Photosensitized degradation of antibiotic in aqueous solution of

Suwannee River natural organic matter

Ana Paula S Batistapresenter

Antonio Carlos S C Teixeira,Barbara A Cottrell, William J Cooper

Introduction

2

Target Compound: sulfonamide

Hyalella azteca(Bartlett et al. 2013)

Toxicity to some organisms

Occurrence of bacterial resistance

Antibiotic pharmaceutical

has attracted attention due to

Bartlett, A.J., et al., (2013) Toxicity of four sulfonamide antibiotics to the freshwater amphipod Hyalella azteca. Environmental Toxicology and Chemistry 32(4), 866-875.

Sulfamerazine (SMR)

contribution

Wastewatertreatment plants

4

Natural waters

Kümmerer, K. 2009 Antibiotics in the aquatic environment – A review – Part I, Chemosphere, 75(4) 417-434.

Sulfonamides are not completely degraded

5

Direct photolysis

photosensitization process (DOM)

Reactive Species

sunlightUV-Vis radiation (solar simulator: 280 – 800 nm)

DOMat excited state

is an important

phenomenon

Indirect photolysis

Photochemical Degradation

6

Hydroxyl Radical

Singlet Oxygen

Improve the photolysis processes

Dissolved Organic Matter (DOM)

due to

Triplet excited state of DOM

HO●1O2 3DOM*

Reactive Species

React with pollutantXu H, Cooper WJ, Jung J, Song W.

Photosensitized degradation of amoxicillin in natural organic matter isolate solutions.

Water Res 2011.45:632-38.

Solution pH

7

Pollutant concentration

Light attenuation

DOM presence

Photochemical Degradation in Waters

influenced

Bahnmüller S, von Gunten U, Canonica S. Sunlight-induced transformation of sulfadiazine and sulfamethoxazole in surface waters and wastewater effluents. Water Res 2014;57:183-92.

parameters

Response Surface Methodology (RSM)

8

the number of experimental runs

response surface

input variable

design space

to minimize generates

of a given

over Solution pH

Pollutant concentration

DOM concentration

Used to determine the optimized experimental condition

? Questions

9

*Does the presence of DOM increase the efficiency of SMR degradation during sunlight irradiation?

Direct photolysis

Efficiency of SMR degradation

Indirect photolysisAddition of SRNOM (1R101N)

? Questions

10

*What is the optimized experimental condition for indirect photolysis of SMR in SRNOM solution?

Optimized Experimental Condition

Indirect photolysisAddition of SRNOM (1R101N)

? Questions

11

*What is the most important parameter for indirect photolysis of SMR ?

Optimized Experimental Condition

Indirect photolysisAddition of SRNOM (1R101N)

Solution pH

Pollutant concentration

DOM concentration

? Questions

12

*What is the mechanism of SMR degradation by indirect photolysis?

Hydroxyl Radical

Singlet Oxygen Triplet excited state of DOM

HO●1O2 3DOM*

SMR indirect photolysis

OBJECTIVES

Degradation of Sulfamerazine (SMR)

UV-Vis radiation ( solar simulator)

13

To evaluate the efficiency of SMR indirect photolysis by usingResponse Surface Methodology.

The optimized experimental condition was applied toinvestigate the role of reactive species in SMR degradation inDOM solutions.

To investigate the mechanism of SMR indirect photolysis inDOM solutions.

Luzchem SolSim solar simulator (Ottawa, Canada) equipped with a rotating table.

300 W ceramic Xe lamp emitting from 290 to 900 nm.

Matched to the AM 1.5 solar spectrum

Samples were irradiated in 4 ml sealed quartz cuvettes (Starna, CA)

Injection volume of 50.0 µL

Eluents were (A) H2O + 0.2% acetic acid and (B) acetonitrile at 85:15 ratio and 0.8 mL

min-1 flow rate.

The DAD detection wavelength was 268 nm.

The retention time was 2.77 min using Germini 3μm C18 – 50 x 4.60.

Reversed phase high-performance liquid

chromatography (HPLC)

concentration of SMR

Results and Discussion

16

17

Initial concentration: SMR = 0.03 mmol L-1

at pH 7 buffered deionized water after 6 h irradiaton (solar simulator)

Hydrolysis (pH 5, 7 and 9)

direct photolysis

indirect photolysis15 mgL-1 SRNOM (1R101N)

Degradation of Sulfamerazine (SMR)

Direct and Indirect Photolysis

K = 2.96 x 10-3

60%

K = 4.24 x 10-3

80%

Run[SMR]TermA

[DOM]TermB

pHTermC

1 0.03 20.00 7.00

2 0.03 15.00 7.00

3 0.05 15.00 7.00

4 0.03 15.00 7.00

5 0.05 10.00 5.00

6 0.01 20.00 5.00

7 0.05 20.00 9.00

8 0.01 10.00 9.00

9 0.03 15.00 7.00

10 0.03 15.00 7.00

11 0.05 10.00 9.00

12 0.01 20.00 9.00

13 0.03 15.00 7.00

14 0.03 15.00 5.00

15 0.01 15.00 7.00

16 0.05 20.00 5.00

17 0.03 15.00 9.00

18 0.03 10.00 7.00

19 0.01 10.00 5.00

20 0.03 15.00 7.00

Design-Expert® SoftwareFactor Coding: ActualDegradation ((%))

Design points above predicted valueDesign points below predicted value89.6

33.7

X1 = A: SMR concentrationX2 = C: pH

Actual FactorB: DOM concentration = 15.00

5.00

6.00

7.00

8.00

9.00

0.01

0.02

0.02

0.03

0.03

0.04

0.04

0.05

0.05

30

40

50

60

70

80

90

100

De

gra

da

tio

n (%

)

A: SMR concentration (mM)

C: pH

Response Surface Methodology (RSM)

18

Response surface

Number of runs and values of variables used

Design-Expert software (version 9, Stat-Ease, Inc., MN, USA)

Design-Expert® SoftwareFactor Coding: ActualDegradation ((%))

Design points above predicted valueDesign points below predicted value89.6

33.7

X1 = A: SMR concentrationX2 = C: pH

Actual FactorB: DOM concentration = 15.00

5.00

6.00

7.00

8.00

9.00

0.01

0.02

0.02

0.03

0.03

0.04

0.04

0.05

0.05

30

40

50

60

70

80

90

100

De

gra

da

tio

n (%

)

A: SMR concentration (mM)

C: pH

Response Surface Methodology (RSM)

19

Design-Expert® Software

Degradation

Color points by value of

Degradation:

89.6

33.7

Actual

Pre

dic

ted

Predicted vs. Actual

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

30.00 40.00 50.00 60.00 70.00 80.00 90.00

Good correlation (R2 = 0.99)

Response surface

Solution pH(term C)

Pollutant concentration(term A)

DOM concentration(term B)

(R2 = 0.99)

Source Sum of squares

df Mean square F value p-value Prob > F

SRNOM

Model 6512.15 9 723.57 385.87 < 0.0001

A-SMR concentration 646.09 1 646.09 344.55 < 0.0001

B-DOM concentration 120.27 1 120.27 64.14 < 0.0001

C-pH 932.00 1 932.00 497.02 < 0.0001

Determination coeficiente (R2) 0.9942 Predicted R2 0.9893 Adjusted R2 0.9945

SMR Indirect Photolysis

20

Analysis of variance (ANOVA) of the response surface model

p-value less than 0.05 is reported as statistically significant

Zarei M, Niaei A, Salari D, Khataee A. Application of Response Surface Methodology for optimization of peroxi-coagulation of textile dye solution using carbon nanotube–PTFE cathode.

J Hazard Mater 2010;173:544-51.

21

Analysis of variance (ANOVA) of the coefficient values from regression model

FactorCoefficientEstimate

df

StandardError

95%CILow

95%CIHigh

Suwannee River natural organic matter (SRNOM)

Intercept 78.58 1 0.47 77.53 79.63A-SMRconcentration -8.04 1 0.43 -9.00 -7.07B-DOMconcentration 3.47 1 0.43 2.50 4.43C-pH -9.65 1 0.43 -10.62 -8.69

The order of importance:

solution pH (term C; -9.65) > SMR conc. (term A; -8.04) > SRNOM conc. (term B; 3.47)

SMR Indirect Photolysis

Relationship with Response Factor: degradation percentege of SMR

22

Efficiency of SMR

indirect photolysis

At circumneutral pH conditions

was more pronounced

Effect of solution pH

An equivalent concentration of protonated and deprotonated SMR molecule (neutral molecules) in the reaction solution.

(Martinez F, Gomez A. J Phys Org Chem 2002;15:874-880).

pK1 (2.24)

pK2 (6.92)

5 < PH < 8

Design-Expert® SoftwareFactor Coding: ActualDegradation ((%))

Design Points89.6

33.7

X1 = B: DOM concentrationX2 = C: pH

Actual FactorA: SMR concentration = 0.03

10.00 12.00 14.00 16.00 18.00 20.00

5.00

6.00

7.00

8.00

9.00Degradation (%)

B: DOM concentration (mg/L)

C: p

H

60

60

70

70

80

80

9085

45

50

50

6

0.03 mmol L-1 SMR6 hours irradiation

23

efficiency of SMR

indirect photolysis

Effect of SMR concentration

Initial

concentration of

SMR

Competition for photons between the pollutant and the DOM

(Zhou L, Ji Y, Zeng C, Zhang Y, Wang Z, Yang X. Water Res 2013;47:153-62)

Design-Expert® SoftwareFactor Coding: ActualDegradation ((%))

Design Points89.6

33.7

X1 = A: SMR concentrationX2 = C: pH

Actual FactorB: DOM concentration = 15.00

0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05

5.00

6.00

7.00

8.00

9.00Degradation (%)

A: SMR concentration (mM)

C: p

H

60

60

70

70

80

45

50

50

7585

6

In 15 mg L-1 DOM6 hours irradiation

24

Design-Expert® SoftwareFactor Coding: ActualDegradation ((%))

Design Points89.6

33.7

X1 = B: DOM concentrationX2 = C: pH

Actual FactorA: SMR concentration = 0.03

10.00 12.00 14.00 16.00 18.00 20.00

5.00

6.00

7.00

8.00

9.00Degradation (%)

B: DOM concentration (mg/L)

C: p

H

60

60

70

70

80

80

9085

45

50

50

6 > 85 % degradation

0.03 mmol L-1 SMR6 hours irradiation

Effect of DOM concentration

High formation of reactive species that are able to react with pollutant

(Wang L, Xu H, Cooper WJ, Song W. Sci Total Environ 2012;426:289-95. )

High concentration of SRNOM (1R101N)

25

At pH 715 mg L-1 DOM

The role of reactive species in the photosensitized degradation of

sulfamerazine

0.0

1.0x10-3

2.0x10-3

3.0x10-3

4.0x10-3

5.0x10-3

6.0x10-3

7.0x10-3

8.0x10-3

N2

Sorbic

acid

2-propanolD2O H

2O

Degra

datio

n r

ate

(m

in-1)

0.01 mmol L-1 SMR

Indirect Photolysis: Optimized Experimental Condition

26

0.01 mM SMR - 15 mg L-1 DOM - pH 7

Design-Expert® SoftwareFactor Coding: ActualDegradation ((%))

Design Points89.6

33.7

X1 = A: SMR concentrationX2 = C: pH

Actual FactorB: DOM concentration = 15.00

0.01 0.02 0.02 0.03 0.03 0.04 0.04 0.05 0.05

5.00

6.00

7.00

8.00

9.00Degradation (%)

A: SMR concentration (mM)

C: p

H

60

60

70

70

80

45

50

50

7585

6

27

DOM

HO●

3O2

1DOM*

3DOM*

1O2

ENER

GY

photon

energy

eletron

Intersystem crossing

Photosensitization Processes

ground state

28

DOM

1DOM*

3DOM*

1O2

ENER

GY

photon

energy

3O2

Role of Singlet OxygenEnhancer: increase of lifetime

ten times longer

in D2O than H2O

Merkel PB, Kearns DR. Radiationless decay of singlet molecular oxygen in solution. Experimental and theoretical study of electronic-to-vibrational energy transfer. J Am Chem Soc 1972;94:7244-53.

Intersystem crossing

0.0

1.0x10-3

2.0x10-3

3.0x10-3

4.0x10-3

5.0x10-3

6.0x10-3

7.0x10-3

8.0x10-3

N2

Sorbic

acid

2-propanolD2O H

2O

Degra

datio

n r

ate

(m

in-1)

Photo-induced oxidation

29

At pH 715 mg L-1 DOM The role of singlet oxygen

(kdeuterium oxide/kwater = 1.3 ± 0.1)

0.01 mmol L-1 SMR

Low reactivity of 1O2 with sulfamerazine

Boreen AL, Arnold WA, McNeill K. Environ Sci Technol 2005;39:3630-38.

30

DOM

HO●

3O2

1DOM*

3DOM*

ENER

GY

photon

eletron

Role of Hydroxyl RadicalScavenger: Hydrogen abstraction by radical from 2-propanol

2-Propanol

H3C-C-CH3

H|

|OH

H2O

Intersystem crossing

0.0

1.0x10-3

2.0x10-3

3.0x10-3

4.0x10-3

5.0x10-3

6.0x10-3

7.0x10-3

8.0x10-3

N2

Sorbic

acid

2-propanolD2O H

2O

Degra

datio

n r

ate

(m

in-1)

Photo-induced oxidation

31

At pH 715 mg L-1 DOM The role of Hydroxyl Radical

(k2-propanol/kwater = 0.59 ± 0.04)

0.01 mmol L-1 SMR

65 mM 2-propanol

High reactivity of hydroxyl radical with sulfamerazine

Mezyk SP, Neubauer TJ, Cooper WJ, Peller JR. J Phys Chem A 2007;111:9019-24.

32

DOM

HO•

3O2

1DOM*

3DOM*

1O2

ENER

GY

photon

Intersystem crossing

energy

eletron

De-oxygenated solutions

Role of Triplet Excited State of DOMRemoval of dissolved oxygen: De-oxygenated solutions

Photo-induced oxidation

33

At pH 715 mg L-1 DOM The role of Triplet Excited State of DOM

0.0

1.0x10-3

2.0x10-3

3.0x10-3

4.0x10-3

5.0x10-3

6.0x10-3

7.0x10-3

8.0x10-3

N2

Sorbic

acid

2-propanolD2O H

2O

Degra

datio

n r

ate

(m

in-1) (knitrogen gas /kwater = 1.8 ± 0.2)

0.01 mmol L-1 SMR

Bubbling Nitrogen

34

DOM

Sorbic Acid

1DOM*

3DOM*

ENER

GY

photon

energy

Role of Triplet Excited State of DOMQuencher: decrease fluorescence intensity

Grebel JE, Pignatello JJ, Mitch WA. Sorbic acid as a quantitative probe for the formation, scavenging and steady-state concentrations of the triplet-excited state of organic compounds. Water Res 2011;45: 6535.

Intersystem crossing

0.0

1.0x10-3

2.0x10-3

3.0x10-3

4.0x10-3

5.0x10-3

6.0x10-3

7.0x10-3

8.0x10-3

N2

Sorbic

acid

2-propanolD2O H

2O

Degra

datio

n r

ate

(m

in-1)

Photo-induced oxidation

35

0.01 mmol L-1 SMR

At pH 715 mg L-1 DOM

The mechanisms proceeds though 3DOM*

(ksorbic acid /kwater = 0.78 ± 0.04) 0.18 mM Sorbic Acid

Conclusions

36

37

Presence of DOM increased the efficiency of SMR degradation during sunlight irradation.

The optimized experimental condition for indirect photolysis of SMR was achieved in low concentration of pollutant at

circumneutral pH conditions and in presence of high concentration of DOM (>15 mg L-1).

The solution pH (term C) was the most statistically significant parameter for indirect photolysis of SMR.

The mechanism of SMR degradation proceeded through HO• and 3DOM* species.

São Paulo Research Foundation Post-Doctoral grant 2013/05041-7

Acknowledgments

38

WJ Cooper, NFS Grant CBET - 1034555

Ana Paula dos S. Batistanocomputador@gmail.com

39

São Paulo Aracaju

BRAZIL

40

Analysis of variance (ANOVA) of the coefficient values from regression model

Factor Coefficient Estimate

df

Standard Error

95% CI Low

95% CI High

Suwannee River natural organic matter (SRNOM) Intercept 78.58 1 0.47 77.53 79.63 A-SMR concentration -8.04 1 0.43 -9.00 -7.07 B-DOM concentration 3.47 1 0.43 2.50 4.43 C-pH -9.65 1 0.43 -10.62 -8.69 AB 1.51 1 0.48 0.43 2.59 AC 2.27 1 0.48 1.19 3.35 BC -9.67 1 0.48 -10.75 -8.59

The order of importance:

solution pH (term C; -9.65) > SMR conc. (term A; -8.04) > SRNOM conc. (term B; 3.47)

SMR Indirect Photolysis

Relationship with Response Factor: degradation percentege of SMR