Recycling the waste from the toilet to fertilise the garden is called anaerobic biodigestion.

Jack Sim, Director of the World Toilet Organisation, recently made a suggestion about recycling the contents of toilets into the soil as fertiliser which could be a good idea in Africa.

This idea would be beyond most people and they would giggle and snigger at the preposterous idea of recycling the contents of toilets which they never see, as the sewerage system in their part of the world works all the time.

It’s a clever idea and it’s already been worked out, all it takes is putting the parts together which can cost quite a bit and is beyond most rural people, the people who would actually benefit most from something of this nature.

The Anaerobic biodigester is the mechanism through which this recycling idea literally springs to life. The waste from humans as well as livestock is processed through a system in an airtight container that produces not only a slurry, drained of toxins, that can fertilise the garden but also a form of biogas, made up of methane and carbon dioxide that can be used for cooking and lighting.

According to Wikipedia in more scientific language, “Anaerobic digestion is a process in which microorganisms break down biodegradable material in the absence of oxygen. The process is widely used to treat wastewater sludges and organic wastes because it provides volume and mass reduction of the input material. As part of an integrated waste management system, anaerobic digestion reduces the emission of landfill gas into the atmosphere. Anaerobic digestion is a renewable energy source because the process produces a methane and carbon dioxide rich biogas suitable for energy production helping replace fossil fuels. Also, the nutrient-rich solids left after digestion can be used as fertiliser.


Exhaustive info on anaerobic biodigester


China is one of the countries that was in the forefront of developing Anaerobic biodigesters in the 70’s on a level where small communities had their own that were managed and maintained by the community. This kind of ownership develops a community spirit and contributes to people being more in control of their daily lives than before.

The lack of control over day to day developments is part of the burden that the rural poor have to live with. A simple matter like utilising waste for a more productive garden as well as providing biogas for cooking purposes could change their way of life totally.

The use of biogas produced from the biodigester would also take the pressure off the surrounding vegetation and trees which normally provide the fuel used for cooking fires.

The environmental aspects of the system are also a bonus with waste not flowing directly back into the water table via rivers and underground springs.

Sim made his suggestion at the World Economic Forum’s Africa Conference in Cape Town last week.

Almost all participants said that the problem of food shortages could only be tackled multilaterally but Obiageli Ezekwesili, vice-president for Africa at the World Bank stressed two critical things.

Firstly, that Africa had placed too much emphasis on developing resources and not enough on maintaining and building agricultural production.

And secondly, Asia has overcome hunger problems with governments investing 10% of their budgets into agriculture. Africa averages less than 3%.

The biodigester option seems small compared to investing more of the budget into agriculture but it would help rural communities solve waste management problems as well as providing fertiliser sustenance for the vegetable gardens and biogas for cooking and lighting.

An idea put forward that was taken as a bit of a joke. It won’t be a joke if government here in South Africa could build some biodigesters and train people to build and maintain them thereby creating job opportunities and giving poor, rural communities a chance to gain some independence and control over their lives.