title: Removal of copper from aqueous solution using iron-containing adsorbents derived from methane fermentation sludge.
abstract: Iron-containing adsorbents prepared from methane fermentation sludge (MFS) were characterized by N(2) adsorption, XRD, SEM, EDX, pH determination and elemental analysis. The experiments for copper removal from aqueous solution using the MFS-derived adsorbents were performed, and the effects of iron content, forms of the iron (hydr)oxides, surface basicity and pH of the aqueous solution on copper removal were elucidated respectively. The desorption studies were also performed and the mechanism of Cu(II) adsorption was proposed. The results indicated that the adsorbent obtained at 700 degrees C for 1h in a steam atmosphere possessed the highest capability for Cu(II) adsorption. The high copper removal ability of the MFS-derived materials is attributed to their intermediate surface area, strong surface basicity and the presence of iron (hydr)oxides on their surface. The Cu(II) adsorption onto the composite adsorbents is via ion-exchange with H, Ca and K ions, surface precipitation and binding with active sites on the surface of iron (hydr)oxides at various pH values. The desorption of copper in deionized water is quite low. The irreversibility of copper adsorption on the iron-containing adsorbents is attributed to the formation of strong bonds between Cu(II) and the iron (hydr)oxides. The adsorbent can be applied to remove copper from water or soil by fixation onto the surface.
authors.affiliation: Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan. qrqian@iis.u-tokyo.ac.jp
authors.forename: Qingrong
authors.initials: Q
authors.lastname: Qian
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Mochidzuki
authors.forename: Takao
authors.initials: T
authors.lastname: Fujii
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Sakoda
mesh_terms: D000327:Adsorption; D003247:Conservation of Natural Resources / Q000379:methods; D003300:Copper / Q000302:isolation & purification*; D005285:Fermentation; D005290:Ferric Compounds; D007474:Ion Exchange; D007501:Iron / Q000737:chemistry*; D008697:Methane; D009584:Nitrogen; D012722:Sewage / Q000737:chemistry*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D005290:Ferric Compounds; D012722:Sewage; D012996:Solutions; D014874:Water Pollutants, Chemical; C000499:ferric oxide; C021024:ferric hydroxide; D003300:Copper; D007501:Iron; D009584:Nitrogen; D008697:Methane