Nothing goes to waste
Organics and Self Sufficiency
Nothing goes to waste
Wednesday, 19 March 2008


Organics and Self Sufficiency Headlines
• Being organic - is it worth it?
• Organic pest control
• Make a certified choice
• A pint of organics
• Organic milk: A better choice
• Sustainable organic farming
• Kiwi scientist's new plant growth enhancer
• Worth a look
• The cycle of recycling
• Assured Quality
• The economics of organics
• Autumn arrival
• Time for organic fertilisation
• What is
• Quality, safety assured
• Water wisdom
• Warming up for winter
• To certify or not to certify...
• Opening a can of worms
• Nothing goes to waste

Everything can be recycled. Yes everything. Even human waste. Composting toilets contain and control the composting of excrement, toilet paper, and added carbon material in a controlled aerobic environment.

Grey water tanks with internal filter at the discharge end.
Grey water tanks with internal filter at the discharge end.
The material is broken down in a completely natural process to 10 to 30 % of its original volume over a number of months. The end result is a stable soil like material called humus.

The primary objective of the composting process is to contain, immobilise, or destroy organisms that cause human disease and to not contaminate the immediate or distant environments.

The composting process occurs in a controlled environment with plenty of air and moisture where bacteria, actinomycetes, and fungi combined with the action of worms reduce the matter into a stable oxidised form. Human waste enters from the top with the addition of some form of added carbon material such as sawdust.

Over a period of time due to the action of gravity and the weight of additional material on top the pile slowly works its way down the inclined slope of the chamber, when it finally gets to the bottom it has been completely oxidised and is in a stable form ready for removal.

Air is provided by inlet holes at the bottom of the chamber and slotted pipes inside the chamber. The movement of air through the system results in the majority of the moisture in the system being removed as water vapour out of the flue.

Excess liquid collects and is removed at the bottom of the vault and is piped to its own mini leach field or into the grey water system.

Unlike a septic tank system and long drop type toilets that have anaerobic bacteria and  a distinct strong smell, composting toilets use aerobic bacteria that do not produce the sulphides etc that produce strong odours. Composting toilets usually have a slight earthy forest humus type smell.

The composting toilet is designed to contain, immobilize, or destroy organisms that can cause human disease (Pathogens). Thus reducing the risk of human infection without contaminating the immediate or distant environment.

500-7500 litre water tanks.
500-7500 litre water tanks.
The toilets if used within their design parameters have a retention period of at least one year and all solid material is fully oxidized well within this period and all pathogens have been virtually destroyed. Liquid is removed mainly by evaporation up the flue which is fan assisted.

Nitrogen removal. Nitrogen entering the composting toilet is virtually all in organic form in the urine. The urine enters in the top and enters the oxygen and organic rich environment of the compost pile.

At this stage most of the nitrogen is lost as ammonia gas and dissipates up the flue. The rest of the nitrogen then slowly seeps through the compost and converts to its nitrite form. The urine/compost liquid is trapped successively for a few days in a series steps on the chamber floor and then onto the bottom of the composter chamber where it is held in an anaerobic environment (anoxic environment) also high in organic carbon and converts to nitrate.

3 stage settling grey water tank with vent option.
3 stage settling grey water tank with vent option.
During this process the nitrogen is reduced to nitrogen gas and again dissipates up the flue. After all this any excess liquid is drained through a stainless mesh filter out of the chamber and dealt with in various ways.

It can be added to the greywater system or put through a separate biological filter (explained below) and then to its own small dispersal field.

Phosphorus removal. This is again achieved by source separation. Phosphates are mainly present in the grey water system as a result of phosphate levels in cleaners and detergents. Consumer education is the key to the removal of these as there are many products that do not contain phosphates.

The bioloo grey water systems behave as high quality baffled septic tanks and use dispersal pipes with breathers in the upper organic layers of the soil wrapped in geo textile cloth to provide an environment high in biological activity in a wide variety of soil conditions.

Composting toilets are cost effective and environmentally friendly.
Composting toilets are cost effective and environmentally friendly.
These biological aerobic conditions result in a discharge of highly treated liquid. The phosphates entering the composting toilets are also treated in aerobic and anaerobic conditions high in organic carbon.

The long retention time and the binding effect of the carbon material result in a very low level of phosphorus in the end liquid. The resulting excess fluid is again put into the grey water system or put through the separate biological filter.

Bioloo biological filter. This filter is connected via a 20mm pipe to the composting unit and is gravity trickle fed as new fluid enters the composter and displaces retained fluid at the bottom. The liquid enters the top and slowly filters down through the media and out via a series of holes drilled in the bottom.

The media consists mainly of Coir dust and particles. We use this pretreated product instead of others such as peat or wood by products because coir has a much greater surface area and biological mass and lasts much longer than them, and is much more efficient in binding elements such as nitrogen and phosphorus.

Coir dust retains moisture better and has a better capillary action than peat and is more resilient and will not compact when wet.

All this provide a stable aerobic environment very rich in biological activity and with good binding properties that ensure that the liquid leaving the filter is very low in potential pollutants and combined with the very small quantities of liquid produced ensure the Bioloo systems have a minimal environmental impact.

The filter size is matched to the design loadings of the composters in worst-case conditions and is designed to last 5 to 10 years depending on which composter size is used.