摘要
A comparison study on the various waste management scenarios of polyethylene terephthalate (PET) bottles has been carried out using the life-cycle assessment (LCA) methodology. The energy and material balances were set up to account for all the energy consumed and the emissions released by each stage of the production and waste management phases of the life-cycle of the PET bottles, and then a mathematical model was derived to illustrate these energy and emissions for the various waste management pathways. For the collection process of the bottles, a nonlinear functional relationship was chosen and included in the model. Using the developed model, the environmental burdens of various waste management alternatives were evaluated to yield a ready comparison of each pathway. We can also easily discern through parameter analysis which waste management scenario is deemed best having the least energy consumed and the smallest emissions released with respect to the environmental burdens in question.