Tuesday, November 15, 2011

Crap in a Bag Could Change the World?

Introducing the Peepoo. This is a novel approach to improving sanitation while at the same time creating useful biomass and fertilizer. The use of night soil has been exploited by farmers for centuries, but the introduction of the Peepoo is a clever idea to prevent disease transmission and to generate income in developing countries.
The Peepoo is a biodegradable plastic bag 14 x 38 cm which people use as a portable toilet. The bag contains urea powder which reacts with the urine and faeces helping decomposition but also raising the pH. Pathogens are inactivated within 2-4 weeks depending on the temperature. The bioplastic is made from a mixture of aromatic co-polyesters and polylactone acid (PLA), with small additives of wax and lime. With time these degrade in the soil to release the N and P as well as adding vital water retaining biomass to the soil. As fertilizer is expensive in developing countries many local suppliers of Peepoo bags pay a small refund if the bag is returned full. These are then stored in heaps and allowed to slowly degrade producing a sellable nutrient enriched biomass for local farmers. One person using the bags for a year is equivalent to an artificial fertilizer loading of 6 kg urea 2 kg Total P and 1 kg potash.

No comments:

Post a Comment