Sulfadiazine

Obtaining the sulfonamides (SAs) concentrations in the water body and sediment bulk was a prerequisite to reveal their transport and partitioning behavior in sediment-water environments and accurately assess their ecological risk. In the present study, the influences of multifactor interactions on the performance of o-DGTs with XAD-18 binding gels were analyzed by central combination experiments and response surfaces analysis, in which the target compounds were 9 SAs. The results indicated that dissolved organic matter (DOM), pH, and suspended particulate matter (SS) had significant effects on the o-DGT sampling, whereas this o-DGT was independent of the ionic strength (IS). Concentning the composite influence of the four factors, the interaction between DOM and SS posed the most significant effect on all 9 SAs compounds. Subsequently, an o-DGT and DIFS model was applied to explore the SAs migration between the water-sediments interface. The difference between desorption rate (k_b) and adsorption rates (k_f) values suggested that the kinetics of SAs was dominated by adsorption. Moreover, the short-term sediment-water partitioning of SAs was clarified on the basis of distribution coefficient (K_dl) for the labile SAs, among which the sulfadiazine (SDZ) had the largest labile pool. The ability of sediments to release SAs to the liquid phase as a sink was determined by response time (T_c). Among the 9 SAs, the long-term release of soseulfamethoxypyridazine (SMP) from the solid phase of sediments would have a potential risk to the aquatic environment, to which more attention should be paid in the future.