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QUIZ 5 IS DUE 11 DECEMBER EXAM 3 WILL BE HELD ON 10 DECEMBER TERM PROJECT IS DUE 10 DECEMBER - TURN IN IN CLASS (NOT LATER) . A Plan to Power 100 Percent of the Planet with Renewables ( Preview )
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QUIZ 5 IS DUE 11 DECEMBER EXAM 3 WILL BE HELD ON 10 DECEMBER TERM PROJECT IS DUE 10 DECEMBER - TURN IN IN CLASS (NOT LATER)
A Plan to Power 100 Percent of the Planet with Renewables ( Preview ) Wind, water and solar technologies can provide 100 percent of the world's energy, eliminating all fossil fuels.
Environmental issues – Will we mess up the planet with all this “bio” stuff?
Things we need to worry about • Forest land (and other landscapes) • Wildlife • Water quality • Biodiversity • Climate change • Toxic air and water emissions • Toxic chemicals
Environmental issues – Toxic Chemicals • Trace elements – metals • Persistent Organic Pollutants (POPs)
Trace Elements • 10 of 89 naturally occurring elements make up approximately 99% of the earth’s crust by weight • The other 79 make up the rest and are referred to as trace elements. • The trace elements are very important in many biological and industrial applications. • Oxygen 49.2 • Silicon 25.7 • Aluminum 7.5 • Iron 4.7 • Calcium 3.4 • Sodium 2.6 • Potassium 2.4 • Magnesium 1.9 • Hydrogen 0.9 • Titanium 0.6
Heavy Metals • Most common trace element accumulations is in heavy metals. • Lead • Mercury • Zinc • Copper • Arsenic • Cadmium • Some are essential for biological processes in trace quantities, but are toxic at higher concentrations. • Metals never go away
Sources, Reservoirs, and Pathways Source: TRACE ELEMENTS AND CONTAMINANTS, Navratil and Minarik.
Sources Of Trace Element Contamination • Mining, smelting, and industrial processing of metals and ores. • Coal combustion • Vehicles • Chemical industry
Heavy Metal Production And Emissions Source: 1998. World Resources 1998-99: Environmental change and human health.
Emissions of Trace Metals Gg is a giga (109) gram which is 1000 metric tons
Persistent Organic Pollutants (POPs) • Compounds can remain in environment for months or years. • Typically have low water solubility and high lipid (fats) solubility. • Accumulations in fatty tissues in living organisms. • Can lead to bioaccumulation.
Persistent Organic Pollutants (POPs) • Pesticides - DDT • Polychlorinated Biphenyls - PCBs • Poly Aromatic Hydrocarbons - PAHs • Benzene, Toluene, and Xylene – BTEX • Dioxins – TCDD • Adsorbable Organic Halides - AOXs
2001 STOCKHOLM CONVENTION ON PERSISTENT ORGANIC POLLUTANTS (POPs) • The Stockholm Convention is a global treaty to protect human health and the environment from persistent organic pollutants (POPs). • One goal is to eliminate production and use of • Aldrin1 • Chlordane1 • DDT1 • Dieldrin1 • Endrin1 • Heptachlor1 • Hexachlorbenzene1,2,3 • Mirex1 • Toxaphene1 • PCB’s2,3 • Chlorinated dioxins3 • Chlorinated furans3 1 Pesticide, 2 Industrial Chemical, 3 Byproduct
PCB Production Source: Hellweger et al., 2003
Dioxin • Viktor Yushchenko: • President – Ukraine • Dioxin Poster Child “Most Toxic Synthetic Chemical Known To Man” ???
Dioxin has impacted at least two major industries: Pulp and paper – elimination of chorine bleaching Municipal waste combustion – halted new construction
Bleaching Chemicals • Prior to 1995 – Chlorine (Cl2) would have been at the top of the list • Chlorine was effective and cheap but it had one BIG problem DIOXIN
WHAT IS DIOXIN? Furan Dioxin Dioxin Precursors
CHLORINATED DIOXINS • Any process that uses chlorine can change or generate chlorinated dioxins and furans • Some chlorinated dioxin have been described as “most toxic substance known” • In some laboratory animals, very small doses can cause death • In human exposure, some studies have shown link with cancer, others were not able to link exposure to cancer
Chlorinated Compounds • Chlorinated Dioxin (2,3,7,8 TCDD) • Chlorinated Furan (2,3,7,8 TCDF)
Some Background • 1950-1980 • Industrial accidents in W. Virginia and Seveso Italy exposed workers to significant levels of dioxin. • Dow, Monsanto, and six other chemical firms settled with Vietnam War Vets exposed to agent orange for $180 million (dioxin implicated). • Dioxin labeled “most toxic synthetic chemical known to man” • Dioxin found in Times Beach and Love Canal. • 1985 - Dioxin found in Androskoggin river - near a pulp mill
How Bad Is Dioxin?“Most Toxic Synthetic Chemical Known To Man” Acute toxicity of TCDD in experimental animals is ascertained on the basis of the LD50 : the dose (in micrograms per kilogram of body weight) that kills half of a test group.
IF DIOXIN WAS AS TOXIC FOR HUMANS AS IT IS FOR GUINEA PIGS – HOW MUCH OF THIS NASTY STUFF WOULD IT TAKE TO KILL YOU?
How Bad Is Dioxin?“Most Toxic Synthetic Chemical Known To Man” Lipophilic – “Fat Loving”. Concentrates in the food chain
How Bad Is Dioxin?“Most Toxic Synthetic Chemical Known To Man” Lipophilic – Ends up in meat and especially fish TEQ ppt – Total equivalent (dioxin level) part per trillion
How Bad Is Dioxin?“Most Toxic Synthetic Chemical Known To Man” Ingestion of dioxin from typical American diet pg – picogram – 0.000000000001 grams
How Bad Is Dioxin?“Most Toxic Synthetic Chemical Known To Man” • Significant exposure of humans to dioxin have resulted in chloracne - a fairly serious skin condition
How Did the Paper Industry Deal With The Crisis? $ $ Billions
Major Process Changes To Eliminate Dioxin In Pulp Mill Effluent • Add oxygen pulping • After kraft digester and before bleaching • Effluent from O2 goes back to pulp mill recovery • Replace Chlorine (Cl2) with Chlorine Dioxide (ClO2) throughout the bleach sequence
US Annual Release Of DioxinToday Total Release = 40, 134 grams (40 kg)
DIOXIN IN PRODUCTS Food contact paper has dioxin levels less than 2 ppt. Industry - FDA goal. One In A Million Risk - 400 miles of air travel 60 miles of travel by car 3/4 of a cigarette 1-1/2 minutes of rock climbing 20 minutes of being a man aged 60
How Bad Is Dioxin? • Cancer: Maybe • Herbicide exposure - yes • Significant dioxin exposure - no (chloracne) • Immune System • Suppressor • Stimulant • 1994 EPA Report: • “Human studies demonstrate that exposure to dioxin and related compounds is associated with subtle biochemical and biological effects whose clinical significance is yet unknown and with chloracne.
Environmental Dioxin Levels Source: C3.org
Human Dioxin Levels Source: C3.org
The Seattle Time 28 September 2008 Dioxin in soil? South Park takes finding in stride Paul Marshall stands Sunday in front of the home that he has been renting for about a year in the South Park area. The former asphalt plant nearby and the neighborhood around it was found to contain high levels of dioxin.
Emissions • Anything that goes into the environment we would rather not. • Atmospheric • Water
Major atmospheric emissions from a that may come from biorefineries • Sulfur dioxide – SO2 • Nitrogen oxides - NOx • Particulates • Reduced sulfur compounds • CO2?????
3 April 2007 Supreme Court Decision Justices Say E.P.A. Has Power to Act on Harmful Gases The Environmental Protection Agency has the authority to regulate heat-trapping gases in automobile emissions. The court further ruled that the agency could not sidestep its authority to regulate the greenhouse gases that contribute to global climate change unless it could provide a scientific basis for its refusal.
Sulfur dioxide – SO2 • Where does it come from: burning compounds that have sulfur in them. • Recall we need to use sulfur in kraft pulping • What is the hazard • Respiratory illness • Children and the elderly. • Acid rain • SO2 can be transported large distances by wind
Nitrogen Oxides - NOx • Where does it come from: Any combustion process. • Largest source is cars and trucks • What is the hazard • Catalyze formation of ozone • Serious respiratory problems. • Smog • Acid rain • Water quality • NOx can be transported large distances
Particulates • Where does it come from: Any combustion process. • What is the hazard • Serious respiratory problems. • Haze • Soil quality • Erosion of buildings and monuments
Reduced Sulfur Compounds • Where does it come from: Incomplete combustion with sulfur present • What are they • Hydrogen Sulfide H2S (rotten egg smell) • Methyl Mercaptan CH3SH • Goes into natural gas to make it smell - safety • What is the hazard • Very toxic chemicals at higher concentrations. • Very strong smell • You can smell it at about 1 ppb (part per billion) • Emission Target 2-5 ppb