title: Sorption of emerging trace organic compounds onto wastewater sludge solids.
abstract: This work examined the sorption potential to wastewater primary- and activated-sludge solids for 34 emerging trace organic chemicals at environmentally relevant concentrations. These compounds represent a diverse range of physical and chemical properties, such as hydrophobicity and charge state, and a diverse range of classes, including steroidal hormones, pharmaceutically-active compounds, personal care products, and household chemicals. Solid-water partitioning coefficients (K(d)) were measured where 19 chemicals did not have previously reported values. Sludge solids were inactivated by a nonchemical lyophilization and dry-heat technique, which provided similar sorption behavior for recalcitrant compounds as compared to fresh activated-sludge. Sorption behavior was similar between primary- and activated-sludge solids from the same plant and between activated-sludge solids from two nitrified processes from different wastewater treatment systems. Positively-charged pharmaceutically-active compounds, amitriptyline, clozapine, verapamil, risperidone, and hydroxyzine, had the highest sorption potential, log K(d)=2.8-3.8 as compared to the neutral and negatively-charged chemicals. Sorption potentials correlated with a compound's hydrophobicity, however the higher sorption potentials observed for positively-charged compounds for a given log D(ow) indicate additional sorption mechanisms, such as electrostatic interactions, are important for these compounds. Previously published soil-based one-parameter models for predicting sorption from hydrophobicity (log K(ow)>2) can be used to predict sorption for emerging nonionic compounds to wastewater sludge solids.
authors.affiliation: Advanced Water Technology Center (AQWATEC), Environmental Science and Engineering Division, Colorado School of Mines, Golden, CO 80401, USA.
authors.forename: John
authors.initials: J
authors.lastname: Stevens-Garmon
authors.forename: Jörg E
authors.initials: JE
authors.lastname: Drewes
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Khan
authors.forename: James A
authors.initials: JA
authors.lastname: McDonald
authors.forename: Eric R V
authors.initials: ER
authors.lastname: Dickenson
mesh_terms: D000327:Adsorption; D000639:Amitriptyline / Q000032:analysis / Q000737:chemistry; D003024:Clozapine / Q000032:analysis / Q000737:chemistry; D003358:Cosmetics / Q000032:analysis / Q000737:chemistry; D006795:Household Products / Q000032:analysis; D006919:Hydroxyzine / Q000032:analysis / Q000737:chemistry; D009930:Organic Chemicals / Q000032:analysis / Q000737:chemistry*; D004364:Pharmaceutical Preparations / Q000032:analysis / Q000737:chemistry*; D018967:Risperidone / Q000032:analysis / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D014700:Verapamil / Q000032:analysis / Q000737:chemistry; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D003358:Cosmetics; D009930:Organic Chemicals; D004364:Pharmaceutical Preparations; D012722:Sewage; D014874:Water Pollutants, Chemical; D000639:Amitriptyline; D006919:Hydroxyzine; D014700:Verapamil; D003024:Clozapine; D018967:Risperidone