9.4 - WATER QUALITY INDICATORS

• PROPER TREATMENT PROCESSES:

  1. SEDIMENTATION - heavier particles sink to the bottom
  2. FILTRATION - catches leftover particles
  3. DISINFECTION - chlorine and ozone are mixed to kill of pathogens
• Enumerate the 6 chemical parameters of water

  1. pH
  2. Dissolved Oxygen
  3. Nitrates
  4. Total phosphates
  5. Hardness
  6. Total Dissolved Solids
• what is the meaning of pH

  potential / power of Hydrogen
• this parameter represents the level of acidity / alkalinity of water

  pH
• pH represents the balance between Hydrogen ions (H+) and Hydroxide Ions (OH-)
• aquatic organisms may be harmed by water with a pH level of _?

  <4.8 and >9.2
• what is the standard for drinking water

  6.5 to 8.5 (acidic to neutral)
• <7


  acidic; H+ < OH-
• >7

  basic: H+ > OH-
• amount of free oxygen dissolved in water

  Dissolved Oxygen
• DO is measured using Dissolved Oxygen meter / DO meter
• Enumerate the three possible ways in which oxygen is mixed into a body of water

  1. wind blowing
  2. photosynthesis
  3. water's movement; waves, etc.
• oxygen can be poorly dissolved in water
• DO and pressure - directly proportional

  DO and temperature - inversely proportional
• 5 - 6 ppm


  sufficient
• > 3 ppm


  stressful
• < 2 ppm


  fatal
• Hypoxia - low DO (2ppm - 0.5 ppm)

  Anoxia - absence of oxygen (0.5 ppm)
• Total phosphates are naturally occurring forms of phosphorus and it is one of the required nutrients for plant growth
• excessive growth of plants and algae can lead to what?

  decrease of water transparency
• excessive growth of plants and algae


  eutrophication
• PHOSPHATE LEVEL LIMIT:

  river draining into a natural lake - 0.05 ppm

  natural lake - 0.025 ppm

  river not flowing into a lake - 0.1 ppm
• Nitrates are more abundant than phosphates
• Any excess amount of nitrates can cause algal bloom and water transparency reduction
• causes of excess nitrates: agricultural and industrial runoff
• limit of Nitrate concentration for drinking water

  50 ppm
• it is the measure of dissolved minerals (calcium, magnesium, etc.)

  hardness
• (hardness) water containing minerals like calcium and magnesium are "hard" because it requires a lot of soap/ detergent to make a foam w/ it.
• hard water is usually (alkaline, neutral or basic?)

  alkaline/basic
• total hardness is represented as ppm of calcium carbonate
• these are the main ions in most "hard" waters

  calcium (CA^2+) and carbonate (CO3^2)
• DEGREE OF HARDNESS:

  soft: 0-60 ppm

  moderately hard: 60-120 ppm

  hard: 120-180 ppm

  very hard: >180 ppm
• this chemical parameter measures how much material (often inorganic solids w/ slight organic content) is dissolved in water

  total dissolved solids
• what is the limit of total dissolved solids for drinking water? (in ppm)

  300 ppm
• enumerate the effects of high level TDS

  1. undesirable taste
  2. laxative effects
  3. unsuitable for aquatic river life
  4. poorcrop irrigation
• enumerate the 6 physical parameters:

  1. Temperature
  2. Turbidity
  3. Conductivity
  4. Color
  5. Taste
  6. Odor
• this physical parameter affects rates of biological processes and chemical processes
• what are the effects of increase of temperature in water?

  reduce capacity to hold DO and promote biological activities
• high temperature can lead to what?

  • cellular enzymes to become active
  • high metabolic functions
  • high photosynthetic activity
• what are the causes of changes in water temperature?

  - changes in season and weather

  • industrial discharge of warm or cold water