Biosorption of Pb(II) ions from aqueous solutions by waste biomass of Streptomyces fradiae pretreated with NaOH

Figures & data

Figure 1 . FTIR spectra of the waste S. fradiae biomass before (a) and after (b) Pb(II) biosorption.

Figure 2. Effect of pH on biosorption of Pb(II) by waste S. fradiae biomass. Note: C_i = 50 mg·dm⁻³, V = 100 cm³, W = 1 g·dm⁻³, t = 120 min.

Figure 3. Effect of contact time and initial Pb(II) concentration on the NaOH-pretreated S. fradiae biomass biosorption capacity. Note: pH = 5.0, V = 100 cm³, W = 1 g·dm⁻³, t = 120 min, C_i = 25, 50, 100 mg·dm⁻³.

Figure 4. Linear plot of the Langmuir isotherm.

Figure 5. Linear plot of the Freundlich isotherm.

Table 1. Isotherm model constants and correlation coefficients for biosorption of Pb(II) ions.

Langmuir model			Freundlich model
qm, mg·g^−1	b, dm^3·mg^−1	R^2	KF, dm^3·g^−1	n	R^2
138.88	0.360	0.997	35.31	2.61	0.964

Figure 6. Linear plot of pseudo-first kinetic model. Note: C_i = 25, 50, 100 mg·dm⁻³.

Figure 7. Linear plot of pseudo-second kinetic model. Note: C_i = 25, 50, 100 mg·dm⁻³.

Table 2. Kinetic constants for Pb(II) biosorption by waste S. fradiae biomass.

	Pseudo-first order kinetic model			Pseudo-second order kinetic model
Pb(II) initial concentration, mg·dm^−3	qe, mg·g^−1	k1, min^−1	R^2	qe, mg·g^−1	k2, g·mg^−1·min^−1	R^2
25	10.08	10.7 × 10^−2	0.995	25.86	19.7 × 10^−3	0.999
50	27.65	8.8 × 10^−2	0.971	54.74	3.7 × 10^−3	0.996
100	55.19	5.6 × 10^−2	0.993	91.82	2.0 × 10^−3	0.997

Figure 8. Biosorption of Pb(II) onto S. fradiae biomass. Notes: 1 – Pb(II) ions only; 2 – Pb(II) and Cu(II) ions; 3 – Pb(II) and Zn(II) ions.