Separation of coal-tar constituents from soil particles in a two-liquid-phase slurry system.
An evaluation has been made of the capability of rapeseed oil to dissolve polycyclic aromatic hydrocarbon (PAH) crystals in a biphasic system and of its capability to extract PAHs from polluted soil in a two-liquid-phase (TLP) slurry system. Up to 220 g l(-1) of the crystalline hydrocarbons could be dissolved in the organic phase, indicating oil/water-partitioning coefficients of 10(5). When soil from a former gasworks site was treated in a TLP slurry system, it was found that a certain critical amount of vegetable oil had to be added in order to form a free oil phase. Single and multiple extractions gave similar results for multiple short-term and single long-term treatments, with a maximum of 87% for pyrene release. Following a 30-day bioslurry treatment, the total concentration of the 16 EPA PAHs in the soil decreased from 2740 mg kg(-1) to 1366 mg kg(-1). This was followed by one of three different 12-day post-bioslurry treatments. Further bioslurry treatment reduced the final concentration to 1002 mg kg(-1). Abiotic treatment with a surfactant (Brij 30) achieved a reduction to 797 mg kg(-1). Treatment with rapeseed oil gave the best reduction to 343 mg kg(-1).
Schuur
J H Berg
JH
Department of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
Mattiasson
B
B
D003031:Coal; D004787:Environmental Pollution / Q000517:prevention & control*; D005229:Fatty Acids, Monounsaturated; D007220:Industrial Waste; D010316:Particle Size; D010938:Plant Oils / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry* / Q000302:isolation & purification*; D000074262:Rapeseed Oil; D012995:Solubility
D003031:Coal; D005229:Fatty Acids, Monounsaturated; D007220:Industrial Waste; D010938:Plant Oils; D011084:Polycyclic Aromatic Hydrocarbons; D000074262:Rapeseed Oil