Discipline: Technology and Engineering
Subcategory: Environmental Engineering
Taylor Hines - Howard University
Presently, the community members of Buea, Cameroon are experiencing environmental health risks and unrealized economic profit due to the inefficient disposal of organic waste. Organic waste produced by Cameroonian homes, restaurants, and marketplaces is often left to decompose in small heaps that line the streets of towns and villages. A process called anaerobic digestion can break down this waste. Anaerobic digestion produces two valuable products: biogas and an effluent called bio-fertilizer. A biotechnological device called an anaerobic digester conventionally carries out this process. A biogas experiment was conducted to verify that biogas could be produced from organic waste in Buea. Organic waste was collected and reduced in particle size by using a mortar and pestle. The waste was mixed with equal part water to form a 2liter slurry mixture. The slurry was placed into the digestion tank and the tank was sealed and placed into a plywood box. A 60W light bulb was suspended from the lid of the plywood box directly over the digestion tank for temperature regulation. A flexible gas hose connected the digestion chamber and gas chamber. A pressure gage was connected to the gas chamber to monitor the production of biogas. Considerable issues such as power outages occurred during data collection, which lead to fluctuating rates of anaerobic digestion and limited biogas production. A pressure reading of 0.02 (bar) was observed on day 9 of 11, which indicated that some biogas was produced.
A small-scale mobile anaerobic digester was designed to solve organic waste management issues in Buea. The design was to be flexible in handling variable waste compositions, safe, affordable, reliable, useable, and mobile. Potential designs were sketched and dimensioned by hand and the best iteration was chosen. The final design was chosen based on the criteria stated above, its simplicity, and its manufacturability from resources readily available in Buea. The anaerobic digester was sketched using AutoCAD. The machine can digest organic waste, produce bio-fertilizer, and produce and store biogas. The anaerobic digester features a metal utility cart for mobility. There are no electric or gas components, as the digester relies solely on atmospheric heating. This design is expected to efficiently solve organic waste management issues in Buea. The University of Buea plans to produce a prototype of the anaerobic digester for on campus testing and future research.
Funder Acknowledgement(s): I would like to acknowledge the University of Buea, the Faculty of Science, and the College of Technology, for their overwhelming support in facilitating this research project. Thank you to Dr. Foba Tendo Josepha for proposing this research project. I would also like to acknowledge Mr. Abongwa for supervising my research project. I also thank M. Gershon Awa for producing the AutoCAD drawings. Lastly, thank you to Mr. Isaiah for assisting me with conducting the anaerobic digestion experiment.This material is based upon work supported by the National Science Foundation under Grant No. HRD-1238466. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Faculty Advisor: Willibroad Abongwa Acho, email@example.com