29 Mercury and Organics I

29 Mercury and Organics I - Chemical Pollutants water...

Info iconThis preview shows pages 1–15. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Chemical Pollutants water tables falling by 20 feet per year 21 million backyard tube wells Failure of 246 surface irrigation projects $600 electric pumps (1% of GDP) India 95 % Deeper Wells and Fluoride Naturally occurring element in Granite which dissolves into the groundwater Fluoride concentrations In U.S. tap water 0.5 1.0 mg/L 1.6 to 6.6 mg/day Colorado Brown Stain Dental Fluorosis Intake: Permissible fluoride limit in India is 1.2 mg/L Fluoride levels between 5-25 mg/L have been found Fluoride levels > 1.5 mg/L 9 mg/day to 12 mg/day Fluorosis has risen from 1 million to 25 million and threatens 60 million people in India. Skeletal Fluorosis Intake Fluoride levels > 10 mg/L Bangladesh and Arsenic ranked among the world's 10 poorest countries Bangladesh Prior to 1970s One of the highest infant mortality rates in the world Principally due to waterborne disease. Ineffective water and sewage systems Periodic monsoons and floods cholera, dysentery water-borne pathogens Deaths Due to Surface water contamination: 250,000/yr 12 million hand-operated tube wells deliver water to over 80% of the rural village population Infant mortality and diarrheal illness reduced by 50% Wells in Floodplain and Delta Sediments Water Bearing Muds Natural erosion of arsenic to water-bearing units. Well depths between 20m and 100 m Majority of wells > 50 ppb arsenic Some wells contain 500 - 1000 ppb WHO/U.S limit: 10 ppb Bangladesh limit: 50 ppb Delta and Floodplain Regions Mercury Mercury is naturally occurring The number 1 anthropogenic source is the combustion of coal Enters water bodies principally from the atmosphere (coal, volcanism, rock weathering) 48 tons of elemental mercury to the atmosphere each year. Forms of Mercury The dominant inorganic forms are Hg o and Hg 2+ ....
View Full Document

Page1 / 42

29 Mercury and Organics I - Chemical Pollutants water...

This preview shows document pages 1 - 15. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online