title: Synthesis of granular activated carbon/zero valent iron composites for simultaneous adsorption/dechlorination of trichloroethylene.
abstract: The coupling adsorption and degradation of trichloroethylene (TCE) through dechlorination using synthetic granular activated carbon and zerovalent iron (GAC-ZVI) composites was studied. The GAC-ZVI composites were prepared from aqueous Fe(2+) solutions by impregnation with and without the use of a PEG dispersant and then heated at 105°C or 700°C under a stream of N(2). Pseudo-first-order rate constant data on the removal of TCE demonstrates that the adsorption kinetics of GAC is similar to those of GAC-ZVI composites. However, the usage of GAC-ZVI composites liberated a greater amount of Cl than when ZVI was used alone. The highest degree of reductive dechlorination of TCE was achieved using a GAC-ZVI700P composite (synthesized using PEG under 700°C). A modified Langmuir-Hinshelwood rate law was employed to depict the behavior of Cl liberation. As a result, a zero-order Cl liberation reaction was observed and the desorption limited TCE degradation rate constant decreased as the composite dosage was increased. The GAC-ZVI composites can be employed as a reactive GAC that is not subject to the limitations of using GAC and ZVI separately.
authors.affiliation: School of Occupational Safety and Health, Chung Shan Medical University, Taichung 402, Taiwan.
authors.forename: Hui-Hsin
authors.initials: HH
authors.lastname: Tseng
authors.forename: Jhih-Gang
authors.initials: JG
authors.lastname: Su
authors.forename: Chenju
authors.initials: C
authors.lastname: Liang
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D014241:Trichloroethylene / Q000737:chemistry*
chemical_list: D014241:Trichloroethylene; D002713:Chlorine; D002244:Carbon; D007501:Iron