Decentralized Wastewater Treatment for Water Reuse in Urban Agriculture in West Africa

Lecturers: Dr. Korbinian Kätzl (University of Kassel) 

Title: Decentralized Wastewater Treatment for Water Reuse in Urban Agriculture in West Africa

West Africa experiences severe water scarcity during dry seasons, while most wastewater is discharged untreated, causing pollution and health risks. To address this, a low-cost two-stage anaerobic filtration system using biochar made from local agricultural waste (rice husks and corn cobs) was developed to treat wastewater. After successful laboratory validation, the system was tested in Northern Ghana, where treated wastewater was used to irrigate crops such as lettuce and jute mallow. Results showed that crops irrigated with treated wastewater had pathogen levels similar to those irrigated with tap water, while retaining beneficial nutrients. This decentralized, locally sourced solution provides a practical way to produce safer irrigation water, improving food security and water availability in resource-limited urban areas.