A Hybrid Smart Bin Approach to Urban Waste Ecology: Enhancing Public Health and Reducing Ecological Risk via Sustainable Energy and Ozone Sanitation

The objective of this study was to develop and evaluate a hybrid smart-bin system integrating solar power, ozone disinfection, and Internet of Things (IoT)-based monitoring to improve urban waste management at the source. The compact, scalable prototype was designed to operate autonomously using solar energy while reducing waste volume and microbial contamination. Performance tests demonstrated a waste-volume reduction factor of 3.15 compared with conventional waste handling. Following a six-hour solar-powered charging cycle, the system remained operational for 168 h, enabling approximately one week of operation without grid electricity. A 10-min ozone treatment reduced the microbial count to 1.25 ± 0.22 log CFU/mL, representing an approximately six-log reduction relative to untreated waste. These findings highlight the system's potential to reduce waste-collection frequency and landfill demand while improving resource efficiency and minimizing exposure to pathogens, leachate, unpleasant odors, and disease vectors. However, potential reductions in transport-related carbon emissions require further verification through a life-cycle assessment (LCA). A multi-year techno-economic assessment incorporating operating and battery-replacement costs indicated that the projected cash flows were insufficient to recover the initial capital investment of 300,000 THB within a 10-year evaluation period at a 10% discount rate, yielding a base-case net present value (NPV) of approximately −139,000 THB. A positive financial return was achieved only under optimistic assumptions of zero maintenance costs and a service life exceeding 20 years. Therefore, the current justification for deployment rests primarily on the system's observed volume-reduction and microbial-reduction performance and its potential public-health benefits. Achieving economic feasibility will require lower capital costs, higher annual net benefits, or a combination of both.