Lab-scale characterization of emissions from incineration of halogen- and sulfur-containing nanowastes by use of a tubular furnace

Abstract : Many solid materials contain nanoparticles to enhance their functionalities. The question of whether they may release nanoparticles at different moments of their life cycle is raised. Lifecycle includes waste management. There is therefore a need to determine the fate of nanoparticles when the materials they are incorporated in are incinerated. The present study aims at shedding light on these issues. In this context, three real-life wastes selected for their specific compositions were combusted in a lab-scale furnace under incineration conditions. The first two wastes contained nanoparticles, namely silica and titanium dioxide. The third waste was purposely nanoparticle free. In addition, the waste containing titanium dioxide did contain chlorine and the nanoparticle-free material was partly made of sulfur. Disposal of halogen and sulfur-containing garbage implies an incineration temperature of 1100 °C. This complex waste composition was seen as an opportunity to assess possible interactions between nanoparticles and hazardous elements such as chlorine and sulfur during the combustion. Most of the analyses were supported by electronic microscopy imaging after having sampled particles in the fumes and in the bottom ashes. Eventually, three mechanistic scenarios were drawn from these experiments. Focus was made on the evolution of the nanostructure. It was observed to be preserved for the first waste. It disappeared both from the aerosol and the residue for the second waste. The third material, though not initially nanostructured, led to the formation of a nanostructure in the aerosol.