Fingerprinting complex mixed oil spills at refineries: Source identification, quantitative source apportionment, and...

Area of Science:

• Environmental Chemistry
• Petroleum Geochemistry
• Forensic Science

Background:

• Chemical fingerprinting is established for marine oil spills but complex for industrial sites.
• Light Non-Aqueous Phase Liquid (LNAPL) plumes present unique forensic challenges.
• Accurate source identification and biodegradation assessment are crucial for contaminated industrial sites.

Purpose of the Study:

• To develop an integrated framework for forensic investigation of a large LNAPL plume.
• To advance source identification, apportionment, and biodegradation assessment methodologies for complex petroleum contamination.
• To provide quantitative scientific support for environmental liability and remediation cost-sharing.

Main Methods:

• Applied an integrated framework combining source identification, source apportionment, and biodegradation assessment.
• Analyzed 28 samples including floating oils, petroleum products, and crude oils.
• Developed a new source apportionment method for ternary oil mixtures and a novel biodegradation index (BdgrI).

Main Results:

• Identified four distinct oil mixtures within the LNAPL plume.
• Quantified varying proportions of reformulated gasoline, catalytic cracking diesel, straight-run diesel, and crude oil.
• Demonstrated limitations of bicyclic sesquiterpanes for source identification in middle distillates from similar feedstocks.

Conclusions:

• The integrated framework significantly enhances forensic capabilities for complex petroleum contamination.
• The new methods improve source identification accuracy and guide targeted bioremediation strategies.
• The study provides quantitative support for environmental liability and remediation cost-sharing at contaminated refinery sites.