Influences of dissolved organic matters on the adsorption and bioavailability of sulfadiazine: Molecular weight- and type-dependent heterogeneities

The bioavailability of contaminants in aquatic environments was highly related with the existing forms (soluble or adsorbed) and properties of dissolved organic matters (DOMs). In this study, the molecular weight (MWs)-dependent effects of DOMs on the adsorption and bioavailability of sulfadiazine were explored. Colloid ZnO and Al2O3 were employed as the representative colloidal particles, and algae-derived organic matter (AOM) and humic acid (HA) were selected as typical autochthonous and allochthonous DOMs. The ultrafiltration procedure was applied to divide the bulk DOMs into high MW (HMW-, 1 kDã0.45 μm) and low MW (LMW-, bulk > LMW-.