Waste Water Treatment 1. Fascinating · PDF fileWaste Water Treatment Aim: • To introduce pupils to key facts about waste water Materials: • A copy of Worksheet 1 at the appropriate
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Waste Water Treatment
Aim:
• To introduce pupils to key facts about waste water
Materials:
• A copy of Worksheet 1 at the appropriate level for each pupil
• String
Method:
• Ask pupils to answer the question 'What is sewerage?'
• Hand out Worksheet 1 and read though with pupils
• Discuss the facts and use the string to demonstrate the diameters of the sewers
• The next step is to find out what happens to the waste water
Rain water from the roads, roofs and gardens is known as surface water.
? The more clean water we use, the more dirty waterwe make.
? Waste water is treated by Scottish Water before it is returned to the environment.
? From your home, the dirty water �ushed down the toilet, wash hand basin and kitchen sink all goes down the foul drain. This drain takes the water to the public sewer which takes it to the waste water treatment works.
? Under every road and street there is a network of sewers, pipes and pumps that carry the waste water away.
? Sewers var y from 150mm (6") diameter leaving the house to 2400mm (96 ") for large city trunk sewers.
Fascinating Facts
Sewage is anything which flows through a sewer including bath water, industrial waste and toilet waste
?Waste Water Treatment - Worksheet 1
SavinterWaste Water Treatment - Worksheet 1
F The more clean water we use, the more dirty water we produce.
F So that the natural environment can be protected and to control the possible spread of waterborne diseases, waste water is treated by Scottish Water before it is returned to the environment.
F From your home, the dirty water flushed down the toilet, wash hand basin and kitchen sink all goes into the drain. This drain carries the water through to the public sewer which takes it to the waste water treatment works.
F Underneath every road and street there is a network of sewers, pipes and pumps that carr y waste water to where it can be treated and returned to the environment.
F Sewers var y in diameter from 150mm (6") leaving a house to the 2400mm (96") of large city trunk sewers.
Fascinating Facts
Sewage is anything which flows through a sewer including bath water, industrial waste and toilet waste. Rain water from the roads, roofs and gardens is known assurface water.
1. Preliminary Treatment Screens trap solid items like rags, pieces of wood, paper and other debris. Grit and sand are removed.
2. Primary Treatment Waste water flows into tanks where solids sink to the bottom leaving a solid free liquid which is passed onto the next stage.
3. Secondary Treatment In secondary treatment a biological process is used. The bacteria consume the organic matter leaving the water clean. The resulting water is clean enough to be returned to the river or sea.
In some works additional treatment is carried out to remove phosphates and ammonia.
The solid material left by the treatment process is known as sludge.
The sludge from the treatment process can be treated by de-watering or sludge digestion and recycled to agricultural land or forestry as a fertiliser and soil conditioner. Where this is not practical de-watered sludge may be used for landfill.
Stage 1: Screens trap rubbish. Stage 2: The grit is removed. Stage 3: The water rests in tanks where any large bits of dirt sink to the bottom. Stage 4: Good bugs grow in the tanks. They eat up any dirt that may be left over Stage 5: The waste water is allowed to rest again and the left over bits sink to the bottom of the tank. The bits of dirt that sink to the bottom of the tank are called sludge.This can be treated and recycled to farmland as a fertiliser.
When you use water you make it dirty. We call this waste water.Sometimes you will hear it called sewage.
Waste water from our toilet, wash hand basin and kitchen sink all goes into underground pipes below the house. These pipes join up with pipes from other houses and with pipes from factories offices and pavements.
All these pipes go into larger pipes called sewers. This is where the word sewage come from. The sewers take all the waste to the waste watertreatment works. Even the waste water from toilets can be cleaned there.It goes through different stages.
This is what happens:
Stage 1: Screens trap rubbish like rags, bits of wood and plastic.
Stage 2: The grit is removed so it doesn 't damage the machinery.
Stage 3: The water rests in these tanks where any solids in the water sink to the bottom. The solids make a slimy mud called sludge. The sludge is drawn off into other tanks to be treated and made harmless. It can be used to make the soil better for growing plants orfor burning to make electricity.
Stage 4: Good bugs (bacteria) grow in the tanks. They eat up any waste material which could harm plants and animals.
Stage 5: The water is allowed to rest again. Large stirrers gently mix the liquid and the left over bits sink to the bottom of the tank.
The treated waste water is returned to the environment.
Use the list below to fill in the missing words to tell the waste water treatment story.
bacteria toilet treated bottom
environment factories sewers waste material
pipes waste water rubbish
tanks sludge liquid
Waste water from our t_______, wash hand basin and kitchen sink all goes into underground p_____. These pipes join up with pipes from other houses and with pipes fromf __________ offices and pavements.
All these pipes go into larger pipes called s_______. The sewers take all the w _____ w______ to the waste water treatment works.
Here screens trap r________ like rags, bits of wood and plastic. The water is piped to large t______ where any solids in thel_____ sink to the bottom. The solids make a slimy mud called s_______. This is drawn off into other tanks to be t_______. B _ _ _ _ _ _ _ or good bugs grow in the tanks. They eat any w______ m________ that might harm plants and animals. Large stirrers gently mix the liquid and the left over 'bits' sink to the b________ of the tank. The treated waste water is then returned to the e__________.
Use the list below to fill in the missing words to tell the waste water treatment story.
tank sewers pipes sludge bad
toilet treatment rubbish good waste material
pipes piped bottom animals
Waste water from our t_______, wash hand basin and kitchen sink all goes into underground p_____. These join other p______from factories, offices and pavements.
All these pipes go into larger pipes called s_______.The sewers take all the waste water to the waste watert__________ works.
At the waste water treatment works screens trapr________ like rags. The water is p______ to large tanks where any solid bits sink to the b______. These solid bits make a slimy mud called s________. This is moved to other tanks and made harmless. Good bugs or bacteria are put into the water. The g____ bugs eat any w_______ m_________ that might hurt plants and animals. Large stirrers push any left over bits to the bottomof the t________. The water is then returned to the environment.
1. Put 2 spoonfuls of earth into a jam jar of water. 2. Put the lid on and shake the jar until the water looks dirty. 3. Leave the jam jar and look at it every 15 minutes throughout the day. (Do not shake the jar again)4. Record what happens.
What next?
1. Do the experiments all over again, but this time use your spoon to stir the top of the water very, very slowly. (Do not put your spoon too far into the water)
2. Stir for 5 minutes and record what happens. Make sure you stir very slowly.
Write a short report about your experiment. Try to answer these questions:
1. What did the first experiment achieve?2. What did the second experiment achieve? What was different
about the result?3. Which stage of the waste water treatment process is each
experiment most like?4. Why do you think stirrers are used later on in the waste water
treatment process?
Other things to do:
Look at the diagram of the waste water treatment process. See if you can design an experiment to show how stage 1 of the cleaningprocess works.
- jam jar with a lid- a large spoon- earth- water- timer
How to find out:
1. Put 2 spoonfuls of earth into a jam jar of water.
2. Put the lid on and shake the jar until the water looks dirty.
3. Leave the jam jar and look at it every 15 minutes throughout the day. (Do not shake the jar again)
4. Describe what you see each time you look at the jar.
What next?
1. Do the experiment all over again. This time use your spoon to stir the top of the water very, very slowly. Do not put your spoon too far into the water.
2. Turn the timer to 5 minutes and stir the water.
3. Describe what happens.
Try to answer these questions:
1. What happened to the earth in the first experiment?
2. What was different about the second experiment?
3. Which stage of the waste water treatment process is each experiment most like?
4. Why do you think stirrers are used later on in the waste water treatment process?
The Water Cycle gives us a constant supply of wate r. We take water from the cycle and use it for lots of different purposes.
After we have used it, we clean our waste water and return it to the environment where it becomes part of the whole Water Cycleonce again. If we returned our waste water without cleaning it, water pollution could cause animals and plants to die.
Look at the pictures below. Each one shows a part of the Water Cycle.
Putting our used water back into the environment
What to do:
1. Cut the pictures out and put them in order to show how we take water out of the water cycle, use it and put it back into the cycle.
2. Once you are sure you have the right order , glue them down to make a Water Cyclediagram. Draw arrows to show how the water moves around in the cycle.