Mg-aminoclay as stabilizer for synthesizing highly stable and reactive nZVI for decontamination

Despite the large surface area and superior reactivity of nZVI, its limited stability is a major obstacle for in situ subsurface remediation. In this study, Mg-aminoclay (MgAC) was applied for the first time as a stabilizer in nZVI synthesis. With increased doses of Mg-aminoclay, nZVI particle growth was inhibited and thin sheathed grape-like nZVI particles with higher crystallinity were produced. The coated nZVI were smaller and non-aggregating, and it can reduced nitrate 350-fold faster than uncoated. The higher stability of MgAC coated nZVI was achieved by electrostatic repulsion from the positively charged MgAC coating. Moreover, the proper washing strategy is essential to keep stability and reactivity during preparation and transport.