title: In situ removal of arsenic from groundwater by using permeable reactive barriers of organic matter/limestone/zero-valent iron mixtures.
abstract: In this study, two mixtures of municipal compost, limestone and, optionally, zero-valent iron were assessed in two column experiments on acid mine treatment. The effluent solution was systematically analysed throughout the experiment and precipitates from both columns were withdrawn for scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffractometry analysis and, from the column containing zero-valent iron, solid digestion and sequential extraction analysis. The results showed that waters were cleaned of arsenic, metals and acidity, but chemical and morphological analysis suggested that metal removal was not due predominantly to biogenic sulphide generation but to pH increase, i.e. metal (oxy)hydroxide and carbonate precipitation. Retained arsenic and metal removal were clearly associated to co-precipitation with and/or sorption on iron and aluminum (oxy)hydroxides. An improvement on the arsenic removal efficiency was achieved when the filling mixture contained zero-valent iron. Values of arsenic concentrations were then always below 10 microg/L.
authors.affiliation: Chemical Engineering Department, ETSEIB, Universitat Politècnica de Catalunya, 08028 Barcelona, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Gibert
authors.forename: J
authors.initials: J
authors.lastname: de Pablo
authors.forename: J-L
authors.initials: JL
authors.lastname: Cortina
authors.forename: C
authors.initials: C
authors.lastname: Ayora
mesh_terms: D001151:Arsenic / Q000032:analysis / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D058085:Iron Compounds / Q000737:chemistry*; D008906:Mining; D010539:Permeability; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D058085:Iron Compounds; D014874:Water Pollutants, Chemical; D014867:Water; D002119:Calcium Carbonate; D001151:Arsenic
references.citation: J Contam Hydrol. 2009 Apr 15;106(1-2):15-28
references.pmid: 19167132
references.citation: Environ Int. 2005 Feb;31(2):213-9
references.pmid: 15661286
references.citation: Water Res. 2004 Nov;38(19):4186-96
references.pmid: 15491666
references.citation: Environ Sci Technol. 2003 Jun 1;37(11):2582-7
references.pmid: 12831047
references.citation: Environ Sci Technol. 2009 Mar 15;43(6):1970-6
references.pmid: 19368200
references.citation: Water Res. 2009 Apr;43(6):1589-96
references.pmid: 19201440
references.citation: Chemosphere. 2005 Apr;59(3):377-86
references.pmid: 15763090
references.citation: J Contam Hydrol. 2009 Apr 15;106(1-2):1-14
references.pmid: 19167133
references.citation: Environ Int. 2009 Apr;35(3):647-54
references.pmid: 19110310
references.citation: J Contam Hydrol. 2007 Dec 7;94(3-4):305-14
references.pmid: 17719126