## Materials and Methods
### Analytical Methods of Cu(II) and its Sequential Extraction  
The procedure proposed by [PERSON] et al. was applied in this study to analyzed different copper species that was usually used to determine the fractionation of heavy metals in soil and sediment samples [20]. The Cu(II) of the five fractions were analyzed, including the exchangeable fraction, carbonates fraction, Fe-Mn oxides fraction (the fraction associated with Fe and Mn oxides), organic matter fraction (the fraction bound to organic matter) and a residual fraction. After the completion of the experimental column, lime sand bricks were taken out and the Cu(II) adsorbed to bricks were analyzed through sequential extraction in order to distinguish different species. The analysis was carried out for the brick flows through different inlet concentration of 0.5, 1.0 and 2.0 mg/L with a residence time of 10 min. The bricks were baked at 105 \({}^{\circ}\)C for 24 h until dry, ground with a mortar and then passed through a 200-mesh screen. Step 1: exchangeable fraction (F1). The solid samples (2 g) were introduced into three 50 mL centrifuge tubes containing a 16 mL magnesium chloride solution (1 mol/L, adjusted to pH 7 with HNO\({}_{3}\) and NaOH) and shaken for 1 h at 25 \({}^{\circ}\)C, respectively. The solution was separated from the solid by centrifugation at 4000 rpm for 20 min. The liquid supernatant was then filtered through a 0.45 \(\upmu\)m membrane filter. The solid residue was retained for subsequent analysis. Step 2: carbonates fraction (F2). A 16 mL volume of sodium acetate solution (1 mol/L, adjusted to pH 5 with HNO\({}_{3}\)) was added to the residue from step 1 in a centrifuge tube, which was shaken for 8 h at 25 \({}^{\circ}\)C. The solution was separated from the solid by centrifugation at 4000 rpm for 20 min. The extraction procedure depicted above was followed. Step 3: Fe-Mn oxides fraction (F3). A 16 mL volume of hydroxylamine hydrochloride solution (0.04 mol/L, adjusted to pH 2 with HNO\({}_{3}\)) to 25% acetic acid solution in acetic acid solution was added to the residue from step 2, which was shaken for 4 h at 95 \(\pm\) 2 \({}^{\circ}\)C. The solution was separated from the solid by centrifugation at 4000 rpm for 20 min. The extraction procedure depicted above was followed. Step 4: organic matter fraction (F4). A 5 mL volume of hydrogen peroxide (30%) and 3 mL nitric acid (0.01 mol/L) were added to the residue from step 2. The mixture is heated to 85 \({}^{\circ}\)C in a water bath and kept at 85 \({}^{\circ}\)C for 2 h with occasional manual stirring. A second 5 mL volume of hydrogen peroxide (30%, adjusted to pH 2 with HNO\({}_{3}\)) was introduced and digested at 85 \(\pm\) 1 \({}^{\circ}\)C for 2 h in a water bath. After that, 5 mL of 3.2 mol/L ammonium acetate (adjusted to pH 2 with HNO\({}_{3}\)) was introduced to the cooled-down residue, which was then shaken for 0.5 h at 25 \({}^{\circ}\)C. Finally, the extract was separated according to the procedure described in step 1. Step 5: residual fraction (F5). We used the same method as determining the total concentration of heavy metals in the sample. The residue from the metal content of step 3 was digested with 10 mL of aquaregia heated on a heater and then evaporated to near dryness according to ISO recommendations. After cooling down, the residues were diluted in 50 mL 5% HNO\({}_{3}\). In order to determine the total concentration of Cu(II) in the top layer of the lime sand bricks in the column, the lime sand bricks were used for digestion by microwave digestion. A total of 0.1 g of brick sample was weighed into a poly tetra fluoro ethylene digestion tank, and a blank sample of 0.1 mL of ultrapure water was used instead of the brick sample in one digestion tank. A total of 5 mL volume of nitric acid, 2 mL volume of hydrogen peroxide and 3 mL volume of hydrofluoric acid were sequentially added to the digestion tank.