The moisture content of a compost pile is very important . Below 40%, organic matter will tend to dry out and not decompose rapidly. Over about 60%, not enough air can get into the pile and it can become anaerobic {no oxygen}.
Moisture & Liquid Separation
All Nature Loo™ compost chambers contain a false/perforated floor to allow the liquid to be separated from the solids. This reduces the naturally high moisture content of human waste and prevents the process from becoming anaerobic. The separated liquid is either evaporated by the ventilation fan or diverted to a small absorption trench.
Temperature
The heat coming from piles of organic material including those found in composting toilets is generated by the feeding and multiplication of millions of microorganisms. Technically, the stage of the temperature cycle below 40°C is termed mesophilic, above 40°C is thermophilic.
Composting is most rapid in the thermophilic stage. As the temperature rises over 40°C, mesophilic organisms die out and are replaced by an upsurge in the population of thermophilic organisms; the agents of fastest decomposition.
Nature Loo™ composting toilets function well in both thermophilic and mesophilic stages, but in most cases, it operates in the faster, thermophilic stage. This happens for a couple of reasons:
- Air is drawn into the Nature Loo composting toilet through the toilet pedestal. As the air inside a house is usually warmer than the air outside, the Nature Loo chamber is kept warm. In colder climates, the chamber can also be insulated with thermal insulation material.
- The containers are black. This means they are an excellent absorber of heat, especially if located in natural sunlight as is recommended once they are full.
Supply of Oxygen & Ventilation
Micro-organisms that require oxygen to survive are called aerobes. Organic materials are composted most rapidly by aerobes ~ much more rapidly than the anaerobes used in septic systems.
Aerobes need many cubic metres of oxygen per day for a rapid breakdown. The small 12-volt ventilation fans housed inside the Nature Loo ventilation pipe supply enough oxygen to keep the process going at optimum levels. This has the added advantage of acting as a highly efficient extractor fan to remove odours from the toilet room.
Microbes
An important function of the composting process is the destruction of pathogens. Most are killed in the thermophilic stage. Composting at temperatures above 55°C for one day kills almost all pathogens.
Depending on the model and frequency of use a Nature Loo™ chamber is in use for around 2 to 6 months and is composting by itself for another 4 to 12 months, there is little chance of any pathogens surviving, even if the composting process does not reach the thermophilic stage. .
When the toilet is first supplied it arrives with a packet of Nature Quick which contains a proprietary strain of microbe that facilitates the composting. This is used when first starting off the compost chamber and only as required to bolster the good bacteria (e.g. if someone is using broad-spectrum antibiotics).
