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Organic Chemicals and Water

Organic Chemicals and Water. Synthetic Organic Chemicals. Principally Carbon, Hydrogen and Oxygen. Organochlorines. Dioxins Pesticides. Dioxin. Chlordane. PCBs. Cleaning agents. DDT. PBDE. Flame Retardants. Potential Toxicity. July November. 2004. Viktor Yushchenko

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Organic Chemicals and Water

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  1. Organic Chemicals and Water

  2. Synthetic Organic Chemicals Principally Carbon, Hydrogen and Oxygen Organochlorines Dioxins Pesticides Dioxin Chlordane PCBs Cleaning agents DDT PBDE Flame Retardants

  3. Potential Toxicity July November 2004 Viktor Yushchenko Ukrainian President 6,000 times the usual concentration in his body the second highest dioxin level ever measured in a human

  4. Water Solubility Organochlorines as well as many other synthetic organic compounds are poorly soluble in water

  5. NaCl Na+ + Cl- Na+

  6. Dioxin

  7. 0.2 µg/L Dioxin PCB 10-31 µg/L (50% Cl) Sodium Chloride 350 g/L Potassium Chloride 280 g/L Ionic compounds are about 1 billion times more water soluble than neutral organics

  8. Hexane Improving Solubility Organic Solvents Soap/detergents Structural/chemical similarity between the chemical and the solvent.

  9. Lipids and Solubility Structural/chemical similarity between the chemical and the solvent.

  10. Solubility A chemical’s solubility in lipids is inversely proportional to its solubility in water. Lipid (Carbon/hydrogen) Carbon/hydrogen water

  11. Toxaphene Biomagnification Seawater 0.0003 ppb Arctic cod muscle 14 - 46 ppb Narwhal blubber 2440 - 9160 ppb BAF = 8 million

  12. What’s been done?

  13. PCBs used extensively in electrical equipment, especially transformers Solubility: 10-31 µg/L PCBs, valued for chemical stability and fire resistance, were manufactured and processed primarily for use as insulating fluids and coolants in electrical equipment and machinery from 1929-1977. Electrical equipment plasticizers inpaints, plastics and rubber products pigments, dyes andcarbonless copy paper PCBs were “banned” in 1979

  14. [EPA press release - April 19, 1979] The Environmental Protection Agency today issued final regulations banning the manufacture of polychlorinated biphenyls (PCBs) and phasing out most PCB uses. PCBs are toxic and persistent chemicals primarily used as insulating fluids in heavy-duty electrical equipment in power plants, industries, and large buildings across the country. The EPA rules will gradually end many industrial uses of PCBs over the next five years, but will allow their continued use in existing enclosed electrical equipment under carefully controlled conditions. EPA estimates that 150 million pounds of PCBs are dispersed throughout the environment, including air and water supplies; an additional 290 million pounds are located in landfills in this country

  15. Spokane River Nov. 2002

  16. Lake Michigan EPA, 2004 N Concentration PCBs µg PCB/Kg sediment

  17. Lake Erie Sediments PCBs EPA, 2004 After 25 years, PCBs continue to persist in the Environment

  18. Persistent Organic Pollutants Poor water solubility High solubility in Lipids and Organic Solvents Potentially long half lives PCB DDT Dioxin

  19. Half Life

  20. ½ Life The time it takes for a chemical to degrade To ½ of its original concentration. Ci ½ Ci time t1/2

  21. ½ Life and Organochlorines PCBs 1 month 2-6 years > 60 years Dioxin 1 - 30 years (7 years in humans) DDT 28 days 15 – 20 years up to 150 years

  22. Environmental Persistence Water Column Solubility of < 0.2 μg/L Short Half life Sediments (longer half-life)

  23. Environmental Persistence, Half Life and Solubility

  24. An Important Organic Solvent: Octanol C8H18O Neutral organic chemicals are soluble in organic solvents

  25. The Octanol-Water Partitioning coefficient C8H18O Octanol and water are immiscible Density: 0.824 g/cm3 C8H18O octanol water

  26. Partitioning Carbon/hydrogen Octanol (Carbon/Hydrogen) water C10H20

  27. separate chemical chemical Add 10 mg chemical 1 L Octanol 1L Water Analyze the water phase for the chemical. Difference between initial amount and amount in water = amount in octanol The ratio between the two yields the Kow

  28. separate chemical chemical Add 10 mg chemical 1 L Octanol 1L Waterl 9.99 mg L 9.99 mg L 0.01 mg L Kow = = 999 0.01 mg L octanol phase Water phase

  29. Kow of some Organochlorine Compounds PCBs 2,000,000 DDT 4,000,000 Dieldrin 158,000 Toxaphene 316,000

  30. Environmental Persistence Water Column Solubility of < 0.2 μg/L Short Half life Sediments (Carbon)

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