Transcript Water Pollution

Water Pollution
Water Pollution
Sources and Examples
Water Quality
Health Effects
Sources
• Two Types: Point sources and nonpoint sources
– Ex: Point: sewage plants; nonpoint: runoff
• Examples of sources:
–
–
–
–
–
–
–
–
–
–
–
Chemicals (metals, solvents, oils)
Air pollution
Microbiological sources
Mining
Noise
Nutrients
Oil spills
Oxygen depleting substances (biodegradable)
Suspended matter
Thermal sources
hormones
Water Quality
1. Cultural Eutrophication: the process by which human activity
increases the amount of nutrients entering surface water.
(nitrogen and phosphorus) nutrients= algae = DEAD ZONES
(oligotrophic = low nutrients Eutrophic= high nutrients)
2. Tests to monitor water quality:
• Nitrogen (Fertilizers)
• Chlorine (disinfects)
• Hardness (usually caused by calcium and magnesium)
• Copper (fertilizers, septic tanks and industrial waste)
• DO (dissolved oxygen) flowing = increase (closer to surface)
• Phosphate: fertilizers
• pH: needs to be close to 7
3. EPA Standards
• Primary: health concerns
• Secondary: aesthetics
We will be testing water on Friday. If
you have water you want to test.
Bring it and we will test it
• Awesome Video
• Infectious diseases
Effects
– Chronic: slowly impairs the function
– Acute: rapidly impairs function
• Spread of disease: epidemic vs. pandemic
– Epidemic: rapid increase of a disease
– Pandemic: the disease spreads to other places
• Toxicology: study of harmful chemicals
– Neurotoxins- disrupt the nervous system ( lead and
mercury)
– Carcinogens: cause cancer (radon, formaldehyde)
– Teratogens: interfere with embryo development
– Allergens: cause an allergic reaction (not pathogens)
– Endocrine disruptors: interfere with normal hormone
function (cleaning products and household goods)
• Biomagnification: the increase of a chemical in animal
tissues as it moves up the food chanin.
What can be done?
• Water treatment
– Septic Tanks: two parts- septic tank and leach
field.
– Sewage treatment plant:
• Primary (reduces oils, includes sand catchers, screens,
and sedimentation)
• Secondary (gets rid of the biological content) includes:
filters, activated sludge, filter (oxidizing) beds, trickling
filter beds, and secondary sedimentation.
• tertiary treatments(final stage before releasing into the
environment. May include: filtration, lagooning,
constructed wetlands, nutrient removal through
biological or chemical precipitation, denitrification
using bacteria, phosphorous removal using bacteria,
microfilration and disinfection using UV, chlorine or
ozone.
– Treatment Methods and remediation technologies
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Adsorption
Disinfection
Filtration
Flocculation
Ion Exchange
Aeration
Air stripping
Bioreactors
Constructed wetlands
Deep-well injections
Enhanced bioremediation
Fluid-vapor extraction
Granulated activated carbon
Hot water flushing
In-well air stripping
phytoremediation
UV oxidation
• Legislation
– Stockholm Convention: (2001): a group of 127
countries gathered in Sweden. 12 chemicals were
banned, phased out or reduced. (the “the dirty
dozen”)
– Clean Water Act: (1972) issued water quality
standards that defined acceptable limits of various
pollutants in US waterways. (Surface water not ground
water)
– Safe Drinking Water Act: (1974, 1986, 1996) sets the
national standards for safe drinking water. (MCL:
maximum contaminant levels)
Noise Pollution
• Causes: Human created sound that disrupts the
environment. (transportation, factories,
appliances, audio entertainment systems)
• Health Effects: hearing loss, cardiovascular
problems, decrease in ability to memorize,
nervousness, pupil dilation, decrease in visual
field, insomnia, bulimia, high blood pressure,
depression, anxiety, and sexual dysfunction.
• Control: noise barriers (trees) and new
technologies.
• Types:
Solid Waste
– Organic: kitchen waste, vegetables, flowers (usually
decomposes in 2 wks ** Wood can take up to 10-15
years)
– Radioactive: spent fuel rods, smoke detectors (100 of
thousands of years)
– Recyclable: paper, glass, metals, and some plastics.
(paper- 10 days, glass- never, metals- 100-500 years,
plastics- some up to 1 million years)
– Soiled: hospital waste (cotton cloth-2-5 months)
– Toxic: paints, chemicals, pesticides (100’s of years.)
• Uses in the US:
• Disposal and Reduction Flow Chart
Solid Waste
• Choices to disposal:
1.
2.
3.
4.
5.
6.
7.
8.
Burning, incineration or energy recovery
Detoxify
Exporting
Land disposal(land fills)
Land disposal (open dumping)
Ocean dumping
Recycling
Reuse