Title: WATER POLLUTION PART I
1WATER POLLUTIONPART I
2NINE TYPES OF WATER POLLUTANTS
- Disease Causing Agents
- Sediment Pollution (suspended solids)
- Inorganic Chemicals and Oxygen-Demanding Wastes
- Organic Chemicals and Oxygen-Demanding Wastes
- Water-Soluble Radioactive Isotopes
- Thermal Pollution
- Genetic Pollution (non-native species)
3DISEASE CAUSING AGENTS
- Bacteria, viruses, protozoa, parasitic worms.
- Waterborne Diseases typhoid, cholera, bacterial
dysentary, polio, and infectious hepatitis. - Cause of Typhoid fever Salmonella typhi bacteria
from food or water or if sewage contaminated with
S. Typhi bacteria gets into the water you use for
drinking or washing food. Typhoid Mary - Cause of Cholera Feces exposure from poor
hygiene and sanitation of food or water. A person
may get cholera by drinking water or eating food
contaminated with the cholera bacterium. - Common in developing nations. Threat following
Katrina in USA!
4DISEASE CAUSING AGENTS
- Pfiesteria piscida Cell from hell
- A microscopic organism that can behave as both a
plant and animal cell. Flips from an algae eater
into a fish-eating dinoflagellate. - Lacks suitable prey to keep population in check.
- Releases neurotoxins that kill fish within 10
hours and the neurotoxins form an aerosol above
the water and can harm humans. - Pfiesteria live in waters from Chesapeake Bay to
Florida. - Scientific research show increased population
growth of Pfiesteria associated with cultural
eutrophication from hog farms. - Joanne Burkholders research was not
well-received from law makers and big business.
Her research indicates that farmers need to
implement nutrient-loading management plans and
that government needs to implement policy and
regulations to limit Pfiesteria outbreaks to
protect human health!
5SEDIMENT POLLUTION
- Sediment Kills Reefs
- Sediment releases into surface waters due to poor
land management decreases water clarity,
increases turbidity, buries organisms, decreases
the availability of light for photosynthesizing
organisms, and brings insoluble toxic pollutants
including PCBs and DDT. - 1.3 million pounds of PCBs in Hudson River from
GE Plant. Must dredge 2.6 million yards! Long
residence time in environment. - DDT banned in the USA for application BUT we are
the 1 producers of DDT for sales worldwide!
Long residence time in environment. DDT
(50years), DDE (200 years).
6INORGANIC CHEMICALS (water-soluble nutrients)
- Heavy metals such as mercury (Hg) and lead (Pb)
from industry, mines, irrigation runoff, oil
drilling, and urban runoff from storm sewers.
(point source and non-point source pollution) - Lead (Pb) additives in gasoline (MTBEs)
contaminate the air. Lead gas banned in the USA
(still available in other parts of the world).
It is also present in incinerator ash. This is
classified as hazardous waste and must be
disposed of in a special landfill. It leaches
into groundwater. Residues can also be found on
food resources located downwind from
incinerators. Lead paints banned in USA, but
can still be found in buildings. - Greatest risk for Pb poisoning are mid-aged men
(high blood pressure), pregnant woman
(miscarriage, premature births and stillbirths),
and young children (mental/physical impairments
hearing loss, hyperactivity, ADD, low IQ, LD).
7INORGANIC CHEMICALS (water-soluble nutrients)
- Mercury (Hg) mostly from industrial processes
(wastewater), also from batteries, paints and
plastics burned in incinerators. Burning
converts it to methyl mercury which readily
enters food webs. - Bioaccumulation in muscle of tuna, shark, and
swordfish. - Biomagnification since they are top predators.
- Long residence time in environment toxic to
humans and causes mental retardation in children
and kidney failure.
8BIOACCUMULATION AND BIOMAGNIFICATION
Biomagnification
9- Nitrogen and phosphorous loading (cultural
eutrophication causes and increase in algae
(bloom) which causes a decrease in DO resulting
in the death of aquatic organisms. Decomposing
aerobic bacteria continue using DO (increase in
BOD) in water until the conditions become Anoxic!
10SEPTIC TANKS
Septic tanks are used in areas where there are no
combined sewers.
Septic tanks (cesspools) must be emptied each
year. Old tanks can crack and leak coliform
bacteria into surrounding soil, groundwater, and
surface waters.
11Figure 9-28Page 196
Septic tank with manhole (for cleanout)
Non-perforated pipe
Household wastewater
Distribution box (optional)
Drain field
Gravel or crushed stone
Vent pipe
Perforated pipe
12SEWAGE TREATMENT
- Sewage treatment means removing impurities so
that the remaining waste water can be safely
returned to the surface waters (river, bay,
ocean) and become part of the natural water cycle
again. - sewage treatment separates solids from liquids
by physical processes and purifies the liquid by
biological and chemical processes
13PRIMARY TREATMENT
- solids like wood, paper, rags and plastic are
removed by screens, washed, dried and taken away
for safe disposal at a licensed waste tip. Grit
and sand, which would damage pumps, are also
removed by settling tanks and disposed of in a
similar way.
14PRIMARY TREATMENT
- the remaining solids are separated from the
liquid by passing the sewage through large
settlement tanks, where most of the solid
material sinks to the bottom. About 70 of solids
settle out at this stage and are referred to as
sludge. The sludge is used on farms after further
treatment called sludge treatment.
15SLUDGE TREATMENT
- Sludge is an excellent soil conditioner and is
used as a fertilizer on farmland. However, it
needs additional treatment to make it suitable.
This treatment is called anaerobic digestion and
takes place in large, enclosed tanks. NYC sludge
has too many heavy metals (Hg, Pb, Cd, Cu) and
may not be used as a soil amendment for food
resources in NY State. - The rate of digestion is increased by heating the
sludge to a temperature where naturally occurring
bacteria (microorganisms) respond to these
comfortable conditions and feed on other
bacteria. On cooling, the well-fed bacteria die
off, and the sludge is suitable for use on
agricultural land. - A by-product of the sludge digestion process is
methane gas. This can be burned to produce
electricity. The electricity can be used to heat
more sludge or to provide heat and light for the
treatment works. Sometimes more energy is
produced than is required. The surplus is sold to
local electric companies.
16SECONDARY TREATMENT
- a biological process which relies on naturally
occurring microorganisms acting to break down
organic material and purify the liquid. - In a simple sewage treatment process,
micro-organisms are encouraged to grow on stones
over which the sewage is trickled. They feed on
the bacteria in the sewage and purify the water.
These treatment units are called percolating
filters.
17SECONDARY TREATMENT
- The rate of this process can be increased by
pumping air into tanks of sewage where the
aerobic digesters float freely and feed on the
bacteria. These treatment units are called
aeration tanks. - Following either form of secondary treatment, the
waste water is settled in tanks to separate the
biological sludge from the purified waste water.
18TERTIARY TREATMENT
- Extra treatment is needed to give the waste water
a final "polish". This is known as tertiary
treatment. Various methods may be used, including
sand filters, reed beds or grass plots
(artificial treatment wetlands). Disinfection,
using ultra violet light to kill bacteria, is
another method, and is being used at a number of
coastal sewage treatment plants.
19Secondary
Primary
Grit chamber
Chlorine disinfection tank
Bar screen
Settling tank
Aeration tank
Settling tank
To river, lake, or ocean
Raw sewage from sewers
(kills bacteria)
Sludge
Activated sludge
Air pump
Sludge digester
Sludge drying bed
Disposed of in landfill or ocean or applied to
cropland, pasture, or rangeland
(Sludge cake or pellets)
20IMPACTS FROM ORGANIC WASTE
8 ppm
Types of organisms
Clean Zone
Recovery Zone
Septic Zone
8 ppm (mg/L)
Dissolved oxygen (ppm)
Decomposition Zone
Clean Zone
Normal clean water organisms (Trout, perch,
bass, mayfly, stonefly)
Biological oxygen demand
Trash fish (carp, gar, leeches)
Fish absent, fungi, sludge worms, bacteria (anaero
bic)
Trash fish (carp, gar, leeches)
Normal clean water organisms (Trout, perch,
bass, mayfly, stonefly)
21WAYS TO REDUCE CULTURAL EUTROPHICATION
- Advanced waste treatment (sewage and industrial)
- Regulate detergents cleaning products for
phosphates. They have been regulated since the
1970s on Long Island! - Promote soil conservation and preservation of
wetlands to capture and filter pollutants before
they enter surface waters. - Regulate fertilizer, pesticide, agricultural and
livestock runoff to control Nitrogen, phosphate,
and PAHs. - Create policies and economic incentives for doing
these things!
22ORGANIC CHEMICALS(Synthetic)
- Pesticides, solvents, industrial chemicals, and
plastics, oil, gasoline, and MTBEs. - Many are hydrocarbons (PAHs) and leach into soil
and groundwater. All of these are toxic to
aquatic organisms. - Standards benzene (1ppb) (DDT)
- MTBE (5 ppb)
- As soon as Clean Air Act Ammendments of 1990 went
into effect, childhood asthma increased as well
as bronchitis, depression, and nuerological
disorders. - Senator Marcellino wants to remove the mandate
for MTBEs. New Hampshire is the only state that
has outlawed MTBEs. - Problematic due to NAFTA violates Article 11
- Oil Spills Exxon Valdez
23EXXON VALDEZ OIL SPIILL
- On March 24, 1989, shortly after midnight, the
oil tanker Exxon Valdez struck Bligh Reef in
Prince William Sound, Alaska, spilling more than
11 million gallons of crude oil. The spill was
the largest in U.S. history. Capt. Joe Hazelwood,
who later admitted to having had several
alcoholic drinks that day, (From Huntington, Long
Island). In jail NOW! - The spill posed threats to the delicate food
chain that supports Prince William Sound's
commercial fishing industry. Also in danger were
ten million migratory shore birds and waterfowl,
hundreds of sea otters, dozens of other species,
such as harbor porpoises and sea lions, and
several varieties of whales. - In the aftermath of the Exxon Valdez incident,
Congress passed the Oil Pollution Act of 1990,
which required the Coast Guard to strengthen its
regulations on oil tank vessels and oil tank
owners and operators. Today, tank hulls provide
better protection against spills resulting from a
similar accident, and communications between
vessel captains and vessel traffic centers have
improved to make for safer sailing.
24OIL SPILLS
- Spills occur at offshore oil drilling rigs during
natural disasters (Katrina) and due to human
error. They are called blowouts - Spills occur from tanker accidents.
- Damage to environment from oil spills is
dependent on type of oil (crude oil most toxic
due to benzene and toluene), weather conditions,
season, and type of organisms in the area. - Oils spill cleanup is difficult and EXPENSIVE.
It is very difficult to save animals who have
ingested the hydrocarbons into their digestive
tracts, especially aquatic birds who preen to
insulate themselves.