Supporting Information

for

Enhanced transportability of zero valent iron nanoparticles in aquifer sediments: surface

modifications, reactivity, and particle travelling distances

Naresh Kumar1,2, Jérôme Labille1,2, Nathan Bossa1,2, Mélaine Auffan1,2, Pierre Doumenq3, Jérôme Rose1,2, Jean-Yves Bottero1,2

1CEREGE, CNRS,Aix Marseille Université - IRD - Collège de France, UM 7330, 13545 Aix-en-Provence, France

2International Consortium for the Environmental Implications of Nanotechnology iCEINT, Aix-en-Provence, France.

3Aix Marseille Université, CNRS, LCE, FRE 3416, Bâtiment Villemin, Europôle de l’Arbois, Avenue Louis Philibert, BP 80, 13545 Aix en Provence, France

Corresponding Author: nareshk@stanford.edu; naresh.cerege@gmail.com

Current postal address: Dr. Naresh KumarDepartment of Geological SciencesStanford University, Stanford CA 94305nareshk@stanford.edu Phone: +1 650 723 7513

S1

Table 1: Molecular Structure and molecular weight if the modifiers used in this study

Molecular structure M.W References

PAA

(Poly Acrylate Acid)

1800 g M-1 (Schrick et al., 2004)

CMC

(Carboxy methyl

cellulose)

90000 g M-1 (He et al., 2010)

Xanthan 4x 106 g M-1 (Vecchia et al., 2009)

Schrick, B., Hydutsky, B.W., Blough, J.L. and Mallouk, T.E. (2004) Delivery Vehicles for Zerovalent Metal Nanoparticles in Soil and Groundwater. Chemistry of Materials 16(11), 2187-2193.

Vecchia, E.D., Luna, M. and Sethi, R. (2009) Transport in Porous Media of Highly Concentrated Iron Micro- and Nanoparticles in the Presence of Xanthan Gum. Environmental Science & Technology 43(23), 8942-8947.

He, F., Zhao, D. and Paul, C. (2010) Field assessment of carboxymethyl cellulose stabilized iron nanoparticles for in situ destruction of chlorinated solvents in source zones. Water Research 44(7), 2360-2370.

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Figure 1: A file photo of (A) the dispersion machine provided by particle manufacturer and (B) the column setup in the laboratory

S3

Figure 2: XRD diffractogram obtained from freshly prepared nano-Fe0 suspension. 2 Theta degrees are represented here against intensity (presented in Arbitary Units)

Figure 3: Particle size distribution in aquifer sediment (this measurement was conducted only for the particle size selected for this experiment).

Figure 4: TCE degradation in milliQ water using modified and unmodified nFe0 particles against control experiment (without nano-Fe0)

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Table 2: Zeta potential/streaming potential measurements

S5

Measured at pH

Values

Un coated nano-Fe0 6.3 +26

CMC- coated nano-Fe0 6.6 -38

Xanthan- coated nano-Fe0 6.6 -73

PAA-coated nano-Fe0 6.3 -13

Aquifer Sediment 6.8 -18

Sand 6.4 -40