A NEW HIGH-PRESSURE SQUEEZING TECHNIQUE FOR PORE FLUID EXTRACTION FROM TERRESTRIAL SOILS

A new plastic-lined high-pressure squeezing device has been developed for the extraction of soil pore solutions. At a maximum pressure of 11 00 kg cm(-2) the water recovery ranged between 30 and 55% of the total water content. Pressure dependent squeezing experiments showed a gene ral increase in Si, Mn, Mg, Ca, K, Na, Al, Fe, Cd, and Zn concentratio ns with progressive pore water extraction and increasing pressure, ind icating that micro pore solutes have the highest concentrations of sol utes. Soil samples with moisture contents of more than about 15% gener ally provided enough water for major and trace element analyses. The d ata do not reveal any contamination of the pore fluids from the squeez ing device. An advantage of this method is that the solution could be closely related to a specific soil horizon on a cm scale and also to t he time of sampling. A further application of this squeezing method is the possibility of pressure dependent sequential squeezing to obtain fluids from different pore spaces.