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Water Quality and Testing. Water Quality Water quality is the physical, chemical and biological characteristics of water The vast majority of surface.

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Presentation on theme: "Water Quality and Testing. Water Quality Water quality is the physical, chemical and biological characteristics of water The vast majority of surface."— Presentation transcript:

1 Water Quality and Testing

2 Water Quality Water quality is the physical, chemical and biological characteristics of water The vast majority of surface water on the planet is neither potable (fit for drinking) nor toxic Approximately 25% of the world’s population has no access to potable water

3 Water Quality No simple property can tell whether water is polluted or not Industrial pollution is a major cause of water pollution –Also runoff from agricultural areas, urban storm water runoff and discharge of untreated sewage (especially in developing countries).

4 Water Contamination Contaminants that may be in untreated water include: –microorganisms (viruses and bacteria) –inorganic contaminants (salts and metals) –pesticides and herbicides –sediments –organic chemical contaminants from industrial processes and petroleum use –radioactive contaminants. Water quality depends on the local geology and ecosystem, as well as human uses (sewage dispersion, industrial pollution, use of water bodies as a heat sink)

5 Water Regulations The Environmental Protection Agency (EPA) regulates limits on the amount of certain contaminants in the water The Food and Drug Administration (FDA) limits contaminants in bottled water Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of these contaminants does not necessarily indicate that the water poses a health risk.

6 Water Tests Electrical conductivity|Conductivity (also see salinity) Dissolved Oxygen(DO) pH Color of water Turbidity Total suspended solids (TSS) Dissolved metals and salts (sodium, chloride, potassium, calcium, manganese, magnesium) Chemical oxygen demand (COD) Biochemical oxygen demand (BOD) Microorganisms such as fecal coliform bacteria (Escherichia coli), Cryptosporidium, and Giardia lamblia Nutrients, such as nitrogen and phosphorus Dissolved metals and metalloids (lead, Mercury (element),arsenic, etc.) Dissolved organics: Colored Dissolved Organic Matter (CDOM), Dissolved Organic Carbon (DOC) Temperature Pesticides Heavy Metals Pharmaceuticals Hormone analogs

7 Temperature Determine types of organisms that can live in water Affects how much oxygen water can hold –Warm water holds less oxygen Thermal Pollution (increased water temperature) –decreasing oxygen supply –killing fish juveniles which are vulnerable to small increases in temperature –affecting ecosystem composition.

8 Dissolved Oxygen Measure of the amount of oxygen dissolved in water Measurement for outdoor bodies of water –More DO generally relates to “healthier” water (oxygen necessary for most aquatic species to breath) Related to Biochemical Oxygen Demand (BOD) –how fast biological organisms use up oxygen in a body of water

9 pH Potential of Hydrogen – measures hydrogen concentration in water 7.0 is neutral on scale of 0 – 14 Can affect how chemicals dissolve in water Representative pH values SubstancepH Hydrochloric Acid, 10M Lead-acid battery0.5 Gastric acid1.5 – 2.0 Lemon juice2.4 Cola2.5 Vinegar2.9 Orange or apple juice3.5 Tomato Juice4.0 Beer4.5 Acid Rain<5.0 Coffee5.0 Tea or healthy skin5.5 Urine6.0 Milk6.5 Pure Water7.0 Healthy human saliva6.5 – 7.4 Blood7.34 – 7.45 Seawater7.7 – 8.3 Hand soap9.0 – 10.0 Household ammonia11.5 Bleach12.5 Household lye13.5

10 Nutrients Eutrophication, strictly speaking, means an increase in chemical nutrients (typically nitrogen and phosphorus) Resultant increase in primary productivity –excessive plant growth and decay Further impacts, including lack of oxygen and severe reductions in water quality and in fish and other animal populations.

11 Turbidity / Total Suspended Solids Amount of particulate matter in water Related to sediment, phytoplankton and nutrients in water Turbidity reflects matter visible to naked eye (measured with Secchi disk) TSS collects dissolved material (filtered) measured as weight

12 Salinity Dissolved salt content in water Influences organisms that can live in that area Oceans are about 35 ppt or so Water salinity Fresh waterBrackish waterSaline waterBrine < 0.05 %0.05 - 3 %3 - 5 %> 5 % < 500 ppm500 - 30 000 ppm30 000 - 50 000 ppm> 50 000 ppm

13 Heavy Metals Living organisms require trace amounts of some heavy metals, including iron, cobalt, copper, manganese, molybdenum, vanadium, strontium, and zinc – excessive levels can be detrimental to the organism. Other heavy metals such as mercury, lead and cadmium are toxic metals –they have no known vital or beneficial effect on organisms –their accumulation over time in the bodies of mammals can cause serious illness

14 Microorganisms E. coli (fecal coliform bacteria) can generally cause several intestinal and extra-intestinal infections Cryptosporidium is a protozoan pathogen and causes a diarrheal illness called cryptosporidiosis Giardia lamblia is a flagellated protozoan parasite that colonises and reproduces in the small intestine, causing giardiasis. Symptoms of include diarrhea, malaise, excessive gas, etc

15 Other Stuff Pesticides - bactericides, fungicides herbicides, insecticides (DDT) Radioactive Materials A lot of this information pertains to soil testing as well.

16 Biotic vs. Abiotic Abiotic components are non-living chemical and physical factors in the environment. –The six major aboiotic factors are water, sunlight, oxygen, temperature, soil and climate. Biotic means relating to, produced by, or caused by living organisms.

17 Biotic vs. Abiotic Salinity Dissolved Oxygen(DO) pH Color of water Turbidity Total suspended solids (TSS) Dissolved metals and salts Chemical oxygen demand (COD) Biochemical oxygen demand (BOD) Nutrients Dissolved metals Temperature Pesticides Heavy Metals Pharmaceuticals Hormone analogs Microorganisms such as fecal coliform bacteria (Escherichia coli), Cryptosporidium, and Giardia lamblia Dissolved organics: Colored Dissolved Organic Matter (CDOM), Dissolved Organic Carbon (DOC) Number of species


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