Stabilized green rusts for aqueous Cr(VI) removal: Fast kinetics, high iron utilization rate and anti-acidification

摘要: Green rusts (GRs) are redox active towards contaminants but they not stable for long distance transport during the soil and groundwater remediation. In this study, green rust chloride (GR) was stabilized by selected regents, including silicate (Si), phosphate (P), fulvic acid (FA), carboxymethyl cellulose (CMC) bone char (BC), then these GR, collectively named GR-X, would be further applied Cr(VI) removal from aqueous solution. The stabilization experiment demonstrated that release of Fe(II) GR effectively suppressed above reagents, enabling at least 50% lower leaching GR-X than pristine GR. intact hexagonal plates crystallinity were also confirmed SEM images XRD patterns after storage 7 days, indicating structure remained. tests, eliminated in seconds with a utilization efficiency over 90%. Cr species examination able to transfer into Cr(III)-Fe(III) precipitates (Fe-Mn oxides fraction). After all reactors exposed air 1 week monitor pH fluctuation evaluated risk acidification. results indicate that, except GR-Si system, other post-remediation systems buffering ability could avoid acidification risk.