World Toilet Day 2021: Value toilets – and what goes into them

World Toilet Day 2021, yearly celebrated on 19 November, has the theme ‘Valuing Toilets.’ The work of IHE Delft Master of Science students show that not only toilets, but also the matter that goes in them, should be valued. Richard Mwembe and Niharika Sharma, who graduated from the IHE Delft one-year Master in Sanitation program last month, used their research to demonstrate the value that faecal excrements can have in households, as compost for agriculture and as fuel for cooking.

Niharika Sharma, a graduate from India who won the best thesis award at the graduation ceremony last month addressed the problem of deforestation caused by firewood use in households in Kenya.

“Clearly, there is an urgent need to switch to alternative cooking fuels and one of these alternatives could be using faecal sludge, in other words, poo,” she said.

She looked at the suitability of using faecal sludge and residues from crops to replace firewood for cooking. Poo samples from 12 different onsite sanitation systems were collected in Kenya and mixed with corncobs, a common crop residue with a high energy content. Niharika analyzed the samples at IHE Delft and found that their combustion properties and heating value make the mix a good fuel that is a viable and sustainable alternative for firewood.

“To me, IHE Delft provides the best environment and equipment to conduct such high-quality research that contributes to the field of water and sanitation,” Niharika said.

Richard Mwembe, a sanitation graduate from Zimbabwe, looked at problems caused by improvised toilets, or pit latrines. Such facilities, often intensively used, can contaminate the environment and expose people to parasites that cause diseases. Humanitarian organizations are seeking to treat this pathogenic waste so that it can be reused as fertilizer or soil conditioner, but they need ways to determine whether the sludge contains eggs from the roundworm, highly infectious parasites that pose a risk to human health.

“In refugee camps for example, humanitarian organizations need to be able to determine the amount of parasite eggs, which is one of the indicators used by WHO to determine whether the sludge is safe to use as fertilizer or soil conditioner,” Richard said. “To find these eggs, I have used two analysis methodologies commonly used for fresh faeces by using pig manure. The amount of parasite eggs could be detected from the samples.”

When completed, Richard’s research will provide humanitarian organizations with a decision framework to guide them in doing egg analysis. Ultimately, this should lower the costs of faecal sludge disposal as it enables the safe use of co-composting and other cost-effective and sustainable treatment technologies. This will promote reuse of faecal sludge for agricultural purposes.

“By looking into practical solutions that enable faecal sludge to be used as a valuable resource, both Niharika and Richard are contributing to solving real-world problems. I look forward to seeing how they continue to make an impact in this field,” said Tineke Hooijmans, Associate Professor of Sanitary Engineering and supervisor of both MSc research projects. Niharika and Richard were mentored by Capucine Dupont, Berend Lolkema and Konstantina Velkushanova.