Optimization of Faecal Sludge Management (FSM) and effectiveness of Refuse Derived Fuel (RDF) Generatio

Abstract

This study presents in-depth research on optimizing Faecal Sludge Management (FSM) and evaluating the effectiveness of Refuse Derived Fuel (RDF) generation from collected sludge in urban areas of Islamabad, Pakistan. The research addresses the inefficiencies in the current collection and transportation of faecal sludge and explores its potential as a sustainable energy source through the production of hydrochar briquettes. A comprehensive literature review highlights the advantages of Hydrothermal Carbonization (HTC) over traditional pyrolysis, noting the higher yield and energy content of hydrochar. The methodology involved collecting sludge samples from Bahria Enclave, followed by dewatering, drying, and processing through HTC at 250°C and 20 bar pressure for 2.5 hours. The resulting hydrochar was then combined with crop residues and binders to form briquettes, which were tested for calorific value, bulk density, emission levels, and mechanical properties. The results indicated that hydrochar briquettes have a calorific value comparable to natural coal, with lower emissions of PM2.5 and PM10. Among the tested briquettes, those with rice husk exhibited optimal balance in terms of energy content, emission levels, and mechanical strength. The economic analysis demonstrated a cost-effective production process with a short return period on investment, suggesting significant potential for scaling up. This study underscores the dual benefits of improved FSM and the valorization of faecal sludge into a viable alternative fuel, contributing to environmental sustainability and energy security. Future work should focus on pilot-scale implementation and long-term performance monitoring to refine the process and enhance its feasibility for broader application.