Transcript adsorption of dyes from aqueous solutions by domestic wastes

NATIONAL WORKSHOP ON “NEW TRENDS IN
BIOTECHNOLOGY: THEORY AND APPLICATIONS
ADSORPTION OF BASIC DYES ONTO LOWCOST ADSORBENTS: ANALYSIS OF THE
EQUILIBRIUM STATE
Dr. Abel E. Navarro
Science Department, Borough of Manhattan Community College, CUNY
Color:
-
Against the natural
conception of pure water. It
hides other types of
pollution.
Prevents the penetration of
sunlight into deep layers of
water – Photosynthesis.
The biological risks have
not been totally discarded
(carcinogenic and toxic
effects).
-
Use of biological techniques to
remove pollutants from air,
soil and water.
Bioaccumulation: Living
organism
Biosorption: Dead biomass
 Use of non-living biomasses to
passively remove pollutants
 Driven
by physico-chemical
processes
 Algae,
crustacean
shells,
eggshell, nutshell, fruit peels,
fruit seeds, TEALEAVES.
 Fast kinetics (saturation time).
 Potential recyclability of waste
Complex structure, mainly
formed by polysaccharides
have many ways for
pollutants to be taken up:
- Metabolism dependent.
- Non-metabolism
dependent.
 Competitive performance.
 Pollutant selectivity.
 Cost effectiveness.
 Pollutant recovery.
 No sludge generation.
 Eco-friendly filtering
technique.
 Alternative for using
man-made resins (x10
more expensive).
 Potentially used for air
and water.
TARGET POLLUTANTS
 Basic Blue 99: Naphthoquinoneimine,
cationic dye. Amino and hydroxyl
groups present.
O
NH
N
Cl
N
N
H3C
N
CH3
CH3
H3C
Basic Yellow (BY57)
Basic Blue 99 (BB99)
OUR ADSORBENTS
 Why? High content of functional organic
groups such as alcohol (fiber and
carbohydrates), carboxylic acids and
amines (structural polysaccharides).
 Widespread use of green tea as a hot/cold
drink. Massive collection from green tea
industries (i.e. Arizona and other bottled
tea-based drinks).
RESULTS
Characterization of the Adsorbents by TGA, SEM, FTIR,
SURFACE AND POROSITY
0
-2
Mass Loss (%)
-4
-6
-8
-10
-12
-14
GT
-16
-18
0
100
200
300
400
500
600
0
Temperature ( C)
FTIR ANALYSIS
cm-1
O-H STRETCH
3436
Surface Area (m2/g)
N-H BENDING
1636
Micropore Volume (cm3/g)
0.692
C=O STRETCH
1656
Total Pore Volume (cm3/g)
1.106
C-O STRETCH
1111
C=O STRETCH
1720
2,735.00
pH Effect
Higher pH promotes higher
adsorption.
100
95
90
90
80
85
70
% ADSORPTION
-
Ionization of adsorbent’s surface and
dye
% ADSORPTION
-
Mass Effect
Minimize amount of adsorbent.
Higher adsorption promotes
formation of aggregates.
60
50
40
30
80
75
70
65
20
BY57
BB99
10
BY57
BB99
60
0
55
2
3
4
5
pH
6
7
8
0
20
40
60
80
100
120
140
Adsorbent Mass (mg)
160
180
200
RESULTS
 Isotherms were modeled by Langmuir and
Freundlich theories.
0.20
BY57
BB99
0.18
Adsorption Capacity (g/g)
0.16
Langmuir
qmax (g/g)
0.06
0.27
0.12
b (L/g)
63.29
25.82
0.10
R2
0.979
0.988
kF (L/g)
0.23
1.27
n
1.829
1.448
R2
0.984
0.978
0.14
0.08
0.06
Freundlich
0.04
0.02
0.00
0.02
0.04
0.06
0.08
0.10
Dye Concentration at Equilibrium (g/L)
0.12
Salinity Effect:
-
Higher the charge, the
stronger the effect.
95
NaCl
NaNO3
Ca(NO3)2
80
70
60
50
40
30
NaCl
NaNO3
Ca(NO3)2
90
% BB99 ADSORPTION
90
% BY57 ADSORPTION
Decreases adsorption due
to competition for the
adsorption sites.
85
80
75
70
65
60
55
20
50
0.0
0.1
0.2
0.3
Salt Concentration (mol/L)
BY57
0.4
0.5
0.0
0.1
0.2
0.3
Salt Concentration (mol/L)
BB99
0.4
0.5
Presence of Heavy Metals
Large and positively charge
ions.
- Present in residual waters.
-
80
Cu(II)
Pb(II)
% BB99 ADSORPTION
% BY57 ADSORPTION
100
Cu(II)
Pb(II)
60
40
20
0
0
10
20
30
40
Heavy Metal Concentration (mg/L)
BY57
50
80
60
40
20
0
0
10
20
30
40
Heavy Metal Concentration (mg/L)
BB99
50
 Green Tealeaves have proven



to be promising adsorbents
for model dyes BY57 and
BB99.
TGA, FTIR, surface/porosity
and SEM studies report
advantages of GT as an
alternative adsorbent.
Langmuir and Freundlich
isotherms modeled the
adsorption indicating a qmax
of 0.06 and 0.27g/g for BY57
and BB99, respectively.
Salinity and heavy metals
have a negative effect on the
adsorption of both dyes, due
to competition for adsorption
sites.
Group Members:
Acknowledgements
Michelle Naidoo
Habib Zahir
Rada Kostadinova
Natalia Fernandez
Alvaro Sponza
San Shairzai
Funding:
Grant 001-2012-L’Oreal-CONCYTEC
2013-BMCC Faculty Development
Grant
CSTEP, PRISM and LSAMP programs