Transcript Slide 1

Cities, Rivers, Wastes and Biological Pollution
Rivers and Cities
London
Thames
Rome
Venice
Tiber
Seine
Paris
Hudson
NYC
Rivers and Cities
Dependable Water Supply
Removal of Wastes
History of Water Supply and Biological Pollution
Sumer 2500 B.C.
Irrigation
Aqueducts
Sewers
Water Supply and Sewer Systems
Aqueduct
sewers
waterways
Roman Aqueducts
255 miles of aqueducts
Stone, lined with cement
Water distributed through
lead pipes and logs
144 public
latrines
1 million people
Saturn: the deity of lead
Lead (Plumbum)
Father of all metals
-lead pipes
-lead acetate
sugar of lead
sweetener for wine
Saturnine: an individual whose temperament
has become uniformly gloomy and cynical.
Possible cause of the dementia which
affected Roman Emperors and Citizens.
Caligula, Nero, Commodus, Julius Caesar, Caesar Augustus
Domitian’s Fountain of leaded wine
Possible contributing factor to the Fall of the Roman empire
After the Fall
500 to 1500 A.D.
Neglect of infrastructure
City wells fouled
Diverted Wealth
drinking water hauled in from springs outside the city limits
reduced the population of the city of Rome from its high of over 1 million in
ancient times to considerably less in the medieval era, reaching as low as 30,000
17th to 19th Centurys
Growth of Urban Populations
Deterioration of wells
Cesspools/outhouses
Leaching
Offensive Odor
And taste.
270,000 cubic meters of manure (Paris, 1780)
Graveyards in City Limits
New York’s Trinity Church held
160,000 graves by 1830.
“rank and offensive mold,
mixed with broken bones and
fragments of coffins”
Basil Hall, 1820
Cesspits
“Nearly every residence had a cesspit beneath the floors. In the best of
homes the nauseating stench permeated the most elegant parlor.”
To river or street
When cesspits filled to overflow, they were built to drain to the street by means
of a crudely built culvert to a partially open sewer trench in the center of the street
London's sewers were open ditches sloped slightly to
drain human wastes toward the River Thames
Methanogenesis
c.a. 1850
Cesspits
Night Soil
Methane (CH4)
Anaerobic organisms: Exist in low oxygen
Methanogenesis is the final step in the decay of organic matter under anoxic conditions
CH4 + 2O2 lamps
= CO2 + 2H2O
Southampton, 1849: "Explosions occurred in two separate locations
where the men had the skin peeled off their faces and their hair singed”.
19th Century
The Age of the Toilet
John Harrington
1596
Alexander Cummings
1775
Not widely adopted until the mid to late 1800s
Thomas Crapper
1866
Effectively marketed the toilet
By 1885, Boston had 100,000 toilets and thousands of
miles of pipe carrying wastewater to rivers.
Toilets, Cesspools, Wastes and Rivers
Wastewater to Rivers
1859
Suspension of British Parliament
1861
Typhoid Epidemic
Thames River: mid-1800s
Connected with contaminated water
Disease
Responsible
pathogen
Route of
exposure
Mode of
transmission
Cholera
Vibrio cholerae
bacteria
gastrointestinal
sewage, often
waterborne
Botulism
Clostridium
botulinum bacteria
gastrointestinal
food/water borne; can
grow in food
Typhoid
Salmonella typhi
bacteria
gastrointestinal
water/food borne
Hepatitis A
Hepatitis A virus
gastrointestinal
water/food borne
Dysentery
Shigella dysenteriae
bacteria or
Entamoeba
histolytica amoeba
gastrointestinal
food/water
Cryptosporidiosis
Cryptosporidium
parvum protozoa
gastrointestinal
waterborne; resists
chlorine
Polio
polioviruses
gastrointestinal
exposure to untreated
sewage; may also be
waterborne
Giardia
Giardia lamblia
protozoa
gastrointestinal
waterborne
Diseases
Typhoid
1837, 1860-1865
186,000 people
Typhoid fever is an illness caused by the
bacterium Salmonella Typhi and is transmitted
by ingestion of food or water contaminated with
feces from an infected person
The worst year was 1891, when the typhoid death rate was 174 per 100,000 persons
Cholera
Intestinal disease
Vibrio cholerae
Occurs through ingesting food or water
which is contaminated with cholera vibrios
In its most severe forms, cholera is one
of the most rapidly fatal illnesses known
Shock from dehydration can
occur in 4 to 12 hours
death within 18 hours to several days
8 major outbreaks from 1816 to 1896 affecting mostly Europe and N. America
1852-1860 - Third cholera pandemic mainly affected Russia, with over a million deaths
Treatment: Rehydration Therapy
Intravenous Fluid Therapy 1831
mortality rate of cholera dropped from 70% to 40%
Oral Rehydration Therapy (1960s)
The Indo-Pakistani War of 1971 – mortality rate of 3%
ORT solution contains:
Gatorade
sodium chloride (NaCl)
trisodium citrate dehydrate
potassium chloride (KCl)
anhydrous glucose
Sodium chloride
Citric acid
Potassium phosphate
glucose
Cholera in New York 1832
Croton Aqueduct system
50 miles of aqueduct
3500 New Yorkers killed
Miasma and Night Air
Theory of used to explain the
spread of disease in London and Paris
A poisonous vapor or mist that is filled
with particles from decomposed matter
(miasmata) that could cause illnesses
and is identifiable by its nasty, foul smell
Doors and windows of homes and factories
were sealed shut at sunset.
The Microscopic Revolution
The Microscope
Anton van Leeuwenhoek: first microbiologist
Microorganisms were first identified
In drinking water in 1845.
1880: Pasteur published
book on germ theory
“people had a dreadful
apprehension of breeding
bullfrogs inwardly.”
Revolutionized knowledge of the causes of disease
1880 - 1885
Organisms Discovered
Malaria
typhoid
tuberculosis
diphtheria
cholera
tetanus
Discovery of coliform bacteria
Greatest impact
on municipal water
systems and water treatment.
Theodor Escherich 1886
Most forms of e. coli are harmless
E. coli
1/3 weight of average uninfected human waste
Biological pollution
Total Coliforms
(including fecal coliform
and E. Coli)
Not necessarily a health threat in
itself; it is used to indicate
whether other potentially
harmful bacteria may be present
Coliforms are naturally present in the environment; fecal
coliforms only come from human and animal fecal waste.
Standards based on presence or absence
Freshwater Standard: ~200 units/100 mL
Drinking Water MCL = no more than 5.0% total
samples coliform-positive in a month
Initiation of Water Treatment
Initial Forms of Water Treatment
Suspended Solids
Flocculation
Sand filtration
Flocculation – bringing together of high numbers
of small particles to create larger particles which
settle out of water quickly.
1872 – Poughkeepsie NY was first American
city with a filtered water supply.
- disease mortality declined by 85%
First water treatment: Flocculation
2000 B.C.
Turbidity
Suspended Organic and inorganic
particles
Suspended particles often function as a habitat for microorganisms
Higher turbidity levels are often
associated with higher levels of
viruses, parasites and bacteria.
Flocculation
- charge
Small organic and
Inorganic particles
Al3+
Al3+
Al3+
- charge
- charge
Settling rate of particles is proportional to the square of the diameter
Small particles settle slowly, large particle settle quickly from water
Flocculation
Al3+
Clear Water
Small, Suspended Particles
Flocculated particles
Filtration
Water
particles
Fast
21 m/hour
solids
Clearer
Water
Slow
0.4 m/hour
Physical straining
Physical/ biological straining
Particles larger
than the pore
spaces between the
sand grains are trapped
Particles smaller
than the spaces between
sand grains are trapped
Antagonistic bacteria destroy
Pathogenic bacteria
Drinking Water Treatment
Intakes
Surface Water
Reservoirs
Groundwater
Pretreatment
90 – 99% viruses
screens
Sedimentation
(flocculation)
Filtration
Final Treatment
Disinfection and Fluoridation
Chlorine Gas
Sodium Fluoride (NaF)
Chlorination
Chlorination
• gaseous chlorine
• chlorinated lime
• sodium hypochlorite
• calcium hypochlorite
Common chemical bleaches include household "chlorine bleach",
a solution of approximately 3-6% sodium hypochlorite (NaClO)
A 12% solution is widely used in waterworks for the chlorination of water
and a 15% solution is more commonly used for disinfection of waste water
in treatment plants.
High-test hypochlorite (HTH) is sold for chlorination of swimming pools
and contains approximately 30% calcium hypochlorite.
Chlorine Disinfection
NaOCl = Na+ + OCl-
hypochlorous acid (HOCl) and hypochlorite ion (OCl-).
Low pH
High pH
hypochlorous acid (HOCl)
is responsible for the
disinfecting power.
Low pH favors high levels
of HOCl over OClDestroys cell
enzymes
Penetrates bacterial cell
Bacterial death is rapid
Cholera and Chlorine
The first known uses of chlorine for water disinfection was by John Snow
in 1854, when he attempted to disinfect the Broad Street Pump water supply
public well had been dug only
three feet from an old cesspit
The intersection of Cambridge and Broad Street, up to 500
deaths from Cholera occurred within 10 days
Applied to municipal water systems in 1909
Chlorination
Chlorine is currently employed by over 98 percent
of all U.S. water utilities that disinfect drinking water
End of Lecture 26
2. Aeration Tank Digestion
Activated Sludge Process
Aeration tank
Waste (organics)
Bacteria-rich slurry
From primary treatment
(activated sludge)
4 – 8 hours
Pathogens also removed by antagonistic microbes, temperature, entrapment
bacteria (90% removal)
viruses (80 -99% removal)
1870–1880’s
1890’s
1908
Scientists
demonstrate
that
microorganism
s can cause
disease.
First
application of
chlorine
disinfectants to
water facilities
in England.
First
application of
chlorine
disinfectants to
U.S. municipal
water facilities
in Jersey City
and Chicago.
1918
Over 1,000
U.S. cities
employ
chlorine
disinfection.
1915
First U.S.
drinking
water
bacterial
standard.
1917
Chloramination
first used in the
U.S. and Canada.
1925
Early 1960’s
1970’s
1972
U.S. drinking
water bacterial
standard
becomes more
stringent.
More than
19,000
municipal
water systems
operate
throughout the
U.S.
Chlorine
dioxide begins
to gain
acceptance as
a drinking
water
disinfectant.
Passage of
the U.S.
Clean Water
Act for
restoring and
maintaining
surface water
quality.
Saturn: the deity of lead
Lead (Plumbum)
Father of all metals
-lead pipes
-lead acetate
sugar of lead
sweetener for wine
Saturnine: an individual whose temperament
has become uniformly gloomy and cynical.
Possible cause of the dementia which
affected Roman Emperors and Citizens.
Caligula, Nero, Commodus, Julius Caesar, Caesar Augustus
Domitian’s Fountain of leaded wine
Possible contributing factor to the Fall of the Roman empire