Desalination Teaching Unit Grade 7 - PBworks · 2020-07-07 · Desalinated Water – Unit of Work...

Unit of Work: Overview

Lesson 1: Let’s get the facts!

Lesson 2: Desalination – A Global Phenomenon

Lesson 3: Decoding Desalination

Lesson 4: Desalination Experimentation

Lesson 5: Desalination hits the headlines!

Desalination Teaching Unit

Grade 7

Desalinated Water – Unit of Work Overview – Grade 7 1

UNIT OF WORK OVERVIEW Unit Title Desalinated Water Year Level Grade 7 Unit Description This unit of work considers desalinated water as a source of water as vital to the future of South East Queensland as water supplies sourced from dams and reservoirs. Today, Queensland’s water supplies are under pressure from residential, agricultural and industrial use. In the future, population growth, drought cycles and climate change will place further demands on our current water sources. With unpredictable rainfall patterns across the State and the threat of more frequent and more severe drought cycles, South East Queensland can no longer rely just on its dams and reservoirs to sustain a growing population. It is therefore imperative that South East Queensland embraces desalinated water as a clean, safe, efficient and climate resilient source of water today and into the future. This Unit of Work on Desalinated Water identifies the relevant curriculum links and provides an overview of the content and structure for the lessons. The individual lesson plans will be tailored to meet the specific needs of upper-middle primary students. Context for Learning By the end of this unit, students will:

• Have an understanding of water sources and water use in Australia from an historical and current day perspective and be able to identify future demands on water supplies in South East Queensland as a result of population growth and climate change;

• Have researched case studies to compare the Gold Coast Desalination Plant with desalination processes from elsewhere in Australia and worldwide.

• Have achieved a practical and theoretical understanding of the key desalination processes and understand the role played by the Gold Coast Desalination Plant in supplying desalinated water to the local community;

• Have an understanding of the environmental factors related to the desalination process, including energy consumption and reuse and the management of brine discharge and diffusion into the marine environment;

• He able to knowingly consider the proposition that desalinated water provides a safe, efficient and sustainable source of water as vital to the future of South East Queensland water supplies as dams and reservoirs.

Curriculum links: Science and Geography The Shape of the Australian Curriculum: Science paper available on the ACARA website has been used to develop curriculum links for this unit of work (http://www.acara.edu.au/sceince.html). This paper proposes that the K-10 curriculum for Science will be organised around three interrelated strands designed to be taught in an integrated way. The order and detail in which the content descriptions are organised into teaching/learning programs are decisions to be made by the teacher.

Content descriptions:


• Science Understanding: science knowledge (facts, concepts, principles, laws, theories and models) represents the building blocks of science understanding; the selection and application of knowledge to new situations and events

• Science Inquiry Skills: evaluating claims, investigating and making valid conclusions

• Science as a Human Endeavour: the need for informed, evidence-based decision making about current and future applications of science.

The Shape of the Australian Curriculum: Geography paper available on the ACARA website has also been used to develop curriculum links for this unit of work (http://www.acara.edu.au/geography.html).

The curriculum focus on developing geographical understanding through sequential studies of the main characteristics of place, space and environments continues from Foundation to Year 6 into Years 7-10. However, a more formal approach to learning is introduced in the secondary year.

Each year, from Years 7-10, still has two sets of core ideas about specific characteristics through which students will cumulatively learn about the basic patterns, processes and principles that explain the geography of their world. One set focuses on the environmental characteristics of places, but also explores related human themes and the other focuses on their human characteristics, but also explores environmental themes.

Each year will still have suggested topics that could be used to teach the core ideas, and other topics that can be used to extend and apply these ideas. However, teachers will be free to choose their own case studies. There are two strands: one sub-strand of topics focuses on environmental patterns and processes and their human significance and the second sub-strand of topics focuses on the human characteristics of places.

Content Descriptions and Core Ideas

Science: Grade 7

Science Understanding

• Oceans and atmosphere: characteristics of the oceans and atmosphere that relate to weather and climate, including the water cycle (ACSSU116).

• Separating substances: separation techniques based on the physical properties of matter and how they are used to extract useful substances (ACSSU113).

• Transferring and transforming energy: useful energy transfers and transformations such as those involving heat, light, sound, moving objects and gravity, and how energy is wasted.

Science as a Human Endeavour

• Scientists from Australia and elsewhere make major contributions to scientific knowledge, engineering and technology.

• People use understanding and skills from across the disciplines of science in their occupations (ACSHE224).

• Science understanding influences the development of practices in areas of human activity such as industry, agriculture and marine and terrestrial resource management (ACSHE121).


Science Inquiry Skills

• Formulate scientific questions to investigate and make predictions based on prior observations and scientific knowledge (ACSIS124).

• Investigation methods: Collaboratively and individually conduct a range of investigations, modelling, field studies, survey, information research and using data from secondary sources (ACIS125).

• Using equipment: use some specialized equipment and materials safely and identify and minimize risk to self and others (ACSIS126) and controlling variables in a fair test.

• Observing and measuring: Collect and record data, making observations and measurement with accuracy appropriate to the task, using ICT where appropriate (ACSIS126).

• Developing explanations: Summarise and explain data, using scientific understanding to draw conclusions (ACSIS130).

• Evaluating evidence: evaluate claims from a scientific perspective, including using real findings (ACSIS131).

Geography: Grade 7

Environmental Processes and their human significance

• Weather and rainfall • Water resource management • Weather hazards (cyclones, storms, droughts and floods). • Hydrologic cycle • World water usage.

Human characteristics of places

• Population and population change

Cross Curriculum links

Aboriginal and Torres Strait Islander histories and cultures

• Country/ Place: OI.2, OI.3

Sustainability • Futures: OI.8, OI.9

English

Mathematics

Technology

ICTs


Learning Overview

Lesson/s Overview Resources

• History of water use in Australia and how water use has changed.

• How do rainfall amounts vary across the State and across Australia?

• Current demands on water in South East Queensland.

• Future demands on water in South East Queensland.

• Visual stimuli – photos. • Seqwater website • WaterSecure website. • Concept mapping software Inspiration. • Bureau of Meteorology. • Queensland Government resources.

• Why is desalination used in Australia?

• Mapping desalination plants across Australia.

• Comparing the Gold Coast desalination plant with case studies of desalination processes at other Australian desalination plants.

• Researching case studies of desalination globally.

• Seqwater website. • WaterSecure website. • Map of Australia. • World map. • Mini-research cards.

• What is desalinated water?

• How is saltwater desalinated?

• Explanation of the technology and processes at the Gold Coast Desalination Plant.

• Desalination and energy use.

• Examination of the management of the discharged brine into the marine environment.

• Seqwater website. • WaterSecure website factsheets: • Desalination- fresh water from the sea. • How reverse osmosis works. • Gold Coast Desalination Plant virtual tour. • Existing teacher activities and Q&A sheet. • FAQs. • Underwater footage. • Desalination dictionary. • Gold Coast Desalination Plant tour.

• Further research into the scientific processes of desalination.

• Classroom based experiments/ activities to illustrate some of the desalination processes such as modeling desalination, osmosis, diffusion and dilution.

• Seqwater website. • WaterSecure website. • Factsheets: • Desalination- fresh water from the sea. • How reverse osmosis works. • Gold Coast Desalination Plant virtual tour. • Experiment resource sheets including equipment lists.


• What is South East Queensland’s water future?

• How should the community be educated in the benefits of using desalinated water?

• Benefits of desalination as a climate resilient water supply.

• Seqwater website. • WaterSecure website. • Newspaper front pages. • Guest speaker Seqwater or Veolia Urban Utilities.

NOTE: All activities in the following sample Lesson Plans can be adapted and used as Enquiry-Based Experimental Activities.

Lets Get The Facts Lesson 1: Desalination 1

Lesson Overview:

Students explore data related to water use, population growth and other factors through graphic organisers. Prior knowledge is determined while providing context for further learning about water management and associated technology.

Learning outcomes:

Students will be able to:

• Identify ways water is used in the community (past and present). • Investigate how the use of water has changed over time. • Identify water related trends and events (i.e. droughts and floods). • Represent trends graphically.

Teacher/ presenter preparation:

• Visual stimuli (water use images and video, including drought, people using water, industry, agriculture, indigenous water use, the ocean etc.)

• Concept mapping software such as Inspiration http://www.inspiration.com.

• Resource Sheet 2: Get the Facts!

• WaterSecure Fact sheet: A new source of pure water http://www.watersecure.com.au/images/stories/factsheets/Corporate_profile.pdf

Lesson steps:

1. Display the word ‘WATER’ and a series of visual stimuli (examples given on Resource Sheet 1). Using the ‘Think, Pair, Share’ strategy, students write down five things they know about water, followed by five ways water is used. (Encourage students to consider non-domestic sources of water use).

2. As a class, incorporate the shared ideas on a concept map.

3. Students produce their own concept map, manually or electronically.

4. Using Resource Sheet 2: Get the Facts! students complete the CLOZE activities.

5. Students analyse, sort and graphically represent key findings using the data provided (manually or electronically). Students provide a written explanation of their findings.

Let’s get the facts Lesson 1 - Desalination

Grade 7


Closure and check for understanding:

• How can we manage water for the future? What do we need to consider? • How has water usage changed over time? • Discuss the visual stimuli. How do they relate to water usage and water management?

Assessment:

Homework task: Students conduct an interview with an adult to discover how the adult used water when they were 12 years old and how they think water will be used and managed in the future. Students should note how water use has changed over time.

Formative: Using water related visual stimuli, students write a brief persuasive paragraph.

Curriculum links: Geography: Environmental Processes and their human significance:

• Weather and rainfall. • Water resource management. • Weather hazards.

Human characteristics of places: • Population and population change.

Science: Nature of science:

• Different cultural groups have different perspectives on science. Cross Curriculum Links: Mathematics. English. ICTs. Aboriginal and Torres Strait Islander histories and cultures:

• Country/ Place: OI.2, OI.3.

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4. The table below shows the population and predicted population (pop’n) for three Queensland regions for the years 2011, 2021 and 2031. It also shows the proportion of all the people in Queensland that live in that region (%). Looking at the table below, add up each column to give the total Queensland population in 2011, 2021 and 2031. Write the totals in the yellow boxes.

(Source: http://www.oesr.qld.gov.au/products/publications/qld-future-population/qld-future-population.pdf)

5. What was the population for the South East Queensland region in 2011?

________________________________________________________________________________

6. What will the population be for the South East Queensland region in 2031?

________________________________________________________________________________

7. How many more people will be living in South East Queensland in 2031 than are living there in 2011?

________________________________________________________________________________

A Changing Climate – How will climate change influence the way we use and manage water? (Reference: Climate Change in the South East Queensland Region, Climate Q: Towards a Greener Queensland, Queensland Government).

8. In the last 10 years, the average temperature in South East Queensland has increased from 19.4 °C to 19.8 °C. It is predicted that by 2070, the temperature in South East Queensland will further increase by up to 4°C. How could an increase in temperature influence the water cycle process?

________________________________________________________________________________

________________________________________________________________________________

9. Over the past 10 years, 16 per cent less rain has fallen in South East Queensland compared with the previous 30 years. If rainfall was to continue to decrease in the future, what could you do to conserve water? What technologies could be used to conserve water or secure sufficient water supplies? ________________________________________________________________________________

________________________________________________________________________________

2011 2021 2031

Region Pop’n % Pop’n % Pop’n %

South East Queensland 3,026,913 66.3 3,678,138 67.1 4,243,837 67.6

Eastern Regional Queensland 1,464,987 32.1 1,724,593 31.5 1,950,872 31.1

Western Regional Queensland 75,805 1.7 75,977 1.4 79,168 1.3

Queensland 100 100 100

Desalination – A Global Phenomenon Lesson 2 – Desalination 8

Lesson Overview:

Through individual research and mapping students investigate where desalinated water is being utilised both in Australia and worldwide.

Learning outcomes:


• Recall the locations of existing or planned desalination plants within Australia and map accordingly.

• Explain why desalination was chosen to supply water in these locations. • Recall a country outside of Australia that uses desalinated water, why they chose desalination

and what the desalinated water is used for.


Desalination in Queensland: There are at least twenty desalination plants in Queensland, including five on the Torres Strait Islands and one on Hamilton Island. There is also a desalination plant at Dalby on the Darling Downs that treats groundwater.

Desalination in Australia: Desalination plants are currently operating or under construction in Binningup (WA), Kurnell (NSW), Port Stanvac (SA) and Wonthaggi (Vic). All are reverse osmosis plants that use seawater.

Around the World: Desalination is also used in the locations below, all of these plants use seawater except Texas (groundwater) and Arizona (irrigation runoff).

• Abu Dhabi • Aruba (Caribbean) • Cyprus • Gibraltar • Israel • Saudi Arabia • Singapore • Trinidad/Tobago • California (USA) • Texas (USA) • Arizona (USA) • Tampa

Desalination is also commonly used on cruise ships and submarines.

Desalination – A Global Phenomenon Lesson 2 - Desalination

Grade 7


Lesson steps:

1. As a homework task, students research existing desalination plants in Australia.

2. Students map the locations of desalination plants on individual outline maps of Australia to provide context.

3. The information gathered by the students is collated on a large Australia class map for a classroom display.

4. The teacher facilitates a class discussion regarding the locations of the desalination plants, the reasons why desalinated water is necessary at each location and what the water is used for. Students can investigate if other regions could utilise desalinated water or if desalinated water could be used in other applications (to provide scaffolding for future lessons).

5. Using the mini-research card provided on Resource Sheet 1, students summarise details of one of the desalination plants in Australia. The research cards are then placed on the class map at their corresponding location. Additional research questions can be extended as necessary.


• What is desalinated water? Where is the water sourced from (i.e. is all desalinated water sourced from the ocean)?

• Currently how many desalination plants does Australia have? Do they all supply water for ‘drinking’?

• Is desalination a new technology? • Where else is desalination happening in the world?

Assessment:

• Formative: Completion of the mini-research card. • Students could research a desalination plant from around the world and complete another

mini-research card for these examples to add to a world map.


Curriculum links:

Geography:

Environmental Processes and their human significance:

• Weather and rainfall. • Weather resource management. • Hydrologic cycle

Science:

Science Understanding:

• Oceans and atmosphere: Characteristics of the ocean and atmosphere that relate to weather and climate, including the water cycle.

Science as a Human Endeavour:

• Nature of science: Different cultural groups have different perspective on science. • Scientists from Australia and elsewhere make major contributions to scientific

knowledge, engineering and technology.

Cross Curriculum Links:

Mathematics.

English.

Aboriginal and Torres Strait Islander histories and cultures:

• Country/ Place: OI.3.


Resource Sheet 1: Mini- research card

The name of the desalination plant is____________________________

It is located __________________________________________________

When was it opened? _______________________

How much water can the plant produce a day or what is its capacity? _______________________megalitres

What is a mega litre?

An interesting fact about this plant ______________________________________________________________________________________________________________________________________________________

____________________________________________

Extension: List the processes used to desalinate water

Mini-research card

The name of the desalination plant is ____________________________

It is located __________________________________________________

When was it opened? _______________________

How much water can the plant produce a day or what is its capacity? _______________________megalitres

What is a mega litre?

An interesting fact about this plant ______________________________________________________________________________________________________________________________________________________

____________________________________________

Extension: List the processes used to desalinate water

Mini-research card

Decoding Desalination Lesson 3 – Desalination 1

Lesson Overview:

This lesson introduces students to the processes and technologies used to produce desalinated water.

Learning outcomes:


• Recall and label the basic steps in a desalination plant. • Provide definitions for key words associated with desalination.


• Desalination Process Flow Chart

• Interactive Virtual Tour: Gold Coast Desalination Plant: http://www.watersecure.com.au/site-tour-and-education/interactive-virtual-tour

• Interactive Virtual Tour – Follow Up Activities: http://www.watersecure.com.au/images/stories/virtual_tours/20110106_Teacher_activities_desalination.pdf

• WaterSecure Fact Sheet: Desalination – fresh water from the sea: http://www.watersecure.com.au/images/stories/factsheets/watersecure_factsheet_desalination_web.pdf

• WaterSecure website: http://www.watersecure.com.au/

• Optional - Tour of the Gold Coast Desalination Plant

Decoding Desalination Lesson 3 - Desalination

Grade 7


Lesson steps:

1. Using the factsheet ‘Desalination- fresh water from the sea’ and the interactive virtual tour, students are introduced to the key stages of the desalination process.

2. Students use the template on Resource Sheet 1 to start a Desalination Dictionary to demonstrate understanding of the key terms, words and their meanings. Additional words should be added.

3. Students use Resource Sheet 2 to complete the flow chart of the desalination process.

4. Using the factsheet ‘Desalination- fresh water from the sea’, students fill in the gaps on Resource Sheet 3.

Extension activity:

• Students use the virtual tour of the desalination plant and their flow diagrams to construct a 3D model of the desalination plant.


• How do we remove the salt from the seawater? • What happens to the desalinated water after it leaves the desalination plant? • What happens to the brine? • How many megalitres can the Gold Coast Desalination Plant produce at full capacity?

Assessment:

Formative: Students complete their Desalination Dictionary, and can recall the pathways of the water via their flow diagram and/or model.


Curriculum links:

Geography:


• Water resource management.

Science:

Science inquiry skills:

• Investigation methods: Collaboratively and individually conduct a range of investigations, modelling, field studies, survey, information research and using data from secondary sources.

Science as a Human Endeavour:

• Scientists from Australia and elsewhere make major contributions to scientific knowledge, engineering and technology.


Technology.

English

ICTs.


Resource Sheet 1: The Desalination Dictionary

Desalination Dictionary

Word

Meaning

What part of the desalination process

is this associated with?

Brine Example: Highly saline water

Outlet pipe

Desalination

Diffusers

Potable water

Freshwater

Minerals

Inlet

Outlet

Sea water

Reverse osmosis

Filtration

Membrane

Renewable energy


Resource Sheet 2: Stages of the Desalination Process

Teacher’s copy


Resource Sheet 2: Stages of the Desalination Process

Task: Using the Water Secure fact sheet – Fresh Water from the Sea fill in the gaps on the following flow chart.


Resource Sheet 3: Fill in the Gaps!

Task: Using the factsheet Desalination – fresh water from the sea, fill in the gaps to complete the stages of the desalination process. Add any new words to your Desalination Dictionary.

Stages of the desalination process

1. Seawater is drawn from the ocean through a submerged _______________ tunnel to the

plant.

2. Pre-________________ involves micro- filtering particles from seawater, and adding

______________ to control the build up of ____________ in pipelines and tanks.

3. Reverse ________________ forces seawater through layers of ________________ to remove

salt and minerals. Concentrated __________ water is separated and returned to the

___________.

4. ________- treatment involves stabilising the water with small amounts of carbon dioxide, then

___________ for disinfection.

5. Desalinated water is blended with other ___________ water supplies and joins south-east

Queensland’s water ___________ to supply homes and _____________.

6. The Gold Coast _____________________ Plant can produce up to 133 _____________ of pure

water a day. The plant can be operated at zero, _______ %, 66% and 100% capacity

depending on demand.

7. The unused seawater (about ________ %), containing dissolved salts and ______________ is

returned to the ocean via an _______________ tunnel, and dispersed 1.2 kilometres out to sea

in water approximately _______ metres deep.

8. The salty concentrated water, called ___________, is released thought a pipeline containing

eight ________________ heads. The brine mixes with the surrounding seawater and is

_________________ by strong tidal currents.

Desalination Experimentation Lesson 4 – Desalination 1

Lesson steps:

1. Revisit or introduce key desalination terms and processes, including osmosis, reverse osmosis, filtration and dilution to foster a deeper understanding of the concepts. Introduce terms such as semi-permeable membrane, high and low concentrations, diffusion. Students can add these terms to their Desalination dictionary.

2. In small groups, students undertake either the egg or the potato osmosis experiment

3. The Predict Observe Explain (POE) strategy can be adopted- refer to Resource Sheet 1.

4. Students are provided with the Experiment Procedure (Resource Sheet 2) and the importance of fair testing is discussed.


• What processes of desalinating water did we model? • Which experiment was the most enjoyable and why? • What were the results from the experiments?

Extension: Students research and design their own experiment to demonstrate one of the processes used during the desalination process.

Lesson Overview: This lesson introduces students to the processes and technologies used to produce desalinated water through a series of classroom experiments.

Learning outcomes: Students will be able to:

• Understand a number of scientific processes and how these are utilised at the desalination plant.

• Undertake classroom experiments and record observations and data.


• Desalination Process Flow Chart

• Interactive virtual tour: Gold Coast Desalination Plant http://www.watersecure.com.au/site-tour-and-education/interactive-virtual-tour

Desalination Experimentation Lesson 4 - Desalination

Grade 7


Assessment: Summative: Students write up their own experiment sheets

Curriculum links:

Science:

Science inquiry skills:

• Formulate scientific questions to investigate and make predictions based on prior observations and scientific knowledge.

• Investigation methods: Collaboratively and individually conduct a range of investigations, modelling, field studies, survey, information research and using data from secondary sources.

• Using equipment: use some specialized equipment and materials safely and identify and minimize risk to self and others.

• Observing and measuring: Collect and record data, making observations and measurement with accuracy appropriate to the task, using ICT where appropriate.

• Developing explanations: Summarise and explain data, using scientific understanding to draw conclusions.

• Evaluating evidence: evaluate claims from a scientific perspective, including using real findings.

Science Understanding:

• Separating substances: separation techniques based on the physical properties of matter and how they are used to extract useful substances.


Resource Sheet 1: Predict, Observe, Explain (POE) Strategy

Experiment Process ____________________________

Predict

What equipment do you need?

What did you do? (Procedure)


What did you observe? (What happened)

Explain

Draw what happened


Experiment Process – Modelling Desalination using solar still

What you will need:

• A 2 litre PET plastic bottle • Small glass or plastic container

without a lid that can fit inside the bottle • Salty water • Scissors

What to do:

1. Half fill a small glass with salty water. Make sure the outside of the glass is clean. 2. Cut the PET bottle in half (about 10cm from the bottom). 3. Place the small container into the bottom half of the PET bottle. 4. Squeeze the top half of the bottle back onto the bottom, so that the top sits just inside the

base. 5. Leave the bottle out in the sun. 6. After an hour or two, check what has happened.

Teacher’s Notes:

The PET bottle is acting as a solar still. Solar stills collect and purify salty water using the sun's energy.

The sun's heat makes the water evaporate, becoming water vapour in the air. The water vapour rises, and when it touches the plastic, it turns back into liquid water. It then drips down into the bottle – your collector.

The impurities in the water do not evaporate and are left behind. (Don't drink the water that you have collected as the purification process is not perfect).

Source: http://www.csiro.au/helix/sciencemail/activities/WaterPurifier.htm


Experiment Process – Modelling Osmosis with Eggs

What you will need:

• Two raw eggs • Measuring cup • 1 litre of vinegar • Spoon • 2 small bowls • Salt • 1 large bowl • Water • 1 jug • Ruler or tape measure

Procedure:

Day 1

1. Place eggs in the large bowl. 2. Completely cover the eggs with vinegar. The eggs will start to bubble. 3. Leave eggs overnight. 4. Create a saturated salt solution; in a jug dissolve as much salt as you can into 500ml water.

Keep adding salt until a few salt crystals are left on the bottom that will not dissolve.

Day 2

1. The eggs should be soft and squishy. Remove from the vinegar and gently brush any remaining shell off the egg until you can see the yolk through the membrane (be very careful handling the egg, remember it is raw).

2. Carefully measure each egg. 3. Carefully put one egg into each of the small bowls. 4. Gently cover one of the eggs with fresh water. 5. Cover the other egg with the salt solution from the jug. 6. Leave both eggs overnight. Measure the eggs again. Have they changed size?

Teacher’s Notes:

Egg shells contain calcium carbonate (CaCO3); the active ingredient in vinegar is acetic acid (CH3COOH). When these chemicals react together you end up with a salt called calcium ethanoate, some water and bubbly carbon dioxide gas.

This chemical reaction dissolves the egg shell and reveals the membrane. The membrane is 'selectively permeable' which means it will let some things through but not others. An egg's membrane will allow small water molecules to pass through but not large salt molecules.

The egg in the salt water should shrink and be noticeably smaller than the egg placed in fresh water. This is a result of osmosis. Osmosis is best defined as the net movement of water molecules across a membrane from an area of lower salt concentration to an area of higher salt concentration until the concentrations are equal. The solution outside the egg in the saltwater is more concentrated so water flows from the dilute solution (inside the egg) to the concentrated solution. The egg in the freshwater has a lower concentration of water; therefore water from the bowl flows across the membrane and the egg expands.

Adapted from: http://www.csiro.au/helix/sciencemail/activities/Eggcellent.html


Experiment Process – Modelling Diffusion

What you will need:

• Teabags • Paper towel • 200mL of warm-hot water

(caution) • Stopwatch

• 200ml of ice cold water • Ruler • 200ml of room temperature water

What to do:

1. Fold the paper towel into quarters. 2. Place a tea bag into the hot water for 15 secs. Remove tea bag from the water and place it

onto the centre of the paper towel for 15 secs. 3. Remove the tea bag and record the diameter of the water stain remaining on the paper towel. 4. Repeat the Steps 2 and 3 using room temperature water and ice cold water 5. Record your observations

Teacher’s Notes:

Diffusion is defined as the movement of a substance from an area of higher concentration to an area of lower concentration. Temperature affects the rate of diffusion through a permeable membrane the same way it does through a tea bag. The size of the water stain should be noticeably greater with the warmer water. The addition of heat to the tea bag causes its molecules to move much faster than at room temperature. This energy is more readily released in a shorter period of time than a tea bag filled with room temperature or cold water.


Experiment Process – Modelling Dilution

What you will need:

• 1 litre of water • 100ml of cordial • 1 measuring cup • Clear container • A bold black and white simple picture

What to do

1. Measure 100ml of cordial and pour it into the clear container. 2. Hold the picture up behind the clear container. Observe and record the colour and the clarity

of the picture. 3. Measure 100ml of water and add it to the cordial concentrate. Repeat Step 2. 4. Repeat Step 3 and then Step 2. 5. Continue until the colour of the solution is diluted.

Teacher’s notes:

To make this experiment more relevant for the unit of work, salt can be used instead of cordial and instead of a black and white picture, salinity can be measured (using a conductivity meter or the like).

Desalination Hits the Headlines! Lesson 5 – Desalination 1

Lesson Overview:

This lesson provides students with the opportunity to culminate learning about desalination by applying their knowledge to produce a front page newspaper article.

Learning outcomes:


• Define the term desalination. • Apply the concepts of desalination. • Identify the benefits of using this technology. • Distinguish the different elements of a newspaper article/front page.


• Collect examples of newspaper articles/front pages

• WaterSecure website: www.watersecure.com.au

• Linking activity –‘ Nature’s Desalinators’ (attached)

Lesson steps:

1. Working in small groups, give each group 6 - 8 different examples of newspapers (front pages).

2. Each group discusses and identifies the key elements of the front page of a newspaper.

3. Key elements are then discussed as a whole class, highlighting the writing genre.

4. Provide students with the journalist’s brief (Resource Sheet 1) and ask students to write down what comes to mind when reading the brief.

5. Discuss the brief as a class to develop ideas.

6. Students then design the front page of a fictional newspaper in response to the journalist’s brief. Students are encouraged to develop fictional characters and realistic fictional ‘water’ events to support their argument.


• What are the key elements of a front-page newspaper article? • What are the benefits of using desalinated water?

Desalination Hits the Headlines! Lesson 5 - Desalination

Grade 7


Assessment:

Summative: Students newspaper front page and article including the planning phases.

Curriculum links:

Geography:


• Weather and rainfall. • Weather resource management. • Weather hazards.

Human characteristics of places:

• Population and population change.


English.

ICTs.

Sustainability

• Futures: OI.8, OI.9.

Linking activity: Nature’s Desalinators’

• Investigate desalination in nature; how do seabirds process salt water; how do mangroves survive the intertidal zone? Mangroves can control their salt levels in 3 different ways:

• Exclusion: some mangroves have features in their roots that act like an ultra filter – effectively desalinating the water by preventing salt molecules from entering the plant.

• Extrusion or secretion: in a process similar to reverse osmosis in desalination plant mangroves remove salt by pumping it to glands on their leaves which excrete the salt.

• Accumulation: some species can tolerate high concentrations of salt in their leaves and other tissues; leaves with excess salt fall from the plant

Suggested activities:

• Research local mangroves – identify what adaptations they use to deal with salt. • What role do mangroves play in the ecology of the environments they live in? • What other adaptations do mangroves have to the intertidal environment?


Resource Sheet 1: Journalist’s Brief

• The year is 2050. • Queensland’s population has increased to nearly 7 million. • Desalinated water is a main water supply in Australia and worldwide. • There are many benefits to using desalinated water. • The Minister for Secure Water Supplies has announced that a search for a suitable site for a

new desalination plant has commenced.

Task: Design the front page of a newspaper that includes an article stating the benefits of using desalinated water

THINGS TO INCLUDE….

• Newspaper name • Headline • Photo or diagram • Statistics and/or the processes involved with desalination • Grab the reader’s attention with an interesting first sentence • First paragraph should answer the following

Who What When Where Why

• The body of your article should then go into detail. Use quotes from people interviewed (you can make these up to support your argument)

• The last paragraph summarises the article. Try ending it will a quote or a catchy phrase.

• At the end of the article state who wrote the article

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Desalination Teaching Unit Grade 7 - PBworks · 2020-07-07 · Desalinated Water – Unit of Work...

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