Biological Scientific Background

As with any scientific project, there is an amalgam of scientific concepts binding the project's components together. This page displays the key scientific ideas for this Division.

Key Ideas:

• Chloramines:
  • Chloramines are formed by when ammonia and chlorine (in its hypochlorous acid) react together and combine with each other.
  • Commonly used as disinfectant for water
  • Used to be an issue from the old project design because chloramines threatened to suffocate the fish life
• Osmosis:
  • "This is a separation technique in which a semipermeable membrane is placed between two solutions containing the same solvent. The membrane allows passage of small solution components (usually the solvent) while preventing passage of larger molecules. The natural tendency is for the solvent to flow from the side where its concentration is higher to the side where its concentration is lower. Reverse osmosis occurs when pressure is applied to the solution on the side of the membrane that contains the lower solvent concentration. The pressure forces the solvent to flow from a region of low concentration to one of high concentration. Reverse osmosis often is used for water purification. Osmosis or reverse osmosis can be utilized in certain instances to perform separations prior to a chemical assay." – https://www.britannica.com/science/c...ysis#ref621100 (chem analysis|Britannica.com)
• Aerobic:
  • "(1) Of, pertaining to, having, or requiring the presence of air or free oxygen."
    • "(2) (biology) Requiring air or oxygen for life or survival, used especially to refer to aerobic bacteria."
    • "(3) (physiology) Pertaining to respiration occurring in the presence of oxygen, as aerobic respiration."
    • – http://www.biology-online.org/dictionary/Aerobic (Aerobic - Biology - Online Dictionary)
• Anaerobic:
  • "(1) Not requiring, or capable of occurring, in the absence of air or free oxygen.

    (2) Caused by, or relating to, the lack of molecular oxygen."

    • "Anaerobic may be used to describe an organism, a cell, a process or a mechanism that can function without air (i.e. air to generally mean oxygen). This is in contrast to the term aerobic, which means requiring air or free oxygen."

    • – http://www.biology-online.org/dictionary/Anaerobic (Anaerobic - Biology - Online Dictionary)

• Buffers:

  • "(1) (chemistry) A buffer solution : a solution containing either a weak acid and a conjugate base or a weak base and a conjugate acid, used to stabilize the pH of a liquid upon dilution.

    (2) (biochemistry) An ionic compound that when added to a solution neutralizes both acids and bases without significantly changing the original acidity or alkalinity of a solution.

    (3) (ecology) A buffer species: a plant or animal species that becomes an alternate prey to a predator that typically feeds on another species.

    (4) Anything that cushions, shields or protects against harm, damage, etc., e.g. a high reproductive rate is an efficient buffer against population crashes."

    • "In ecology, a buffer species is a plant or an animal that becomes an alternate prey to a predator. This happens when the predator's preferable, usual prey species is scarce or absent.

      A buffer may also refer to a vegetated area near a stream that plays a conservatory role in the environment. Such buffer is particularly called a riparian buffer.

      In biochemistry, a buffer, specifically a buffer solution, is essential for many biochemical processes. It serves to maintain the correct pH necessary as many enzymes work only under precise pH conditions."

    • – http://www.biology-online.org/dictionary/Buffer (Buffer - Biology-Online Dictionary)

• Nitrates:
  • "nitrates are minerals needed by plants, to produce protein in order for the plant to grow. Nitrates may be obtained by the plant via the root Hair cells on roots by activeuptake/transport." – http://www.biology-online.org/dictionary/Nitrates (Nitrates - Biology - Online Dictionary)
  • "Nitrates are inorganic compounds made up of nitrogen and oxygen, NO3 (one nitrogen and three oxygen molecules)."
    • "These compounds combine with other elements like sodium and potassium to make sodium nitrate or potassium nitrate. They are used as preservatives and color fixatives in cured meats and have other industrial uses, such as in gunpowder, explosives, fertilizers, and glass enamels."
    • – http://study.com/academy/lesson/what...e-effects.html (What Are Nitrates? - Definition, Foods, & Side Effects)
• Buffering

The best method for buffering is using carbonates and testing KH (water hardness) to maintain buffer capacity. We will ensure that the least amount of salinity is being added that the system by using buffers that will double as nutrients or gas off in the case of CO2. It is expected that the pH will remain stable slightly above ~7 as long as there is enough carbonates avalible (buffer capacity).

*KH should be tested weekly and be above a 4 dKH. Remember that as your system matures, it will create more acid from the nitrification process that will eat up the buffering capactiy. As you approach a dKH of 4 or lower, add potassium bi-carbonate.

*The primary source of carbonates will mimic a natural ecosystem by using either egg shells, live rock or coral comprised of CaCO3 (calcium carbonate) that will solubilize as carbonate is used. The coral will also house the intial bacteria introduced into the system. The coral will be placed in the fish tank.

Note - Calcium Bi-Carb/Calcium Hydroxide can be used as well but potassium was selected as the plants have a higher nutritional requirement for potassium.

Potassium Bi-Carbonate - KHCO3 *To lower pH

Weak acids could be used to lower pH the system if pH is significantly out of range.

Potassium Hydroxide - KOH *To Raise pH

CO2 gas can be injected to automate the regulation of pH without added salinity to the system. Avoiding adding salinity means the plants can receive only ions that will be utilized as food and not have unnecessary ions in the water. The fish and plants will both die or fall ill if the salinity of the system is to high. CO2 gas can also double as enhancement of plant growth by being injected into a confined space with the plants growing as this will facilitate photosynthesis and the cellular processes of the plant better than normal air with a lower concentration of CO2. http://www.drsfostersmith.com/Produc...fm?pcatid=9933

• Nitrification

Video: Comprehensive explanation of nitrification: https://www.youtube.com/watch?v=gF8rZVmuipw

Nitrobacter/Nitrosomonas (Nitrofiles, autotrophs):

All species of Nitrosomonas use ammonia (NH₃) as an energy source during its conversion to nitrite (NO₂). Ammonia is firstly converted (hydrolyzed) to an amine (NH₂) compound then oxidized to nitrite. This conversion process allows Nitrosomonas to utilize a few simple amine compounds such as those formed by the conversion of ammonia by chemical ammonia removers.

Nitrosomonas is capable of utilizing urea as an energy source.

All species of Nitrobacter use nitrites for their energy source in oxidizing them to nitrate (NO₃^-).

*A high oxygen enviroment is required to keep the bacteria process aerobic. A lack of free oxygen in the water can cause the bacteria to go anaerobic process and create toxic levels of ammonia. Airlifts or air pumped into the water shoulld be adequate.