Resource recovery from treatment products are a key aspect of sustainable management of sanitation, and can contribute to benefits such as stimulating proper operation and maintenance of a treatment plant, reducing pressure on local resources, and offsetting operation costs. As part of an engineering design approach, a focus on resource recovery can also support in defining treatment objectives where official standards do not exist.
Resource recovery from faecal sludge can have many different forms and product types, such as fuel, nutrients, feed, materials, and (irrigation) water. As referenced below in publications, previous work of the Management of Excreta, Wastewater, and Sludge (MEWS) research group has included production of various forms of solid fuel endproducts, including demand as an industrial fuel, carbonization through optimizing slow-pyrolysis processes, co-processing faecal sludge with other organic wastes, and pelletization for use as a fuel and to enable faster drying. Much of this work is summarized in the literature review, To Char or Not to Char , including how to select a treatment technology for producing a solid fuel endproduct. Also see below for use of plants from planted drying beds as an animal feed, and recommendations for optimal operation of planted drying beds.
When deciding on what faecal sludge endproduct is most appropriate, it is important to consider which products are desirable from a financial and market perspective, along with social and cultural considerations, embedded in an appropriate integrated planning approach. However, since markets for faecal sludge endproducts frequently do not exist, we developed the Market Driven Approach (MDA), a tool that helps to determine the market attractiveness of a future faecal sludge endproduct in a local context.
Planning for sustainable implementation also includes developing resource recovery based business models. As part of the RRR initiative (Resource, Recovery, and Reuse), MEWS contributed to a comprehensive overview of resource recovery focused business models for the waste and sanitation sector published by IWMI.