Freshwater Pollution its Control Safe Drinking Water free
- Slides: 39
Freshwater Pollution & its Control
Safe Drinking Water= free of diseasecausing organisms & toxic substances
World Commission on Water ½ of our world’s rivers are “seriously depleted & polluted, degrading & poisoning the surrounding ecosystems, threatening the health & livelihood of people who depend on them
Pollution • Can be physical, chemical or biological • Can affect water, air, soil Freshwater Pollution: • Nutrient pollution • Biological pollution by disease-causing organisms • Toxic chemical pollution • Physical pollution by sediment • Thermal pollution
Source of Pollution Point Source • Distinct location • Particular factory pumping waste into a nearby stream • Sewage treatment plant discharging wastewater from a pipe into ocean Nonpoint Source • Multiple cumulative inputs over large areas • Entire farming region • Suburban community with many laws & septic systems • Storm runoff from parking lots The distinction can help control pollutant inputs into waterways
Nutrient Pollution, N & P • In addition to wastewater, N & P are also products of decomposition, fertilizers and are found in soaps & detergents Eutrophication • Hypoxia: extremely low dissolved oxygen concentrations in a body of water • 1. Influx of nutrients • 2. Rapid growth of algae “algal bloom”, blocks light (plants die less photosynthesis less oxygen produced) • 3. Algae eventually dies • 4. Decomposers consume most of oxygen as feed on algae (high BOD) • 5. Larger organisms, like fish, die due to lack of oxygen
Dead zones: low DO
Pathogens & waterborne diseases • 1. Drinking water that is contaminated with waste from inadequately treated wastewater or animal feedlots • Pathogens: viruses, protists, bacteria • Fecal coliform bacteria=lives in the intestinal tracts of people & other vertebrates; not pathogenic but serve as indicators of fecal contamination • Cholera, Giardiasis, Typhoid, Hepatitis A, Dysentery • Wastewater dumped into natural bodies of water undergoes decomposition by bacteria • Increases Biological Oxygen Demand (BOD) • BIOLOGICAL POLLUTION BY PATHOGENS CAUSES MORE HUMAN HEALTH PROBLEMS THAN ANY OTHER TYPE OF WATER POLLUTION
Pathogens & waterborne diseases • Most outbreaks occur in less developed countries where no sewer or sanitation facilities exist • How to reduce risks: • Treating sewage • Use chemicals to disinfect water • Hygienic measures • Standards: • Drinking water→ no coliforms allowed • Swimming pool→ no more than 200 coliforms/100 m. L→ closed if amount too great. Same for beaches, lakes & rivers
Indicator Species • Indicator species are an easy way to test whether water is polluted with harmful pathogens • Fecal coliform bacteria • Indicator species: E. Coli • Fecal coliform bacteria test • Water sample passed through filter • Filter disk placed on growth medium that supports coliform bacteria for 24 hours • Count number of colonies of coliform bacteria
Oxygen Sag • Illustrates changes that occur in a flowing system when oxygen demanding wastes are added • Area upstream of wastes→ good • Where wastes added→ Dissolved Oxygen drops due to increased Biological Oxygen Demand • As water flows→ system slowly recovers back to original state
As BOD increases, DO decreases • Biological Oxygen Demand (BOD) • Dissolved oxygen (DO) • A measure of the oxygen used by microorganisms to decompose organic waste • The amount of oxygen available for use in the water • If there is a large supply of organic waste, bacterial count will be high, resulting in a high BOD • As BOD increases, DO decreases because the oxygen that is available is being consumed by the bacteria
Lower BOD values= less polluted water
Pathogens & waterborne diseases • Disease: Schistosomiasis • A problem in Nile River/High Dam • Cause: pathogen vector • Warm, stagnant water allows the Schistosoma parasite (worm) to exist • The infectious form of the parasite lives in certain types of freshwater snails & can emerge, contaminating water. • People can become infected when their skin comes in contact with contaminated freshwater. • Symptoms: • Initial invasion of the skin • Itching and a rash (swimmer's itch). In this condition, the schistosome is destroyed within the skin. • Can migrate through blood to Intestine & Bladder • Abdominal pain & diarrhea • Frequent urination, painful urination (dysuria), and blood in the urine (hematuria).
Toxic Chemicals: Synthetic Organic Compounds • Pesticides • Lethal to amphibians at low concentrations • Gills burst & tadpoles suffocate • Pharmaceuticals & hormones • Drugs that mimic estrogen connected to male fish growing female eggs • PCBs • Used in manufacturing of plastics & insulation of electrical transformers • Now banned • Carcinogen • PBDEs • Flame retardants • Found in aquatic birds, fish & breast milk • Exposure to some types lead to brain damage
Heavy metals • Lead • Contaminates water when it passes through pipes of older homes • Fetuses & infants most sensitive • Damage brain, nervous system, kidneys
Heavy metals • Arsenic • Occurs naturally in Earth’s crust but increased by human activity • Mining breaks up rock deep underground • Industrial uses for arsenic like wood preservatives • Can be removed from water via fine membrane filtration, distillation & reverse osmosis • Cancer of the lungs, skin, kidneys & bladder • Takes 10 or more years to develop after exposure • 1942 -1999 acceptable level 50 ug/L • 1999 acceptable level 10 ug/L
Heavy metals • Mercury • Occurs naturally in Earth’s crust but increased by human activity • 2/3 burning of fossil fuels (coal) • Incineration of garbage, hazardous waste, medical & dental supplies • Raw materials that go in to manufacturing cement • Exploration of petroleum • Each petroleum well produces 180, 000 gallons of contaminated wastewater & mud • Water usually dumped at drilling site • Enter nearby waterways or infiltrate soil & pollute groundwater
Heavy metals • Mercury • Inorganic mercury not harmful but once mercury finds its way into water bacteria converts it into methylmercury • Methylmercury damages nervous system, particularly in young children & developing embryos. Causes impairment of coordination & affects the senses of touch, taste, & sight • Human exposure mostly due to eating fish & shellfish bioaccumulates up food chain. • Tuna top predator • Common source of bioaccumulated mercury
Heavy metals • Acid deposition “Acid rain” • Source of lower p. H in water due to smokestacks of industrial plants that were burning coal & releasing SO 2 & NO 2 • Chemicals in atmosphere converted to sulfuric & nitric acid • Acids return to earth as acid deposition (acid rain) • Causes p. H of water bodies to go below 5 • Toxic to many aquatic organisms • Coal scrubbers • Passes hot gas through limestone, which reacts with the acidic gas, removing the S & N from the hot gases that leave the smokestack
Heavy metals • Acid mine drainage • Causes low p. H in bodies of water • Abandoned underground mines become flooded, which allows a rock called pyrite to break down & produce iron & hydrogen ions. • Produces acidic water with a low p. H • Occurs w/mountaintop removal when tailings dumped into stream beds • Can produce water that is close to a p. H of 0 • Trying to hold mining companies responsible • Passing stream water through limestone treatment facilities
Solid waste- Garbage • Medical waste • Threat to people (beach) • Coal ash • Contains mercury, arsenic, lead • Not considered hazardous waste • Most states have either no regulation or weak regulations governing this waste
Sediment #1 Water Pollutant • Some bodies of water are naturally sediment rich, but most are not • An increase in sediment in a body of water can cause the habitat to dramatically change- no longer have a clearwater environment- less light coming through • • The higher the “turbidity”, the higher the cloudiness of the water Raises temperature of water Less light affects photosynthesis (less producers) less O 2 Clogs fish gills less O 2 • Cause: mining, clear-cutting, land clearing for housing development & careless cultivation of farm fields expose soil to wind & water erosion • Removing vegetation increases erosion
Thermal Pollution • Increasing the water temperature decreases the amount of dissolved oxygen • When human activities raise water temperatures, some aquatic organisms may not survive • Electric & Nuclear power plants, Industrial plants • Water removed & used for cooling & then later discharged back into the river, but at a higher temperature • Thermal shock= dramatic change in temperature can kill many species • High temperature causes them to increase respiration, but there’s less O 2 in water • The solution: Cooling towers & holding tanks- water held in tanks until they cool down, then released into body of water.
Noise pollution • Noise from ships/submarines can interfere with animal communication • Loud sonar negatively affecting whales that rely on lowfrequency, long-distance communication • Beached whales been connected to use of military sonar & loud, underwater air guns • US Navy requested to install network of long-range sonar systems across ocean floor to detect incoming submarines • Rejected by federal judge due to impacts on endangered whales • Supreme Court ruled the President of the US could exempt the navy from environmental laws that related to sonar effects on ocean life
Clean Water Act, 1972 • All US waters “swimmable & fishable” • DOES NOT PROTECT GROUNDWATER • Regulates the discharge of wastes, especially from industry, into rivers & streams (Monitors point sources) • Protects wildlife & established a system for granting permits for the discharge of pollutants • Sets standards for industrial wastewater, contaminant levels in surface water & funded construction for sewage treatment plants • Nonpoint sources are harder to regulate & therefore have a greater impact on water quality in the US • Govt. limits development on watershed land surrounding reservoirs
• Safe Drinking Water Act • Sets nat’l standards for drinking water • EPA responsible for establishing maximum contaminant levels for over 80 different substances/chemicals in surface & groundwater • Federal Water Pollution Control Act, 1948 • Establish controls for each major pollutant • Provide billions of dollars for sewage treatment plants • Great Lakes Water Quality Act, 1972 • Canada & U. S. • Huge strides in cleaning up area • London Dumping Convention, 1990 • Regulations for dumping industrial wastes, effluent, and plastics in ocean by 1995. Results still remain to be seen • Superfund Act • Provides funding for cleanup of contaminated abandoned sites that may be affecting water quality
Contaminant category Contaminant Microorganism Inorganic chemical Organic chemical Giardia Fecal Coliform Arsenic Maximum contaminant level (ppb) 0 0 10 Mercury 2 Benzene 5 Atrazine 3
Potable water = Drinking Water • “Safe Drinking Water Act”: The EPA sets standards for over 80 drinking water contaminants • Before it’s sent to your tap, water from a reservoir or aquifer is treated … • 1. To clarify water →add coagulants → chemicals that will coagulate dirt & other particles by causing them to stick together & sink • 2. Water passed through filter → removes disease-causing agents • 3. Disinfected →using UV light, ozone or chlorine • 4. Many areas add fluoride to increase dental health (4 mg/L) • Best drinking water • Des Moines, Iowa; Austin, Texas; and Sioux Falls, S. D. • Worst drinking water • Pensacola, FL; Riverside, CA; Las Vegas, NV
Purification of Drinking Water • The Chlorine Dilemma • Chlorine is added to drinking water to kill pathogens • Chlorine has recently been linked to several types of cancers (rectal and bladder) • Add chemicals to water to remove chlorine after use
Water Quality Testing • Biological properties Intolerant to stress Tolerant to stress Mayflies Pouch snails Caddisflies Tubifex worms Stoneflies Leeches • Presence of fecal coliform & disease-causing organisms • Algae & aquatic invertebrates are biological indicators • Chemical properties • Nutrient concentrations (P & N), p. H, taste & odor, hardness, dissolved O 2 • Hardness • High concentrations of Ca & Mg • Prevents soap from lathering, leaves chalky deposits when heated • Dissolved oxygen • Indicator of an aquatic ecosystems health • Surface waters low in DO are less capable of supporting aquatic life
Chemical Testing- p. H 4. 0 4. 5 5. 0 Noted Effects No fish below this point Lower limit for most fish, amphibians & insects Decomposition processes inhibited, organic debris accumulates 6. 0 - 7. 5 8. 5 9. 0 Optimal range for most fish eggs & larvae Upper limit for most algae Upper limit for most fish
Chemical Testing- alkalinity • Not to be confused with p. H • A measure of the buffering capacity– the degree to which water can resist changes in p. H • This capacity is determined by the amount of carbonate (CO 32 -) & bicarbonate (HCO 3 -) ions in the water • These ions react with, or buffer, incoming hydrogen (H+) ions that would otherwise lower the p. H • Natural source of carbonate: Limestone
Water Quality Testing • Physical properties • Turbidity= measures the density of suspended particles (sediment) • Turbid water= carries a lot of sediment; muddy-looking • Test: Secchi Disk • Color • Some forest streams are colored due to tannins in decomposing leaf litter • Temperature • High temperatures can interfere w/biological processes • Warmer water holds less dissolved oxygen
Secchi Disk
Groundwater Pollution • Toxins that occur naturally in groundwater that are toxic at high concentrations • Aluminum, fluoride, nitrates, sulfates • Nitrates in drinking water cancer, miscarriages • Arsenic Bangladesh natural occurrence • Industrial, agricultural, urban wastes leaching into aquifers • Leakage from underground septic tanks • Contaminated sites near groundwater or surface water are high on the Superfund list
- Water and water and water water
- Methods of water pollution
- Source of thermal pollution
- Control measures of water pollution ppt
- Freshwater wetlands purify water by
- Safe feed safe food
- Safe people safe places
- Drinking water watch
- Drinking water state revolving fund
- Oregon water treatment certification
- Idem drinking water branch
- Drinking water watch
- Lithium in drinking water
- Typhoid medicine course
- Drinking water system operator certificate
- Prime drinking water
- Nm drinking water watch
- Characteristics of sanitary well
- Dispensers for safe water
- Dispensers for safe water
- Safe water entry
- Sources of groundwater pollution
- Explain water pollution
- Water pollution through the years
- Major sources of water pollution
- What are the terrible twelve water pollution
- Solutions to water pollution
- Water pollution introduction
- 2 causes of soil pollution
- Air pollution consequences
- Land water and air pollution
- Effects of water pollution
- Ddt water pollution
- What are 5 effects of water pollution?
- Objectives of water pollution
- How to overcome water pollution
- Conclusion of water pollution
- Types of water pollution
- Water pollution and unequal distribution illustration
- Summary of water pollution