Researchers from Cornell University and Maseno University, in partnership with Fresh Life and the Kisumu Young Agripreneurs (KIYA), have successfully commercialized a circular bionutrient fertilizer named KIYA Gold. Operating in Kenya, this collaborative initiative collects human waste from informal settlements, processes it via high-temperature pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More, and converts it into a safe, nutrient-dense soil amendmentA soil amendment is any material added to the soil to enhance its physical or chemical properties, improving its suitability for plant growth. Biochar is considered a soil amendment as it can improve soil structure, water retention, nutrient availability, and microbial activity.   More. By scaling up neighborhood-level bionutrient cycles, the project demonstrates a viable methodology for linking urban sanitation improvements directly with regional agricultural revitalization.

The initiative addresses a compounding ecological and socio-economic crisis in the port city of Kisumu, located on the edge of Lake Victoria. Inadequate sanitation infrastructure in dense, informal housing settlements like Nyalenda has traditionally allowed untreated human waste to flow directly into the lake, spreading disease and devastating local fish populations. Simultaneously, smallholder agricultural communities surrounding the city face severely depleted soils and exorbitant commercial costs for imported synthetic fertilizers. These combined forces have historically trapped young local farmers in a cycle of depressed crop yields and economic stagnation.

To mitigate these overlapping public health and agricultural challenges, the project partners developed an integrated logistical and thermal solution. The private waste recovery company Fresh Life maintains a network of removable toilet facilities within the Nyalenda informal settlement to aggregate the necessary organic inputs. This material is transported to a dedicated processing site operated by KIYA, where the solid feces undergo controlled drying and subsequent processing inside a Kontiki kiln. The automated pyrolysis process successfully converts the organic matter into sterile biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More, while human urine is separately stabilized using acid or lime before being infused into the carbon matrix.

The outcomes of this interdisciplinary collaboration prove that human waste can be successfully converted into a high-performing, inoffensive commercial asset. Agronomic testing shows that KIYA Gold promotes plant growth at rates matching or exceeding conventional synthetic alternatives while delivering the durable carbon structure inherent to biochar for long-term soil health. Financially, the localized production model significantly lowers input costs, expanding profit margins for a network of 1,000 farmers in the Kisumu region. Environmentally, the system successfully interrupts the flow of dangerous pathogens into Lake Victoria, protecting regional aquatic ecosystems and public health.