Details

Autor(en) / Beteiligte

• Gheju, Marius
• Balcu, Ionel

Titel

Effect of Sand Co-Presence on Cr[sup.VI] Removal in Fe[sup.0]-H[sub.2]O System

Ist Teil von

• Water (Basel), 2023-02, Vol.15 (4)

Ort / Verlag

MDPI AG

Erscheinungsjahr

2023

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The aim of the present study was to provide new knowledge regarding the effect of non-expansive inert material addition on anionic pollutant removal efficiency in Fe[sup.0]-H[sub.2]O system. Non-disturbed batch experiments and continuous-flow-through column tests were conducted using Cr[sup.VI] as a redox-active contaminant in three different systems: "Fe[sup.0] + sand", "Fe[sup.0] only" and "sand only". Both experimental procedures have the advantage that formation of (hydr)oxide layers on Fe[sup.0] is not altered, which makes them appropriate proxies for real Fe[sup.0]-based filter technologies. Batch experiments carried out at pH 6.5 showed a slight improvement of Cr[sup.VI] removal in a 20% Fe[sup.0] system, compared to 50, 80 and 100% Fe[sup.0] systems. Column tests conducted at pH 6.5 supported results of batch experiments, revealing highest Cr[sup.VI] removal efficiencies for "Fe[sup.0] + sand" systems with lowest Fe[sup.0] ratio. However, the positive effect of sand co-presence decreases with increasing pH from 6.5 to 7.1. Scanning electron microscopy-energy dispersive angle X-ray spectrometry and X-ray diffraction spectroscopy employed for the characterization of Fe[sup.0] before and after experiments indicated that the higher the volumetric ratio of sand in "Fe[sup.0] + sand" system, the more intense the corrosion processes affecting the Fe[sup.0] grains. Results presented herein indicate the capacity of sand at sustaining the efficiency of Cr[sup.VI] removal in Fe[sup.0]-H[sub.2]O system. The outcomes of the present study suggest that a volumetric ratio Fe[sup.0]:sand = 1:3 could assure not only the long-term permeability of Fe[sup.0]-based filters, but also enhanced removal efficiency of Cr[sup.VI] from contaminated water.