Pyrolytic Treatment and Fertility Enhancement of Soils Contaminated with Heavy Hydrocarbons.
Pyrolysis of contaminated soils at 420 °C converted recalcitrant heavy hydrocarbons into "char" (a carbonaceous material similar to petroleum coke) and enhanced soil fertility. Pyrolytic treatment reduced total petroleum hydrocarbons (TPH) to below regulatory standards (typically <1% by weight) within 3 h using only 40-60% of the energy required for incineration at 600-1200 °C. Formation of polycyclic aromatic hydrocarbons (PAHs) was not observed, with post-pyrolysis levels well below applicable standards. Plant growth studies showed a higher biomass production of Arabidopsis thaliana and Lactuca sativa (Simpson black-seeded lettuce) (80-900% heavier) in pyrolyzed soils than in contaminated or incinerated soils. Elemental analysis showed that pyrolyzed soils contained more carbon than incinerated soils (1.4-3.2% versus 0.3-0.4%). The stark color differences between pyrolyzed and incinerated soils suggest that the carbonaceous material produced via pyrolysis was dispersed in the form of a layer coating the soil particles. Overall, these results suggest that soil pyrolysis could be a viable thermal treatment to quickly remediate soils impacted by weathered oil while improving soil fertility, potentially enhancing revegetation.
Department of Civil and Environmental Engineering, ‡Department of Chemical and Biomolecular Engineering, and §Department of Earth Science, Rice University , Houston, Texas 77005, United States.
Julia E
JE
Vidonish
Department of Civil and Environmental Engineering, ‡Department of Chemical and Biomolecular Engineering, and §Department of Earth Science, Rice University , Houston, Texas 77005, United States.
Kyriacos
K
Zygourakis
Department of Civil and Environmental Engineering, ‡Department of Chemical and Biomolecular Engineering, and §Department of Earth Science, Rice University , Houston, Texas 77005, United States.
Caroline A
CA
Masiello
Department of Civil and Environmental Engineering, ‡Department of Chemical and Biomolecular Engineering, and §Department of Earth Science, Rice University , Houston, Texas 77005, United States.
Xiaodong
X
Gao
Department of Civil and Environmental Engineering, ‡Department of Chemical and Biomolecular Engineering, and §Department of Earth Science, Rice University , Houston, Texas 77005, United States.
Jacques
J
Mathieu
Department of Civil and Environmental Engineering, ‡Department of Chemical and Biomolecular Engineering, and §Department of Earth Science, Rice University , Houston, Texas 77005, United States.
Pedro J J
PJ
Alvarez
D017360:Arabidopsis / Q000254:growth & development; D002244:Carbon; D005308:Fertilizers; D006838:Hydrocarbons / Q000032:analysis / Q000737:chemistry*; D017745:Incineration; D018545:Lactuca / Q000254:growth & development; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*; D013672:Technology / Q000379:methods; D013818:Thermogravimetry
D005308:Fertilizers; D006838:Hydrocarbons; D011084:Polycyclic Aromatic Hydrocarbons; D012987:Soil; D012989:Soil Pollutants; D002244:Carbon