Thermal disposal of waste containing nanomaterials: first investigations on a methodology for risk management

G Ounoughene,B Debray,C Chivas-Joly,J-M Lopez-Cuesta,O Lebihan,L Le Coq,A Joubert,C Longuet

doi:10.1088/1742-6596/838/1/012024

Abstract

Considering the wide use and production of NMs since last two decades, these trendy nanomaterials (NMs) are expected to end up in thermal disposal and waste incineration plants (WIP). It seems relevant to assess the risks related to the thermal disposal and incineration of waste containing NMs (WCNMs). The objective of this work is to present a first approach to develop a preliminary methodology for risk management in order (1) to give insights on nanosafety of exposed operators and on potential environmental risks related to the incineration and thermal disposal of WCNMs, and (2) to eventually support decision-makers and incineration plant managers. Therefore, the main challenge is to find (a) key parameter(s) which would govern the decision related to risk management of NMs thermal disposal. On the one hand, we focused on the relevant literature studies about experimental works on incineration of NMs. On the other hand, we conducted an introductory discussion with a group of experts. The review of this literature highlights that the nano-object’s nanostructure destruction appears as a relevant indicator of the risks related to the NMs incineration. As a consequence, we defined a “temperature of nanostructure destruction” (TND) which would be the temperature from which the nanostructure will be destroyed. This parameter has been assumed to be a consistent indicator to develop a preliminary methodology. If the combustion chamber temperature is higher than the TND of the NM (or if they are close to each other), then the nanostructure will be destroyed and no risks related to NMs remain. If the TND of the NMs is higher than the combustion chamber temperature, then the nanostructure will not be destroyed and risks related to NMs have to be considered. As a result, five groups of NMs have been identified. WCNMs including carbonic NMs appear to be in good position to be destroyed safely in WIP. On the other hand, based on this criterion, there would be no available thermal disposal plants to safely manage WCNMs including CeO2 and ZrO2. Finally, a decision tree has been designed. TND is used as criteria to assess if a waste can be managed safely or not by a specific thermal disposal and which safety measures have to be taken.

Highlights

Since the last few years, the disposal via incineration of waste containing nanomaterials (WCNMs) has increasingly drawn attention of the authorities, the scientists and the waste incineration plant (WIP) managers.Toxic effects of different types of NMs have been demonstrated (Kühnel & Nickel 2014; Wang et al 2014)
The objective of this work is to present a first approach to develop a preliminary methodology for risk management in order (1) to give insights on nanosafety of exposed workers and on potential environmental risks related to the incineration and thermal disposal of waste containing NMs (WCNMs) and (2) to eventually support decision-makers and incineration plant managers
In order to provide a first insight into nanosafety regarding the incineration of WCNMs, the present study proposes an introductory approach for developing a preliminary methodology for managing the risks through the design of a decision tree

Summary

Introduction

Since the last few years, the disposal via incineration of waste containing nanomaterials (WCNMs) has increasingly drawn attention of the authorities, the scientists and the waste incineration plant (WIP) managers.Toxic effects of different types of NMs have been demonstrated (Kühnel & Nickel 2014; Wang et al 2014). The data are incomplete and more detailed studies are required. Their potential releases in the environment during their life cycle and their subsequent impacts on health have been an increasing concern for many years: firstly, the workers exposure to NMs during production (Oberdorster et al 2010, Wohlleben et al 2014, Bressot et al 2015), the emissions related to the wear and tear of products containing NMs (Shandilya et al 2015), their end of life (storage or recycling) and their elimination via thermal disposal like incineration (which is the most widespread thermal disposal treatment technology in Europe). Roes et al (2012) have evaluated the risks related to waste incineration of polymer nanocomposites without experimental works

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