Nepal WASH Blog Water, Sanitation and Hygiene (WASH) & Development in Nepal

December 31, 2010

Pee – the new fertilizer!

Filed under: Sanitation,Urine — Anita Pradhan @ 1:14 pm

The benefits of using composted solid waste as a fertilizer are well known. But how many people also know that human urine is packed with valuable nutrients essential for plant growth? Regrettably, most of these nutrients are lost when they are flushed away into water bodies or landfills, never benefiting agricultural soil and often causing (ground)water pollution. 

The majority of Nepal’s farmers rely on imported urea and phosphate fertilisers like DAP to fertilize their land. However, when you consider that mined rock phosphate is a non-renewable resource afflicted by record rates of depletion, the need to explore ways of recovering these lost nutrients from urine and recycling them to agricultural land becomes ever more urgent around the globe.. The workshop to present key findings of a two year research programme on struvite recovery from urine in Nepal was held in Kathmandu. 

The project, named STUN (Struvite Recovery from Urine in Nepal) is a joint initiative between UN-Habitat and Eawag; the Swiss Federal Institute of Aquatic Science and Technology

The team have been exploring a number of approaches, the first of which is ‘struvite precipitation, a method of extracting struvite (MAP or magnesium ammonium phosphate) from urine by adding magnesium to produce a safe bio-available powder fertilizer. This powder form has the advantage of being easier to transport than urine; it’s lighter and takes up less space, the nutrients can be stored over time and the lack of odour makes it a much more user-friendly product. The technology used in the process is simple and cost effective; the reactor used to produce struvite was built using only parts purchased in Kathmandu. Unfortunately with this process only a fraction of the nitrogen in urine is captured. To make a sustainable business out of urine treatment, a technology to capture and reuse this nitrogen will also need to be developed. 

In case you’re wondering, urine can actually be applied directly to the field, so long as it’s diluted with water in a ratio of 1:3, to avoid a concentration of nutrients burning the plants. However, when applied with a bucket, what happens is that part of the ammonium volatilizes, meaning that some of the precious nitrogen nutrients are lost. One way to minimise the losses is  to apply the urine with drip irrigation: the liquid flows through a set of hoses, and reaches the plants directly with the irrigation water. But, one ropani (5476 sq. ft. square feet) of land in just one sowing season would need almost 750 litres of urine!, This is equal to the amount that one adult and one child excrete together in a year. 

So the challenge for farmers using urine is finding a way of acquiring enough urine. The project team explored various collection methods in their pilot village Siddhipur on the outskirts of the Kathmandu valley. A ‘urine bank’ was installed in Siddhipur and someone was employed to collect urine from houses in the village and transport it on a pee-cycle outfitted with two 20 litre jerrycans. (Finding someone who was prepared to overcome the stigma of transporting urine was yet another challenge!) Collection from larger institutions such as schools turned out to be the most efficient option by far. 

The two year research project is now nearing its end, but it has definitely thrown up some interesting ideas. Recycling liquid waste to produce fertilizer from urine would undoubtedly improve sanitation if it were rolled out on a large scale. It could contribute to local food security; reversing soil degradation which is caused by imbalanced use of chemical fertilizers. As DAP is expensive many farmers rely on urea only, which leads to over fertilisation of nitrogen and depletion of other plant nutrients as phosphate and potassium. Enriched soil would yield better quality, organic produce which could possibly be sold at higher prices on the market. It could lead to nutrient independence, providing cheaper fertilizer for Nepal’s farmers currently reliant on chemical fertilizers imported at prices that are not always affordable, if at all available. 

Acquiring enough urine is still an issue and for the idea to develop into a workable system, changes would need to be made at a policy level, creating, for example a policy whereby offices were required to supply urine to the collection system. Cost is also a factor; setting up the infrastructure needed would undoubtedly require a significant investment. Add to this the stigma associated with handling urine, and the hygiene education that would be needed, and it’s clear there is still some way to go. 

In Kathmandu alone, 1 billion litres of nutrient-rich urine are currently being wasted each year, polluting our rivers and ground water – just think how many crop yields could be enriched if it were to be put to use!

Listen to an Interview with Eawag Researchers Raju Khadka and Marijn Zandee

Written by Anita Pradhan, Documentation Manager, WaterAid in Nepal and Yvonne Struthers


Pee cycle

December 17, 2010

Why fuss about sanitation?

Filed under: MDG,Sanitation,Urine — Tags: , , — Kabir Das Rajbhandari @ 5:46 pm

It is not an exaggeration to say that poor sanitation limits economic growth and cripples developing world economies. We know that poor sanitation invariably leads to low productivity. Without good sanitation, workers are less healthy and therefore less productive, live shorter lives, save and invest less and their children are less likely to attend school. On the other hand, with good sanitation, women, for example, are healthier, have more time for childcare and for income generating work. 

It has been estimated that meeting the sanitation Millenium Development Goals’ (MDG) target would yield economic benefits in the region of $63 billion each year (rising to $225 billion if universal access to sanitation were achieved.) Even conservative estimates predict that adequate investments in sanitation could provide the estimated annual 3% economic growth. Put even more simply, for every $1 invested in sanitation, $9 is returned to national economies in increased productivity and a reduced burden of healthcare. 

There are many examples of how improved sanitation can contribute towards economic development. For example, huge quantities of nitrogen, phosphorous and potassium in human excreta, particularly in urine, are wasted in sewerage systems and pit latrines. This represents a financial loss for public and private sewerage treatment services. Both rural and urban agriculture could benefit from nutrients from human urine and faeces to improve people’s livelihoods. 

Also, by preventing human excreta from polluting the human environment, the transmission of pathogens is also reduced. People are able to enjoy better health, allowing them to spend more time and energy on productive activities, mobilizing their assets while the costs of poor health are reduced. 

It is undeniable that improved sanitation is fundamental to improved livelihoods. Who can argue against the importance of safe sanitation and its effects on the livelihood improvements of the poorer sections of society? 

Buddhi and his grand-daughter Gyani Maya Sipai from Thimee, Bhaktapur, Nepal with produce grown using compost from latrines

Written by Kabir Rajbhandari, Programme Manager – Urban, WaterAid in Nepal

This blog was created by WaterAid under the creative commons licence