Removal of heavy metals from aqueous solutions using Eucalyptus Camaldulensis: An alternate low cost adsorbent

Figures & data

Figure 1. SEM image of E. camaldulensis activated carbon

Figure 2. Effect of adsorbent particle sizes on adsorption of Cd, Cr and Pb onto E. camaldulensis activated carbon (EACA) (dose = 1 g; pH = 7; Time = 2 h; concentration = 0.25 mg/L in 100 mL volume of solution at room temperature)

Figure 3. Effect of adsorbent dosage of E. camaldulensis activated carbon on to Cr, Cd and Pb (Concentration 0.25 mg/L, pH = 10.0 for Cd and Cr, pH = 12.0 for Pb, 0.063 mm adsorbent particle size and 2 h)

Figure 4. The effect of contact time on removal of Cr, Cd & Pb using E. camaldulensis activated carbon (Size 0.063 mm; dose = 1 g; pH = 7; concentration = 0.25 mg/L in 100 mL volume of solution at room temperature)

Figure 5. Effect of pH on biosorption of Pb, Cr and Cd using E. camaldulensis activated carbon (Size = 0.063 mm; dose = 1 g; Time = 2 h; concentration = 0.25 mg/L in 100 mL volume of solution at room temperature)

Figure 6. Effect of initial concentration on biosorption of Pb, Cd and Cr using E. camaldulensis activated carbon (Size = 0.063 mm, Time = 2 h, pH = 10 for Pb and Cr and 12 for Cd, dose = 1g)

Table 1. Adsorption isotherms constants for Pb, Cr and Cd

Langmuir Isotherm					Freundlich Isotherm
Metals	Qmax (mg/g)	b(L/mg)	RL	R^2	KF (mg/)	n (L/mg)	R^2
Cr	47.619	0.002	0.998	0.994	−1.046	1.98	0.914
Cd	6.173	0.015	0.992	0.98	4.025	0.778	0.804

Table 2. Comparison of the maximum adsorption capacity of Eucalyptus activated carbon with different studied commercial activated carbon as adsorbents

Sorbents	Sorption capacity (mg/g)			Reference
	Cr	Cd	Pb
Commercial activated carbon	11.13	-	-	Barkat, Nibou, Chegrouche, and Mellah (2009)
	-		8.89	Rawat, Ranjana, and Singh (1993)
		8.00	-	Mohanah et al. (2007)
Eucalyptus activated carbon	47.6190	6.1728	9.2592	Present work

Table 3. Results of preliminary biosorption experiments for total Pb, Cd and Cr (bio-sorbent dose = 1 g, pH (Pb and Cd = 10: Cr = 12), contact time = 2h) from real sample

Samples	Heavy metal	Treated	Untreated	(%)Removal
ATA	Cr	0.08	0.02	72
	Pb	0.03	0.00	100
	Cd	0.03	0.01	62
BTA	Cr	0.02	0.00	100
	Pb	0.02	0.013	21
	Cd	0.06	0.003	94.5
MAT	Cr	0.073	0.02	72.6
	Pb	0.02	0.00	100
	Cd	0.033	0.01	69
WAT	Cr	0.996	0.913	83.3
	Pb	0.03	0.007	77.6
	Cd	0.037	0.01	72.6
WBT	Cr	11.83	11.20	5.3
	Pb	0.017	0.01	59.9
	Cd	0.04	0.013	66.78

Table 4. Column adsorption of Cr, Pb, and Cd at 11g, pH of 10, 2 h wastewater at 5 and10 ml/min of flow rate

Flow rate (ml/min)	Removal (%) of metals
	Pb	Cd	Cr
5	100	87	100
10	89	82	93

Figure 7. Desorption of Cr, Cd and Pb by HCl from E. camaldulensis activated carbon (condition 11g, 2 h and 200 rpm)

Barkat, M., Nibou, D., Chegrouche, S., & Mellah, A. (2009). Kinetics and thermodynamics studies of chromium (VI) ions adsorption onto activated carbon from aqueous solutions. Chemical Engineering and Processing, 48(1), 38–47. doi:10.1016/j.cep.2007.10.004

 Web of Science ®Google Scholar

Rawat, N. S., Ranjana, P. K., & Singh, D. (1993). Characteristic adsorption of aqueous lead (II) on bituminous coal. Indian Journal of Environmental Protection, 13(3), 193–197.

 Google Scholar

Mohanah, D., Pittmanjr, C. U., Bricka, M., Smith, F., Yancey, B., Mohammad, J., Steele, P. H., … Gong, H. (2007). Sorption of arsenic, cadmium, and lead by chars produced from fast pyrolysis of wood and bark during bio-oil production. Journal of Colloid Interface Sciences, 310(1), 57–73. doi:10.1016/j.jcis.2007.01.020

 PubMed Web of Science ®Google Scholar