Ideas with Potential
As the basis for our own innovation we’ve reviewed the very latest science and technology developments which could help tackle the problem of pit filling.
Adding bacteria and/or enzymes to pit contents is the main approach currently taken in marketed products. We wanted to further explore the use of ‘bioadditives’ and other possible options relevant to waste accumulation in latrines.
Many of these fall within the biotechnology field, including microbiology, enzymology and biomass conversion.
We started by looking at bioadditive products which are claimed to reduce pit latrine contents.
These are typically powders composed largely of dried bacteria, added directly to the latrine to enhance waste breakdown and prevent or reduce flies and smells. They’re marketed worldwide, but their effectiveness is unproven by published independent scientific studies.
To find out more, we conducted a large-scale Bioadditives Survey with around 80 companies involved in manufacturing or retailing such products. We asked what ingredients they used and what evidence they had for their effectiveness. Many companies responded and we’re grateful for their support.
We found some similarities in the types of bacteria being used in their products: they’re generally isolated from the environment, secrete hydrolytic enzymes capable of breaking down organic waste, and can tolerate varying oxygen levels. But the survey revealed no new scientific evidence for their effectiveness.
Based on our existing knowledge, we set up five different hypotheses about how pit-fill rates could potentially be reduced, then tested them against the evidence from a broad survey of science and patent literature.
For example, knowing that latrines are likely to contain large numbers of bacteria, one hypothesis was that stimulating the right bacteria already present to work harder (rather than adding new ones) could be an effective way to enhance waste breakdown.