Pharmaceutical compounds and dissolved organic matter ( @entity13304 ) are co-introduced into the environment by irrigation with reclaimed wastewater and/or application of biosolids. In this study, we evaluate the role and mechanism of interaction of the pharmaceuticals @entity1623 and @entity2049 with structural fractions of biosolids-derived @entity13304 . Sorption interactions were estimated from dialysis-bag experiments at different pHs. Sorption of @entity1623 and @entity2049 by the hydrophobic acid fraction exhibited strong pH- @entity734 . With both pharmaceuticals, the highest sorption coefficients (K( @entity4420 )) were at pH 4. With the hydrophobic neutral fraction, pH affected only @entity1623 sorption (decreasing with increasing pH). Among the hydrophilic @entity13304 fractions, the hydrophilic acid fraction exhibited the highest K( @entity4420 ) value for @entity2049 , probably due to their bipolar character. In the hydrophilic acid fraction- @entity1623 system, significant anionic repulsion was observed with increasing pH. The hydrophilic base fraction contains positively charged functional groups. Therefore with increasing ionization of @entity1623 (with increasing pH), K( @entity4420 ) to this fraction increased. The hydrophilic neutral fraction exhibited the lowest K( @entity4420 ) with both studied pharmaceuticals. The K( @entity4420 ) value of @entity2049 with the bulk @entity13304 sample was higher than the calculated K( @entity4420 ) value based on sorption by the individual isolated fractions. The opposite trend was observed with @entity1623 at pH 8: the calculated K( @entity4420 ) value was higher than the value obtained for the bulk @entity13304 . These results demonstrate that @entity13304 fractions interact with each other and do not act as separate sorption domains.

Sorption of the pharmaceuticals @entity2049 and XXXX to dissolved organic matter: role of structural fractions.

@entity734 :: ('MESH:D019966', 'Disease') :: ['dependence'] @entity1623 :: ('MESH:D009288', 'Chemical') :: ['naproxen'] @entity13304 :: ('MESH:D004290', 'Chemical') :: ['DOM'] @entity2049 :: ('MESH:D002220', 'Chemical') :: ['carbamazepine'] @entity4420 :: ('CHEBI:16973', 'Chemical') :: ['DOC']
@entity1623 :: (MESH:D009288,Chemical) :: ['naproxen']
