Pore water extraction

Pore water extraction and determination of the soluble salt content of soils by refractometer... 

Di Bonito, M., Breward, N., Crout, N., Smith, B., and Young, S. (2008). Soil pore water extraction methods for trace metals determination in contaminated soils. In Environmental Geochemistry Site Characterization, Data Analysis, and Case Histories (B. De Vivo, H. E. Belkin, and A. Lima, eds.). Elsevier Science Publishers, Amsterdam, The Netherlands. 

Overview of Selected Soil Pore Water Extraction Methods for the Determination of Potentially Toxic Elements in Contaminated Soils Operational and Technical Aspects... 

Overview of Selected Soil Pore Water Extraction Methods... 

For the soil pore water sampling, the procedure described by Knight et al. (1998) and Tye et al., (2003) can be normally followed. Samplers are inserted into soil containers and soil pore water extracted by connecting a syringe to each sampler and applying a suction. 

Uses and limitations for soil pore water extractions... 

Figure 10.5 Pore water extraction by (A) drainage centrifugation using a swing-out rotor and (B) immiscible liquid displacement using a fixed-angle rotor (after Kinniburgh and Miles, 1983).

Most of the excess pore pressure dissipates during primary consolidation. Secondary consolidation involves the movement of particles as they adjust to the increase in effective pressure and the dissipation of excess pore pressure from very small pores. The pore water extracted during squeezing is mainly because of primary consolidation. 

The percentage of the available pore water extracted, E, (Entwisle and Reeder, 1993) is determined as follows ... 

Figure 10.13 Cumufative voiume of pore water extracted for the three soifs tested with increasing pressure the dotted line represents the pressure corresponding to the hygroscopic coefficient, that is, the upper limit for the capillary water.

In summary, the importance of the method employed for soil pore water extraction should not be underestimated. Experimental design and performance should be chosen to reflect the particular aim of the study, reported in sufficient detail to allow others to make appropriate comparisons and the parameters operationally defined as a function of the method employed. 

Much higher concentrations of arsenic frequently occur in pore waters extracted from unconsolidated sediments than in overlying surface waters. Widerlund and Ingri (1995) reported concentrations in the range 1.3-166 p.g in pore waters from the Kalix River estuary, northern Sweden. Yan et al. (2000) found concentrations in the range 3.2-99 p.g in pore waters from clay sediments in Saskatchewan, Canada. 

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