Bio-Synthesis of Nitrates from Ammonia: Small Scale Setup for Test of Concept:
On a rocket chemistry discussion group the topic of producing saltpeter came up. The classic method of large piles of decomposing organic matter takes a lot of time and space, not to mention distance from homes due to the odor. The question came up if this same chemical process could be achieved with just the base nitrogen source such as urea and or ammonia. This would eliminate the rotting organic mess. It is from this challenge of concept that I set out on the following experiment:
We need the correct micro-organisms and starting chemicals (food) but before that we need a chamber that can provide the environment and bacterial growth surface area so that the bacteria can do their chemical conversion job. Here is what I came up with:
The filter is porous Polyurethane foam. This will provide a large amount of surface area for the nitrifying bacteria to grow and adhere.
The air pump sends air up tube which brings aerated water up tube and onto top of foam filter.
The filter enclosed in a plastic box with an opening at the top and a small opening at bottom for fluid exit. The initial nutrient ammonia solution will be free of organics.
The inorganic nutrients are based very roughly on Nitrifier media
Trial setup:
Before starting the actual experiment I needed to know if this setup was going to move aerated fluid through the foam to maximize bacterial exposure to nutrients and oxygen
So I did an experiment with food dye:
Setup with air bubbles running plus dye:
Time = 0
Time = 1 minute:
Time = 1 minute from side view:
Time = 2 minute:
Time = 3 minute:
Time = 4 minute:
Looks like plenty of aeration and circulation.
Discussion on the KN03 list mentioned foaming is an issue with urine as the nutrient source. So I decided to use a larger taller jar just in case my non-organic media would also foam:
To keep the solution warmed in the garage I used a pot, catch basin, aquarium heater, thermometer, and a cover made of an old set of nylons. Styrofoam peanuts floating on top of pot of heating water is to retain heat and reduce evaporation.
With the reactor ready now it is time for designing and making culture media: reactor media ingredients.
