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Technical University of Crete
Technical University of Crete
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| URI: | http://purl.tuc.gr/dl/dias/FADA3C3B-B1C7-40F5-9EA1-4A1B2BE38D1D | ||
| Year | 2010 | ||
| Type of Item | Conference Full Paper | ||
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| Bibliographic Citation | G.Bartzas, K.Komnitsas, " Solid phase studies and geochemical modelling of low-cost permeable reactive barriers, " in 2010 6th Iinternational Conference on Instrumental Methods of Analysis – Modern Trends and Applications, doi: 10.1016/j.jhazmat.2010.07.024 https://doi.org/10.1016/j.jhazmat.2010.07.024 | ||
| Appears in Collections |
A continuous column experiment was carried out under dynamic flow conditions in order to study the efficiency of low-cost permeable reactive barriers (PRBs) to remove several inorganic contaminants from acidic solutions. A 50:50 w/w waste iron/sand mixture was used as candidate reactive media in order to activate precipitation and promote sorption and reduction-oxidation mechanisms. Solid phase studies of the exhausted reactive products after column shutdown, using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), confirmed that the principal Fe corrosion products identified in the reactive zone are amorphous iron (hydr)oxides (maghemite/magnetite and goethite), intermediate products (sulfate green rust), and amorphous metal sulfides such as amFeS and/or mackinawite. Geochemical modelling of the metal removal processes, including interactions between reactive media, heavy metal ions and sulfates, and interpretation of the ionic profiles was also carried out by using the speciation/mass transfer computer code PHREEQC-2 and the WATEQ4F database. Mineralogical characterization studies as well as geochemical modelling calculations also indicate that the effect of sulfate and silica sand on the efficiency of the reactive zone should be considered carefully during design and operation of low-cost field PRBs.
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