Assessment of sorbent/water ratio effect on adsorption using dimensional analysis and batch experiments

Area of Science:

• Environmental Science
• Soil Science
• Physical Chemistry

Background:

• Adsorption in solid-liquid systems is influenced by numerous factors, with the sorbent/water (S/W) ratio being critical but poorly understood.
• The precise impact of varying S/W ratios on the adsorption of contaminants in diverse soil matrices remains unclear.

Purpose of the Study:

• To investigate the effect of different S/W ratios on the adsorption of four contaminants (copper, cadmium, Butachlor, and Deltamethrin) in six soils with varying textures.
• To develop a predictive model for adsorption phenomena based on dimensional analysis and S/W ratio.

Main Methods:

• Conducted batch experiments to study contaminant adsorption in six different soil types.
• Employed dimensional analysis to establish a relationship between adsorption and the S/W ratio.
• Assumed total sorbate sorption is a function of equilibrium concentration, solution volume, and sorbent amount.

Main Results:

• A power function (Freundlich-like) model was derived using dimensional analysis.
• This model accurately describes adsorption phenomena for various sorbents and sorbates in paddy soil moisture conditions.
• The model effectively accounts for the solids effect, providing reliable adsorption parameters.

Conclusions:

• The developed power function model offers a precise method for characterizing adsorption across different soil and contaminant combinations.
• This model facilitates the accurate prediction of solute fate in soil environments through solute transport models.
• Understanding the S/W ratio's role is crucial for effective environmental risk assessment and soil remediation strategies.