Simulated Ageing of Crude Oil and Advanced Oxidation Processes for Water Remediation since Crude Oil Pollution

Filomena Lelario,Sabino Aurelio Bufo,Laura Scrano,Giuliana Bianco

doi:10.3390/catal11080954

Filomena Lelario, Sabino Aurelio Bufo + Show 2 more

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https://doi.org/10.3390/catal11080954

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Journal: Catalysts	Publication Date: Aug 10, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: University of Johannesburg, University of Basilicata

Abstract

Crude oil can undergo biotic and abiotic transformation processes in the environment. This article deals with the fate of an Italian crude oil under simulated solar irradiation to understand (i) the modification induced on its composition by artificial ageing and (ii) the transformations arising from different advanced oxidation processes (AOPs) applied as oil-polluted water remediation methods. The AOPs adopted were photocatalysis, sonolysis and, simultaneously, photocatalysis and sonolysis (sonophotocatalysis). Crude oil and its water-soluble fractions underwent analysis using GC-MS, liquid-state 1H-NMR, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and fluorescence. The crude oil after light irradiation showed (i) significant modifications induced by the artificial ageing on its composition and (ii) the formation of potentially toxic substances. The treatment produced oil oxidation with a particular effect of double bonds oxygenation. Non-polar compounds present in the water-soluble oil fraction showed a strong presence of branched alkanes and a good amount of linear and aromatic alkanes. All remediation methods utilised generated an increase of C5 class and a decrease of C6–C9 types of compounds. The analysis of polar molecules elucidated that oxygenated compounds underwent a slight reduction after photocatalysis and a sharp decline after sonophotocatalytic degradation. Significant modifications did not occur by sonolysis.

Highlights

The composition of petroleum crude oil varies widely depending on the source and processing
Information on the composition of the oil watersoluble fraction obtained through GC-MS, liquid state 1 H NMR and FT-ICR-MS was the basis for this investigation
FT-ICR MS evidenced an augmentation of compounds with low molecular weight and a slight increase of the number of oxygen atoms in the oxygenated species, as depicted in Kendrick and van Krevelen diagrams

Summary

Introduction

The composition of petroleum crude oil varies widely depending on the source and processing. Many oil constituents can be carcinogens, neurotoxins, respiratory irritants, hepatotoxins, nephrotoxins, and mutagens. Their toxic effects can be acute and chronic, causing many direct symptoms and major long-term injuries, including reproductive problems and cancer [1]. Heteroatomic compounds constitute a relatively small portion of crude oils, less than 15%. They have significant implications since their presence, composition, and solubility, which depend on the origin of the crude oil, can cause either positive or negative effects in the transformation processes and are of environmental concern [2,3]

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