Abstract
Batch sorptions of acetazolamide (AZ) were conducted using four soils from China. Sorption of AZ was found to be impacted by OC, clay content, and soil pH, with higher kd values for soils with higher clay content. The kd values of SOM-removed soils are much lower than those of bulk soils. Sorption data were well fitted with a Freundlich model (r2 > 0.99). Chelating with the metal ions on the surfaces of soil particles was probably involved. With pH increase, the electrostatic attraction between anionic AZ and positively charged soil surface may increase. The sorption capacity decreased when the temperature increased from 20 to 40°C, and the calculated thermodynamics parameters of ΔG0, ΔH0, and ΔS0 indicated that the sorption was a non-spontaneous, physisorption, and exothermic process. Sorption coefficients (kd) for the compound in soil were low (ranging from 0.42 to 1.19 L·kg−1) and indicated that low level sorption of AZ with appreciable risk of ground water contamination.
Acknowledgements
This work was financially supported by the National Special Purpose on Public Welfare of Environmental Protection Foundation (200809016), and Jiangsu Key Lab. of Environmental Engineering Open Foundation (KF2009008).
Notes
aStandard error.