Technical Guide to EcoSan Promotion

2.1 The Philosophy of Ecological-sanitation
The underlying philosophy of ecological sanitation hereafter referred to as EcoSan,
is that if treated properly, human waste is a valuable resource. EcoSan operates on
the basic principle of separating urine and faeces so that each can be safely disposed
of, then processed individually.
Eco-san can be viewed as a three pronged process that entails the following:
containment of pathogens so as not to cause diseases; sanitization of waste so as not
to pollute the environment and finally; reclamation, recycling and reuse of energy,
water and nutrients through a modular circular system. This implies a complete
recovery of nutrients in human waste and household wastewater so that they can
be recycled as high-nutrient fertilizer for agriculture.
Pathogens are contained through their destruction using temperature, time and
pH factors. The destruction is achieved via: dehydration or drying to reduce
moisture; composting as a heating process; and anaerobic digestion to reduce
faecal coliforms, BOD and COD. Thermophylic composting uses a ratio of 69% raw
faecal matter, 20% vegetative matter, 10% soil and 1% of ash to reduce the existence
or proliferation of ascaris by inactivating its eggs.
With regard to time as a critical factor, it is important to note that it takes a shorter
time in the tropics as compared to temperate zones for pathogens to be destroyed
(See Figure 1 below).
Figure 1 : Average survival time in days of pathogens in wet sludge
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