[Assessment of bioaccessibility of PAHs in microbial degradation process using solid phase micro extraction and solid...

Area of Science:

• Environmental Science
• Environmental Chemistry
• Soil Science

Background:

• Polycyclic Aromatic Hydrocarbons (PAHs) are persistent organic pollutants commonly found in coking plant soils.
• Assessing the bioaccessibility of PAHs is crucial for understanding their environmental fate and effective remediation.
• Microbial degradation is a promising strategy for PAH remediation in contaminated soils.

Purpose of the Study:

• To investigate the variation in PAH bioaccessibility during microbial degradation.
• To analyze the relationship between PAH degradation rates and changes in bioaccessibility.
• To evaluate the efficacy of microbial agents in remediating PAH-contaminated coking plant soil.

Main Methods:

• Remediation of PAH-contaminated soil using a microbial agent.
• Assessment of PAH bioaccessibility using Solid Phase Micro Extraction (SPME) and Solid Phase Extraction (SPE).
• Analysis of PAH concentrations in soil and soil pore water.
• Determination of fast desorption fractions using Tenax-TA extraction.

Main Results:

• Microbial remediation achieved 68.3% total PAH degradation, predominantly low molecular weight (LMW) PAHs.
• LMW PAHs significantly decreased in soil pore water, though individual PAH reductions were lower than degradation rates.
• Fast desorption fractions of LMW PAHs decreased, while high molecular weight (HMW) PAHs remained largely unchanged.
• Strong correlations were observed between PAH degradation and PAH concentration in soil pore water or Tenax-TA fast desorption fractions.

Conclusions:

• Microbial remediation effectively reduces PAH concentrations in contaminated soils.
• PAH concentration in soil pore water and Tenax-TA fast desorption fractions can serve as reliable indicators for predicting PAH degradation.
• These findings provide a theoretical basis for optimizing the remediation of PAH-contaminated coking plant soils.