Development of an automated microcontroller-based in-vessel composting system for the household setting

• Main Authors: Co, Malcolm Andersen H., Go, Jan Ralph U., Magallanes, Francis John N., Vong, John Matthew B.
• Format: text
• Language: English
• Published: Animo Repository 2023
• Subjects: Composters (Containers)—Automatic control; Microcontrollers; Compost; Computer Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etdb_ece/30; https://animorepository.dlsu.edu.ph/context/etdb_ece/article/1031/viewcontent/Development2_of_an_automated_microcontroller_based_in_vessel_compo.pdf
• Institution: De La Salle University

The Philippines is currently facing problems in terms of food waste disposal due to rapid urbanization contributing to the increase in waste production. Despite laws creating solutions to the growing demand for food waste disposal, the country still has poor solid waste management schemes due to its heavy reliance on landfills which is detrimental to the environment. As such, it is important to consider different forms of food waste disposal such as composting. Composting provides economic and environmental benefits such as cheaper expenses and a reduction of carbon footprint. In-vessel composting is a type of composting that is done through a contained vessel where multiple parameters such as temperature and moisture are being controlled and monitored. These parameters help optimize the time needed for food wastes to turn into compost especially when an EM-1 inoculant is added. With these being said, the researchers created a microcontroller-based in-vessel composting system that will automate the process of in-vessel composting process for two weeks with a help of a user interface. Various sensors and actuators would be used to grind the food waste, provide aeration, monitor and control temperature and soil moisture through a fuzzy-logic control system, and provide water and inoculum. The system was evaluated with accuracy testing, system testing, fuzzy logic controller testing, system usability scale survey, and compost testing. The sensors were calibrated and provided accurate readings with a 5% margin of error. The system was also tested by inputting 4L of food waste for a period of two weeks. The automation process was successful by analyzing the log files generated by the system. The fuzzy logic controller was also able to maintain a temperature of 55-65 °C between the pre-composting and composting phase and 40-50 °C during the maturation phase. Furthermore, soil moisture of 30-50 % was also maintained during the composting phase. The system’s user interface was also intuitive or usable as it scored an adjective rating of excellent in the System Usability Scale (SUS) survey. Lastly, the compost harvested from the system also satisfied the minimum compost requirements in total NPK, salmonella presence, total coliform level, and compost characteristics (i.e., smell, color, and consistency) set by the Philippine National Standard’s PNS/BAFS 40:2016.