Mercury speciation in fluorescent lamps by thermal release analysis

Area of Science:

• Environmental Chemistry
• Materials Science
• Analytical Chemistry

Background:

• Fluorescent lamps contain mercury, a toxic element, posing environmental and health risks upon disposal.
• Understanding mercury's chemical form (speciation) in waste is crucial for effective management and risk assessment.

Purpose of the Study:

• To investigate mercury speciation in phosphorus powder and soda lime glass matrices from fluorescent lamp waste.
• To determine the mobility and potential hazards associated with different mercury forms in these waste materials.

Main Methods:

• Thermo-desorption/atomic absorption spectrometry (TDAAS) for mercury analysis.
• X-ray diffraction (XRD) for matrix characterization.
• Cold vapor-atomic absorption (CV-AAS) and inductively coupled plasma/atomic emission spectrometry (ICP/AES) for mercury quantification.

Main Results:

• TDAAS identified mobile oxidized mercury forms (Hg(1+) and Hg(2+)) in powder matrices, particularly at high mercury concentrations.
• Glass waste profiles indicated mercury strongly bound to the matrix, desorbing only at elevated temperatures.
• The presence of mobile mercury species highlights potential leaching and environmental contamination risks.

Conclusions:

• Mercury speciation in fluorescent lamp waste varies significantly between phosphorus powder and glass matrices.
• Oxidized mercury forms in powder matrices represent a mobile hazard.
• Mercury's strong binding in glass waste suggests stabilization but requires high-temperature treatment for release.