## 3 Results and Discussion
### Multiple Factors' Interaction in EFLP Suspension
#### 3.3.2 Multiple Factors' Interaction on EFLP Suspension at 36-h Reaction  
As for the test data for the 3-h reaction (Supplementary Material), the second-order polynomial Equation (3) was obtained for the test data for the 36-h reaction, and Equation (3) could be effectively used in the present study.  
\[\eta=91.85+4.87\text{A}+4.74\text{B}+3.97\text{C}-3.64\text{AB}-2.87\text{AC}+ 4.21\text{BC}+6.84\text{A}^{2}-4.29\text{B}^{2}-3.77\text{C}^{2} \tag{3}\]  
The \(\eta\) value was different for different hydro-chemical components: the \(\eta\) value was the greatest for Cu(NO\({}_{3}\))\({}_{2}\), followed by NaF, and the smallest for NaNO\({}_{3}\) (Figure 6I-a,II-A). This order was different from that obtained for the 3-h reaction (Figure 5). The contour line for the interaction of hydro-chemical component and concentration in the 36-h reaction was saddle instead of elliptical in nature, showing that the interaction between the corresponding variables was significant and their effects were almost equal in magnitude [61]. These differences showed that the roles of the two factors changed in their interaction processes and indicated that the influence of the hydrochemical components varied along the groundwater flow.  
Figure 6: _Cont._  
The interaction between hydrochemical component and particle size (Figure 6I-b,II-B) was roughly the same as that between hydrochemical component and concentration in the 36-h reaction (Figure 6 II-a,II-A) discussed above. The contour was saddle instead of elliptical in nature and the relative strength of their influence depended on the components and particle size in the 36-h reaction, which was different from the 3-h reaction (Figure 5I-b,I-B). This further proved that the influence of the hydrochemical components varied along the groundwater flow. However, the interaction between component concentration and the particle size in the 36-h reaction (Figure 6 II-c,II-C) was almost the same as that in the 3-h reaction (Figure 5 I-c,I-C), showing that the interaction between component concentration and particle size for 1.1 \(\upmu\)m particle sediments almost remained stable during the whole experimental process. Thus, all this showed that the role of the hydrochemical component weakened while the role of particle size strengthened along the groundwater flow path. Ultimately, the significance ranked in the order of hydrochemical component, diameter size and hydrochemical concentration.  
Comparing Equations (2) and (3) showed that the symbols of each coefficient for the three factors were not changed, indicating that they always had the potential to enhance the particles' AS and suspension along the groundwater flow path, but their coefficient values in Equation (3) were smaller than those in Equation (2), showing that their potential decreased with increasing reaction time, as discussed above. Further analysis of these values revealed that the values decreased by nearly 75% over the 36-h reaction compared with the 3-h reaction, implying that the main hydrochemical components were more conducive to EFLP AS and suspension along the groundwater flow path, which was also in turn beneficial to the transport in the groundwater system.  
Although the studied factors enjoyed a combined effect on particle AS and suspension, their effects weakened throughout the whole reaction process, and the relative contribution of the component decreased while the contributions of the component concentration and particle size both increased, showing that the relative contributions for these studied factors were changed in magnitude and tended to be equal and stable. Therefore, considering the effect characteristics of the studied factors, the CCC value for each solute depended on these studied factors, just like the results obtained above for the single-factor experiment.