title: Enhanced transport of phenanthrene and 1-naphthol by colloidal graphene oxide nanoparticles in saturated soil.
abstract: With the increasing production and use of graphene oxide, the environmental implications of this new carbonaceous nanomaterial have received much attention. In this study, we found that the presence of low concentrations of graphene oxide nanoparticles (GONPs) significantly enhanced the transport of 1-naphthol in a saturated soil, but affected the transport of phenanthrene to a much smaller extent. The much stronger transport-enhancement effect on 1-naphthol was due to the significant desorption hysteresis (both thermodynamically irreversible adsorption and slow desorption kinetics) of GONP-adsorbed 1-naphthol, likely stemmed from the specific polar interactions (e.g., H-bonding) between 1-naphthol and GONPs. Increasing ionic strength or the presence of Cu(II) ion (a complexing cation) generally increased the transport-enhancement capability of GONPs, mainly by increasing the aggregation of GONPs and thus, sequestering adsorbed contaminant molecules. Interestingly, modifying GONPs with Suwannee River humic acid or sodium dodecyl sulfate had little or essentially no effect on the transport-enhancement capability of GONPs, in contrast with the previously reported profound effects of humic acids and surfactants on the transport-enhancement capability of C60 nanoparticles. Overall, the findings indicate that GONPs in the aquatic environment may serve as an effective carrier for certain organic compounds that can interact with GONPs through strong polar interactions.
authors.affiliation: College of Environmental Science and Engineering/Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University , Tianjin 300071, China.
authors.forename: Zhichong
authors.initials: Z
authors.lastname: Qi
authors.forename: Lei
authors.initials: L
authors.lastname: Hou
authors.forename: Dongqiang
authors.initials: D
authors.lastname: Zhu
authors.forename: Rong
authors.initials: R
authors.lastname: Ji
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
mesh_terms: D000327:Adsorption; D002412:Cations; D003300:Copper / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D007700:Kinetics; D053758:Nanoparticles / Q000737:chemistry*; D009284:Naphthols / Q000737:chemistry*; D009994:Osmolar Concentration; D010616:Phenanthrenes / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000032:analysis; D013501:Surface-Active Agents / Q000032:analysis
chemical_list: D002412:Cations; D006812:Humic Substances; D009284:Naphthols; D010616:Phenanthrenes; D012987:Soil; D012989:Soil Pollutants; D013501:Surface-Active Agents; C029350:1-naphthol; D012967:Sodium Dodecyl Sulfate; C031181:phenanthrene; D006108:Graphite; D003300:Copper