Environmental assessment of formal and informal waste treatment of liquid crystal display (LCD) monitors.

Abstract

In Santiago, Chile, 315,000 liquid crystal display (LCD) monitors are discarded annually. Of this amount, the formal sector of refurbishment and recycling manages only 5 %, creating the conditions for the emergence of informal management systems. This study provides the first comprehensive environmental and circularity assessment of monitor treatment across multiple impact categories, identifying trade-offs associated with formal and informal operations. For this, a life cycle assessment approach is utilised at both the product-level and the municipal management systems level, addressing the processes from the collection of the monitor to its end-of-life. At the product-level, two formal and two informal routes for managing an LCD monitor were evaluated. The results reveal that formal treatment companies have the best environmental performance in all the midpoint categories of ReCiPe, achieving benefits 42,000 times greater than formal disposal for marine eutrophication, and 25 % better than informal flea market traders across all categories. The analysis of management processes attributes most environmental benefits to refurbishment, representing between 76 % and 99 % of the magnitude of the assessed environmental impacts. A sensitivity analysis shows that the environmental performance of an informal trader surpasses that of a formal treatment company when both offer the same expected lifespan for a refurbished monitor and maintain their respective refurbishment rates offered. The municipal-level analysis was carried out through the evaluation of three scenarios. The results indicate that the scenario in which the informal sector cooperates with the formal sector and exclusively dedicates to collecting monitors exhibits superior environmental performance, averaging environmental benefits that are ten times greater than the current scenario and achieving valorisation rates of 22 %, the highest among the evaluated scenarios. The results of this research contribute to the discussion on formalisation and the promotion of the circular economy in the Global South.