Tables at a glance

Table 1

Table 2

Table 3

Figures at a glance

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Table 1

pseudo first-order				pseudo second-order
Metal Ions	qe,	K₁×10^-2	R²	qe	K₂×10^-2	R²
Cu²⁺	179	0.92	0.94	39.5	0.72	0.983
Pb²⁺	172.5	0.72	0.95	31	0.61	0.985

Table 1: Pseudo - First and second order parameters for the adsorption of Cu(II) and Pb(II) on NH₂-MS

Table 2

Metals	Langmuir constants (NH2-MS)			Freundlich constants (NH2-MS)
Metals	Qmax (mg/g)	KL	R²	KF	1/n	R²
Cu(II)	163.16	0.38	0.988	1.4	0.79	0.93
Pb(II)	147.79	0.44	0.989	1.2	0.71	0.92

Table 3

Adsorbent	q_m (mg/g)	Ref.
Silica-Activated Carbon	178.5	2
Metal oxide nanoparticles Fe3O4	127.4	3
Rice husk ash	39.87	4
Poly(ethyleneimine)- Functionalized Silica	36.8	21
NH2-MS	179	This study

Table 3: comparison of the maximum adsorption capacity of heavy metals onto different adsorbents

FIGURE 1

Figure 1: (A) Small-angle X-ray diffraction (SAXRD) patterns and (B) wide-angle XRD (WAXRD) patterns of the calcined MSNs.

FIGURE 2

Figure 2: Nitrogen adsorption isotherms (A) and pore size distribution (B) of MSNs and the TMK sensor

FIGURE 3

Figure 3: FESEM images of the MSNs(A) and MSNs-NH2(B)

FIGURE 4

Figure 4: Representative TEM images of the MSNs

FIGURE 5

Figure 5: Scanning electron microscope images of MSNs (A) and NH2/ MSNs (B)

FIGURE 6

Figure 6: IR shows of the samples (A)Si and (B) NH2-MS

FIGURE 7

Figure 7: pH-dependent metal uptake of metal ion

FIGURE 8

Figure 8: Metal uptake of metal ion with time

FIGURE 9

Figure 9: Plots of log(qe-qt) ainst time for the exchange of Cu (II) and Pb(II) ions on NH2-MS

FIGURE 10

Figure 10: Pseudo second order model for the exchange of Cu (II) and Pb(II) ions on NH2-MS

FIGURE 11

Figure 11: plot of (Ce/qe) ainst Ce for Cu (II) and Pb(II) metals ions

FIGURE 12

Figure 12: plot of log qe versus log Ce for Cu (II) and Pb(II) metals ions