Initiation of Motion and Form Drag of Plastic Waste in Landfills

Abstract:

Globally, a significant portion of plastic waste ends up in landfills due to limited management strategies for plastics. Plastic waste in landfills is at a risk of being transported to sensitive environmental systems, such as rivers and oceans through a variety of pathways – wind, floods, scavenging by animals, among others. Large-scale models have tried to estimate the environmental loss of plastic form landfills due to wind. However, such estimations require the assessment of fluid mechanical properties (i.e., drag, lift, critical velocity for initiation of motion) of the plastic objects being transported by wind. Such data is non-existent in the literature. To characterize the drag and initiation of motion, we conducted experiments in a wind tunnel at the Ecohydraulics and Ecomorphodynamics Laboratory at the University of Illinois Urbana-Champaign. Load cells were used to measure the drag and critical velocities for initiation of motion of a range of plastic materials of various sizes, shapes, and densities, at various attack angles. Using low-cost anemometers to measure windspeed, our data allows us to predict more accurate bulk estimates of plastic transport on landfills. Our findings, incorporated to existing models for transport in open landfills, will provide better tools to monitor and manage the spread of macro- and microplastics in the environment.