Počet záznamů: 1

In situ co-adsorption of arsenic and iron/manganese ions on raw clays

  1. 1.
    0370222 - UACH-T 2012 RIV NL eng J - Článek v odborném periodiku
    Doušová, B. - Lhotka, M. - Grygar, Tomáš - Machovič, V. - Herzogová, L.
    In situ co-adsorption of arsenic and iron/manganese ions on raw clays.
    Applied Clay Science. Roč. 54, č. 2 (2011), s. 166-171 ISSN 0169-1317
    Výzkumný záměr: CEZ:AV0Z40320502
    Klíčová slova: Arsenic * Groundwater * Co-adsorption * Raw clays * Pre-modified clays * Fe/Mn
    Kód oboru RIV: DD - Geochemie
    Impakt faktor: 2.474, rok: 2011

    The use of clays as effective arsenic sorbents has been strongly limited due to their low pH(ZPC) and cation active behaviour in aqueous systems at pH>3.5. A simple Fe/Al/Mn pre-treatment can significantly improve their sorption affinity to oxyanions, including arsenites and arsenates. The dynamics of arsenic adsorption from groundwater is also controlled by dissolved Fe/Mn ions, which behave as promoters of As adsorption, or competitors to adsorption sites. Low grade calcinated kaolin (MT) and bentonite (BT) were used as clay sorbents. Arsenic adsorption on raw clays without presence of Fe/Mn ions is very slow and limited. During co-adsorption the Fe/Mn ions and As oxyanions were adsorbed together onto a sorbent surface. Both Mn and Fe particles demonstrated a good sorption affinity to the clay surface, but only Fe particles supported As adsorption considerably (80% of As were removed in Fe/As system, while <30% only in the Mn/As system). The kinetics of co-adsorption compared to the use of Fe/Mn pre-modified sorbents indicated a more dynamic process, while all mechanisms corresponded to the first order run (k approximate to t 9.10(-6)-1.10(-4) s(-1)). Arsenic was strongly stabilized in pre-modified sorbents.
    Trvalý link: http://hdl.handle.net/11104/0204086