Design and Performance Evaluation of a Seawater Waste Contraption for Floating-Waste Collection in Docking Areas

Abstract

Marine debris commonly accumulates in calm coastal and docking areas where tidal currents reverse direction. This study designed and evaluated an automated seawater waste contraption that uses current-responsive doors and a screened basket to collect floating and semi-submerged waste. We assessed an experimental prototype in a controlled environment using opposing electric fans to simulate bidirectional tidal flow and 150 pieces of crumpled paper per trial as surrogate waste. We evaluated three test conditions in five trials each: an unrestricted bank configuration, a configuration with guiding walls that directed the simulated current toward the basket opening, and a door-retention test during current reversal. The unrestricted configuration produced a mean collection efficiency of 28.27% (SD = 7.78), whereas the guiding-wall configuration achieved 77.87% (SD = 10.85), representing an improvement of 49.60 percentage points. The bidirectional door mechanism retained all 150 pieces in every trial, corresponding to 100% retention reliability. The findings indicate that the device can prevent collected waste from escaping during simulated current reversal. However, its collection efficiency depends strongly on channel geometry and the use of flow-guiding structures. The prototype may be applicable to calm docking areas, canals, creeks, and tidal coastal communities when integrated with trap lanes or guide walls. Because the tests used airflow and paper substitutes rather than seawater and actual marine debris, field-scale hydrodynamic, corrosion, electrical-safety, and durability testing is required before deployment.