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Biosorption of lead ,cadmium,and
mercury ions on loofa sponge
immobilized biomass of Aspergillus
terreus
指導老師: 孫逸民教授
學
生: 田汶玄
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Introduction(1)
Heavy metals are discharged from
various industries such as electroplating,
metal finishing, textile, storage batteries,
mining, ceramic and glass.
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Introduction(2)
The commonly used procedures for
removing metal ions from wastewater
include chemical precipitation, ion
exchange, membrane separation,
reverse osmosis, and electrolysis.
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Introduction(3)
However, these techniques have certain
disadvantages such as incomplete
removal, high reagent and energy
requirements, generation of toxic sludge.
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Introduction(4)
The search for alternative treatment
techniques has focused attention on the
use of biological materials such as algae,
fungi, yeast and bacteria for the removal
and recovery technologies and because
of the better performance and low cost
of these biological materials .
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Introduction(5)
The purpose of the present study is to
provide an immobilized biosorption
system using a low cost, physically
strong, and highly porous immobilization
matrix; loofa sponge.
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Introduction(6)
The study investigated the use of loofa
sponge immobilized fungal biomass as a
biosorbent for the removal of lead,
cadmium ,and mercury from aqueous
solution.
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Materials and Methods
Microorganism
The Aspergillus terreus was maintained
by pure culturing on potato dextrose
agar slants at 28 ℃ for 7 days.
Mycelium suspensions from 7-day old
cultures, preculture on glucose at 28 ℃
for 24 hours.
Then, above Mycelium suspensions was
main culture for 15 days.
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culture medium
medium
KH2PO4
K2HPO4
FeSO4．7H2O
MnSO4．4H2O
ZnSO4．7H2O
CuCl2．2H2O
H3BO3
(NH4)6Mo7O24．4H2O
Mono-hydrate sodium glutamate
Glucose
MgSO4‧7H2O
CaCl2．2H2O
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concentration (g/l)
5
5
0.2
0.1
0.2
5
11
5
12.5
45
0.1
20
Pretreatment of loofa sponge
The fibrous sponge was cut into discs of
approximately 0.2g , soaked in boiling
water for 30 min, thoroughly washed
under tap water, and left for 24 h in
distilled water, changed 3-4 times.
The sponge piece were oven dried at 70
℃.
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Immobilization of A.terrues within
loofa sponge
The mycelium suspension (2.5 ml) was
inoculated into 250 ml flasks containing 50
ml of the growth medium and pre-weighed
loofa sponge discs.
The inoculated flasks were incubated at 28
℃ and shaken at 200 rpm.
After 15 days of incubation, loofa sponge
immobilized A.terrues were harvested from
the medium, washed twice with distilled
water and stored at 70 ℃ until use.
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Biomass of fungal growth
The dry weight of the fungal biomass
entrapped within sponge pieces was
determined by weighing sponge pieces
before and after fungal growth after 48 h
drying at 70 ℃.
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Metal solutions
HgCl2 (Riedel-de Haën)
CdCl2‧2.5H2O (Panreac )
PbCl2 (J. T. Baker)
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Biosorption studies
The biosorption capacity of FBILS (fungal biomass
immobilized in loofa sponge) was determined by
contacting 100 ml metal solution of known concentration
in 250 ml flasks.
The metal solution was shaken on an orbital shaker at 200
rpm and 30 ℃.
FBILS were separated from the solution by decantation.
Residual metal concentration in the metal solutions by
centrifugation at 3000 rpm for 5 min
Supernatant was analysed for residual metal ions
concentration was determined using flame atomic
absorption spectrophotometer.
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Effect of contact time and pH on
metal ion biosorption
For the determination of rate of metal
biosorption by FBILS, the supernatant
was analysed for residual metal ions
after the contact period of 10, 20, 30, 60,
120, 240 and 360 min.
The effect of pH on metal ions sorption
by FBILS was determined by
equilibrating the sorption at different pH
values of 2, 3. 4, and 5.
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Chemical and physical stability of
FBILS
For the purpose, FIBILS was shaken on
an orbital shaker at different rotation
speed for 2 days.
Similarly, soaking of FBILS in buffer of
various pH (2.0–12.0 for 20 days) was
shaken on an orbital shaker at 200 rpm
for 20 days had weight loss 20% of the
FBILS were observed during this period.
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data analysis
q = V(Ci - Ceq)/M
q is the metal uptake (mg metal ions /g dry weight of
fungal biomass entrapped within sponge)
V is the volume of metal solution (ml)
Ci is the initial concentration of metal ions in the
solution (mg/l)
Ceq is the final concentration of metal ions in the
solution
M is the dry weight of fungal biomass
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Results and discussion
Fungal biomass immobilized within
loofa sponge
(a)
(b)
(a) natural loofa sponge covered with A. terrues biomass
(b) artificial loofa sponge covered with A. terrues biomass
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biomass of immobilize loofa
sponge(g)
Growth curve — Aspergillus terreus
immobilized loofa sponge
1
0.8
0.6
natural
0.4
artificia
l
0.2
0
0
1
3
5
7
9
11
13
growth phase (day)
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15
18
23
30
Effect of different phase on metal
uptake by FBILS
Pb adsorbed(mg/g)
400
300
200
100
0
0
3
7
15
diferent phase(days)
100 ml single metal solution (6000mg/l) was contacted with different
days of FBILS on orbital shaker at 200 rpm at 30 ℃ at pH3 for 30 min
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30
Time-course profiles for metal ion
biosorption by FBILS
Pb adsorbed(mg/l)
350
300
250
200
150
100
50
0
0
10
20
30
60
120
240
360
480
960
Hg adsorbed (mg/g)
time(min)
50
40
30
20
10
0
0
10
20
30
60
120
180
240
300
time(min)
Cd adsorbed(mg/g)
40
30
20
10
0
0
10
20
30
time(min)
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60
120
metal ion adsorbed(mg/g)
effect of pH on metal uptake by
FBILS
350
300
250
200
150
100
50
0
Pb
Cd
Hg
1
2
3
4
5
6
7
pH
Metal solution was contacted with 15 days of FBILS at optimal condition
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metal ion adsorbed(mg/g)
Effect of temperature on metal
biosorption by FBILS
350
300
250
200
150
100
50
0
Pb
Cd
Hg
0
10
20
30
40
50
60
temperature(℃ )
Metal solution was contacted with 15 days of FBILS at optimal condition
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metal ion adsorbed(mg/g)
Effect of rotation rate on metal
biosorption by FBILS
350
300
250
Pb
200
Cd
150
Hg
100
50
0
0
50
100
150
200
250
rotation(rpm)
Metal solution was contacted with 15 days of FBILS at optimal condition
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Effect of initial metal ion
concentration
Pb adsorbed(mg/g)
400
300
200
100
0
0
1000
2000
3000
4000
5000
6000
7000
8000
initial concentration (mg/l)
Hg adsorbed(mg/g)
50
40
30
20
10
0
0
200
400
600
800
1000
1200
Cd adsorbed (mg/g)
initial concentration (mg/l)
35
30
25
20
15
10
5
0
0
100
200
300
400
initial concentratiom (mg/l)
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500
600
Chemical stability of LIBCS
weight loss (%)
100
80
60
before weight
40
after weight
20
0
2
4
6
8
10
12
pH
soaking of FBILS in buffer of various pH (2.0–12.0 for 20 days)
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physical stability of FBILS
weight loss (%)
100
80
60
before weight
40
after weight
20
0
50
100
150
200
250
rotation speed(rpm)
soaking of FBILS in pH7 buffer for 2 days
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Conclusions
Loofa sponge is an effective immobilization
carrier for the entrapment of A.terreus to
produce FBILS.
The biosorption capacity of FBILS for single
metal decreased in the order Pb > Hg > Cd
FBILS showed an excellent potential for the
removal lead(II) from aqueous solution.
FBILS showed an good physical and chemical
stability.
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Thanks for your attention

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