Comparative studies on biosorption ability of metal oxide nanoparticles using marine micro

and macro algae

A. Raj Manoj Reddy & Ankit Kumar TiwariSathyabama University

Biosorption• Biosorption is a physiochemical process that occurs naturally in

certain biomass which allows it to passively concentrate and bind contaminants onto its cellular structure

• Biosorption of metal ions using biological materials such as algae, bacteria, fungal and yeast have received greater attention due to its advantages over conventional method (Arica et al., 2001). It has been defined as the property of biomass such as algae, bacteria, fungal and yeast to bind with metal ions from aqueous solutions (Dursun, 2006; Wang and Chen, 2006; Volesky, 2007).

• The major advantages of biosorption process over conventional technologies include (Kratochvil and Volesky, 1998; Ahalya et al., 2003):

• Low cost • High efficiency • Minimization of sludge production • Biosorbent can be regenerated and • Possible of metals recovery

ObjectiveThis study is being carried out with the following objectives:

• To study the effect of different parameters (pH,time & biomass concentration) on absorption of toxic metal nanoparticles by marine macro alga Kappaphycus alvarezii and micro algae Chlorella vulgaris , Scenedesmus.

• To study the equilibrium and kinetics of heavy metal oxide (ZnO and Fe2O3) removal by freely suspended and immobilized cells of K. alvarezii in batch system.

• To study the desorption /regeneration of metal ions from the immobilized biosorbent.

• To study the best biosorbent based on the percentage of uptake of the metal nanoparticle in three different forms viz., powdered biomass, liquid extract and carrier based seaweed biosorbents.

• To study the characterization of macro and microalgae before and after biosorption process.

MethodologyBiosorbents used• Macro algae- Kappaphycus alvarezii • Micro algae – Scenedesmus sp.

Parameter OptimizationEffect of contact Time, pH and concentration of

metal oxide solutionBiosorption and Desorption of metal ions

Effect of time on absorbents for zinc and iron oxide

Effect of pH on absorbents -for zinc oxide

Effect of pH on absorbents - iron oxideEffect of pH on absorbents - iron oxide

Biosorption and Desorption

250mg of dried biomass

Added to 50ml metal oxide solution

Agitation in a rotary shaker at 180rpm for 3

hrs

Filtration

Metal oxide quantification and further analysis

0.5g of treated biomass

Added to 0.1M HCL

Agitation in rotary shaker at 150rpm for 1 hr

Filtration

Metal quantification

Biosorption Desorption

Characterization studies- Atomic Absorption Spectroscopy

PARAMETER UNIT RESULT

Iron Oxide as Fe2O3 mg/l 12.32Zinc Oxide as ZnO mg/l 7.76

Macro algae

Micro algaePARAMETER UNIT RESULT

Iron Oxide as Fe2O3 mg/l 13.7Zinc Oxide as ZnO mg/l 0.25

Metal uptake capacity of seaweeds

Q= V (Ci - Cf)/SQ - metal ion uptake capacity (mg/g)

Ci= Initial metal concentration in the solution before the sorption analysis (mg/l)

Cf =final concentration of metal in solution after the sorption analysis(mg/l)

S =dry weight of biosorbent (g)V = solution volume (L) (Volesky, 2003).

Metal uptake capacity of seaweeds

S. no

Seaweeds Biomass (g/L) Concentration of metal (mg/g)

1 Kappaphycus alvarezii

2.5 11.072

2 Scenedesmus sp. 2.5 10.52

Iron oxide

Zinc oxideS. no

Seaweeds Biomass (g/L) Concentration of metal (mg/g)

1 Kappaphycus alvarezii

2 16.12

2 Scenedesmus sp. 2.5 15.9

SEM images of macro algae

Iron Oxide Zinc oxide

SEM images of micro algae

Iron Oxide

Zinc Oxide

FT-IR Characterization of Macro algae

Control- Macro algaeSpectrum Name: IR-P-A.sp

4000.0 3000 2000 1500 1000 500 400.00.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100.0

cm-1

%T

3760.73

3399.52

2412.84

2214.10

1572.03

1482.92

1400.18

1263.54

1125.30

923.09

831.85

762.83699.80

651.52618.89

430.39

FT-IR Characterization of Macro algae

Zinc Oxide- Macro algaeSpectrum Name: IR-P-B.sp

4000.0 3000 2000 1500 1000 500 400.00.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100.0

cm-1

%T

3796.31

3402.44

2406.802168.34

1573.42

1397.48

1265.701126.53

922.84

834.59

761.87706.16

651.34

FT-IR Characterization of Macro algae

Iron Oxide- Macro algaeSpectrum Name: IR-P-C.sp

4000.0 3000 2000 1500 1000 500 400.0

0.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100.0

cm-1

%T

3400.99

2171.25

1572.35

1482.11

1400.15

1262.411124.86

923.33

831.75

762.37699.55

651.33

618.39

428.33

FT-IR Characterization of Micro algae

Spectrum Name: IR-P-D.sp

4000.0 3000 2000 1500 1000 500 400.00.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100.0

cm-1

%T

3396.37

2926.97

2855.37

2170.27

1571.72

1481.80

1401.63

1260.79

1121.34

924.53

831.03

762.59697.48

651.46

617.39578.63

428.36

Control- Micro algae

FT-IR Characterization of Micro algae

Zinc Oxide- Micro algaeSpectrum Name: IR-P-E.sp

4000.0 3000 2000 1500 1000 500 400.00.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100.0

cm-1

%T

3395.04

2925.29

2855.12

2169.84

1571.18

1402.60

1258.65

1119.84

829.78

761.64697.60

651.68

616.32

430.00

FT-IR Characterization of Micro algae

Spectrum Name: IR-P-.sp

4000.0 3000 2000 1500 1000 500 400.00.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100.0

cm-1

%T

3390.71

2922.89

2853.94

2256.37

1570.56

1402.89

1257.51

1118.54

829.16

761.92698.10

652.06615.17

429.89

Iron Oxide- Micro algae

Thank You