The design, setup and evaluation of a vermicomposting system for Imvepi Refugee Camp, Terego District

Abstract

This study designed and evaluated the effectiveness of vermicomposting in transforming dewatered fecal sludge (FS) at Imvepi refugee camp into a nutrient-rich, stabilized compost using fruit and vegetable waste as bulking agents. The main objective was to design a sustainable vermicomposting system for efficient dewatered fecal sludge management. It also aimed at assessing the changes in nutrient contents; nitrogen (N), phosphorus (P), and organic carbon (C) across different treatment combinations: sludge only (F1), sludge with fruit waste (F2), and sludge with vegetable waste (F3) all mixed in the ratio of 50%:50%. The experiment was conducted using triplicated treatments, and nutrient analysis was performed using standard laboratory methods. Results indicated that the incorporation of bulking agents significantly influenced nutrient dynamics and compost maturity. F3 showed the highest nitrogen content (2.36%) and a C:N ratio of 10.89, falling within the ideal range for mature compost (10:115:1), while F2 recorded the highest carbon content (30.54%) but had a higher C:N ratio (17.58) with high microbial activity, indicating incomplete stabilization. ANOVA revealed significant differences in nitrogen and carbon across treatments at 5% level of significance (p < 0.05), but not in phosphorus. Comparisons with traditionally stored sludge (6 months) revealed that vermicomposting substantially improved nutrient retention. The study concludes that vermicomposting, particularly with vegetable waste, is an effective method for managing FS and producing high-quality compost suitable for agricultural application in resource-constrained settings such as refugee settlements.