title: In situ modification of activated carbons developed from a native invasive wood on removal of trace toxic metals from wastewater.
abstract: Activated carbons were developed by phosphoric acid activation of sawdust from Prosopis ruscifolia wood, an indigenous invasive species of degraded lands, at moderate conditions (acid/precursor ratio=2, 450 degrees C, 0.5h). For in situ modification of their characteristics, either a self-generated atmosphere or flowing air was used. The activated carbons developed in the self-generated atmosphere showed higher BET surface area (2281m2/g) and total pore volume (1.7cm3/g) than those obtained under flowing air (1638m2/g and 1.3cm3/g). Conversely, the latter possessed a higher total amount of surface acidic/polar oxygen groups (2.2meq/g) than the former (1.5meq/g). To evaluate their metal sorption capability, adsorption isotherms of Cu(II) ion from model solutions were determined and properly described by the Langmuir model. Maximum sorption capacity (Xm) for the air-derived carbons (Xm=0.44mmol/g) almost duplicated the value for those obtained in the self-generated atmosphere (Xm=0.24mmol/g), pointing to a predominant effect of the surface functionalities on metal sequestering behaviour. The air-derived carbons also demonstrated a superior effectiveness in removing Cd(II) ions as determined from additional assays in equilibrium conditions. Accordingly, effective phosphoric acid-activated carbons from Prosopis wood for toxic metals removal from wastewater may be developed by in situ modification of their characteristics operating under flowing air.
authors.affiliation: Programa de Investigación y Desarrollo de Fuentes Alternativas de Materias Primas y Energía (PINMATE), Universidad de Buenos Aires, Pabellón de Industrias, Intendente Güiraldes 2620, Ciudad Universitaria, C1428BGA Buenos Aires, Argentina.
authors.forename: J
authors.initials: J
authors.lastname: de Celis
authors.forename: N E
authors.initials: NE
authors.lastname: Amadeo
authors.forename: A L
authors.initials: AL
authors.lastname: Cukierman
mesh_terms: D002244:Carbon / Q000032:analysis* / Q000737:chemistry*; D008670:Metals / Q000032:analysis* / Q000633:toxicity; D008956:Models, Chemical; D029862:Prosopis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*; D014934:Wood / Q000737:chemistry*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D002244:Carbon