Standoff Identification of Plastic Waste Using a Low-Cost Compact Laser-Induced Breakdown Spectroscopy (LIBS)...

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Accurate identification of post-consumer plastic waste is crucial for effective recycling and waste management.
• Traditional methods for plastic waste analysis can be time-consuming and costly.
• Remote sensing technologies offer potential for rapid, in-situ waste characterization.

Purpose of the Study:

• To develop and evaluate a compact, low-cost standoff laser-induced breakdown spectroscopy (ST-LIBS) system for remote identification of plastic waste.
• To assess the system's performance in terms of speed, accuracy, and cost-effectiveness compared to existing methods.

Main Methods:

• Utilized a single plano-convex lens for optical emission collection at a 6.5 m standoff distance.
• Employed a compact, non-gated Czerny-Turner charge-coupled device (CT-CCD) spectrometer for spectral analysis.
• Applied principal component analysis (PCA) and artificial neural network (ANN) analysis for data interpretation.

Main Results:

• Achieved tenfold cost reduction and significant decrease in system size and weight compared to telescopic systems.
• Demonstrated rapid identification using single laser shots, enabling real-time analysis of numerous samples.
• PCA showed excellent sample separation, and ANN achieved up to ~99% accuracy in plastic waste identification within ~10 ms testing time.

Conclusions:

• The developed ST-LIBS system offers a compact, low-cost, and rapid solution for post-consumer plastic waste identification.
• This technology has the potential to significantly improve real-time waste management processes.
• The system's high accuracy and speed make it suitable for deployment in recycling facilities.