Lecture 20 Metals - Major Determinants of Water Quality and...

Info iconThis preview shows pages 1–13. 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
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Major Determinants of Water Quality and the Impact or Availability of Water Pollutants Organisms Solubility Oxygen pH Nutrients (N, P) Metals (Hg, Pb, As) Organic Chemicals (PCBs, Dioxins) Nutrients: Nitrogen and Phosphorus Both are limiting to primary productivity Excess amounts can severely alter ecosystems Availability in the environment is controlled by Oxygen pH Organisms Sources: fertilizers, manures, wastewater discharge Nitrogen Dominant Forms: NH 4 + and NO 3-Forms are controlled by organisms NH 4 + is converted to NO 3-by aerobic bacteria Forms are controlled by Organisms Oxygen pH NO 3-is much more mobile in the environment than NH 4 + the highest density of point sources in the entire St. Johns River. Within this area, the river receives about 30 percent of its total amount of nitrate and ammonia nitrogen and 33 percent of its phosphate As the lower St. Johns River widens downstream of Palatka, the speed of water flow decreases, making the river lake-like and making conditions favorable contaminant accumulation. The roughly 30,000 acres of row crop agriculture in this area of the river basin supplies 40 percent of the spring season inorganic nutrients that enter the river between Palatka and Green Cove Springs . Algae typically peak in this area Large, prolonged high tides can cause water to reverse its flow in the river as far upstream as Lake George. This delays the dispersal of pollutants. St. Johns Wastewater Treatment Agriculture Slow Flow of contaminants Surface Water and Nitrates • residential and commercial septic systems in rural areas • about 300 row crop and vegetable farms • 44 dairies with more than 25,000 animals • 150 poultry operations with more than 38 million birds Lower Suwannee River Watershed Nitrates NO 3 Drinking water standard: 10 ppm Phosphorus Availability and pH Phosphorus Availability and pH Low pH High pH Aluminum and Iron phosphates Calcium Phosphates Insoluble solids There is a limited ability of soils to immobilize phosphorus If the capacity is exceeded, phosphorus becomes mobile Mobile phosphorus can contaminate surface and groundwater Phosphorus loading to S. Florida Ecosystem Inputs North and South of Okeechobee Dairy/Beef Agriculture (EAA) Kissimmee Basin Organic soils possessing high natural fertility Historically flooded Everglades Agricultural Area Under flooded conditions, oxygen levels tend to be low The diffusion of oxygen through water is about 1000 times slower than diffusion through air Water restricts the movement of oxygen Flooded Marsh Anaerobic heterotrophs: live in low-oxygen environments Aquatic Plants and Algae Die Heterotrophic microorganisms decompose tissues Aerobic heterotrophic organisms use oxygen Oxygen becomes depleted in water; it cannot diffuse fast enough to support aerobic heterotrophs Anaerobic heterotrophs become dominant C 6 H 12 O 6 + 3 NO 3-+ 3H 2 O = 6HCO 3-+ 3NH 4 + 1796 kJ C 6 H 12 O 6 + 3 SO 4 2-+ 3H + = 6HCO 3-+ 3HS-453 kJ C 6 H 12 O 6 + 6 O 2 → 6CO 2 + 6H...
View Full Document

This note was uploaded on 07/31/2011 for the course SOS 3022 taught by Professor Staff during the Fall '08 term at University of Florida.

Page1 / 66

Lecture 20 Metals - Major Determinants of Water Quality and...

This preview shows document pages 1 - 13. Sign up to view the full document.

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