End-of-Life Heavy Metal Releases from Photovoltaic Panels and Quantum Dot Films

Hazardous Waste Concerns or Not?

Frank Christopher Brown, Yuqiang Bi, Shauhrat Chopra, Kiril Hristovski, Paul Westerhoff, Thomas L. Theis

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

To determine if there are potential concerns related to the environmental end-of-life impacts of photovoltaic (PV) or quantum-dot display (QD) technologies, the goal of this study was to assess the magnitude of heavy metal leaching using simulated landfill methodologies from devices in an attempt to forecast the lifecycle environmental impacts of subsequent generations QD-enabled PV technologies. The underlying hypotheses are (H1) existing PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California regulatory limits; and (H2) the disposal of PV and QD thin-film technologies does not exceed Land Disposal Restrictions (LDR). Three task-oriented objectives were completed: (O1) five representative PV panels and two representative thin-film displays with QD technology were obtained from commercial sources; (O2) RCRA Toxicity Characteristics Leaching Procedure (TCLP) tests and California Waste Extraction Tests (WET) were conducted in addition to microwave-assisted nitric acid digestion; and (O3) results were compared to the existing regulatory limits to examine the potential environmental end-of-life concerns. The heavy metal concentrations obtained from PV panels and QD thin-film displays when exposed to simulated landfill environments and extreme case leaching scenarios were generally several orders of magnitude lower than the promulgated standards and probably not of major concerns related to end-of-life safe disposal of these commercially available products. With exception to the findings for lead under the RCRA rules, the results confirmed that PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California characteristic hazardous waste regulatory limits. However, lead, mercury, and potentially other heavy metal releases have to be monitored to ensure that the disposal of this type of waste is in compliance with RCRA's LDR requirements and universal treatment standards because the second underlying hypothesis could not be completely supported for the leaching of these heavy metals. It could be anticipated that newer and more sophisticated soldering materials and approaches in the next generation of PV panels would significantly reduce the use of RCRA heavy metals or nanomaterials. However, although the generated data is limited to these representative PV and QD technologies and as such should not be considered applicable to the entire gamete of present-day technologies, these findings suggest that their release from future PV QD technologies would likely be greater from non-end-of-life processes, than from traditional land disposal routes.

Original languageEnglish (US)
JournalACS Sustainable Chemistry and Engineering
DOIs
StateAccepted/In press - Apr 15 2018

Fingerprint

Hazardous Waste
Heavy Metals
hazardous waste
Semiconductor quantum dots
Heavy metals
Display devices
heavy metal
Leaching
leaching
Thin films
landfill
Land fill
acid digestion
Lead
gamete
Nitric Acid
nitric acid
Mercury (metal)
Soldering
compliance

ASJC Scopus subject areas

  • Chemistry(all)
  • Environmental Chemistry
  • Chemical Engineering(all)
  • Renewable Energy, Sustainability and the Environment

Cite this

@article{9a8b6eacb41f4a2087789e71ba8aa4a9,
title = "End-of-Life Heavy Metal Releases from Photovoltaic Panels and Quantum Dot Films: Hazardous Waste Concerns or Not?",
abstract = "To determine if there are potential concerns related to the environmental end-of-life impacts of photovoltaic (PV) or quantum-dot display (QD) technologies, the goal of this study was to assess the magnitude of heavy metal leaching using simulated landfill methodologies from devices in an attempt to forecast the lifecycle environmental impacts of subsequent generations QD-enabled PV technologies. The underlying hypotheses are (H1) existing PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California regulatory limits; and (H2) the disposal of PV and QD thin-film technologies does not exceed Land Disposal Restrictions (LDR). Three task-oriented objectives were completed: (O1) five representative PV panels and two representative thin-film displays with QD technology were obtained from commercial sources; (O2) RCRA Toxicity Characteristics Leaching Procedure (TCLP) tests and California Waste Extraction Tests (WET) were conducted in addition to microwave-assisted nitric acid digestion; and (O3) results were compared to the existing regulatory limits to examine the potential environmental end-of-life concerns. The heavy metal concentrations obtained from PV panels and QD thin-film displays when exposed to simulated landfill environments and extreme case leaching scenarios were generally several orders of magnitude lower than the promulgated standards and probably not of major concerns related to end-of-life safe disposal of these commercially available products. With exception to the findings for lead under the RCRA rules, the results confirmed that PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California characteristic hazardous waste regulatory limits. However, lead, mercury, and potentially other heavy metal releases have to be monitored to ensure that the disposal of this type of waste is in compliance with RCRA's LDR requirements and universal treatment standards because the second underlying hypothesis could not be completely supported for the leaching of these heavy metals. It could be anticipated that newer and more sophisticated soldering materials and approaches in the next generation of PV panels would significantly reduce the use of RCRA heavy metals or nanomaterials. However, although the generated data is limited to these representative PV and QD technologies and as such should not be considered applicable to the entire gamete of present-day technologies, these findings suggest that their release from future PV QD technologies would likely be greater from non-end-of-life processes, than from traditional land disposal routes.",
author = "Brown, {Frank Christopher} and Yuqiang Bi and Shauhrat Chopra and Kiril Hristovski and Paul Westerhoff and Theis, {Thomas L.}",
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T1 - End-of-Life Heavy Metal Releases from Photovoltaic Panels and Quantum Dot Films

T2 - Hazardous Waste Concerns or Not?

AU - Brown, Frank Christopher

AU - Bi, Yuqiang

AU - Chopra, Shauhrat

AU - Hristovski, Kiril

AU - Westerhoff, Paul

AU - Theis, Thomas L.

PY - 2018/4/15

Y1 - 2018/4/15

N2 - To determine if there are potential concerns related to the environmental end-of-life impacts of photovoltaic (PV) or quantum-dot display (QD) technologies, the goal of this study was to assess the magnitude of heavy metal leaching using simulated landfill methodologies from devices in an attempt to forecast the lifecycle environmental impacts of subsequent generations QD-enabled PV technologies. The underlying hypotheses are (H1) existing PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California regulatory limits; and (H2) the disposal of PV and QD thin-film technologies does not exceed Land Disposal Restrictions (LDR). Three task-oriented objectives were completed: (O1) five representative PV panels and two representative thin-film displays with QD technology were obtained from commercial sources; (O2) RCRA Toxicity Characteristics Leaching Procedure (TCLP) tests and California Waste Extraction Tests (WET) were conducted in addition to microwave-assisted nitric acid digestion; and (O3) results were compared to the existing regulatory limits to examine the potential environmental end-of-life concerns. The heavy metal concentrations obtained from PV panels and QD thin-film displays when exposed to simulated landfill environments and extreme case leaching scenarios were generally several orders of magnitude lower than the promulgated standards and probably not of major concerns related to end-of-life safe disposal of these commercially available products. With exception to the findings for lead under the RCRA rules, the results confirmed that PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California characteristic hazardous waste regulatory limits. However, lead, mercury, and potentially other heavy metal releases have to be monitored to ensure that the disposal of this type of waste is in compliance with RCRA's LDR requirements and universal treatment standards because the second underlying hypothesis could not be completely supported for the leaching of these heavy metals. It could be anticipated that newer and more sophisticated soldering materials and approaches in the next generation of PV panels would significantly reduce the use of RCRA heavy metals or nanomaterials. However, although the generated data is limited to these representative PV and QD technologies and as such should not be considered applicable to the entire gamete of present-day technologies, these findings suggest that their release from future PV QD technologies would likely be greater from non-end-of-life processes, than from traditional land disposal routes.

AB - To determine if there are potential concerns related to the environmental end-of-life impacts of photovoltaic (PV) or quantum-dot display (QD) technologies, the goal of this study was to assess the magnitude of heavy metal leaching using simulated landfill methodologies from devices in an attempt to forecast the lifecycle environmental impacts of subsequent generations QD-enabled PV technologies. The underlying hypotheses are (H1) existing PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California regulatory limits; and (H2) the disposal of PV and QD thin-film technologies does not exceed Land Disposal Restrictions (LDR). Three task-oriented objectives were completed: (O1) five representative PV panels and two representative thin-film displays with QD technology were obtained from commercial sources; (O2) RCRA Toxicity Characteristics Leaching Procedure (TCLP) tests and California Waste Extraction Tests (WET) were conducted in addition to microwave-assisted nitric acid digestion; and (O3) results were compared to the existing regulatory limits to examine the potential environmental end-of-life concerns. The heavy metal concentrations obtained from PV panels and QD thin-film displays when exposed to simulated landfill environments and extreme case leaching scenarios were generally several orders of magnitude lower than the promulgated standards and probably not of major concerns related to end-of-life safe disposal of these commercially available products. With exception to the findings for lead under the RCRA rules, the results confirmed that PV and QD thin-film technologies do not release heavy metals at concentrations exceeding RCRA or State of California characteristic hazardous waste regulatory limits. However, lead, mercury, and potentially other heavy metal releases have to be monitored to ensure that the disposal of this type of waste is in compliance with RCRA's LDR requirements and universal treatment standards because the second underlying hypothesis could not be completely supported for the leaching of these heavy metals. It could be anticipated that newer and more sophisticated soldering materials and approaches in the next generation of PV panels would significantly reduce the use of RCRA heavy metals or nanomaterials. However, although the generated data is limited to these representative PV and QD technologies and as such should not be considered applicable to the entire gamete of present-day technologies, these findings suggest that their release from future PV QD technologies would likely be greater from non-end-of-life processes, than from traditional land disposal routes.

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