School of Water Sciences
Cranfield University
School of Water Sciences
Look at processes that make
water suitable for drinking or
treat waste water before it is
discharged to rivers and seas
School of Water Sciences
Where do we work?
Cranfield sewage works
Pilot Hall
School of Water Sciences
Where do we work?
Or…Cranfield Labs
School of Water Sciences
Jar Tester
Where do we work?
Or…Placements in the UK
Albert Reservoir,
Halifax
School of Water Sciences
Where do we work?
Or…Placements abroad
Rocky Mountains,
Colorado
School of Water Sciences
Presentation
• Talk about water and pollution.
• Talk about some of the processes used to treat
the water before you drink it.
• Show you some of the processes in action.
School of Water Sciences
Water facts
• 18 million litres provided to 58 million people in the
UK every day
• 2200 Water Treatment Works
• 400,000 km of mains pipework
School of Water Sciences
Why is water important?
It’s Everywhere!
School of Water Sciences
Not all of the water is drinkable
School of Water Sciences
What things pollute water?
– Human waste
School of Water Sciences
What things pollute water?
– Human waste
– Animal waste
School of Water Sciences
What things pollute water?
– Human waste
– Animal waste
– Fertilisers and
pesticides
School of Water Sciences
What things pollute water?
– Human waste
– Animal waste
– Fertilisers and
pesticides
– Chemicals from
industry
– Gases from industry
School of Water Sciences
How do pollutants affect water?
• Taste
• Smell
• Colour
• Health
School of Water Sciences
The Water Cycle
Water
Treatment
Wastewater
Treatment
School of Water Sciences
Contaminants
1. Colour (Organic matter)
2. Particles (Turbidity)
3. Algae
4. Parasites (Cryptosporidium)
5. And more…..
School of Water Sciences
Algae
Microcystis aeruginosa
Blue Green Algae
from Rutland Water
School of Water Sciences
More algae
Asterionella
Stephanodiscus
Microcyctis
Nitzshia
School of Water Sciences
Cryptosporidium Oocysts
• Protozoan parasite found in
man, many other mammals
and also in birds, fish and
reptiles
• Regulation is one oocyst in
10 litres
• Trial of human volunteers(!)
reported that half were
infected by a dose of just 10
oocysts.
School of Water
Sciences
Effects of Cryptosporidium
Symptom
Watery diarrhea
Mean = 12days; median = 9days (1-55d)
Mean = 19/days; median = 12/d (1-90)
Percent
(%)
93
39% recurred after 2 days free of symptoms
Abdominal cramps
Weight loss (median = 10 lb, 1-40 lb)
Fever (median = 38.3°, 37.2°-40.5°)
Vomiting
84
75
57
48
Guerrant, R Emerging Infectious Diseases 3(1):51-57, 1997; MacKenzie et al. A
massive outbreak in Milwaukee of Cryptosporidium infection transmitted through the
public water supply. N Eng J Med 1994;331:161-7.
School of Water Sciences
Colour
Turn river water… …Into Tap Water!
School of Water Sciences
Coagulation and flocculation
Add
and Fast mix
Slowchemicals
Mix
School of Water Sciences
Dissolved Air Flotation
Add air
Clean Water sludge
School of Water Sciences
Filtration
Anthracite
Sand
Gravel
NO!!
But is this safe to drink now?
School of Water Sciences
Disinfection
Chlorine
School of Water Sciences
Questions….
•What % of the worlds population is without safe
drinking water? 25%
•What percentage of the water treated is used for
drinking and cooking? 1%
•You could live for a month without food- how
long could you live without water?
Less than 1 week
•How many tonnes of pollutants pour into lakes
and rivers each day in the US alone? 500
School of Water Sciences
Thank you for listening…..
……Any Questions so far?
School of Water Sciences