IWWG Task Group on
Engineered Nanomaterials in Waste

TG Leader: Nicole Berge and Florian Part

Background

The unique properties of engineered nanomaterials (ENMs) have enabled them to be used in a variety of consumer or industrial products, including construction materials, textiles, electronics, and medical devices. Examples of common consumer products containing ENMs include: cosmetics (TiO2, ZnO, Ag etc.), sporting goods (carbon nanotubes, fullerenes etc.), electronics (carbon nanotubes, quantum dots etc.), batteries (carbon nanotubes, graphene etc.), and textiles (Ag, carbon nanotubes).

As these ENM-laden materials and/or products reach the end of their useful life, the development of appropriate end-of-life management strategies is critical to minimize human and/or environment exposure. There are significant knowledge and data gaps associated with the fate of these embedded ENMs in waste management processes (e.g., landfilling, incineration, recycling) that limit our current ability to develop end-of-life strategies. The ultimate goal of this IWWG Task Group on Engineered Nanomaterials in Waste is to develop guidance on the appropriate end-of-life management strategies for these ENM-containing products and/or waste streams.

Initial Aims of the Task Group

The initial aims of the Task Group are to:

• Develop and write a critical literature review detailing current knowledge associated with engineered nanomaterial-containing products/wastes and highlighting the data gaps and research needs for publication in Waste Management.
• Compile literature that report on engineered nanomaterial-containing products/wastes, including what is known about material release from consumer products, material behaviour in waste environments, and analytical techniques.
• Develop a policy statement regarding appropriate disposal options for engineered nanomaterial-containing products/wastes.
• Develop appropriate protocols for conducting engineered nanomaterial-containing product/waste research in waste environments.

Members

Next Task Group Meeting

To be announced

News and Activities

June 2018:
The Task Group conducted a workshop during the 10th ICLRS in Lulea (Sweden). The goals of this workshop were to: (1) assess the current knowledge of the fate and transport of engineered nanomaterials in waste, (2) discuss potential implications associated with engineered nanomaterial disposal in landfills, (3) discuss challenges associated with the study of engineered nanomaterial fate and transport, and (4) discuss potential for future collaborations to further research on this topic. Nicole Berge held the introductory presentation “Exploring Interactions Between Engineered Nanomaterials and HDPE Geomembranes used in MSW Landfills and Leachate Treatment/Collection Ponds” and Florian Part presented the topic “Modelling frameworks for risk assessment of nanomaterials – from their use in products to landfilling”. After this, 17 international experts discussed the following questions:

• Do ENMs have an adverse impact on microbial activity in landfills?
• What are the main mechanisms triggering ENM release and transfer from solid matrices to the leachate stream? 
• How significant is ENM mobility through landfills, especially those in which no barrier system exists?
• How can ENM deposition/attachment efficiency be determined for different types of landfilled waste?
• What is the fate of ENMs during leachate treatment processes?
• Which analytical techniques are robust enough regarding standardisation in order to quantify ENM transformation, particularly aggregation, as well as to determine particle size distribution and shape in complex landfill leachates?

May 2018:
A comprehensive review about the behaviour, fate and transport of ENMs in wastes was published in Waste Management. In this review, identified knowledge gaps and future research questions were also summarised:

Part, F., Berge, N., Baran, P., Stringfellow, A., Wenjie, S., Bartelt-Hunt, S., Mitrano, D., Li, L., Hennebert, P., Quicker, P., C. Bolyard, S. and Huber-Humer, H. (2018). A review of the fate of engineered nanomaterials in municipal solid waste streams. Waste Management 75 (2018) 427–449. doi.org/10.1016/j.wasman.2018.02.012.

Previous Activities

October 2017:
To face the challenges associated with ENMs in wastes, the Task Group conducted a workshop during the 16th International Waste Management and Landfill Symposium in Sardinia (Italy) with the purpose of highlighting: (1) currently existing knowledge associated with ENM fate in waste management processes, (2) potential implications associated with ENM disposal, (3) challenges associated with conducting ENM-based research in waste environments, and (4) research needs.
During this workshop, Florian Part, Nicole Berge and Pierre Hennebert provided brief introductory presentations about different topics related to ENMs in waste. Following these presentations, a group discussion focused on identifying important research questions in this area was conducted. Results from this discussion indicate there is a need for additional information related to understanding factors influencing the potential transfer of ENMs from consumer products in conditions relevant to landfills and understanding whether current testing protocols (such as the TCLP and/or the CEN/TC 444 methods) are appropriate to study particle release and/or potential toxicity. In addition, there is a need for identifying analytical methods that are available and applicable to differentiate between dissolved ions and nanoparticulate species.

May 2016:
An editorial based on the workshop conducted during the 15th International Waste Management and Landfill Symposium (Oct. 2015) was published in Waste Management:

Part, F., Berge, N.D., Huber-Humer, M. (2016). Engineered Nanomaterials in Waste Streams. Waste Management 51, 1-2. doi.org/10.1016/j.wasman.2016.04.002.

October 2015:
The Task Group organized a workshop during the 15th International Waste Management and Landfill Symposium in Sardinia (Italy). Twenty-two experts in waste management attended this workshop. After the introductory lectures by Marion Huber-Humer and Florian Part (both BOKU, Vienna, Austria), Pierre Hennebert (INERIS, France), Shinya Suzuki (Fukuoka University, Japan), and Stephanie Bolyard (University of Central Florida, USA) presented their latest studies. At the conclusion of these presentations the current knowledge gaps in the field of “nanowaste” were discussed.

October 2014:
Two activities associated with this Task Group occurred during the 8th ICLRS in Crystal River, Florida, USA: (1) Session on engineered nanomaterials in waste and (2) Task Group meeting.

1.  Technical session on engineered nanomaterials in waste:
A portion of a session on emerging contaminants in MSW landfills was dedicated to discussing new advancements in understanding different aspects of engineered nanomaterials in waste. Two presentations were given. First, Shannon Bartelt-Hunt (University of Nebraska-Lincoln) presented results from work conducted to evaluate the influence of estradiol sorption on nanomaterial fate in landfills. Shannon Bartelt-Hunt reported that based on experimental results and using classical filtration theory that the presence of estradiol generally increased n-TiO2 mobility distance. Dr. Bartelt-Hunt also reported that solution ionic strength had a greater effect on mobility distance when compared with estradial concentration.

The second presentation was given by Florian Part (University of Natural Resources and Life Sciences, Vienna) and was on the topic of the traceability of quantum dots in mature landfill leachate. Florian Part reported that quantum dots may be used as model nanoparticles to study the fate and transport of engineered nanomaterials in waste environments. The significance of this finding is that quantum dots can be qualitatively detected using fluorescence microscopy at low detection limits. Using such an approach may provide a means to differentiate between engineered nanomaterials and naturally occurring colloids/particles, which is quite difficult to do using other analytical techniques.

A short discussion following the presentations took place. A significant component of the group discussion centered around the fact that many complications associated with evaluating engineered nanomaterial fate exist because of a lack of applicable and robust experimental techniques. There was also a discussion about whether nanomaterials in leachate is truly an issue. It is possible that landfills may serve as a sink for these particles. As a result of this discussion, the group agreed that many questions about the fate of engineered nanomaterials in waste management processes remain and that significant research in this area is needed.

2.  First official TG meeting
The first official meeting of the IWWG Task Group on Engineered Nanomaterials in waste took place during the 8th ICLRS in Crystal River. The specific goal of this first meeting was to revisit the task group’s goals and objectives, and to develop a strategy to begin addressing them.