DBPapers
DOI: 10.5593/sgem2017/14/S06.081

EX-SITU REMEDIATION OF PETROLEUM-CONTAMINATED SOIL BY PYROLYSIS PROCESS

D.M. Cocarta, C. Streche, D.M. Dumitru, M.A. Stoian
Monday 11 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-00-3 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 14, 643-650 pp, DOI: 10.5593/sgem2017/14/S06.081

ABSTRACT

One of the main environmental problems nowadays is related to contaminated soils. Soils can be contaminated with different compounds among which, the most widespread being the petroleum hydrocarbons (PH). The contamination of soil with petroleum hydrocarbons (PH) could take place during oil exploration. In this context, contaminated soil remediation is highly necessary. Over the years, different treatment methods for contaminated soil remediation have been applied. The present research illustrates the thermochemical method for the remediation of soil contaminated with petroleum hydrocarbons (PH). Soil samples were collected from Southeastern region of Romania where contamination due oil spills took place. In the contaminated soil, a concentration of Total Petroleum Hydrocarbons (TPH) C10-C40 of 1.420,28 mg/kgd.w.was identified. This concentration is quite higher respect to the limit indicated by the Romanian regulation in force concerning the alert thresholds (200 mg/kgd.w in case of sensitive use and respectively, 1000 mg/kgd.w. for the less sensitive use of soils), below the intervention threshold for less sensitive use (2000 mg/kgd.w,), but higher than the reference level for the intervention threshold for sensitive use (500 mg/kgd.w). As different regulated thresholds were overcome, the pyrolysis thermal treatment method for soil remediation was tested. Consequently, the non-oxidative thermal technology was used in the context of the present study for the removal of petroleum products from contaminated soils. The experimental study supposed testing the pyrolysis efficiency at different temperatures: 400°C, 600°C and 800°C. The total petroleum hydrocarbons (TPH) initial concentration decreased significantly after applying the pyrolysis process, but with no significant differences according to the temperatures scale. The efficiency concerning the TPH remediation from the contaminated soil was around 99% in case of every tested temperature (concentration of TPH in the solid residues was lower than 5 mg/kgd.w.). The obtained results showed that pyrolysis could be a good choice for the treatment of the contaminated soils with TPH, but, simultaneously with the process conditions, costs (energy consumption) and level of emissions into air must be considered.

Keywords: pyrolysis, petroleum hydrocarbons, contaminated soils, remediation degree