Determining Adsorption Parameters of Potentially Contaminant-Releasing Materials Using Batch Tests with Differing...

Area of Science:

• Environmental Science
• Geochemistry
• Soil Science

Background:

• Accurate prediction of contaminant release from potentially contaminant-releasing materials (PCMs) requires adsorption parameters for advection-dispersion models.
• Conventional adsorption tests are insufficient for determining these parameters for materials like dredged sludge and coal ash.

Purpose of the Study:

• To develop and validate a novel method for determining adsorption parameters for PCMs.
• To assess the applicability of the developed method using sandy soil derived from marine sediment.

Main Methods:

• A liquid-solid ratio parallel (LS-parallel) batch test method was developed.
• Tests were conducted on sandy soil with varying liquid-solid ratios (1–300 L/kg) and water-contact times (10 min–28 d).
• Adsorption parameters were determined, and their effectiveness was validated using column percolation tests.

Main Results:

• The LS-parallel test successfully obtained adsorption parameters for substances under adsorption control.
• Good agreement was observed for sulfate (SO₄²⁻) and boron (B) release predictions.
• Discrepancies for fluoride (F⁻) and arsenic (As) indicate areas for methodological and model improvement.

Conclusions:

• The LS-parallel test is a viable method for determining adsorption parameters for PCMs.
• The method shows promise for improving contaminant release predictions, particularly for substances like SO₄²⁻ and B.
• Further research is needed to refine the LS-parallel test procedure and advection-dispersion models for broader applicability.