Fig. 1 is a schematic diagram of SWE setup used in this study.
The lab-scale superheated water extractor was described in detail
in our previous work [16]. Before using the distilled water, it was
purged with nitrogen for 30 min to remove dissolved oxygen. The
pump (FWT, FX series, type: FXS C/A, Flow rate: max. 10 mL/min,
0.01 mL/min accuracy, max. pressure 20 bar) was operated in the
constant pressure mode to supply water through the 5 L stainless
steel reservoir to the extraction cell. 5 g of contaminated soil was
filled into the extraction cell and it was assembled in the oven. After
that, the extraction cell was placed in the oven using appropriate
connections, the pump was turned on and pressure increased
up to 20 bar. Then, the pump was turned off and temperature of
oven was raised to the desired value. The pump was turned on and
the flow rate was adjusted at the required rate. Water was passed
through the extraction cell with the water flowing from top to bottom.
To investigate the effect of temperature and extraction time
on removal efficiency, experiments were designed and performed
according Table 1. When the temperature of extraction cell was
reached to the set point, recording of extraction time was started.
At the end of extraction time, heater and pump were turned off
and the pressure was released to the atmospheric pressure