Feces TO Fertilizer : An Innovative Vermicomposting Method For Environmentally Sustainable Faecal Sludge Managment

Abstract

Urbanization and rapid population growth worldwide have increased the amount of organic waste, especially fecal sludge (FS), which presents problems for traditional waste management techniques like landfilling and incineration. In Bangladesh, where FS management is a relatively new concept, sludge treatment plants in suburban areas and towns, supported by organizations like WaterAid Bangladesh and the Bangladesh Association for Social Advancement, have proven effective. Notably, the Sakhipur Municipality's facility, operational since 2016, has successfully treated FS and organic waste, producing high-quality compost sold to local farmers through co-composting. Vermicomposting of fecal sludge is an eco-friendly solution that addresses sanitation challenges, provides agricultural benefits, and reduces environmental impact by diverting sludge from landfills. Despite its advantages, careful management is crucial to address concerns about pathogens, requiring proper pre-treatment and optimal conditions for earthworm activity, along with cultural sensitivities for public acceptance of recycled waste use. The research employed a comprehensive approach, combining quantitative and qualitative data from diverse sources. The Sakhipur FSTP in Tangail was visited, and information was gathered from journals, articles, videos, photos, and reports in the laboratory phase, the collection of a 5kg dried fecal sludge sample from Sakhipur FSTP prioritized safety precautions for vermicomposting. The Soil Resource Development Institute (SRDI) in Khamar Bari, Dhaka, conducted standard lab tests on approximately 250 grams of compost after 45 days, following established procedures and conducting multiple tests for each parameter to minimize errors. In the vermicomposting process, 900g of cow dung was utilized as organic solid waste, combined with fecal sludge at a 1:3 ratio. The resulting compost exhibited favorable characteristics, including a dry, dark gray appearance, absence of unpleasant odors, and satisfactory color and moisture levels. Physiochemical assessments revealed a mature compost with a pH of 8.32, a high Electrical Conductivity (EC) of 8.1 mS/cm (potentially due to sodium chloride dissolution), Total Organic Carbon (TOC) at 14.60%, and Total Organic Nitrogen (TON) at 2.1%, all falling within standard ranges. The C/N ratio of 7.35:1, below the 20:1 limit set by the Bangladesh Ministry of Agriculture, indicates suitability for soil enrichment. Analysis from the Soil Resource Development Institute (SRDI) in Dhaka confirmed acceptable levels of heavy metals such as lead (26 ppm) and nickel (8 ppm), along with other chemical constituents like phosphorus, potassium, and sulfur, within standard limits. In conclusion, utilizing fecal sludge as compost or soil conditioner yields a nutrient-rich product suitable for household-level horticultural use, as affirmed by SRDI's findings. The study emphasizes the role of vermicomposting in sustainable fecal sludge management and highlights its promising potential for treating fecal sludge. The article highlights the need to recognize limitations and advocates for more research and development to strengthen vermicomposting's contribution to environmental sustainability, public health, and global sanitation, even though it presents strong evidence