Researchers have provided an important insight into public adoption of domestic anaerobic digesters: the green technology that enables users to transform their domestic toilet waste into biogas.
One pioneering process enables home toilets to be connected to an anaerobic digester — known as toilet-linked anaerobic digesters (TLAD) — which converts the waste into biogas for use as a clean cooking fuel and fertilizer to improve soils. However, despite its efficiency, recycling human waste in this way is uncommon because most cultures consider it unsavory.
The team at the University of Stirling believe that their findings – part of a larger study – will help decision-makers understand and overcome the barriers preventing uptake of new technologies designed to reduce impact on the natural environment.
Multidisciplinary researchers from the University of Stirling conducted in-depth interviews in Nepal, where uptake of toilet-linked anaerobic digesters (TLAD) is high, to understand how people overcame their cultural aversion. Those who adopted TLAD improved their home sanitation, indoor air quality and use of resources, the study found.
“I believe we have all the technology and the means to solve the world’s problems, but whether we are using it or not often depends on social factors,” said Natalie Boyd Williams, a PhD researcher in the division of Biological and Environmental Sciences at Stirling. “Particularly in the West, decision-makers often make assumptions about what people will or won’t accept – meaning that they don’t properly explore how certain technologies can be adopted. There has been community resistance to wind farms and biogas plants, for example, that has been dismissed and overlooked by developers, when engagement with these communities can in fact lead to acceptance.”
“We wanted to challenge the assumption by exploring how an initially unacceptable technology – in this case, toilet-linked anaerobic digesters in Nepal – can become widely adopted. This is understood in Nepal but less so outside it.”
The researchers conducted in-depth interviews with rural householders about how they overcame their cultural and religious objections around purity and pollution.
“We found that uptake was high where there was one risk-taker who led the way,” said Williams. “For example, in one village, one former policeman, who said he didn’t care what people thought, adopted the unit – and within a year most of the villagers had their own.”
“This also happened because people could go into his house to see how it worked,” Williams continued. “Demonstration was another important pathway to adoption, so people could see and understand how it functioned.”
In the United Kingdom (UK), sewage and food waste are converted into biogas and agricultural fertilizers using anaerobic digestion on an industrial scale — but smaller scale biogas units remain futuristic, despite their potential contribution to the circular economy.
Further research plans to compare TLAD adoption in Nepal and India, and acceptance of (and resistance to) products made from sewage in the UK.
