Reverse logistics for empty pesticide containers: optimal design for sustainable management over wide areas

Empty pesticide containers (EPCs) are a source of high-quality high-density polyethylene with a few different colors and a practically constant quality over time; thus, EPCs are economically valuable and fully recyclable. There are two key aspects to the successful recycling of these containers, their cleaning and collection, the latter being especially challenging in areas where the distances between the generation nodes are large. This paper presents the development of a multi-period Mixed Integer Linear Programming model for the optimal design of a reverse logistics network for EPCs in large territorial areas and its application to the Buenos Aires province of Argentina. The model structure is based on the current legislation and reflects the interactions among society, development and the environment, allowing a quantification of the technical and economic implications of sustainable development. The proposed formulation takes into account investment and operating costs for each temporary collection center (TCC) and recycling plant, as well as transportation costs between nodes. The kilometers travelled to operate the network help to estimate the minimum number of vehicles required and the global climate change impacts of each studied alternative. Moreover, the model incorporates restrictions and operational alternatives commonly used in large territorial areas. This work is part of a broader project in collaboration with national agencies to develop tools to strengthen the political role and facilitate the implementation of the extended producer responsibility principle (EPR) in the context of EPCs management system. Moreover, the conclusions drawn from scenario studies serve as guidelines for its implementation in other countries or regions.