Sorption, Fate, and Mobility of Sulfonamides in Soils

Fan, Zhaosheng; Casey, Francis X. M.; Hakk, Heldur; Larsen, Gerald L.; Khan, Eakalak

Sorption, Fate, and Mobility of Sulfonamides in Soils

2011

Fan, Zhaosheng | Casey, Francis X. M. | Hakk, Heldur | Larsen, Gerald L. | Khan, Eakalak

Sulfonamides (SAs) are one of the broadly used antibiotics in domestic animal operations and have a notable potential of entering the environment through animal manure management practices. In this study, sulfamethazine (SMZ) was used as a prototype to study the sorption, fate, and transport of SAs in soil–water systems using batch and miscible-displacement experiments. Sulfamethazine was degraded to a polar metabolite (PM). The batch experiments indicated that the linear sorption partitioning coefficient (K d) values for the PM ranged from 7.5 to 206.2 L kg−1. Strong relationships between the sorption of PM and various soil fractions and organic matter were also observed. The miscible-displacement experiments showed that 33–70% of SMZ was degraded within 6 h during transport in the soil columns. Also, 69–99.7% of SMZ and PM were recovered in the effluents suggesting their high mobility. Also, the simultaneous degradation, sorption, and transport of SMZ and PM were described using a two-site chemical nonequilibrium fate and transport model, using the K d values obtained from the batch experiments. The parameters of this model were uniquely estimated using a global optimization strategy, the stochastic ranking evolutionary strategy.

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