design of the Unit 4.1 Multi-purpose Benefits The Dual Water Distillation Unit is a design that incorporates not only one of the Bendee Downs community needs, but two. As stated in the EWB challenge design brief, the Kooma Tribe need a method to distil the bore water for consumption (EWB Challenge Bendee Downs 2010) as well as a Cost effective rainwater capture and storage system (EWB Challenge Bendee Downs 2010). The single unit design s main feature is to distil the unhealthy bore water so it can be used as a sustainable source for the permanent residents and its fluctuating number of tourists. As the fluctuating number is unknown, there is a possibility that the system will not have enough output to accommodate for everyone, hence the rainwater collection system was added to the design. This rainwater collection system allows for rain to be collected all year round, and directed into one main storage tank. This gives the Kooma people a backup water supply, and the supply to cater for a growing number of eco-tourists in the area, which is the main goal. The rainwater collection system incorporates adding gutters to all sides of the unit, made from aluminium sheets bent into shape, or a most cost effective design of cutting a large PVC pipe in half and mounting it to the side. The water will then flow down the gutter, as they will be slanted, down the pipe and ends up in the water tank. Not only does this allow for an extra means of water, it also accommodates for the lower supply of distilled water in the wet season. By adding an external gutter, the still cover can be used for rainwater collection to supplement the solar still output (Practical Answers: Solar Distillation 2009). When the solar radiation is low, there will be less water distilled, but more rain will occur. The multipurpose design gives the single distillation unit an extra and important feature, lowering the ratio of cost of production to water output. 27

28 4.2 Multiple Unit Setup The Dual Water Distillation Unit focuses on the production of a single unit for the Kooma community, but to meet their water needs, the idea of constructing multiple units and installing them together is a much more effective means of reaching high water output. By combining many of the simple single units together, a large system is able to be formed, allowing for a greater catchment of rainwater and a larger area for solar radiation to take effect. When combining multiple units money can be saved on tanks and pipes, by connecting many of the units to a single larger tank, which makes it easier for all concerned, as seen in figure 4.1. The pipes can easily be joined and redirected by the use of a T joint, which connects two pipes and combines them to a single pipe. The Kooma tribe need a large output of water to account for the growing number of permanent residents and eco-tourists. The single unit is simple enough to join, yet effective enough to remain efficient with the slight modifications as seen in figure 4.2. Nine units are recommended as a start for the Kooma community, as this is efficient to produce enough water to be stored for when tourists start to arrive. As seen in Appendix E, the amount of units needed, will change according to population. 28

29 Figure 4.1. Multiple unit setup: Nine Units connected. Figure 4.2. Underside of Multiple Units: Less tanks. 29

30 4.3 Unit Features There are many features to the single unit design that both incorporates benefits in bore water distillation and rain water collection. These features are part of the single unit design to maximise efficiency, minimise cost, reduce complicated design processes and to make the unit more applicable to the Kooma tribe and their eco-tourists. Many parts of the design were influenced by the weather of Bendee Downs and the desire for large water outputs when many units are connected together. Gutters are added to the unit to collect rainwater all year round. These gutters will be added to all sides, and have a pipe connected that diverts the water to a storage tank. This feature was added to account for the lower distilled water output in the wet season, and give the Kooma tribe more water for more ecotourists. The gutters are cheap, being made from shaped aluminium or PVC Figure 4.3. Outside gutters A grate was added on the rainwater collection area, where the rainwater flows down the pipe into the storage tank. This feature was added to ensure that the water entering the storage tank is free from large impurities that can damage the tank, or cause health risks to the Kooma tribe. The grate is an effective filter and will be made from flyscreen, so it can be replaced when needed. Figure 4.4. Screen grate The Aluminium base of the unit will be covered in Black GE High Temperature silicone (Solar Water Distiller n.d.). This feature give the solar radiation a greater chance to be absorbed, allowing the water to be heated at a much higher rate, increasing water output. As light is absorbed Figure 4.5. Black silicone by black surfaces more, it is a necessary feature for the solar still to meet the Kooma Tribes needs. 30

31 Silicone seals and rubber seals for the unit will keep the unit as air tight as it can be, not allowing airflow to enter the unit and heat to be lost (Practical answers: Solar Distillation 2009). The silicone seals will be added to all joints of the aluminium sheeting and the rubber seals will be added to all joints of the glass with the rest of the unit. The rubber seals also provide further benefit, by allowing for thermal expansion of the materials. Hinges will be added to the join at the top of the glass, with a central support beam made from PVC pipe, to allow for the glass roof to be open. The feature was added to the unit to extend the life of the solar still, by making it possible for the inside to be cleaned to reduce the build up of unwanted minerals and to stop the growth of algae. Glass hinges will be used as normal door hinges are not satisfactory. Figure 4.6. Glass Hinges An overflow outlet of bore water will be added to the side of the single unit to ensure that the water does not rise over a certain height. This was added to maximise efficiency of the unit and to ensure the unit does not get flooded. A small hole will be cut in the side as the overflow feature. A cleaning pipe will also be added to the unit, to allow for the water present in the unit to be disposed of, so proper cleaning can take place. This is necessary as to stop the build up of unwanted minerals. Figure 4.7. Overflow Outlet To maintain the water level of the bore water in the unit, a dripper system was added that adds water at the same rate that water is being distilled. This keeps the water at a certain height for maximum efficiency and increases water output for the Kooma Tribe. This dripper system will run from the bore water storage tank and be black in colour to absorb solar radiation, allowing it to be at a high heat as it Figure 4.8. Dripper system enters the unit. 31

32 The bore water storage tank is a necessary feature as to allow the ongoing input of bore water into the unit, without the need of an external pump. This storage tank will be kept at a higher potential to the distillation units, allowing gravity to pump the water. This storage tank also helps heat the water before being added to the system, allowing for greater output of drinkable water. The clean distilled water tank will be kept underneath the units. This feature was added to reduce the area to which the system takes up and to also keep it cool for drinking straight away. Mud brick walls will Figure 4.9. Distilled Water Tank also be added around the tank and under the unit: firstly, to hold the unit in place and secondly, act as an insulating device for the system. This feature will also give a steady support for the Kooma Tribe to walk on when cleaning the units. The Bricks will be cheap and can be made from materials already on site. 4.4 Materials All materials chosen are due to the fact that they are the best option for the design. Properties will be discussed and their roles made relevant. They will be made or bought in bulk to reduce cost if failure is to occur and these will be stored on the site Metals Aluminium has been selected for the sides and base of the water still. Aluminium has a low density with a specific weight of 2.7g/cm 3. This will help keep the structure to a low density and will allow for lower strength materials to support the water still. Aluminium was also selected since it is a non-toxic material and because of its protective oxide coating which is resistant to corrosion. These are important since the role of the aluminium casing is to store water and the water must not be contaminated or cause the casing to corrode. Aluminium is also a good reflector of light which is one of aluminium s most important attributes towards the water still. When the sunlight enters the water still through the glass the aluminium will reflect the light inside the water still, which will consequently increase 32

33 the temperature of the still, speeding up the process of water distillation. The metal is completely recyclable, so if the Kooma Tribe ever wish to upgrade or modify the system they can recycle the aluminium appropriately. The metal is also extremely malleable and can be shaped at the site rather than shaping it and then transporting it to Bendee Downs. This will be effective in reducing transportation costs. To join the aluminium sheets rivet joints will be used. Rivet joints are strong under tension and especially strong under shear stress. This makes them ideal for use in holding the aluminium structure together as the main force acting on the aluminium sheet will be shear stress. The original as well as the formed head both rest both very well as the parts having been compressed into place. This makes for a snug and sealed joint which will prevent any water from creeping under the heads and corroding underneath (Heintz 1986). This is important because it means that no water can escape the water still and there will be no water wastage which will increase the efficiency of the unit Non-metals To transfer the water from the water still to the storage tanks, PVC piping has been selected. PVC is a thermoplastic material that is a polymer of vinyl chloride. An experiment conducted in Canada concluded that drinking water transferred by PVC piping in the summer time had insignificant amounts of organotin. An additional study in summer 1996, of locations where the highest organotin levels were detected in the winter-spring survey, indicated that organotin levels had decreased in most distribution water samples (Sadiki and Williams 1998, 1541). Since Canada s summer climate is of similarity to the annual climate of Bendee Downs it can be assumed that PVC piping would be a safe way of transferring drinking water. PVC is not recommended for use around temperatures that exceed 70⁰C. Since the temperature of Bendee Downs has a mean temperature of well below this it can be assumed that the temperature will not be enough to cause the pipes to exceed 70⁰C. It can be assumed that the water going through the pipes will not be of this temperature, as the vapour condenses on the glass and loses most of its heat before entering the PVC piping. PVC is also known to have a good UV resistance which means that it should be fine to be left outside in the sun. 33

34 To join the PVC piping, silicone sealer was selected as the best choice. Silicone sealer is a strong method of joining different parts of the unit together. However, silicone sealer is not recommended for use in water for extended periods of times. It is assumed though that the amount of water running through the pipes and where silicone sealer is present will not affect the silicone sealer to any recognizable damage. If any damage were to happen it can be noticed prematurely to any fractures in the materials and can easily be repaired by applying more silicone sealer. For the dripper system a simple low density polyethylene reticulation pipe will be used. Low density polyethylene is strong and also quite flexible. This will make it ideal for the purpose of the dripper system as it can bend around corners to reach all the units whilst maintaining the required amount of strength. Glass was selected for the roofing of the water still. The macroscopic properties of glass such as optical transmission and absorption, refraction of light, thermal expansion (Glasses for Photonics) are excellent for the dual water system. The ability for light to enter the water still is obviously an important attribute for the roofing material to obtain. This is significant since the sun s energy is what is going to start the whole water distillation process. Once the light has entered the water still it will be totally internally reflected by the glass which will keep the temperature of the water higher. Total internal reflection will occur when the ray of light hits the glass boundary at an angle larger than the critical angle of glass. This will help keep rays of light inside of the water still. When the surface of glass is first touched, in consequence of its density and extreme smoothness, a great number of particles come into contact with the skin; each of these particles, having a tendency to an equilibrium of temperature, takes heat from the skin until they acquire the same temperature as the body which is in contact with them. When the surface of the glass, or perhaps the particles to some very small depth within it, have acquired the temperature of the skin, then the glass will cease to feel cold, because it s bad conducting power does not enable it to attract more heat from the body (Lardner 1854, 95). 34

35 This fact makes glass ideal for the roofing as it allows the steam to condense on the roof into water vapour, in which it can then be tapped off via the PVC pipes. There will be rubber seals for the glass to rest on when leaning on the aluminium casing. This will stop the glass from becoming scratched which would decrease the efficiency of the unit. There will also be handles on the glass so that it easy to lift the glass roofing up by the handle and able to clean inside of the water still as well as both sides of the glass roofing. Inside of the water still at the bottom there is going to be black GE high temperature silicone. This is to help absorb the sunlight and heat the water faster and thus increasing the rate at which water is purified. The rainwater collection area was designed to incorporate a fly screen grate over the top. This was done to act as a filter for the rainwater, removing large impurities such as leaves and environmental build-up. The flyscreen is strong enough to withstand the pressure from these impurities whilst remaining effective due to the small hole design Structural What makes Mud bricks the ultimate building material for raising our unit above the ground and for support is that it is a natural material that is not only readily available on site, but also simple to process and leaves no carbon foot prints on the environment, and is thus an eco friendly solution to our problem. Moreover, it excludes transportation and provides an ease for maintenance and unit extensions if required. Mud bricks are extremely durable and environmentally sustainable as most of the energy required in processing them is acquired from the sun and after a lifetime of use the brick decomposes and breaks down into the earth in which it originally came from. They are extremely dense and thus lack the ability to trap air particles within their actual structures, making them excellent at resisting heat transfer and thus able to keep the heat inside our unit and hence increase the overall efficiency. 35

36 How they are made: Equipment needed is outlines in figure Figure Equipment for making mud bricks. (Google Images, 2010) Equipment Rake Water supply Hoe Pitchfork Mould Clay Wheel barrow Aggregates Shovel Straw 36

37 Method of making mud bricks: 1. First, select an appropriate site with a levelled ground and a close by water supply for mixing the soil mixture. 2. Start mixing the clay with some soil and enough water as you go along. Note that the general composition of the bricks ranges from percent clay, percent water and percent of aggregates like rocks, stones etc.(adding straw to the mix decreases the cracking dramatically, and is thus highly advised to). 3. After a relatively stiff mixture is formed, transport the mix to the drying area, which should have a sand or straw base in order to prevent the bricks from binding to the ground. In addition, it is extremely important that the drying area is not in direct sunlight in order to get a consistency of dryness throughout the brick. 4. Place the mix into moulds of size 250mm*150mm*50mm and leave to dry for 1 day before turning over on other side, in order to allow for consistent dryness throughout the brick. 5. Lay the brick in the manner according to the dimensions of the unit. Figure Mud Bricks (Australia DLF, 2010) 4.5 Life Expectancy Graph 4.12 has the life expectancy of all the significant materials in the design and the life expectancy of each material. The major materials affecting the life expectancy of the design is the glass, aluminium, PVC and the water storage tanks. It can be noticed on the graph that the shortest life expectancy of the materials is the water storage tanks, which is 40 years. Hence, it can be assumed that as long as the glass or any other material is not damaged the life span of the unit can be estimated to be 40 years. 37

38 Graph Life expectancy of unit materials 4.6 Units Efficiency The efficiency of the single unit is the key to the overall running and benefit from the unit. If the unit does not have high efficiency for the cost, constructions and added features, the unit would not be worth manufacturing and using. The Dual Water distillation unit has many features that contribute to the overall efficiency of the unit, which helps maximise solar radiation input, maximise daily water 38

39 output for both summer and winter, minimise cost and maximise the number of people that can survive on one unit. The features which help all these things to happen include: A black solar radiation absorbing surface that increases the energy added to the system. Al-Hayek and Badran (2004, 126) state that this allows for the water to be heated at a greater rate and minimises the amount of solar radiation that is reflected form the water or absorbed elsewhere. Lowering the water level of the bore water in the system. As stated by Al-Hayek and Badran (2004, 124), by lowering the water, less energy is needed to give the water sufficient energy to turn into pure water gas, allowing for a greater amount of water to be distilled daily, while replacing the water as it is distilled. Insulation from the mud brick walls holding the unit up. By enclosing the unit in a mud brick wall, this causes a lowering of energy loss to the surroundings. Insulation is key to retain heat, and through this method, the system can retain heat. Reflection from the aluminium sides. The high reflection of the aluminium allows the solar radiation that would not be absorbed by the water, be directed to the water and absorbed by the black silicone base, raising energy input. Pumping the bore straight into storage tanks ready for use. The bore water reaches the surface at around 45 degrees Celsius (EWB Challenge Bendee Downs 2010), allowing for less energy needed to raise it to its 100 degree Celsius boiling point. The formula for efficiency is given by: Q = (E x G x A)/2.3 where: Q = Daily output for distilled water (L/day) E = Overall efficiency G = Daily solar radiation (MJ/m 2 ) A = Area of still base (m 2 ) (Practical Answers: Solar distillation 2009) 39

40 Through use of the formula and assuming the overall efficiency is 35%, the daily solar radiation in 26 MJ/m 2 in summer and area of still base is 3m 2, this gives a daily water output of 12L per day, per still. This value would fluctuate due to clouds, temperature, and time of year and much larger outputs can be generated by connecting multiple units. Appendix E gives the calculations to the above formula and a table of recommended units for fluctuating numbers of people. 40

41 5.0 Implementation of the Unit 5.1 Cost Breakdown The total cost of the dual water filtration unit is a maximum of $2000. This covers the materials, labour and transportation costs. Taking into consideration the distance and the hours perused in reaching Bendee Downs, the overall cost has the potential to be much smaller. However in considering the life time of the unit and the average amount of fresh the unit produce over a 1 year period, then it is estimated that it will cost 3c to provide 1L of clean drinking water this figure means that it will cost $54.75 to nourish 1 person for 1 year over the life span of the unit. To reduce the cost of water per litre, this can be done by adding additional units to the first unit. This is due to the tanks already being present and only the distiller itself being needed. This shows that each additional unit will cost just $300, making it more affordable and appropriate to the Bendee Downs community. 41

42 Table 5.1. Cost of materials and other related items MATERIALS DIMENSIONS UNIT PRICE QUANTITY COST 150mm (diameter) $31.50 per m 4.06m $ PVC 90mm $5.30 per m mm $9.90 per 3m m $1.14 PVC joiners Variable sizes $1-$3 5 $10 Taps Variable sizes $15 3 $45 Glass 2m 2 $100 per sheet 1.5 $ mm*450mm*10m Aluminium $ m $35.22 roll sheets 0.7mm*300mm*10m $117 4m $46.8 Brackets Variable sizes $1 4 $4.00 Fly screens (UV 810mm width $6.76 per meter 1.00m $6.76 stabilized) Rivets - $5 per pack 2 packs $10.00 Hinges 10mm-70mm $1.50-$ $3.00 Silicon sealer (aluminium) Water hose (U.V stabilised) Tanks Polytube (reticulation hose) - $5.47 per bottle 2 $ mm diameter $15 per 15m 1.505m $ l $299 2 $ l $ l $ l $665 1 $665 20mm diameter $9 per 20m 2 $18 19mm diameter $17.25 per 25m - - Mud bricks 10m² - Being made - Truck(rental ) 1 week $300 1 $300 Total $ Total with Transport $ (one unit) 42

43 5.2 Detailed Construction and Instillation Below gives a step by step guide to the construction of a single unit of the Dual water distillation Unit. All steps have written information to describe what is happening, with the addition of images. All tools, devices and construction material are outlined in bold. Materials and Tools: Figure 5.1 shows the materials and tools used in the construction of the single unit. All tools are numbered and can be referred to throughout the construction procedure. Figure 5.1. Materials and tools used. 43

44 Step 1: Setup the Aluminium and draw all lines accordingly as outlines in Figure 5.2. The lines should be drawn using a metal ruler (3) with a pencil. The black lines show bends in the metal and the red lines show cuts in the metal. Figure 5.2. Dimension of aluminium sheet Step 2: Cut the aluminium to size out of the whole sheet following figure 5.2 above. Use the aluminium cutters (4) and cut along the red lines. When cutting remember gloves and safety glasses and apply pressure to the metal. Figure 5.3. Cutting the aluminium sheet 44

45 Step 3: Using an aluminium file, file down the edges of the metal to remove the excess aluminium splinters. The step is to ensure safety, and for best results, file in only one direction. Figure 5.4. Finished cutting product Step 4: For the unit to start taking shape, the metal has to be bent along the lines in figure 5.2. To do this, pressure should be added to the metal whilst hammering the sides at the bends. This allows maximum force for ease of formation. Figure 5.5. Bending of the sides Step 5: Bend the overlaps so that they line up on the sides of the unit. As this point, using the drill (1) and a 3mm drill bit (7), drill holes for the pop rivets(8). Add the rivets to the riveter (6) and apply pressure to the tool. The rivet should pop out and make the unit rigid. Add 5 rivets to each overlap of the unit. Figure 5.6. Riveter for the aluminium 45

46 Step 6: Using the silicone gun (2), silicone the inside of the unit along the bends and the joins on the side. This ensures the unit water tight and maintains high efficiency. For an ever spread of silicone, slowly move the silicone gun along the edge. Figure 5.7. Silicone gun on edges Step 7: For extra stability of the unit, drill one hole at the top of each triangle on either end. Once done, thread metal wire through and tighten off, restricting the movement of the metal. Step 8: Using the black silicone, silicone the base of the unit to raise the efficiency and solar radiation absorption. Spread this silicone evenly across the base using scrap wood. Step 9: Cut the pieces of aluminium lengths for the gutters on the inside of the unit. These gutters are fitted on either side of the unit and are angled for the water to flow to one end. Use the pop riveter (6) to attach these gutters on the gutter holders (9). Figure 5.8. Silicone gun on the inside gutters 46

47 Step 10: Silicone the gutters to ensure they are water tight using the silicone gun (2). For best coverage, move the gun slowly across the join and remember to silicone around the rivets to stop corrosion and for a closed system. Step 11: Using a metal and plastic saw, cut a 14cm piece of PVC pipe to add as the central support in the single unit. File down the top of the section to allow for the slant of the glass using the metal file. Attach this piece using silicone as the glue at its base. Figure 5.9. PVC central support for glass Step 12: Cut the aluminium gutters for the outside rainwater collection of the unit. This is done using the aluminium cutters (4) with pressure being supplied to one side. Bend these cut sections into a right angled shape for unit attachment. Step 13: Attach the gutters to the side of the unit using the pop riveter(6) and the gutter holders(9). Drill the holes on the holders first to ensure easy construction. Use two pop rivets(8) on each attachment for most support. Figure Gutters for outside of unit 47

48 Step 14: Silicone the outside of the gutters where the connection to the unit occurs to ensure that they are water tight. Use the silicone gun(2) at a steady pace for even coverage. Step 15: Add the glass sections(5) to the top of the unit by the addition of silicone to the underside of the glass where it connects to the metal. Do this to both pieces so that they join at the top. Before this is set, add the glass hinge so the roof can be opened. Figure Glass added to the top of the unit Step 16: Add the pipes from the distilled water and rainwater collection areas by first drilling the right size holes then adding silicone to the pipes to set them in place. Step 17: Add the dripper pipe through the unit by drilling two holes in the sides at one end of the unit. Holes should be added to this pipe at 10cm intervals to ensure the water flowing into the unit is equal to the water flowing out. This can be done through hammering a nail into the pipe. Step 18: Drill the overflow and disposal outlet into the side of the unit. This can be done using a 10mm drill piece(7). Add the screen grate to the top of the where rainwater collection takes place and set it rigid by adding silicone to all sides. 48

49 Figure Finished construction of the single unit Extra information: Silicone needs time to set, so no addition should be made to the unit whilst it is still drying. Additions could cause movement and deform the structure. Safety equipment should be worn throughout the entire construction. 49

50 6.0 Maintenance and Cleaning Programs 6.1 Testing for Impurities Unfortunately testing on site cannot be done by the Kooma people. The technology required for such tests are only available in specified labs. Before the bore water is distilled, samples must be bottled appropriately and sent off to the nearest water testing laboratory for a complete professional analysis. The same should be done for the distilled water as well. Frequency of test should be carried out every 5 to 6 years. Although it could hurt financially, it is of utmost importance to monitor the potentially fatal pathogens and chemicals that may be present in the water and to test the effectiveness of the dual water system. The Australian Water Quality Centre has guidelines on what to give for sampling. The primary indicator of contamination of Microorganisms is the rotten egg smell. Due to the annihilating properties that UV radiation has towards micro bacteria, chances of microorganisms surviving the purification unit non-existent. However, in the unlikely case of the smell originating from the purified bore water, consumption should be stopped immediately and appropriate testing and rectification should be carried out. Figure 6.1. Process of microbiological removal Ph level tests are used to determine how acidic or alkaline a water sample is. Ground water can range from a ph level of 6 to 8.5. Rain water, depending on atmospheric 50

51 conditions can experience ph levels of 3 to 6. The ph value can vary from 1 to 14 and is temperature dependant, most measurements and values are determined at 25 0 C. A value of 1 will label a sample as highly acidic, and that of 14 identifies an extremely alkaline sample. Pure water has a value of 7 which is located directly in the middle of both the extremes (refer to figure 11.1.). This is an example of a simple ph gauge. Soft water is considered to have ph levels lower than 6.5 and contains increased amounts of metals. Wilkes University states that... water with a low ph could contain elevated levels of toxic metals, cause premature damage to metal piping, and have associated aesthetic problems such as a metallic or sour taste... and the characteristic bluegreen staining of sinks and drains. (1). If there is a high amount of cationic metals such as those previously mentioned in section 2.1. then the metal used in the dual water system may be subject to degradation and or staining. Fortunately the design does not involve metal piping only an aluminium base which is resistant to corrosion due to water and its constituent metal ions. After purification, the dual water system will alter water levels to the approved neutral state of 7. Anything to high or low around this mid level range is not healthy for the human body as teeth and internal body parts being to suffer. Rainfall generally has a ph of 5 to 6.5 (Wilkes University). The most affordable and meaningful way to test the ph of any water sample is by using Universal Indicator (UI). It is a cheap and reliable source of information which works by the UI causing the colour of the water sample to change. The resulting colour can be verified with a colour coded scale similar to the one in figure 11.1 (Appendix F). Testing and interpreting the results should be carried out once a fortnight along with cleaning programme outlined in section 6.2 as it will also enable the effectiveness of the unit to be monitored. Figure 6.2 below shows a summary for the reasons for testing. 51

52 Figure 6.2. Summary for testing 6.2 Appropriate Cleaning Styles During the distillation process, water is evaporated and then it condenses on the inner side of the glass A-frame. From here the water will go into storage. This surface needs to be extremely clean to ensure that distilled water is not re contaminated. A simple rubber squidgy will suffice in making sure the inner glass is not touched by human hands which can be a contaminating factor and secondly that no water marks will be left on the glass. No chemicals will be used to clean the interior side of the glass as most cleaning agents contain harmful chemicals. When cleaning the glass it is advised that rubber gloves are used. The exterior glass that is subject to environmental conditions and debris is recommended to be cleaned with a soft damp cloth with plain rain water from the rain water tanks. This will prevent any rough sand particles from potentially scratching the glass surface. No chemicals are required in the cleaning process. Through the course of the distillation process, cationic metals present in the impure water will be precipitated out and thus will collect at the bottom of the distillation unit. As is 52

53 section 2.1, the various metals present in contaminated water, metals such as iron, aluminium, calcium and nickel will increase in concentration as more bore water is distilled. In order to clean out solid material, the inflow of unclean aquifer water needs to stop and the process of distillation should continue as per usual until minimal water is left. This is estimated to take up to nine hours. If cleaning is to be done, system water supply should be cut off in the morning so that emptying out of waste material can be done in the evening. This is to make the most out of the solar radiation present during the day that will evaporate and condense the water. No cleaning chemicals need to be used as water in contact with the tray is evidently yet to be distilled. A separate firm squidgy needs to be used to round up waste into a container similar to a dust pan. Larger objects such as leafs and insects may collect in the outer exposed gutters. The fly screen mesh acts as a filter and will prevent unwanted materials from entering water storage pipes that transport the rain water to the tanks associated with them. In order to prevent blockage due to build up of large material, mesh will need to be checked and cleaned after every two or three days, depending on the weather experienced at the Bendee Downs site. This includes higher than usual winds that could cause transportation of unwanted materials. If cases occur, the system will need an immediate check up and outer system cleaned. The outer Gutter, which channels rain water to a common point for future storage is not isolated from the environment and requires frequent monitoring. There is no water purifying filter attached to the pipe as rain water is pure. On the other, particles such as grains of sand deposited in the gutter due to various weather conditions can penetrate through the mesh filter and enter into the storage tank. This is an unwanted occurrence, firstly, cleaning the storage tank of solid material will be a difficult task as they are closed systems. Secondly, it will decrease the storage capacity of the tank thus a new tank may need to be purchased. The cost of buying a new tank can be averted if proper preventative measures were to be followed. Using a simple dust pan and broom will be an efficient way to rid of sand. A quick wipe with a damp, clean cloth specific to the use of cleaning the water unit will be more than capable of removing any fine pieces of sand. 53

54 7.0 Limitations of Implementations As with any other design our design has both technical end environmental dilemmas. However, we believe that our design has far less than any other proposed design solution. The problems presented seem to be only slight dilemmas and if the unit is used correctly most of these problems will never occur or disrupt the efficiency of the design. 7.1 Technical Technical: Since inexperienced labourers will be installing the water still, there may be poor fittings and joints which will increase the cold air flow from outside into the still. If the glass is not carefully looked after cracking, breakage or scratches may occur on the glass, which will reduce the solar transmission and may also let cold air inside the water still. There may be growth of algae and deposition of dust or bird droppings making the glass dirty and effectively decreasing the efficiency of the unit. To avoid this, the glass and unit should be cleaned regularly. There may be damage to the blackened absorbing surface on the bottom of the still. There will be a collection of salt at the bottom of the water still. The still should be cleaned regularly to dispose of any salt accumulation at the bottom. If the dripper system makes the water level too high or lets the water level drop too low it will decrease the efficiency of the water distillation. The water level should be constant around 20mm. Build up of algae and leaves and other unwanted materials inside of the storage tank for the rainwater. 54

55 7.2 Environmental Environmental: Since our design has to be built close the already existing bore water pump, the terrain near the pump must be suitable for our design. If there is a dry month or two the unit will not be able to capture any rain water. If there is overcast for a few days the efficiency of water distillation will be decreased. If there is any shade on the water still blocking off the sunlight the intensity of the sun will be decreased and the water distillation efficiency will be decreased. 55

56 8.0 References Adelaide Hills Council Rain Water Tanks and Rain Water Quality. (accessed May 21, 2010) Al-Hayek, I., and O. O. Badran Solar Distillation. Desalination 169 (1): Science Direct. (accessed April 30, 2010). Aluminum Substructure (accessed May 14, 2010) APEC. n.d. Complete Drinking Water Contaminants Fact Sheet: contaminants index page. (accessed May 21, 2010) APEC. n.d. Overview of Contaminants & Their Potential Health Effects. (accessed April 15, 2010) APEC. n.d. Water Education: Water Purification vs. Basic Filtration. (accessed April 5, 2010) APEC. n.d. Water Education: Water quality of surface waters. (accessed March 28, 2010) Aqueous Solutions. n.d. Bore Water Test. (accessed April 14, 2010) Artesian and sub-artesian water basins in Australia. Image (accessed March 19, 2010) Australia. Design for Lifestyle and Future Your Home Technical Manual : Mud bricks. (accessed May 18, 2010) 56

57 Australian Water Quality Centre Bore Water Testing - For Private use: Information Sheet. F8AC30967C0F/0/BOREinfosheets.pdf (accessed March 4, 2010) Boersma, A., and J. Breen Long Term Performance of Existing PVC Water Distribution Systems. International PVC Conference Callister, W Materials Science and Engineering: An Introduction. United States of America. Quebecor Versailles Climate Statistics for Australian Locations. Image (accessed April 29, 2010). Commonwealth of Australia: Bureau of Meteorology Australian Water Availability Project. (accessed April 8, 2010) CSIRO Australia Design Concept. Image (accessed March 28, 2010) Designer Tanks. n.d. Water Tanks Victoria. (accessed April 30, 2010). Engineers Without Borders Australia Kooma Energy Project: Announcements. (Accessed May 2, 2010) Engineers Without Borders Australia Partner Profile: Kooma Traditional Owners Association. (Accessed March 19, 2010) ExploreOz Bendee Downs - QLD. (accessed March 27, 2010) Geiger, J., and N. Mesner.2005.Understanding Your Watershed: ph.. (accessed April 5,2010) 57

58 Green Living Tips Rainwater tank materials. (accessed April 3, 2010) Heintz, C Riveted Joints. EAA Light Plane World Magazine. Informit Online. (accessed April 29, 2010). Home s Components Life Expectancy. ml (accessed April 29, 2010). Lardner, D., ed The museum of science and art. Walton and Maberly. Mayrah Yarraga. Indigenous Australia: protocol for visiting Aboriginal land. (Accessed April 2, 2010) Lenntech Water Treatment Solutions: A Drinking Water Purification Process. (accessed April 13,2010) Lenntech Water Treatment Solutions: WHO s Drinking water standards (accessed April 13, 2010) Mayrah Yarraga. Indigenous Australia: Introduction Aboriginal Culture. (Accessed April 2, 2010) Nann, S Potentials for Tracking Photovoltaic Systems and V-Troughs in Moderate Climate. International Journal of Scientists, Engineers and Technologists in Solar Energy and its Applications 44(6): National water Quality Management Strategy: Australian 5 Drinking Water Guidelinessummary (accessed May 9, 2010) Noble, N., G. Tiwari, and A. Tiwari Practical Answers: Solar Distillation. (accessed March 28, 2010) 58

59 Paul Doyle Plumbing Trades and Handymen: Plumbing /cat/tradeshandyman/. (Accessed March 18, 2010) Planet Earth Acid Rain. (Accessed May 1, 2010) Plastic Properties of Low Density Polyethylene (accessed April 28, 2010). Plastic Properties of Polyvinylchloride (accessed April 28, 2010). Queensland. Department of Environment and Resource Management Water: Water Bores. (accessed April 5, 2010) South Australia. Department of Health Water Quality Fact sheet: Using Bore Water Safely. (accessed March 30, 2010) South Australia. Department of Health Water Quality Fact sheet: Rain Water Tanks, Maintenance and Water Care. (accessed 30, 2010) The ph Scale. Image. n.d. (accessed May 16, 2010) Western Australia. Department of Health Water Unit: Standard Drinking Water Assay. say.pdf (accessed May 3, 2010) Western Australia. Department of Health Water Unit: Drinking Water Catchment Protection. Protection.pdf (accessed April 19, 2010) Wilkes University. n.d. Water Quality and Water ph: ph. (accessed April 12,2010) 59

60 Appendix A: Technical Mind Maps 60

61 61

62 Appendix B: Technical Assumptions. The assumptions for the task and the Dual water system include: 1. The Kooma Tribe have an effective means of pumping bore water to the surface. These pumps comply with water regulations. 2. A dual joint can be added to the pump to direct water into a bore water storage tank. 3. Efficiency of 35% is assumed due to efficient features. 4. There is level ground to construct unit. 5. There is no object to provide shade in surrounding areas near the unit. 6. There is area that is close to pump that can be used. 7. Water will evaporate and condense on glass surface without energy being wasted. 8. When the water condenses on the glass surface, it will lower to a temperature that will not damage the physical properties of the PVC piping, hence not melting it. 9. The building of tanks is too difficult for the Kooma Tribe. 10. The Kooma Tribe will be able to construct and form the units themselves using simple tools and applications described and shown too them. 11. Only one trip will be needed to transport all materials to the site. 12. The aluminium forms the oxide layer to protect against environmental corrosion. 13. Efficiency will remain high with appropriate cleaning. 14. The higher potential of the bore water tank will supply an even flow to all the units. 15. The rate of flow into the unit will remain within 5% of water output of the unit. 16. The mud bricks will have the desired strength to hold the unit and remain a reliable source of stability for the tribe to continue maintenance twice weekly. 17. A large portion of the water distilled everyday will be used, only needing the rain water to be stored, hence smaller and fewer tanks can be used. 18. Galvanic corrosion will not be an issue as silicone will protect from water and oxygen. 19. The materials will last within 10% of their life expectancy and backup materials will be available to use. All tools will be available to use on the site. 62

63 Appendix C: Process of Design The process of design involved the following steps to incorporate cost efficiency with water output as well as incorporating the needs of the Kooma community. 1. Choosing the best area to cover the report on. Water was chosen as water is needed for life and without a sufficient supply of water for the community then they will not be able to survive and ecotourism would not be possible. 2. The best options for water purification were considered. These are outlined in appendix F. Water distillation and rain water catchment was chosen for the design. 3. Research on different models was undertaken to find the best solution for the Kooma Tribe. The CSIRO base model was chosen to improve by adding extra features. 4. Research on features was undertaken and the second major and equally important feature of rainwater catchment was added to the design. 5. Research on water impurities, climate and the conditions at Bendee Downs was finalised and unit features were changed to meet these conditions. This was our situation analysis.zx 6. Materials were chosen for the unit that maximised the life expectancy and water output was minimising cost and complications through in producing water. 7. All discrepancies were sorted out for the task including the graphical design, all features and materials to be incorporated as well as assumptions and limitations that may occur. 8. Graphics were designed for the task that incorporated the single unit, multiple units, rainwater and bore water tanks. These were scale models to give a real life perspective for the Kooma Tribe to view. These images were rendered. 9. The report was written and all information was added of importance and need for the Kooma Community to best convey the design and involve them in the construction and instillation process. 63

64 Appendix D: Graphical Design Top side angle of the single unit with the tank underneath. Rainwater collection pipe can be seen leading off to the left of the image and the bore water storage tank can be seen in the right corner. Front on view of the single unit with the full view of the bore water storage tank. The clean water collection tank can be seen underneath the unit with pipes flowing into it. 64