Efficient and cost-effective adsorbent brick sand nanoparticles used for removal of heavy metals

Figures & data

Figure 1. XRD spectrum of brick sand particles.

Figure 2. a) removal of heavy metals (pb, Cd & Cr) using untreated and b) removal of heavy metals (pb, Cd & Cr) using treated brick nano particles as an adsorbent with respect to time.

Figure 3. a) removal of heavy metals (pb, Cd & Cr) using untreated and b) removal of heavy metals (pb, Cd & Cr) using treated brick nano particles as an adsorbent with respect to temperature.

Figure 4. a) removal of heavy metals (pb, Cd & Cr) using untreated and b) removal of heavy metals (pb, Cd & Cr) using treated brick nano particles as an adsorbent with respect to pH.

Figure 5. Point zero charge (pH_PZC) for adsorbent.

Figure 6. Fitting of Longmuir adsorption isotherm model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb [(a) &; (b)], Cd [(c) &; (d)] and Cr [(e) &; (f)].

Table 1. Summary of the three-adsorption model used in the study for removal of heavy toxic metals (pb, Cd & Cr) from aqueous solution using brick sand nanoparticles as an adsorbent.

Toxic Heavy Metals	Brick Nano Particle	Langmuir Adsorption Isothermal Model		Freundlich Adsorption Isothermal Model		Temkin Adsorption Isothermal Model
		Rl	R^2	1/n	R^2	$B_T$ (Jmole^−1)	$K_T$ ($\mathit{Lm}{g}^{-1}$)	R^2
Pb	Untreated	0.857083	0.9998	0.9974	0.9992	0.35882	0.141688	0.9895
	Treated	0.9397008	1	0.99874	1	0.21589	0.2387362	0.9899
Cd	Untreated	1.03829702	0.99998	1.0033	0.99997	10.498	0.07633	0.99018
	Treated	0.40585348	1	0.99815	1	5.233	0.24189	0.82805
Cr	Untreated	1.19629317	0.9996	1.00113	0.99971	0.5603	0.487737	0.99839
	Treated	0.621451968	0.9997	0.99561	0.999784	0.4918	0.557	0.99598

Figure 7. Fitting of Freundlich adsorption isotherm model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb [(a) &; (b)], Cd [(c) &; (d)] and Cr [(e) &; (f)].

Figure 8. Fitting of Temkin adsorption isotherm model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb [(a) &; (b)], Cd [(c) &; (d)] and Cr [(e) &; (f)].

Figure 9. Fitting of Hill De Boer adsorption isotherm model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb, Cd, and Cr.

Table 2. Summary of the hill de boer, elovich and redlich-petersons adsorption model used in the study for removal of heavy toxic metals (pb, Cd & Cr) from aqueous solution using brick sand nanoparticles as an adsorbent.

Toxic Heavy Metals	Brick Nano Particle	Hill De Boer Adsorption Isothermal Model		Elovich Adsorption Isothermal Model		Redlich-Peterson Adsorption Isothermal Model
		K1	R^2	Qm (mg/g)	R^2	B	-lnA	R^2
Pb	Untreated	11.93448	0.9625	−1.85224	0.02307	0.0026	3.99523	0.00905
	Treated	6.7565	0.9839	−206.6518	0.98382	0.00126	3.99601	0.3993
Cd	Untreated	17.89942	0.9169	7542.30	0.85139	−0.0033	1.26206	0.3057
	Treated	4.46943	0.95487	22716.63	0.87029	0.00185	1.24438	0.90882
Cr	Untreated	14.96071	0.99426	−123.8708	0.99483	0.00126	3.99601	0.3993
	Treated	8.97856	0.9942	−101.8680	0.9951	0.00439	2.29971	0.1056

Figure 10. Fitting of Elovich adsorption isotherm model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb, Cd, and Cr.

Figure 11. Fitting of redlich-petersons adsorption isotherm model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb, Cd, and Cr.

Figure 12. Fitting of Intra-particle diffusion model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb, Cd, and Cr.

Table 3. Summary of the intra-particle diffusion, elovich and boyd kinetic model used in the study for removal of heavy toxic metals (pb, Cd & Cr) from aqueous solution using brick sand nanoparticles as an adsorbent.

Metal		Intra-particle Diffusion			Elovich Kinetic Model			Boyd Model
	Condition	Kdiff	C	R^2	α	β	R^2	Intercept	R^2
Pb	Untreated	4.61352×10^−4	0.18989	0.14026	714.28	2.36×10^55	0.22069	3.52277	0.13186
	Treated	0.00401	0.15138	0.04375	207.90	7.11×10^11	0.01074	0.81317	1.0
Cd	Untreated	−8.99×10^−4	0.19008	0.12459	−418.41	3.44×10^−33	0.14999	2.90154	0.02762
	Treated	−0.00164	0.19616	0.09359	−261.09	1.053	0.08731	3.01221	0.79268
Cr	Untreated	−1.14152×10^−4	0.1985	0.36085	−0.405	2.66	0.28722	7.78749	0.98392
	Treated	−1.1051×10^−4	0.19864	0.24158	−0.334	2.80	0.30242	6.49053	0.05287

Figure 13. Fitting of Elovich kinetic model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb, Cd, and Cr.

Figure 14. Fitting of Boyd model for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb, Cd, and Cr.

Figure 15. Kinetic for removal of heavy metals using untreated and treated brick sand nanoparticles for Pb [(a) &; (b)], Cd [(c) &; (d)] and Cr [(e) &; (f)].

Table 4. Pseudo 2nd order reaction kinetics parameter for untreated and treated brick sand nano-particles for removal of heavy toxic metals Pb, Cd, and Cr.

Metals	Condition	K2	R^2
Pb	Untreated	−84.1668	0.99967
	Treated	0.69481055	0.84244
Cd	Untreated	−20.6399	0.998
	Treated	−5.92044	0.9846
Cr	Untreated	−83.021	0.9998
	Treated	−1495.65	0.9999

Table 5. Thermodynamics parameter for untreated and treated brick sand nano-particles (pb, Cd, and Cr) using R = 8.316 Jmol⁻¹K^−1..

Metals	ΔH^0 (Jmol^−1)	ΔS (Jmol^−1 K^−1)	T (Temperature)	ΔG^0
Pb (untreated brick nanoparticles)	49.012	−33.135	30° C = 303 K	10.08
			40° C = 313 K	10.42
			50°C = 323 K	10.75
			60° C = 333K	11.08
			70°C = 343 K	11.41
Pb (treated brick nanoparticles)	2.0537	−33.250	30° C = 303 K	10.07
			40° C = 313 K	10.4
			50°C = 323 K	10.74
			60° C = 333K	11.07
			70°C = 343 K	11.4
Cd (untreated brick nanoparticles)	−37.032	−10.51	30° C = 303 K	3.14
			40° C = 313 K	3.25
			50°C = 323 K	3.35
			60° C = 333K	3.46
			70°C = 343 K	3.56
Cd (treated brick nanoparticles)	34.21	−10.29	30° C = 303 K	3.15
			40° C = 313 K	3.25
			50°C = 323 K	3.35
			60° C = 333K	3.46
			70°C = 343 K	3.56
Cr (untreated Brick Particles)	−69.64	−19.39	30° C = 303 K	5.80
			40° C = 313 K	5.99
			50°C = 323 K	6.19
			60° C = 333K	6.38
			70°C = 343 K	6.58
Cr (untreated brick nanoparticles)	−86.33	−19.449	30° C = 303 K	5.80
			40° C = 313 K	6.00
			50°C = 323 K	6.19
			60° C = 333K	6.39
			70°C = 343 K	6.58

Figure 16. EDS spectrum of untreated brick sand nanoparticles(a), untreated brick sand nanoparticles adsorbed Pb (b), untreated brick sand nanoparticles adsorbed Cd (c), untreated brick sand nanoparticles adsorbed Cr (d).

Figure 17. EDS spectrum of treated brick sand nanoparticles adsorbed Pb (a), treated brick sand nanoparticles adsorbed Cd (b), treated brick sand nanoparticles adsorbed Cr (c).