Dog poo disposal by anaerobic digestion
Composters have been able to deal with dog poo at home using a dog poo wormery but when out it has normally been a case of “bag it and bin it”. The waste then being sent to landfill or treated as clinical waste.
There may soon be an alternative using anaerobic digestion. as a pilot project by Brian Harper in the Malvern Hills Area of Outstanding Natural Beauty is showing how dog poo can be used to power street lighting in the area where it is bagged. The bags of dog poo are deposited in a small anaerobic digester attached to the lamp post, a handle is turned to stir and heat the material. Microorganisms break down the stool to produce methane. A containment box collects and stores the methane until dusk, whereupon a timer releases the gas to light up the lamp. to assist bacterial decomposition. It is estimated that the methane produced from ten bags of faeces can light the lamp for about two hours.
A similar system called the “Park Spark" has been installed in a park in Cambridge, Massachusetts since 2010, In this larger device by Matthew Mazzotta, a conceptual artist, the methane powers an “eternal flame” lamp post it that that sufficient people will provide dog poo in biodegradable bags to provide power for other uses.