The Desolenator: Producing Clean Water - IELTS Reading Answers & Explanations
From Cambridge IELTS 15 Academic Reading Test 3 · Part 2 · Questions 14–26
Reading Passage
The Desolenator: producing clean water
A
Travelling around Thailand in the 1990s, William Janssen was impressed with the basic rooftop solar heating systems that were on many homes, where energy from the sun was absorbed by a plate and then used to heat water for domestic use. Two decades later Janssen developed that basic idea he saw in Southeast Asia into a portable device that uses the power from the sun to purify water.
B
The Desolenator operates as a mobile desalination unit that can take water from different places, such as the sea, rivers, boreholes and rain, and purify it for human consumption. It is particularly valuable in regions where natural groundwater reserves have been polluted, or where seawater is the only water source available.
Janssen saw that there was a need for a sustainable way to clean water is both the developing and the developed countries when he moved to the United Arab Emirates and saw large-scale water processing. ‘I was confronted with the enormous carbon footprint that the Gulf nations have because of all of the desalination that they do,’ he says.
C
The Desolenator can produce 15 litres of drinking water per day, enough to sustain a family for cooking and drinking. Its main selling point is that unlike standard desalination techniques, it doesn’t require a generated power supply: just sunlight. It measures 120 cm by 90 cm, and it easy to transport, thanks to its two wheels. Water enters through a pipe, and flows as a thin film between a sheet of double glazing and the surface of a solar panel, where it is heated by the sun. The warm water flows into a small boiler (heated by a solar-powered battery) where it is converted to steam. When the steam cools, it becomes distilled water. The device has a very simple filter to trap particles, and this can easily be shaken to remove them. There are two tubes for liquid coming out: one for the waste – salt from seawater, fluoride, etc. – and another for the distilled water. The performance of the unit is shown on an LCD screen and transmitted to the company which provides servicing when necessary.
D
A recent analysis found that at least two-thirds of the world’s population lives with severe water scarcity for at least a month every year. Janssen says that by 2030 half of the world’s population will be living with water stress – where the demand exceeds the supply over a certain period of time. ‘It is really important that a sustainable solution is brought to the market that is able to help these people,’ he says. Many countries ‘don’t have the money for desalination plants, which are very expensive to build. They don’t have the money to operate them, they are very maintenance intensive, and they don’t have the money to buy the diesel to run the desalination plants, so it is a really bad situation.’
E
The device is aimed at a wide variety of users – from homeowners in the developing world who do not have a constant supply of water to people living off the grid in rural parts of the US. The first commercial versions of the Desolenator are expected to be in operation in India early next year, after field tests are carried out. The market for the self-sufficient devices in developing countries is twofold – those who cannot afford the money for the device outright and pay through microfinance, and middle-income homes that can lease their own equipment. ‘People in India don’t pay for a fridge outright; they pay for it over six months. They would put the Desolenator on their roof and hook it up to their municipal supply and they would get very reliable drinking water on a daily basis,’ Janssen says. In the developed world, it is aimed at niche markets where tap water is unavailable – for camping, on boats, or for the military, for instance.
F
Prices will vary according to where it is bought. In the developing world, the price will depend on what deal aid organisations can negotiate. In developed countries, it is likely to come in at $1,000 (£685) a unit, said Janssen. ‘We are a venture with a social mission. We are aware that the product we have envisioned is mainly finding application in the developing world and humanitarian sector and that this is the way we will proceed. We do realise, though, that to be a viable company there is a bottom line to keep in mind,’ he says.
G
The company itself is based at Imperial College London, although Janssen, its chief executive, still lives in the UAE. It has raised £340,000 in funding so far. Within two years, he says, the company aims to be selling 1,000 units a month, mainly in the humanitarian field. They are expected to be sold in areas such as Australia, northern Chile, Peru, Texas and California.
Questions
Questions 14–20 Matching Headings
The Reading Passage has nine paragraphs, A-H
Choose the correct heading for each section from the list of headings below
Write the correct number, i-x, in boxes on your answer sheet.
List of Headings
i Getting the finance for production
ii An unexpected benefit
iii From initial inspiration to new product
iv The range of potential customers for the device
v What makes the device different from alternatives
vi Cleaning water from a range of sources
vii Overcoming production difficulties
viii Profit not the primary goal
ix A warm welcome for the device
x The number of people affected by water shortages
Questions 21–26 Summary Completion
Complete the summary below.
Choose ONE WORD ONLY from the passage for each answer.
Write your answers in boxes on your answer sheet.
How the Desolenator works
The energy required to operate the Desolenator comes from sunlight. The device can be used in different locations, as it has 21. Water is fed into a pipe, and a 22 of water flows over a solar panel. The water then enters a boiler, where it turns into steam. Any particles in the water are caught in a 23. The purified water comes out through one tube, and all types of 24 come out through another. A screen displays the 25 of the device, and transmits the information to the company so that they know when the Desolenator requires 26.
Answers & Explanations Summary
| # | Answer | Evidence | Explanation |
|---|---|---|---|
| Q14 | iii | Two decades later Janssen developed that basic idea he saw in Southeast Asia into a portable device that uses the power from the sun to purify water | Excerpt/Passage Explanation: The passage talks about how Janssen took an idea he saw in Southeast Asia and turned it into a portable device that can purify water using solar power. Answer Explanation: The answer indicates that this section is about the journey from the initial inspiration of the water-purifying idea in Southeast Asia to the development of the portable device. Reason For Correctness: The correct answer is 'iii' because it accurately matches the content of the excerpt, focusing on the process of going from the initial inspiration ('basic idea') to creating a new product (portable water-purifying device). This heading perfectly captures the essence of the section described in the excerpt. |
| Q15 | vi | The Desolenator operates as a mobile desalination unit that can take water from different places, such as the sea, rivers, boreholes and rain, and purify it for human consumption. | Excerpt/Passage Explanation: The passage talks about a machine called the Desolenator that can clean water from different sources like the sea, rivers, boreholes, and rain to make it safe for people to drink. Answer Explanation: The answer means that this section of the text discusses how the Desolenator cleans water from various places. Reason For Correctness: The correct answer is 'vi' because the excerpt specifically mentions how the Desolenator works as a mobile desalination unit that purifies water from different sources. This aligns perfectly with the description of cleaning water from a range of sources provided in option 'vi'. |
| Q16 | v | Its main selling point is that unlike standard desalination techniques, it doesn’t require a generated power supply | Excerpt/Passage Explanation: The passage explains that the device's main advantage is that it doesn't need an external power source like other methods to make saltwater drinkable. Answer Explanation: The answer highlights the unique feature that sets the device apart from other options. Reason For Correctness: The correct answer is 'v' because it directly addresses what makes the device different from alternatives, which aligns with the information given in the excerpt about its distinctive selling point of not needing external power. |
| Q17 | x | A recent analysis found that at least two-thirds of the world’s population lives with severe water scarcity for at least a month every year | Excerpt/Passage Explanation: The passage talks about a big problem in the world: not having enough water for everyone. It says that a big part of the world's population faces this problem for at least one month every year. Answer Explanation: The answer is x, which is 'The number of people affected by water shortages'. It's talking about how many people are affected by not having enough water. Reason For Correctness: The correct answer is x because the passage talks about water scarcity and how many people are affected by it. The sentence 'at least two-thirds of the world’s population lives with severe water scarcity' clearly states the number of people affected, which matches the heading option x. |
| Q18 | iv | The device is aimed at a wide variety of users – from homeowners in the developing world who do not have a constant supply of water to people living off the grid in rural parts of the US. | Excerpt/Passage Explanation: The passage describes the device being suitable for a wide range of users, including those without consistent access to water in developing countries and individuals living in rural areas of the US with no connection to the main water supply. Answer Explanation: The answer 'iv' suggests that this section discusses the range of potential customers for the device. Reason For Correctness: The correct answer is 'iv' because the excerpt explicitly mentions the device being targeted towards various users both in developing countries and rural parts of the US, highlighting the diverse range of potential customers for the product. |
| Q19 | viii | We are a venture with a social mission. We are aware that the product we have envisioned is mainly finding application in the developing world and humanitarian sector and that this is the way we will proceed | Excerpt/Passage Explanation: The passage talks about a company that is focused on helping others rather than solely making a profit. They recognize that their product is mainly needed in poorer countries and for humanitarian purposes. Answer Explanation: The answer indicates that profit is not the main goal for the company, which aligns with the passage's emphasis on a social mission. Reason For Correctness: The correct answer is 'viii' because the excerpt highlights the company's social mission and their focus on addressing needs in developing countries and humanitarian sectors rather than purely aiming for profit. |
| Q20 | i | It has raised £340,000 in funding so far | Excerpt/Passage Explanation: The passage talks about how the company has received £340,000 in funding. Answer Explanation: The answer suggests that this section is about getting the finance for production. Reason For Correctness: The correct answer is 'i' because receiving £340,000 in funding aligns with the idea of needing finance for production, indicating that this section is likely discussing how the company secured funding for their project. |
| Q21 | wheels | It measures 120 cm by 90 cm, and it easy to transport, thanks to its two wheels | Excerpt/Passage Explanation: The passage mentions that the Desolenator is easy to transport because it has two wheels. Answer Explanation: The answer 'wheels' refers to the round objects attached to the Desolenator that help in moving it around. Reason For Correctness: The correct answer is 'wheels' because the excerpt explicitly states that the device is easy to transport thanks to its two wheels, indicating that the Desolenator has wheels for mobility. |
| Q22 | film | Water enters through a pipe, and flows as a thin film between a sheet of double glazing and the surface of a solar panel | Excerpt/Passage Explanation: The passage describes water moving in a very thin layer between a piece of glass and a solar panel. Answer Explanation: The answer refers to a thin layer of water called a 'film'. Reason For Correctness: The correct answer matches the description in the passage where water flows as a thin film over a solar panel, capturing the essence of how the Desolenator works. |
| Q23 | filter | The device has a very simple filter to trap particles | Excerpt/Passage Explanation: The passage says the Desolenator has a very simple thing that catches tiny pieces in the water. Answer Explanation: The answer means a special tool that catches little bits and pieces. Reason For Correctness: The correct answer is 'filter' because the excerpt explains that the Desolenator uses a simple 'filter' to catch the particles in the water. |
| Q24 | waste | There are two tubes for liquid coming out: one for the waste – salt from seawater, fluoride, etc. – and another for the distilled water | Excerpt/Passage Explanation: The passage mentions that one tube is used for the waste, which includes salt from seawater, fluoride, and other impurities. Answer Explanation: The answer 'waste' refers to the undesirable or harmful substances that are removed during the water purification process. Reason For Correctness: The correct answer 'waste' is accurate because it corresponds to the mention in the passage that one of the tubes is specifically for the waste materials such as salt from seawater and fluoride, which are separated during the water purification process. |
| Q25 | performance | The performance of the unit is shown on an LCD screen | Excerpt/Passage Explanation: The passage shows that information about how well the Desolenator is working is displayed on a screen. Answer Explanation: The answer 'performance' refers to how well something is functioning or operating. Reason For Correctness: The correct answer 'performance' matches the idea that the LCD screen displays the unit's performance, indicating how effectively the Desolenator is working. |
| Q26 | servicing | transmitted to the company which provides servicing when necessary | Excerpt/Passage Explanation: The passage mentions that information about the Desolenator is sent to the company, and the company provides servicing when necessary. Answer Explanation: The answer refers to the maintenance and repair work done on the Desolenator by the company. Reason For Correctness: The correct answer 'servicing' is accurate because it represents the action taken by the company to maintain and repair the Desolenator based on transmitted information indicating the need for servicing. |
