Wastewater as a resource

At the heart of our work to promote the circular economy is a mindset that regards ‘waste’ as raw material that can be converted into an economically valuable commodity for agriculture or energy. This has the twin benefits of reducing the cost of dealing with the waste and increasing its value in the local economy. This approach is the essence of Resource Recovery and Reuse (RRR), a subprogram under the Rural-Urban Linkages Flagship that the International Water Management Institute (IWMI) manages for the CGIAR Research Program (CRP) on Water, Land and Ecosystems (WLE).

In 2019, our work on RRR in Ghana and Sri Lanka was the subject of an Outcome Evaluation of Research for Development. The evaluation was “very positive overall,” and the published report goes on to describe the work as “a very successful pioneering research-for-development program which offers lessons for other CRPs and WLE Flagships.”

In Ghana, we have been developing three public-private partnerships (PPPs) to build sustainable businesses using waste streams as resources. Two of these PPPs are increasing production of the innovative product Fortifer™, a clean and safe agricultural fertilizer produced from fecal sludge, which is available in various formulations, e.g., the conversion of solid organic waste into briquettes to be used as a low-cost fuel. The third PPP is using treated domestic wastewater to hatch the brood stock for aquaculture in separate freshwater ponds. The waste stream thus creates additional value in the form of an important food source.

In July 2019, building on our experience in Ghana, IWMI joined the Food and Agriculture Organization of the United Nations (FAO) to assist what is now the Ministry of Urban Development, Water Supply and Housing Facilities of Sri Lanka in a project to explore innovative approaches to reduce, recycle and reuse food waste. Approximately 60% of the 700 tonnes of solid waste generated in the capital city, Colombo, each day is organic waste, and food waste is the largest portion. The main focus of the project is on reducing the amount of food that is not eaten, in order to complement IWMI’s earlier emphasis on composting the waste, which will inevitably remain. In November 2019, this work was summarized in a video on YouTube.

In addition to our efforts to promote the conversion of ‘waste’ into a valuable resource, we will also be contributing to an evidence-based national strategy on food waste for the Government of Sri Lanka.

A pilot project was launched in September 2019, together with CGIAR colleagues at World Agroforestry (ICRAF) and the International Center for Tropical Agriculture (CIAT), to reduce land degradation around refugee settlements and their host communities in Ethiopia, Kenya and Uganda. This is a new focus for CGIAR projects, recognizing that meeting the energy needs of refugee settlements leads to severe deforestation, which can in part be addressed through RRR. For example, waste briquettes will provide an alternative energy source. The project will also aim to recycle resources to improve soil fertility and resilience in the plots that supply refugees with nutritious fruits and vegetables, while also improving sanitation. We will be exploring many other technologies to improve the lives of people in the settlements, including the safe use of ‘gray’ water for irrigation, all with an eye on the circular economy.

Sharing information is crucial if we are to enable others to build their own circular economies. Therefore, we feed lessons learned into our technical reports on RRR. In 2019, these reports included Guidelines and regulations for fecal sludge management from on-site sanitation facilities and Global experiences on waste processing with black soldier fly (Hermetia illucens): From technology to business.

Overall, our research on the circular economy produces a virtuous circle of its own. Successful projects generate a revenue stream that enhances the management of the resource and adds to its sustainability. That, in turn, directly improves the urban environment. The additional products created from ‘waste’ contribute to the city’s resilience and food security.

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