LEAF

Method 1314 – Percolation Column

Liquid-Solid Partitioning (LSP) as a Function of Liquid-to-Solid Ratio for Constituents in Solid Materials Using an Up-flow Percolation Column Procedure

Summary

Diagram of Percolation Column Setup

Schematic of percolation column layout used in Method 1314.

This test is designed to provide the liquid-solid partitioning of constituents in a granular solid material as a function of liquid-to-solid ratio (L/S), based on elution volume, under percolation conditions. Granular material is moderately packed into a cylindrical glass column and is contacted by leaching solution at a low flowrate. Solution is introduced in an up-flow pumping mode to minimize air entrainment and flow channeling. Eluate concentrations and cumulative mass releases of constituents of potential concern are plotted as a function of cumulative L/S. Eluate concentrations may be compared to quality control and assessment limits for interpretation of method results.

Detailed Description:

Method 1314 is a percolation column test designed to obtain liquid-solid partitioning (LSP) information as a function of liquid-solid ratio (L/S). L/S is represented as the cumulative volume of leaching solution passing through a column containing a known mass of material. For some materials, particle size reduction may be required to meet column dimension requirements and facilitate the approach to equilibrium.

Solid material is loosely packed into a borosilicate glass column and contacted with a percolating leaching solution at low flowrate. Liquid is pumped in an up-flow direction to minimize channel and air entrapment. Eluates are collected at specific cumulative L/S values between L/S 0.2 and 10 mL/g-dry. Eluate concentrations and constituent cumulative release plotted as a function of L/S.

Example results of Method 1314

Barium LSP as a function of L/S in two coal combustion fly ash samples. Solubility-control is indicated by a line with slope = 1.

The results of Method 1314 provide an estimate of porewater concentrations at low L/S and illustrate how LSP changes as soluble constituents are released during succesive pore volumes.

Downloads:

Overview Presentation of Method 1314

Method 1314 Document (PDF)

Method 1314 Data Template (Excel)