
<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Erbs, J. J.</style></author><author><style face="normal" font="default" size="100%">Berquo, T. S.</style></author><author><style face="normal" font="default" size="100%">Reinsch, B. C.</style></author><author><style face="normal" font="default" size="100%">Lowry, G. V.</style></author><author><style face="normal" font="default" size="100%">Banerjee, S. K.</style></author><author><style face="normal" font="default" size="100%">Penn, R. L.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Reductive dissolution of arsenic-bearing ferrihydrite</style></title><secondary-title><style face="normal" font="default" size="100%">Geochimica Et Cosmochimica Acta</style></secondary-title><alt-title><style face="normal" font="default" size="100%">Geochim. Cosmochim. Acta</style></alt-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ABSORPTION-SPECTRA</style></keyword><keyword><style  face="normal" font="default" size="100%">COORDINATION CHEMISTRY</style></keyword><keyword><style  face="normal" font="default" size="100%">EXAFS</style></keyword><keyword><style  face="normal" font="default" size="100%">GOETHITE</style></keyword><keyword><style  face="normal" font="default" size="100%">IRON-OXIDES</style></keyword><keyword><style  face="normal" font="default" size="100%">KINETICS</style></keyword><keyword><style  face="normal" font="default" size="100%">MINERALS</style></keyword><keyword><style  face="normal" font="default" size="100%">Nanoparticles</style></keyword><keyword><style  face="normal" font="default" size="100%">OXYHYDROXIDES</style></keyword><keyword><style  face="normal" font="default" size="100%">SURFACE COMPLEXATION</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2010</style></year><pub-dates><date><style  face="normal" font="default" size="100%">Jun</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">&lt;Go to ISI&gt;://000277945500003 </style></url></web-urls></urls><number><style face="normal" font="default" size="100%">12</style></number><volume><style face="normal" font="default" size="100%">74</style></volume><pages><style face="normal" font="default" size="100%">3382-3395</style></pages><isbn><style face="normal" font="default" size="100%">0016-7037</style></isbn><language><style face="normal" font="default" size="100%">English</style></language><abstract><style face="normal" font="default" size="100%">Ferrihydrites were prepared by coprecipitation (COP) or adsorption (ADS) of arsenate, and the products were characterized using solid-state methods. In addition, the kinetics of reductive dissolution by hydroquinone of these well-characterized materials were quantified. Characterization and magnetism results indicate that the 10 wt% As COP ferrihydrite is less crystalline and possibly has smaller crystallite size than the other ferrihydrites, which all have similar crystallinity and particle size. The results from reductive dissolution experiments show similar reaction rates, reaction mechanism, and activation energy for ferrihydrite precipitated with or without added arsenate. However, a marked decrease in reactivity was observed for 10 wt% As ADS ferrihydrite. The decrease is not attributed to differences in activation energy but rather the preferential blocking of active sites on the ferrihydrite surface. Results demonstrate that arsenic may be released by the reductive dissolution of arsenic-bearing ferrihydrite regardless of whether the arsenic is coprecipitated with or adsorbed onto the ferrihydrite. However, under these reaction conditions, release from materials with adsorbed arsenate greatly exceeds that from materials with coprecipitated arsenate. In fact, a considerable amount of arsenic was released from the 10 wt% ADS ferrihydrite before reductive dissolution was initiated. Therefore, the characterization of arsenate-bearing iron oxide materials to determine the method of arsenate incorporation into structures perhaps by quantification of Fe Fe coordination with EXAFS spectroscopy-may lead to improved predictions of the large-scale release of arsenic within aquifer systems under reducing conditions. (C) 2010 Elsevier Ltd. All rights reserved.</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type><accession-num><style face="normal" font="default" size="100%">ISI:000277945500003</style></accession-num><notes><style face="normal" font="default" size="100%">ISI Document Delivery No.: 599WUTimes Cited: 0Cited Reference Count: 59</style></notes><auth-address><style face="normal" font="default" size="100%">[Erbs, Jasmine J.; Penn, R. Lee] Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. [Berquo, Thelma S.; Banerjee, Subir K.] Univ Minnesota, Inst Rock Magnetism, Dept Geol &amp; Geophys, Minneapolis, MN 55455 USA. [Reinsch, Brian C.; Lowry, Gregory V.] Carnegie Mellon Univ, Dept Civil &amp; Environm Engn, Pittsburgh, PA 15213 USA. [Reinsch, Brian C.; Lowry, Gregory V.] CEINT, Pittsburgh, PA 15213 USA.Penn, RL, Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA.rleepenn@umn.edu</style></auth-address></record></records></xml>