EESA11.pdf - UTSC EESA11H3 MIDTERM EXAM STUDY GUIDE find more resources at oneclass.com Lecture 7 Water Pollution Part 1 The water cycle Sources and

EESA11.pdf - UTSC EESA11H3 MIDTERM EXAM STUDY GUIDE find...

This preview shows page 1 - 5 out of 26 pages.

UTSC EESA11H3 MIDTERM EXAM STUDY GUIDE
Lecture 7: Water Pollution Part 1 The water cycle Sources and pathways of water pollution o Agriculture  growing corps o Agriculture animal operations o Timber-cutting operations o Construction cities o Cities/suburbs (paved surfaces) o Industrial outfalls o Mining operations Two major types of water pollution o Point source  specific spot (pipe, ditch, ship or smokestack) o Nonpoint sources runoff across large areas, urban areas (streets, parking lots, roofs), rural (agriculture, logging, mining sites) Watershed o A watershed includes all the land that drains to a common body of water. o Using a watershed-based approach to wetland protection ensures that the whole ecosystem is protected. o Polluted runoff can influence waters distant from its origin o Wetlands o Aquifers (groundwater) Sewage Pollution o Sanitary sewer  wastewater from homes/commercial places to a treatment plant o Storm sewer  carries street runoff o Combined sewer carries both sanitary wastewater and storm runoff heavy storms (discharges into the water bodies) Atmospheric deposition upon land and water o Non-point source pollution PCBs (polychlorinated biphenyls) Metals (lead and mercury) Nitrogen oxides (NO3- Nitrate input) Conventional pollutions find more resources at oneclass.com find more resources at oneclass.com
o Biochemical oxygen demand (BOD) Dissolved oxygen (DO) needed for microorganisms to decompose waste 14mg/L for low temperature and salinity 6mg/l of DO for high temperature and salinity Lots of sewage = high BOD= less oxygen available Hypoxic (low oxygen) conditions  fish moves away but crabs and snails may die Total biochemical oxygen demand CBOD  carbonaceous biochemical oxygen demand NBOD Nitrogenous biochemical oxygen demand Total BOD=CBOD+NBOD Bacteria are capable of oxidizing ammonia to nitrite and subsequently to nitrate (starts 6-7 days after CBOD) Lo= the amount of oxygen used to completely decompose or stabilize all the biodegradable organics in a given volume of water is called the ultimate BOD or BODL o Nutrients Manufactured fertilizes Contain concentrated reactive nitrogen and phosphorus (extra portion runs off into water bodies) Cascade effects  stimulate plant growth in water bodies (algae), as the vegetation die it becomes BOD, bacteria also digest the fecal pellets of zooplankton Reactive nitrogen = bioavailable nitrogen (ammonia and nitrate) Oxygen sag downstream of an organic source (U.S.EPA) Clean zone Decomposition zone Septic zone Recovery zone Eutrophication Enrichment of body water Eutrophic lake o Lots of nutrients o Poor light penetration o Low dissolved waters o Shallow waters o High algal growth o Silt, sand, or clay botton o Cloudy water Oligotrophic lake o Fewer nutrients o Good light penetration o High dissolved oxygen o Deep waters o Low algal growth o

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture