ECHEM GASES IN WATER

    Cards (21)

    • What is the most common source of acidity in water?
      CO2
    • How does CO2 enter the water?
      Equilibrium with the atmosphere and biological degradation
    • What is the equation for the equilibrium of CO2 between air and water?
      CO2 (aq)  CO2 (g)
    • What is the ocean carbon pump?
      Process by which CO2 is stored in deep water
    • What are the two sections of the carbon pump?
      Physical pump and biological pump
    • How does the physical pump work?
      Water movements sequester CO2 into deep waters
    • What is the equation for photosynthesis?
      6CO2(aq) + 6H2O (+ light energy) → C6H12O6 + 6O2
    • What is "dark" photosynthesis?
      Temperature-dependent reaction, catalysed by enzymes
    • What is the impact of temperature on photosynthesis?
      Rate of photosynthesis increases with temperature, but slows down at temperatures >40°C
    • What is the equation for the formation of carbonic acid?
      CO2(aq) + H2O → H2CO3(aq)
    • What is the impact of excess nitrogen in a body of water?
      Causes eutrophication
    • What is the oxygen demand of an aquatic system?
      Amount of dissolved oxygen needed for aerobic organisms to break down organic material
    • What are the conditions that impact dissolved oxygen levels in water?
      Temperature, biological demand, agricultural run-off, salinity
    • How does hydrogen sulfide (H2S) occur naturally in natural waters?
      Through anaerobic bacterial action, decay of sulfur-rich soil/rocks, and volcanic gases
    • What are the properties of hydrogen sulfide (H2S)?
      Toxic, explosive, flammable, gives off an unpleasant "rotten egg" odour
    • How is methane (CH4) removed from water?
      Through aeration
    • What is the main source of ammonia (NH3) in natural waters?
      Agricultural run-off (fertiliser usage)
    • How is ammonia (NH3) removed from water?
      Through ion exchange, reverse osmosis, distillation, and submerged aeration filters (SAFs)
    • What is the ocean carbon pump and how does it work?
      • The ocean carbon pump is a process by which CO2 is stored in deep water
      • It consists of two sections: the physical pump and the biological pump
      • The physical pump works through water movements that sequester CO2 into deep waters
      • The biological pump works through the conversion of CO2 into organic carbon through photosynthesis
    • What are the conditions that impact dissolved oxygen levels in water?
      • Temperature
      • Biological demand
      • Agricultural run-off
      • Salinity
    • How do the different gases in water impact aquatic life?
      • CO2: affects pH and can lead to acidification
      • N2: excess can cause eutrophication
      • O2: essential for aquatic life, depletion can lead to death
      • H2S: toxic, explosive, and flammable
      • CH4: can displace O2, leading to asphyxiation
      • NH3: toxic to fish, can cause coma and death
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