Abstract: Improper treatment of recycled household appliances could cause serious environment pollutions. However, in the current recycling and treatment system, the government recycles only a small portion of used household appliances with environmental protection while the private section does a large portion of them without environmental protection. Therefore, it is appealing to study the strategies for recycling and treating used household appliances via building dynamic systems based models. In this study, Beijing's recycling and treatment system of used household appliances is investigated, its inventory flow chat is created and the dynamic model of inventory flow is established. The numerical simulations illustrate the effectiveness of our model. Furthermore, analysis based on our model show that the collaborations among the government, the appliance manufacturers and the recycling companies can not only improve the recycling and treatment system with environmental protect, but also increase the profit of enterprises. The theoretic basis could be provided for the government to optimize the recycling and treatment of used household appliances.

Key words: systems dynamics, used household appliance, recycling, environmental protection, inventory flow