EESA10H3 Chapter Notes - Chapter L#3: Fecal Coliform, Osmosis, Bottled Water

72 views3 pages
LECTURE #3
CHAPTER 7 (pg 303-309)
Public Water Supplies
- Pathogens and chemical contaminants are of biggest concern
- Many large cities rely on water form surface sources, as well as a surplus to sustain
them through dry period (eg. Use lake)
- Smaller communities rely
on groundwater sources 
require less filtering and
treatment b/c
groundwater is naturally
filtered through the soil
(though there are
measures taken to remove
nitrates from the water)
Lead Pipe in Drinking Water
Distribution System
- lead damages cognitive
functioning  gradually
many lead water pipes
have been replaced w/
copper or plastic pipes
Basic Treatment of Drinking Water
- Let large particles settle by gravity  tiny particles of clay/silt remain suspended in the
water (turbidity is concern b/c they can harbor pathogens)  coagulation and
flocculation; add aluminum sulfate to neutralize the –ve charges of these particles and
form clumps called flocssedimentation allows for the flocs to settle out by gravity
(create sludge like the first step)  the sludge is discharged into the sewer system while
the water is then filtered through sand filter (trickles gently through a bed of sand
driven by gravity) –
Disinfection of Drinking Water
- Chlorination is very effective against bacteria, but not very effective against viruses and
protozoa (use disinfection using ozone for G. lamblia and C. parvum)
- Residual chlorine is deliberately left in the water as it leaves the treatment plant  this
ensure that the water is disinfected throughout the distribution system
However: residual chlorine in older pipes can react w/ organic matter itn eh water  eg.
Decomposition of leaves can create organic compounds called disinfection byproducts
(DBPs) like trihalomethanes (THMs) (eg. Chloroform); association between chronic
exposure and bladder cancer
Fluoridation of Drinking Water
-Fluoridation programs aim to achieve fluoride conc of 0.7-1.2 mg/L
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

Document Summary

Pathogens and chemical contaminants are of biggest concern. Many large cities rely on water form surface sources, as well as a surplus to sustain them through dry period (eg. use lake) Smaller communities rely on groundwater sources require less filtering and treatment b/c groundwater is naturally filtered through the soil (though there are measures taken to remove nitrates from the water) Distribution system lead damages cognitive functioning gradually many lead water pipes have been replaced w/ copper or plastic pipes. Chlorination is very effective against bacteria, but not very effective against viruses and protozoa (use disinfection using ozone for g. lamblia and c. parvum) Residual chlorine is deliberately left in the water as it leaves the treatment plant this ensure that the water is disinfected throughout the distribution system. Fluoridation programs aim to achieve fluoride conc of 0. 7-1. 2 mg/l. When fluorine is at high levels causes fluorosis (disfiguring of the teeth)

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related Documents