Nanomaterial disposal by incineration

Abstract

As nanotechnology-based products enter into widespread use, nanomaterials will end up in disposal waste streams that are ultimately discharged to the environment. One possible end-of-life scenario is incineration. This review attempts to ascertain the potential pathways by which nanomaterials may enter incinerator waste streams and the fate of these nanomaterials during the incineration process. Although the literature on incineration of nanomaterials is scarce, results from studies of their behavior at high temperature or in combustion environments for other applications can help predict their fate within an incinerator. Preliminary evidence suggests nanomaterials may catalyze the formation or destruction of combustion by-products. Depending on their composition, nanomaterials may undergo physical and chemical transformations within the incinerator, impacting their partitioning within the incineration system (e.g., bottom ash, fly ash) and the effectiveness of control technology for removing them. These transformations may also drastically affect nanomaterial transport and impacts in the environment. Current regulations on incinerator emissions do not specifically address nanomaterials, but limits on particle and metal emissions may prove somewhat effective at reducing the release of nanomaterials in incinerator effluent. Control technology used to meet these regulations, such as fabric filters, electrostatic precipitators, and wet electrostatic scrubbers, are expected to be at least partially effective at removing nanomaterials from incinerator flue gas.

Behavior of TiO2 nanoparticles during incineration of solid paint waste: A lab-scale test

“…The furnace temperature was fixed at 950°C, and the temperature in the lab-scale incineration reactor was measured with a thermocouple placed near the crucible. The chosen temperatures falls in the range of 850-1200°C, which are typical combustion temperatures of a full-scale incineration plant (Holder et al, 2013). During the experiments the air inlet was adjusted at 3 l/min, in accordance with the ISO 19011 (ISO, 2011).…”

“…nanowaste). However, very limited information and experimental data are available concerning the fate of ENPs during waste treatment (Holder et al, 2013). According to Bystrzejewska-Piotrowska et al (2009) and Moore (2006), the impact of nano-based products introduced to the market should be addressed before waste containing ENPs appears in the environment.…”

Leaching of nano-ZnO in municipal solid waste

“…It was reported that silica, titanium, alumina, iron and zinc oxides dominated the ENM market in 2010 based on material mass flow analysis. Among these ENMs, zinc oxide (ZnO), the focus of this study, is commonly used in cosmetics, electronic and optics, Even though various studies predict that the majority of ENMs will end up in landfills either through direct disposal or as sludge and bottom and fly ash matrix from waste incineration [2,[6][7][8][9], information about the fate of ENMs during waste stabilization is still scarce [10]. It is however reported that future research activities should at least include analytical techniques to characterize nano-waste, definition of acceptable limit values for exposure and to determine the release mechanisms of ENMs [10].…”

Risk of Nanowastes

“…Also, there is a need to develop research in the scope of nanowaste treatment and to reduce the unintentional release into the environment. But the lack of adequate tools and methods to measure emissions of nanoparticles accurately and significant gaps in data, monitoring, and technology hinder the precise determination of nanoparticle emissions [5]. From the other hand, governments have to take a proactive approach towards developing a waste strategy for nanomaterials, for prevention against long-term unintended consequences.…”

“…Manufactures ENMs comprise seven main classes: carbonaceous nanomaterials (e.g., carbon nanotubes); semiconductors (e.g., quantum dots); metal oxides (e.g., zinc oxide); nanopolymers (e.g., dendrimers); nanoclays; emulsions (e.g., acrylic latex); and metals (e.g., silver). Except for carbon black, the TiO 2 nanomaterial is produced most often; in order of most to least produced ENMs, TiO 2 >SiO 2 >ZnO>Fe and FeOx>Al 2 O 3 >CeO 2 >CNT>Ag [1,5,6]. It should be noted that the nanomaterials can be released to the environment at any stage of the life cycle of products (LCA -Life Cycle Assessment), from the manufacture, use, and disposal or recycling processes.…”