Effect of extraction vessel geometry and flow homogeneity on recoveries of polycyclic aromatic hydrocarbons in pressurised hot water extraction.

Extraction vessels of different length, internal diameter and volume were tested to evaluate the effect of vessel geometry on the recovery of polycyclic aromatic hydrocarbons (PAHs) from certified sediment by pressurised hot water extraction (PHWE). Pressurised hot water extractions were performed at 300 degrees C with both liquid water (pressure 250 kg cm(-2)) and steam (pressure 50 kg cm(-2)). In addition, the effects on the recoveries of sediment packing and water flow direction were examined in two vessels. The geometry of the vessel, the packing of the sediment and the flow direction of the water had only minor effect on the recoveries.