Rheology modification of reduced graphene oxide based nanoscale zero valent iron (nZVI/rGO) using xanthan gum (XG): Stability and transport in saturated porous media

Controlled treatment of a high velocity anisotropic aquifer model contaminated by hexachlorocyclohexanes

“…Values close to the unit were reported for simple materials like uniform glass beads [40,41,60]. However, higher 14 values (1.7-2.4) were obtained for the injection of amendments, like nZVI, suspended in xanthan solution in sands [61,62]. Nevertheless, shift factors close to one show that the bulk rheological characterization allows the good estimation of pressure gradients in the porous medium [40].…”

Cr(VI) removal from groundwater by calcium alginate coating microscale zero‐valent iron and activated carbon: Batch and column tests

“…Cr(VI) removal capacity decreased from 2.31 to 1.05 mg/g when the pH increased from 2 to 8. The valent of chromium was highly dependent on the pH level of the solution, the dominant species was HCrO 4 − at acidity (pH < 5) when reaction system was neutral or alkaline the dominant species changed to CrO 4 2–51 . When the pH is less than 3.5, CrOH 2+ , Cr(OH) 2+ , Cr(OH) 4 − , and Cr(OH) 3 0 existing in system due to the hydrolysis of aqueous Cr(III) 52 .…”

“…Furthermore, nZVI is easily oxidized so the preparation process needs to strictly maintain an anaerobic environment which ulteriorly increases cost and operational complexity. Intrinsic drawbacks of nZVI such as rapid aggregation, [7][8][9] immobilization, [10][11][12] passivation, 13,14 biotoxicity, [15][16][17] and metal leaching 18 also inhibit its performance. The attractiveness of mZVI for practical applications is more than nZVI if its drawback, insufficient reactivity, could be reduced.…”

Rheological behavior of xanthan gum suspensions with Fe-based nanoparticles: the effect of nanoparticles and the mechanism

“…27 Similar results were reported in a study by Ren et al , where the XG solution was employed to stabilize particles of the nZVI-reduced graphene oxide composite (nZVI/rGO). 28 However, some studies have reported that the presence of particles can reverse the rheological properties of polymer solutions from shear thinning behavior to shear thickening behavior, as seen in the case of a polyethylene glycol suspension of silica nanoparticles and polystyrene microspheres. 29,30 These studies highlight the influence of particles on the rheological properties of the solution.…”