Estimation of bioavailability and potential risks of naphthalene in soils with solid phase microextraction

Area of Science:

• Environmental Science
• Microbiology
• Soil Science

Background:

• Naphthalene contamination poses environmental risks.
• Understanding naphthalene bioavailability is crucial for effective bioremediation.
• Soil properties significantly influence contaminant fate and transport.

Purpose of the Study:

• To investigate naphthalene bioavailability variations in diverse soil types.
• To assess the correlation between extractable naphthalene and biodegradation rates.
• To evaluate Solid Phase Microextraction (SPME) as a method for estimating bioremediation efficacy.

Main Methods:

• Batch experiments using soils with modified organic matter and texture.
• Solid Phase Microextraction (SPME) for quantifying extractable naphthalene.
• Measurement of naphthalene biodegradation rates by indigenous microorganisms over 300 hours.
• Ultrasonic extractability to assess sequestration in aged soil samples.

Main Results:

• Biodegradation rates increased with higher silt/clay content (0.30 to 0.48 μg g⁻¹ h⁻¹).
• Higher soil organic matter (SOM) content (1.3% to 5.2%) decreased biodegradation rates (0.30 to 0.20 μg g⁻¹ h⁻¹).
• Naphthalene bioavailability decreased with increasing SOM.
• SPME measurements showed a strong correlation with biodegraded naphthalene amounts.
• Sequestration was observed in aged soils, with no significant difference between 4 and 16 months.

Conclusions:

• Soil texture and organic matter content are key factors influencing naphthalene biodegradation.
• SPME is a reliable and promising technique for assessing the bioremediation potential of contaminated soils.
• Findings support the development of targeted bioremediation strategies based on soil properties.