Polycyclic aromatic hydrocarbons in solid residues from waste incineration.

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Waste Management

Background:

• Incineration of clinical waste generates solid residues like bottom ash and fly ash.
• Polycyclic aromatic hydrocarbons (PAHs) are a group of organic pollutants of concern.
• Understanding PAH levels in incineration residues is crucial for environmental risk assessment.

Purpose of the Study:

• To quantify polycyclic aromatic hydrocarbon (PAH) levels in solid residues from clinical waste incineration.
• To determine PAH mass emission rates and emission rates relative to waste burned.
• To investigate factors influencing PAH levels and environmental fate in incineration byproducts.

Main Methods:

• High-Performance Liquid Chromatography (HPLC) with fluorescence detection was employed for PAH analysis.
• Solid residues, specifically bottom ash and fly ash, were collected and prepared.
• PAH mass emission rates were calculated based on residue composition and incineration throughput.

Main Results:

• Bottom ash exhibited consistent physical properties and PAH levels, with significantly elevated low molecular mass PAHs compared to literature values.
• High molecular mass PAH levels in bottom ash were comparable to previous studies after accounting for sample preparation differences.
• No PAHs were detected in fly ash, an unexpected result attributed to potential matrix effects from high lime content.

Conclusions:

• The composition of clinical waste, combustion conditions, and sample preparation methods may contribute to elevated low molecular mass PAHs in bottom ash.
• The absence of PAHs in fly ash warrants further investigation into matrix effects and their implications for emission estimations.
• Further research is needed to fully elucidate the partitioning and environmental fate of PAHs from clinical waste incineration residues.