Development and application of a predictive modelling approach for household packaging waste flows in sorting facilities.

Household packaging waste sorting facilities consist of complex networks of processes to separate diverse waste streams. These facilities are a key first step to re-enter materials into the recycling chain. However, so far there are no general methods to predict the performance of such sorting facilities, i.e. how efficiently the heterogeneous packaging waste is sorted into fractions with value for further recycling. In this paper, a model of the material flow in a sorting facility is presented, which allows changing the incoming waste composition, split factors on the sorting units as well as the setup of the sorting facility. The performance of the sorting facility is judged based on the purity of the output material (grade) and the recovery of the input material. A validation of the model was performed via a case study on Belgian post-consumer packaging waste with a selection of typical waste items that can be found in this stream. Moreover, the model was used to predict the possible sorting qualities of future Belgian post-consumer packaging waste after an extension of the allowed waste packaging items in the waste stream. Finally, a sensitivity analysis was performed on the split factors, which are a key data source in the model. Overall, the developed model is flexible and able to predict the performance of packaging waste sorting facilities as well as support waste management and design for recycling decisions, including future design of packaging, to ensure proper sorting and separation.

Assessing the determinants of intentions and behaviors of organizations towards a circular economy for plastics.

The production and consumption of plastics, although inevitable in our modern life, are predominantly unsustainable and inefficient. Hence, the concept of a circular economy for plastics has been proposed as a sustainable approach to thrive both economy and our modern life. To implement a circular economy for plastics, an understanding of both individuals' and organizations' behaviors is needed since psychological effects often undermine technical solutions. We particularly focus on organizations' behaviors since commercial plastic waste has not been thoroughly investigated compared to household plastic waste. Using the Theory of Planned Behavior (TPB) and Partial Least Squares Structural Equation Modeling (PLS-SEM), we assess the determinants of intentions and behaviors of 637 organizations in Belgium towards a circular economy for plastics. Our PLS-SEM analysis support that attitudes, subjective norms, and perceived behavioral control of decision makers positively influence organizations' intentions to implement best practices of plastic recycling. Furthermore, organizations' intentions, perceived behavioral control, pressures, and enablers positively, whereas barriers negatively, influence organizations' behaviors. Our study shows that most organizations have positive intentions, yet they seem to be failing in implementing best practices of plastic recycling due to some critical barriers. To overcome this intention-behavior gap and to attain a circular economy for plastics, our study suggests some measures.