Remediation of Petroleum-Contaminated Soil and Simultaneous Recovery of Oil by Fast Pyrolysis

Abstract

Petroleum-contaminated soil (PCS) caused by the accidental release of crude oil into the environment, which occurs frequently during oil exploitation worldwide, needs efficient and cost-effective remediation. In this study, a fast pyrolysis technology was implemented to remediate the PCS and concurrently recover the oil. The remediation effect related to pyrolytic parameters, the recovery rate of oil and its possible formation pathway, and the physicochemical properties of the remediated PCS and its suitability for planting were systematically investigated. The results show that 50.9% carbon was recovered in oil, whose quality even exceeds that of crude oil. Both extractable total petroleum hydrocarbon (TPH) and water-soluble organic matter (SOM) in PCS were completely removed at 500 °C within 30 min. The remaining carbon in remediated PCS was determined to be in a stable and innocuous state, which has no adverse effect on wheat growth. On the basis of the systematically characterizations of initial PCS and pyrolytic products, a possible thermochemical mechanism was proposed which involves evaporation, cracking and polymerization. In addition, the energy consumption analysis and remediation effect of various PCSs indicate that fast pyrolysis is a viable and cost-effective method for PCS remediation.

Removal of Total Petroleum Hydrocarbons from Contaminated Soil through Microwave Irradiation

“…Petroleum contaminated soil is considered to be hazardous waste that causes local and diffuse pollution in the environment [ 3 ]. Total petroleum hydrocarbons (TPH) are composed of a complex mixture of saturated hydrocarbons (primarily paraffins, 60–80%) and aromatic hydrocarbons (20–40%) [ 4 , 5 ].…”

Formation of environmentally persistent free radicals and reactive oxygen species during the thermal treatment of soils contaminated by polycyclic aromatic hydrocarbons

“…After entering the soil, PAHs are stable or degrade slowly due to their chemical stability and as a result of soil conditions that inhibit degradation, e.g., physical sequestration and anoxia (Lichtfouse et al 1997;Chiou et al 1998). Chemical oxidation (Do et al 2009), bioremediation (Gan et al 2009), photo-degradation (Wang et al 2015;Jia et al 2015a, b) and thermal treatment (Li et al 2018) have been used to remediate soils contaminated by PAHs. Thermal treatment is widely used to decontaminate industrial soils because this method is fast and has low cost and high efficiency (Henner et al 1997;Gan et al 2009).…”

High contribution of hydrocarbon transformation during the removal of polycyclic aromatic hydrocarbons from soils, humin and clay by thermal treatment at 100–200 °C

“…Remediation techniques for PAH-contaminated soils include chemical oxidation (Si-Hyun et al 2009), washing (Trellu et al 2016), thermal treatment (Bucala et al 1994;Li et al 2018) and bioremediation (Gan et al 2009;Harvey et al 2002;Wilson and Jones 1993). Thermal treatment is used for fast and efficient remediation (Merino and Bucalá 2007).…”