Dataset consists of:
1) Figure 1 (a) Empirical relation between cell concentration and bacteria OD600 of S. pasteurii. (b) zeta potentials of S. pasteurii and sands measured under ionic strengths of 0.5, 30, 500, 1000 mM NaCl.
2) Figure 3. Experimental and modelled breakthrough curves of the tracer (NaCl) in saturated sand columns at different velocities (50 cm/h, 100 cm/h, 200 cm/h) for Experimental 0.
3) Figure 4. Experimental and modelled bacterial BTCs (normalised) under different IS conditions (Experiment 1). Error bars represent standard deviations in results from replicate experiments. The modelled tracer BTC is also plotted (black dash line) for comparison. Black arrow marks where the injection of bacterial solution was changed to the background solution.
4) Figure 5. Experimental and modelled deposition profiles due to pore straining along the column length under different ionic strength conditions (Experiment 1).
5) Figure 6. (a) DLVO interaction energy between S. pasteurii 372 and quartz sands and (b) between bacterial cells as a function of separation distance under different ISs. The insets mark the secondary energy minimum.
6) Figure 7. Experimental and modelled bacterial breakthrough curves under different flow velocity conditions (Experiment 2). Error bars represent standard deviations in results from replicate experiments. Due to the enhancement of the IS at Stage 2, the overall attaching/straining rates were enhanced accordingly. Black arrow marks where the injection of bacterial solution was changed to 0.5M CaCl2 solution.
7) Figure 8. Experimental and modelled bacterial breakthrough curves under initial OD600 of 1 and 0.48 (Experiment 3). Error bars represent standard deviations in results from replicate experiments. Black arrow marks where the injection of bacterial solution was changed to 0.5M CaCl2 solution.
8) Figure 9. Experimental and modelled bacterial (and tracer) breakthrough curves in shorter columns (length: 150 mm) under two IS conditions: (a) 100 mM; (b) 500 mM (Experiment 4). Error bars represent standard deviations in results from replicate experiments. Flushing of 5 PVs of DI water leads to a partial bacterial detachment in stage 3.
9) Figure S1. Particle size distribution of the tested quartz sands.
10) Figure S2. (a) Bacteria OD600 and (b) specific urease activity after 24h incubation. The inoculums were suspended into DI water, tap water, 500 and 1000 mM NaCl solution, and originally centrifuged media for 5 hours.
11) Figure S3. Experimental and modelled breakthrough curves of the tracer (NaCl) under different ionic strength conditions (Experiment 1). Note that the tracer breakthrough data under tap water (0.5 mM) condition are not plotted since the electrical conductivity of tap water is too close to the initial pore solution.
12) Figure S4. (a) Normalised (based on ionic strengths) experimental and modelled breakthrough curves of tracers (100mM NaCl at stage 1 and 0.5M CaCl2 at stage 2) under different flow velocity conditions (Experiment 2) and under an initial OD600 of 0.5 (Experiment 3). (b) an example of changes in electrical conductivity of the effluent samples at the flow velocity of 100 cm/h, which were used to obtain the normalised breakthrough curves (C/C0) as shown in (a).
13) Figure S5. Experimental and modelled breakthrough curves of the tracer (NaCl) in 50-mm columns under ionic strengths of 100 mM and 500 mM (Experiment 4).