The chromium pollution of water is an important environmental and health issue. Cr(VI)removal by means of metallic iron is an attractive method. Specifically, nanoscopic zero valent iron(NZVI) shows great reactivity, however, its applicability needs to be further investigated. In thepresent paper, NZVI was supported on MgO grains to facilitate the treatments for remediation ofchromium-contaminated waters. The performances and mechanisms of the developed composite,in the removal of hexavalent chromium, were investigated by means of batch and continuous tests.Kinetic studies, under different operating conditions, showed that reduction of Cr(VI) could beexpressed by a pseudo second-order reaction kinetic. The reaction rate increased with the square ofFe(0) amount, while it was inversely proportional to the initial chromium concentration. The processperformance was satisfactory also under uncontrolled pH, and a limited influence of temperature wasobserved. The reactive material was efficiently reusable for many cycles without any regenerationtreatment. The performances in continuous tests were close to 97% for about 80 pore volume ofreactive material.
Removal of Cr(VI) from Water Using a New Reactive Material: Magnesium Oxide Supported Nanoscale Zero-Valent Iron
Alessio Siciliano
2016-01-01
Abstract
The chromium pollution of water is an important environmental and health issue. Cr(VI)removal by means of metallic iron is an attractive method. Specifically, nanoscopic zero valent iron(NZVI) shows great reactivity, however, its applicability needs to be further investigated. In thepresent paper, NZVI was supported on MgO grains to facilitate the treatments for remediation ofchromium-contaminated waters. The performances and mechanisms of the developed composite,in the removal of hexavalent chromium, were investigated by means of batch and continuous tests.Kinetic studies, under different operating conditions, showed that reduction of Cr(VI) could beexpressed by a pseudo second-order reaction kinetic. The reaction rate increased with the square ofFe(0) amount, while it was inversely proportional to the initial chromium concentration. The processperformance was satisfactory also under uncontrolled pH, and a limited influence of temperature wasobserved. The reactive material was efficiently reusable for many cycles without any regenerationtreatment. The performances in continuous tests were close to 97% for about 80 pore volume ofreactive material.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.