Developing Targeted Treatment Strategies
for Pharmaceuticals and
Wastewater-Derived Micropollutants
Timothy J. Strathmann
Department of Civil & Environmental Engineering
Center of Advanced Materials for Purification of Water with Systems
University of Illinois, Urbana-Champaign, IL
90683701-0
Strathmann Environmental Chemistry Group
Outline
I.
Pharmaceuticals and Wastewater-Derived
Micropollutants
II. Research Questions
III. Current Projects
A. Conventional: Oxidation by MnO4-
B. Future: Oxidation by visible light photocatalysis
C. Future: Reduction by H2-activated metal catalysts
IV. Challenges to Treating Pharmaceuticals
Strathmann Environmental Chemistry Group
Strathmann Group Research Questions
• Can we identify improved strategies for treating
Pharmaceuticals & WW-derived micropollutants?
– Redox transformation to inactive byproducts
– Selective
– Sustainable
• What are the mechanisms controlling
micropollutant redox transformations?
– kinetics
– transformation products
– effects of water quality & non-target constituents
Strathmann Environmental Chemistry Group
A. Oxidation
by MnO4• Goal: Assess
pharmaceutical fate
during existing
treatment processes
• Previous work
examined reactions
with other water
treatment oxidants
(Cl2, O3), but little
known about
reactions with MnO4-
Table 1. List of Target Pharmaceuticals Examined in Studya
Cl
H
N
CH3
OH
O
HO
N
H
O
O
HO
O
N
H
H2N
Acetaminophen
(analgesic)
COOH
Atenolol
(antihypertensive)
O
Cl
Bezafibrate
(lipid regulator)
HO
OH
N
N
Cl
N
N
H
S
H
S
O
S
Cl
O
Caffeine
(psychostimulant)
HOOC
H
N
Bisphenol A
(plasticizer)
NMe 2
Me
S
F
OH
NH
2
Cl OH
Carbamazepine
(anticonvulsant)
O
OH
O
O
Chlortetracycline
(antibiotic)
Ciprofloxacin
(antibiotic)
OH
O
COOH
HO
Diclofenac
(antiphlogistic)
Ibuprofen
(antiphlogistic)
17-Ethynyl estradiol
(ovulation inhibitor)
S
H2N
S
S
CH3
H2N
OH
MeO
O
N
MeO
Sulfamethoxazole
(antibiotic)
H
N
Sulfamethizole
(antibiotic)
O
O
OH
O
N
Cl
N
I
N
NDMA
(wastewater DBP)
H
N
H
N
O
H3C
O
N
H
OH
I
Iopromide
(X-ray contrast medium)
H2N
N N O
Lincomycin
(antibiotic)
I
O
H3C
OH
N
O
O
Cl
N
HN
CH3 OH
Cl
O
N
OH
NH2
OH
O
OH
OH
S
O
OH
CH3
O
Cl
Cl
Triclosan
(antiseptic)
N
NH2
OMe
Trimethoprim
(antibiotic)
Strathmann Environmental Chemistry Group
A. Oxidation by MnO4• Kinetic model developed from lab experiments accurately predicts
extent of carbamazepine removal from utility source waters
• LC-MS2 and NMR methods combined to identify products and
elucidate reaction mechanism
Carbamazepine (g/L)
10
 E (T - 298) 
k 2,T  k 2,298Kexp  a

298RT


measured (utility 1)
measured (utility 2)
Model prediction
8
k2,298K = 310 M-1 s-1
6
Ea = 21 kJ mol-1
4
Cinit = 10 g/L
2 mg/L KMnO4
25 ºC, pH 8.0
2
Rate pH independent
0
0
5
10
15
20
Time (min)
25
30
Hu et al., manuscript in prep
Strathmann Environmental Chemistry Group
B. Oxidation by TiO2 Photocatalysis
Goals:
1. Characterize kinetics and
mechanism of antibiotic oxidation
2. Identify strategies for improving
chemical selectivity
hn
O
O
S
N O
N
H
HCO3-, NH4+,
SO42-
H2N
-
+
Ciprofloxacin, C/Co
1.0
0.8
Direct UV photolysis
Hombikat
UV 100
UV + TiO
0.6
2
O
0.4
F
OH
N
0.2
O
N
HN
Cipro
0.0
0
10
20
30
40
50
Time (minutes)
Nanophase TiO2
Strathmann Environmental Chemistry Group
60
O
Photocatalysis Under Visible Light?
(l > 400 nm)
F
N
OH
N
HN
• Photocatalytic
degradation under
visible light?
1.0
Ciprofloxacin, C/C 0
Cipro
O
0.8
Dark Control
>450 nm
>420 nm
>400 nm
>324 nm
0.6
0.4
• Atypical behavior can
be exploited for
selective treatment
within mixed waste
streams
0.2
0.0
0
10
20
30
40
Time (minutes)
50
60
Paul et al., ES&T (2007)
Hu et al., Wat Res(2007)
Strathmann Environmental Chemistry Group
Br-
O2-
-OH
Visible Light Photocatalysis Mechanism
hn (visible)
O
BrO3-
O2
e-
O
O
HO
N
O
O
C.B.
N
N
TiO2
-OH
F
NH
F
N
N
H
V.B.
stable
organic
byproducts
Strathmann Environmental Chemistry Group
C. Reduction by H2-activated catalysts
• Reductive processes are functional-group selective
OH
Cl
Cl
Cl
Cl
Cl
Cl
H3C
H
Cl
halogenated
DBPs, solvents
N
N
H3C
N-DBPs
O
I
O
N
H
OH
N
O
I
H
N
O
I
OH
Cl
OH
O
OH
Cl
Cl
O
triclosan
(antibacterial soap)
Iodinated
contrast agents
Goals: 1. Characterize kinetics and mechanism
2. Improve process sustainability
H3C
N N O
H3C
nanophase
Pd0/Pt0/Ni0
NH4+
H3C
+
NH
H3C
H
nanophase
Pd0/Pt0/Ni0
Strathmann Environmental Chemistry Group
Pd-Catalyzed Reduction of X-ray Contrast Agents
•
•
X-ray contrast agents highly resistant to conventional wastewater treatment
Rapidly dehalogenated to more biodegradable product
(1
diatrizoate (Dia-I3)
(Dia-HI2)
(Dia-H2I)
(Dia-H3)
[diatrizoate] (M)
20
filtered effluent
filtered + GAC-treated effluent
deionized water
15
10
4.9 mg/L DOC
GAC treatment
5
1.3 mg/L DOC
pH 7.0
PH2 = 1 atm
1.4 mgPd L-1
0
0
10
20
30
Time (min)
40
50
Knitt et al., ES&T (2008)
Frierdich et al., ES&T (2008)
Figure 5. Pd-catalyzed hydrodehalogenation of diatrizoate in deionized water, filtered
Strathmann
Environmental
wastewater effluent, and filtered wastewater effluent
that has been
passed through a Chemistry
Group
Energy Efficiency and
Removal of Pharmaceutical Potency
Photochemical and Photocatalytic Oxidation of Fluoroquinolone Antibiotics
PEQ = potency equivalents
of product mixture relative to
parent pharmaceutical
Cipro C/Co or PEQ
1
0.1
C/Co, UV
C/Co, Vis/TiO2
0.01
C/Co, UV/TiO2
PEQ, UV
PEQ, Vis/TiO2
PEQ, UV/TiO2
0.001
0
2
4
6
8
10
12
14
16
I * t (W.min/cm2)
I*t = fluence = photon energy
delivered to during treatment
Dodd et al., in prep
Strathmann Environmental Chemistry Group
Challenges to Treating
Pharmaceutical Micropollutants
• Removing the drop of poison in the ocean of water
• How low should we go?
• Which pharmaceuticals/metobolites?
• New solutions should be sustainable
– Energy efficient
– Limited chemical inputs
• Membrane processes
• Heterogeneous catalytic processes
Strathmann Environmental Chemistry Group
Micropollutant Reduction Strategies
Andrew Frierdich
Lindsay Knitt
Claire Joseph
Micropollutant Oxidation Strategies
Tias Paul
Lanhua Hu
Matt Sugihara
Heather Martin
Strathmann Environmental Chemistry Group