International Summit on Past and Present Systems of Green Chemistry Philadelphia, August 26th 2014
Dr. Abel E. Navarro Science Department, Borough of Manhattan Community College, CUNY
Heavy Metals Present in human activities, from food to metalmechanic and paints. Are not biodegradable Can be bioaccumulated and transferred to humans through the food chain. Copper, Zinc, Cobalt, and Iron. Most toxic: Lead, Cadmium, Mercury and Chromium.
-
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
Competitive performance.
Pollutant selectivity.
Cost effectiveness.
Pollutant recovery.
No sludge generation.
Domestic waste found in the kitchen:
Why? High content of functional organic groups such as alcohol (fiber and carbohydrates), carboxylic acids and amines (structural polysaccharides).
Why? Easy preparation and massive collection.
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).
Alginate and other polymers gelify in contact with divalent cations (Calcium ions). High porosity and stability. Encapsulating matrix
Teabags were boiled, dried, stored and used in adsorption experiments. Solutions of pollutants were prepared and taken to proper pH, mass of adsorbent, dye concentrations, salinity, and crowding.
Duplicate experiments were carried out at room temperature and shaken during 24h.
Metal concentrations were measure by the color of the complex with Zincon.
Adsorbents were characterized using Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), Infrared Spectroscopy (FTIR), X-ray Energy Dispersion Spectroscopy (EDS). Surface and porosity were determined by colorimetric and redox experiments.
Characterization of the Adsorbents TGA: Temperature resistance and presence of volatile compounds
ADSORBENT
Surface Area (m2/g)
Micropore Volume (cm3/g)
Total Pore Volume (cm3/g)
AB
228
0.056
0.137
CM
1063
0.397
0.578
CT
231
0.149
0.529
DGT
274
0.219
0.592
GT
2736
0.692
1.106
PGT
221
0.058
0.411
PM
946
0.892
0.961
2
CM DGT GT PM
0 -2
Surface Area and Porosity: Compared to Activated carbon (SA+ 1000 – 2500 cm2/g
% Mass Loss
-4 -6 -8 -10 -12 -14 -16 -18 -20 0
50
100
150
200
250
300
350 0
400
Temperature ( C)
450
500
550
600
PM
CM
GT
DGT
GT
100
100
PM 90
% Transmittance
% Transmittance
95
90
85
80 70 60 50
80
40 75 4000
4000 3600
3200
2800
2400
2000
1600
1200
3600
3200
800
2800
2400
2000
1600
1200
800
-1
Wavenumber (cm )
-1
Wavenumber (cm )
DGT
100
CM
100
95
% Transmittance
% Transmittance
90
90 85 80 75
80
70
60
70 4000
3600
3200
2800
2400
2000
1600 -1
Wavenumber (cm )
1200
800
50 4000
3600
3200
2800
2400
2000
1600 -1
Wavenumber (cm )
1200
800
PM
PM + Co
PM + Cu
pH Effect - Ionization of adsorbent’s surface and metals (aquo- and hydroxocomplexes. - Higher pH promotes higher adsorption. 70
50
60
% Co(II) Adsorption
60
% Cu(II) Adsorption
70
AB CT GT PM
40 30 20
50 40 30 20 10
10
AB PM
0 0 2
3
4
5
pH
6
7
8
2
3
4
5
pH
6
7
8
Mass Effect - Minimize amount of adsorbent. - Higher adsorption promotes formation of aggregates. 70
% Cu(II) Adsorption
60 50 40 30
AB CT GT PM
20 10 0 0
50
100
150
200
Adsorbent Mass (mg)
250
Isotherms were modeled by Langmuir, Freundlich, Dubinin-Radushkevich and Temkin theories. 50
AB CT GT PM
40
q Cu(II) (mg/g)
30
20
10
0 0
30
60
90
120
150
Ceq (mg/L)
180
210
240
B
Adsorption Isotherm
Parameters
AB
CT
qmax (mg/g)
79.87
16.28
b (L/mg)
0.0162
0.045
p-value
< 0.0001
< 0.0001
R2
0.984
0.930
kF (L/g)
2.045
3.142
n
1.349
3.199
Freundlich
p-value
0.00062
< 0.0001
Dubinin-Radushkevich
R2
0.959
0.982
qDR (mg/g)
46.84
14.59
B x 10-4 (mol2.J2)
0.235
0.892
E (J/mol)
146
75
p-value
< 0.0001
0.00186
R2
0.969
0.823
aT
0.291
0.406
bT x 10-4 (J/mol)
0.312
1.104
p-value
0.00055
< 0.0001
R2
0.924
0.987
Langmuir
Isotherm Theory Langmuir
Equation Freundlich
Dubinin-Radushkevich
Temkin
Temkin
Salinity Effect: Decreases adsorption due to competition for the adsorption sites. Higher the charge, the stronger the effect. 80
AB CT GT PM
70 60
% Cu(II) Adsorption
-
50 40 30 20 10 0 0
20
40
60
[Ca(NO3)2], mmol/L
80
100
Mild acidic conditions were enough to desorb both dyes. Competition of hydronium for active sites. Water has weak desorbing properties. AB CT GT PM
90 80
% Cu(II) Desorption
70 60 50 40 30 20 10 0
H2O
HCl
NaOH
NaCl
Ca(NO3)2
Desorbing Solutions
EtOH
Acetone
GT
GT + Cu
GT – 5 cycles
Challenge in Remediation: Real Conditions. Crowding Agent: Ficoll, Polyethylene glycol. Steric Hindrance, access to active sites 90
AB CT GT PM
80 70
% Cu(II) Adsorption
60 50 40 30 20 10 0 0
2
4
6
Crowding Agent (%m/v)
8
10
Mixtures of metals: Cu + Zn Explore other more toxic metals, proteins, PAHs, emerging pollutants. Column studies Chemical modification of adsorbents Characterization: Elemental Analysis, Potentiometric Titration, BET, AFM.
1.0
AB CH
AB-En
Emerging Pollutants – Antibiotic Enrofloxacin
0.9
UV Absorbance (ABS)
16
12
8
4
0.8
0.7
pH effect and kinetics
0.6
0 2
3
4
5
6
7
0.5
8
0
50
pH
100
150
200
250
Time (min)
CM
0.5
Absorbance (ABS)
Enrofloxacin Adsorption (%ADS)
20
Continuous-flow experiment: Chamomile as an adsorbent of Cu(II) ions. Conditions: 1.8g of CM, flow 7mL/min, pH 6, 100ppm Cu(II).
0.4
0.3
0.2
0.1 0
10
20
30
40
Time (min)
50
60
70
Figure 3: Schemes for the chemical modifications: sulfonation (top) and thiolation (bottom) of cellulose-based materials.
Figure 3: Schemes for the chemical modifications: sulfonation (top) and thiolation (bottom) of cellulose-based materials.
OH
O
*
OH
OH
NaIO4
2NaHSO3
O
*
O
O
* O
O *
HO
*
-NaIO3
OH
*
HO
O
-H2O
O
SO3
Na O OH
OH SH HO
O
*
O
*
O
O *
HO
0
38 C
*
HO
OH
SO3
OH
Na
Enhance adsorption affinity by the incorporation of more reactive functional groups: Carboxyl, thiol, sulfonic
O
O
SH
ADSORBENT
CCOOH (mmol/g)
ADSORBENT
CCOOH (mmol/g)
ADSORBENT
CCOOH (mmol/g)
CM
1.36
GT
1.72
PM
1.4
TCM
1.48
TGT
1.88
TPM
2
SCM
1.76
SGT
1.92
SPM
1.48
CCM
1.08
CGT
1.72
CPM
1.36
Table: Acidic Group content (mmol/g) of all the adsorbents
20 16 12 8 4
CM
TCM
SCM
24 20 16 12 8 4 0
CCM
Copper Adsorption Percentage
Copper Adsorption Percentage
Copper Adsorption Percentage
24
0
28
28
28
12 9 6 3
9 6 3
CCM
GT
TGT
SGT
6
4
2
CM Adsorbent and Derivatives
SPM
CPM
12 9 6 3
PM
TPM
SPM
CPM
10
8
6
4
2
0
CCM
TPM
PM Adsorbent and Percentage
Cobalt Adsorption Percentage
Cobalt Adsorption Percentage
8
SCM
PM
15
0
CGT
10
TCM
4
PM Adsorbent and Derivatives
GT Adsorbent and Derivatives
10
CM
8
18
12
0
SCM
12
CGT
15
CM Adsorbent and Derivatives
Cobalt Adsorption Percentage
SGT
Zinc Adsorption Percentage
Zinc Adsorption Percentage
Zinc Adsorption Percentage
15
0
TGT
18
TCM
16
GT Adsorbent and Derivatives
18
CM
20
0
GT
CM Adsorbent and Derivatives
0
24
GT
TGT
SGT
GT Adsorbent and Derivatives
CGT
8
6
4
2
0
PM
TPM
SPM
CPM
PM Adsorbent and Derivatives
Adsorption of heavy metals onto raw and modified adsorbents: Copper (red), Zinc (blue), and Cobalt (green) at pH 6, using 5omg of adsorbent in a 100 ppm metal solution.
Tealeaves have proven to be promising adsorbents for model metals and other pollutants. They also serve as scaffold for chemical modifications.
Characterization studies report advantages of tealeaves and alginate beads as an alternative adsorbent.
pH has a strong effect on the adsorption. Likewise, salinity and crowding effects have a negative impact.
Carboxylation and sulfonation improve the adsorption of metals.
Jung, S., Naidoo, M., Shairzai, S., Navarro, AE. On the adsorption of a cationic dye on spent tea leaves. Book Chapter in: Urban Water II, Edited by S. Mambretti and CA. Brebbia, WIT Press, 2014, Volume 139.
Zahir H, Naidoo M, Kostadinova R, Ortiz K, Sun M, Navarro AE. Decolorization of hairdye by lignocellulosic waste materials from contaminated waters. Front. Environ. Sci. (2014) 2:28. doi:10.3389/fenvs.2014.00028
Navarro, AE., Chang, E., Chang, P., Yoon, SY., Manrique, A. Separation of Dyes from aqueous systems by magnetic alginate beads. Trends in Chromatog., 2013, 8, 31-41.
Kim, T., Yang, D., Kim, J., Musaev, H., Navarro, AE. Comparative adsorption of highly porous and raw adsorbents for the elimination of copper (II) ions from wastewaters. Trends in Chromatog., 2013, 8, 97-108.
Diaz, C., Jacinto, C., Medina, R., Navarro, AE., Cuizano, N., Llanos, B. Study of the biosorption of chromium (VI) on cross linked quaternary chitosan for their application on the bioremediation of wastewaters. Rev. Soc. Quím. Perú, 2013, 79(4): 304-318.
Group Members: Md Emran Masud Lianhua Shen Minyeong Hong Humoyun Musaev Paul Isaac Jenish Karmacharya Patrycja Lai Natalia Fernandez
Funding: CSTEP, LSAMP, BMCC Faculty Development Grant, PSC-CUNY, MCC-Puerto Rico (EDS facilities)
