Post on 13-Jul-2020
HETEROGENEOUS SODİUM DECATUNGSTATE CATALYSTS FORCONTAMİNANTS DEGRADATİON İN AQUEOUS MATRİX
Luisa Pasti, Claudia Stevanin, Tatiana Chenet, Alessandra Molinari Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Italyluisa.pasti@unife.it
Sources of organic contaminants in surface waters
Human: incomplete removal in wastewater treatment, production plant, waste disposal
Veterinary: via manure dispersion and animal excretion onto soils
Increase of antibiotics resistance
Pharmaceuticals
Remediation technologies:
Advanced Oxidation
Nanofiltration
Adsorption
Advanced Oxidation
Ozone
Hydrogen peroxide
photocatalysys
Levofloxacin(antibiotic)
Sulfamethoxazole(sulfa drug)
Trimethoprim(antibiotic)
Carbamazepin(antiepilectic)
Atenolol/Propranololb- BLOCKER
361.4
253.3
290.3
363.3
266.3
1.44 mg/mL
0.459 mg/mL
0.615 mg/mL
0.152 mg/mL
0.0794 mg/mL
5.4
5.6
7.1
13.9
9.6
pKaSwMW
LEVO
SMX
TMP
CBZ
ATN/PRP
………….and study how to remove them by an ADVANCED OXIDATION METHODbased on the use of Na4W10O32
323 nmSpectralpropertiessimilar to those of TiO2
General mechanism in water:
Drugmolecule
RHOH
Formation of OH• has been definitely demonstrated by:
350 400 450 500 550 600
Em
issio
n i
nte
nsit
y [
a.u
.]
Wavelength (nm)
(a)
(b)
(c)
O O O OHO
+ OH. (4)
3425 3450 3475 3500
inte
nsi
ty (
a.
u.)
magnetic field (gauss)
DMPO DMPO-OH.
ESR spin trapping technique Luminescence
(lecc= 322 nm, lanal=455 nm)
cumarin 7-hydroxycoumarin
5,5-dimethyl-1-pyrroline-N-oxide
ATN
LEVO
TMP
Removal of atenolol, levofloxacin, trimethoprim, propranolol, sulfamethoxazole and carbamazepine from water occurs by irradiation of Na4W10O32
• mediation by OH• radicals• hydroxylated derivative compounds
(HPLC-MS)
Drug t1/2
(min)
k (min-1) R2
ATN 7.5 0.0924 0.9915
LEVO 38.5 0.0180 0.9866
TMP 53.3 0.0128 0.9882
Molinari A., Sarti E., Marchetti N., Pasti L., Applied Catalysis B: Environmental 203 (2017) 9-17
Heterogenization of decatungstate anion
Drug t1/2 (min) k (min-1) R2
ATN 102 0.0068 0.9822
LEVO 94 0.0074 0.9861
TMP 124 0.0056 0.9811
PRP 119,5 0.0058 0.9867
SMX 1980,4 0.00035 0.9881
CBZ 1732,0 0.00040 0.9837
Silica-NH3+-- - -Na3W10O32
-
amino-functionalized silica particles
RHOH
DMPO
Why CBZ and SMX are not degraded?Does it depend on the photocatalyst?
Dissolved Na4W10O32 Silica-NH3+-- - -Na3W10O32
-
Without CBZ
With CBZ (10 ppm)
Conclusion: it does notdepend on W10O32
4-
DMPO[DMPO-OH] ·
RH
%
pH
%
pH
ATN
CBZ
SMX
At the operative pH of 6:• ATN is positive• CBZ is neutral• SMX is neutral and negative
Silica-NH3+-- - -Na3W10O32
-
Why CBZ and SMX are not degraded?Does it depend on the nature of support?
%
pH
Heterogenization of decatungstate anion
Na4W10O32/SiO2/BTESE
Simultaneous hydrolysis of tetraethylorthosilane (TEOS) and of 1,2 bis(triethoxysilyl)ethane (BTESE).
SSA 725 m2g-1.
Micro and important fraction of mesopores with
a pore width between 13 and 28 ˚A.
This material concentrates toluene from water
0
2
4
0 0,1 0,2n
ads
(mm
ol/
m2)
p/po
BTESE
Microgravimetric adsorption isotherms of toluene vapour
The photocatalytic systemdegrades propranolol(PRP) as well.
We understand that the charged form of the drugis not the only factor, but
HYDROPHOBICITYof the support is alsoimportant0 10 20 30 40 50 60
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
time (min)
C/C
0
CBZ L
CBZ D
SMX L
SMX D
PRP L
PRP D
Irradiation of Na4W10O32/SiO2/BTESE system degrades CBZ and SMX and…also PRP
Pasti L., Sarti E., Martucci A., Stevanin C., Marchetti N., Molinari A., Applied Catalysis B: Environmental (2018) https://doi.org/10.1016/j.apcatb.2018.08.015
HPLC-MS of oxidation intermediates of SMX.
Degradation of SMX passes throughhydroxylated
products
Precursor Ion
(m/z)
tr
(min)
MS2
(m/z)
Structure
301 9.18 177
133
283 9.18 239
177
133
270 10.25 206
228
174 10.20 156
190 3.76 158
216 13.54 198
288 14.46 270
228 14.70
HPLC-MS of oxidation intermediates of CBZ
Degradation of CBZpasses throughhydroxylated
products
Precursor Ion
(m/z)
tr
(min)
MS2
(m/z) Structure
237.1 14.35 194.01
220.06
251.1
253.1
12.3 208.0
210.0
236.0
267.1 16.2 168
196.1
211.1
271.1 9.6 210
253
RHOHRH
drugdegradation
CONCLUSIONS
Photoexcited W10O324- is able to oxidize water producing OH• radicals
OH• radicals attacks drug molecule and produce mono or dihydroxylated intermediates
Then, these intermediates degrade to lighter molecules
Silica-NH3+-- - -Na3W10O32
- and Na4W10O32/SiO2/BTESE are recyclable material.
Na4W10O32/SiO2/BTESE is active in the degradation of every kind of the explored drugs
independently from their charge
Hydrophobicity is an important parameter of the support to be considered
Na4W10O32/SiO2/BTESE IS THE FIRST EXAMPLE IN PHOTOCATALYTIC DEGRADATION OF
DRUGS THAT COMBINES ADSORPTION CAPABILITY OF THE SUPPORT WITH PHOTO
ACTIVITY OF THE CATALYSTS
Dott.ssa TognoloChiaraDott. Colla Davide
Dr. Sarti ElenaDr. Marchetti Nicola
Prof. Alessandra Molinari
…..and all of you for your very kindattention!
PRP
ATN
Distribution diagram of propranolol: