Comparative evaluation of performance and usability of small-scale household composting with different geometric models

The evaluation of layout influence on the operational performance and usability of small-scale composters contributes to produce compact solutions with simplified operation and sanitary safety, suitable for reduced spaces and continued use. This study aims to report the influence of different designs on the composting process and the usability of compost bins. Five composters of similar scale (3 liters) and different geometric shapes were designed, manufactured, and tested. Bench tests were carried out for 60 days, and physical, chemical, and sanitary parameters were monitored, as well as the quality of the compost, according to agronomic parameters. The composters were filled with the same proportions of organic res-idues (food residues, dry leaves, and lawn trimming) to obtain the ideal C:N ratio. Three ge-ometrical layouts were tested concerning usability (hexagonal prism, cube, and parallelepi-ped) by volunteers for 50 days. The performed tests associated with the statistical treatment of results showed that the geometry of the prototypes interfered with the quality of the final compost and the composter operation. The hexagonal prism and the cube showed greater us-ability. The results represent a significant contribution to the advancement of solutions in decentralized composting.