Research Article Degradation Effect of Sulfa Antibiotics by …downloads.hindawi.com/journals/bmri/2015/169215.pdf · 2019-07-31 · Research Article Degradation Effect of Sulfa Antibiotics

Research ArticleDegradation Effect of Sulfa Antibiotics by Potassium FerrateCombined with Ultrasound (Fe(VI)-US)

Kejia Zhang12 Zhang Luo12 Tuqiao Zhang12 Naiyun Gao3 and Yan Ma34

1College of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China2Key Laboratory of Drinking Water Safety and Distribution Technology of Zhejiang Province Zhejiang UniversityHangzhou 310058 China3State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai 200092 China4Shanghai Urban Water Resources Development and Utilization National Engineering Center Co Ltd Shanghai 200082 China

Correspondence should be addressed to Naiyun Gao gaonaiyun1126com and Yan Ma my041203126com

Received 5 February 2015 Accepted 21 March 2015

Academic Editor Jie Fu

Copyright copy 2015 Kejia Zhang et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Sulfa antibiotics are a family of typical broad-spectrum antibiotics which have become one of the most frequently detectedantibiotics in water posing a great threat to human health and ecosystem Potassium ferrate is a new type of high-efficiencymultifunctional water treatment agent collecting the effects of oxidation adsorption flocculation coagulation sterilization anddeodorization Performance and mechanism of degradation of typical broad-spectrum antibiotics by Fe(VI)-US were furtherstudied investigating the degradation effect of sulfa antibiotics by single ultrasound single potassium ferrate and potassiumferrate-ultrasound (Fe(VI)-US) It was found that Fe(VI)-US technology had a significant role in promoting the degradation ofsulfa antibiotics via orthogonal experiments Factors evaluated included sulfa antibiotics type pH value potassium ferrate dosageultrasonic frequency and ultrasonic power with the pH value and potassium ferrate dosage being affected most significantly Onereason for synergy facilitating the degradation is the common oxidation of potassium ferrate and ultrasound and the other isthat Fe(III) produced promotes the degradation rate According to the product analysis and degradation pathways of three sulfaantibiotics ferrate-sonication sulfa antibiotics are removed by hydroxyl radical oxidation

1 Introduction

Due to the toxicity of antibiotics and their wide usageand even abuse in the treatment of human and poultrybeasts of infectious diseases antibiotics have become ahot issue in water treatment nowadays Recently a certainconcentration of antibiotic residues has been detected insurface water groundwater drinking water sludge and soiland some other environmental media [1 2] Ninety kindsof organic pollutants were detected in 139 rivers from morethan 30 states of USA including pesticides pharmaceuticalsveterinary drugs and hormones [3] Sampleswere taken fromthe 7 sites and 15 substations of agricultural watershed ofthe USA and the existence of antibiotics in water sampleswas measured [4] A certain concentration of antibioticswas detected in municipal wastewater farmland soil surface

water and even drinking water in Germany [5] It wasfound that they contained high concentration of antibioticsin the sediments of fish farming area of Wujiangdu reser-voir (China) with chloramphenicol (CAP) 5ndash37120583gsdotkgminus1oxytetracycline (OTC) 21ndash156120583gsdotkgminus1 tetracycline (TC) 84ndash248120583gsdotkgminus1 and chlortetracycline (CTC) 42ndash90120583gsdotkgminus1 [6]In Guiyang (China) antibiotics were also found in city lifesewage with CAP 18ndash43 120583gsdotLminus1 OTC 5ndash8120583gsdotLminus1 TC 44ndash10 120583gsdotLminus1 and CTC 0ndash22 120583gsdotLminus1

As typical broad-spectrum antibiotics sulfa antibioticsare commonly used in clinical treatment animal husbandryand aquaculture With the rapid development of Chineseanimal husbandry the usage of sulfa antibiotics as veterinarydrugs and fishery drugs increased Some studies analyzed thecontent and distribution of four kinds of sulfa antibiotics in

Hindawi Publishing CorporationBioMed Research InternationalVolume 2015 Article ID 169215 12 pageshttpdxdoiorg1011552015169215

2 BioMed Research International

the dung of 20 scale farms in Guangdong province (China)the results showed that sulfa compounds in dung was 19259ndash133995 120583gsdotkgminus1 mainly sulfamerazine and sulfamethoxazoleSulfa antibiotics detection rate in cow dung was more than90 the content ofwhichwas 10394ndash159303120583gsdotkgminus1mainlysulfamethoxazole and sulfamerazine [7] Sulfa antibiotics infarm manure discharged into waters with rainwater runoffand farm wastewater in abundance which have become oneof the most frequently detected antibiotics in water and theirdistributions in the environment were not optimistic [3]From 2006 to 2007 19 water companies in USA detectedraw water treated water and pipeline water the most com-monly detected compounds reached up to 11 kinds andsulfa antibiotics (sulfamethoxazole) was one of them [8]Twenty-two kinds of antibiotics were detected in the lakeof Baiyangdian (China) among which sulfa antibiotics werethe most widely distributed and were of the highest levelsthe concentration reached 086ndash1563 ngsdotLminus1 [9] Chinarsquos PearlRiver Basin was studied by Xu [10] which included theresidue of antibiotics both in Guangzhou and Shenzhenrivers the content of sulfamethoxazole in Shenzhen riverreaching 880 ngsdotLminus1 Typical broad-spectrum sulfa antibioticscan be detected both in surface water and drinking waterall over the world which not only explains the seriousmaterial pollution now but also declares the fact that theconventional treatment process cannot remove sulfa antibi-otics effectively Fortunately more and more attention hasbeen given to the research of degradation of antibiotics inwater environment Generally speaking there are physicalchemical and biological treatment methods for the removalof antibiotics in wastewaters all these methods can removeantibiotics effectively with high concentration of antibioticsHowever these methods cannot work well for drinking watersources with low levels of antibiotics Therefore much moreenergy should be devoted to study of the degradation of sulfaantibiotics in order to find out effective control methodsimproving water quantity and ensuring water security

The German chemical and physicist Georg Stahl firstdiscovered and reported the ferrate in 1702 since then theinternational research of ferrate has never stopped In recentyears potassium ferrate has gained widespread attention inthe field of water treatment for its strong oxidation It ishexavalent (Fe(VI)) for iron element of potassium ferratepotassium ferrate exists in the form of FeO

4

2minus in aque-ous solution having extremely strong oxidizing with redoxpotential +220V and +072V respectively in acidic andalkaline conditions [11] Potassium ferrate have strong oxi-dizing under acid condition the oxidation of which is muchstronger than the commonwater treatment disinfectants suchas chlorine ozone hydrogen peroxide and chlorine dioxide[12]

Potassium ferrate oxidation has a strong selectivity forpollutants and the oxidation rate and efficiency in differentcompounds are differentThe removal rate of some refractoryorganics is not high when potassium ferrate is used aloneand potassium ferrate itself is easily decomposed at low pHvalue affecting its oxidation efficiency Therefore there is aneed to research potassium ferrate coupling technique for

achieving better treatment effect Potassium ferrate couplingtechnique is a hot topic and application direction in the studyof potassium ferrate the existing techniques mainly includepotassium ferrate-aluminium potassium ferrate-ozone andpotassium ferrate-photocatalysis

This study took the typical broad-spectrum sulfa antibi-otics as target pollutants removed by Fe(VI)-US oxidationstudying different impacts of degradation effect of sulfadi-azine establishing the reaction kinetics model investigatingthe degradation mechanism of sulfa antibiotics and provid-ing certain theoretical basis and technical support for drugspolluted water treatment

2 Materials and Methods

21 Chemicals Sulfadiazine (purity gt 99) sulfamerazine(purity gt 99) and sulfamethoxazole (purity gt 99) wereall purchased from Sigma-Aldrich (USA) their physical andchemical properties (molecular formula structural formulamolecular weight ionization equilibrium constant pKa etc)were shown in Table 1 Oxidant potassium ferrate (purity gt90) was also purchased from Sigma-Aldrich (USA) Buffersolution used in the experiment was made up of analyt-ical grade of potassium hydroxide dipotassium hydrogenphosphate potassium dihydrogen phosphate and potassiumborate with sodium thiosulfate being reaction terminatorsMobile phases of formic acid purchased from Fluka (Switzer-land) and acetonitrile purchased from Sigma-Aldrich (USA)are chromatographic grade formic acid solution was pre-pared fromMilli-Q ultrapure water (182Ω) Other chemicalswere of analytical grade and above and all were purchasedfrom Sinopharm Chemical Reagent Co Ltd Water used inexperiment was deionized water

22 Experimental Apparatus and Methods

221 Apparatus and Methods of Ferrate Oxidation Degra-dation of sulfa antibiotics by Fe(VI) took place in 150mLconical flask The pH value of reaction solution was adjustedby buffer solution add a certain amount of Fe(VI) into thereaction solution under the condition of magnetic stirringtake samples at scheduled time and then add a smallamount of 01molsdotLminus1 sodium thiosulfate to terminate thereaction Samples taken were analyzed after centrifugationat 6000 rmin for 10min all experiments were performed atroom temperature (25 plusmn 2∘C)

222 Apparatus and Methods of Ultrasonic Reaction Ultra-sonic reactor used was purchased from Shanghai Poly FiberUltrasound Equipment Co Ltd consisting of ultrasonicgenerator ultrasonic transducer and reaction vessel Thereare four ultrasonic generators the models are respectivelyHF-200 (ultrasonic frequency f = 223 kHz) HF-400 (f =400 kHz) HF-600 (f = 600 kHz) and HF-800 (f = 800 kHz)ultrasonic power can be adjusted ranging from 30 to 100Wwith maximum power density 3Wsdotcmminus2 Ultrasonic reactionwas conducted in an open stainless steel cylinder (inner

BioMed Research International 3

Table 1 The physical and chemical properties of standards

Substance name Formula Structure Molecular weightDa pK119886

pK1198861

pK1198862

Sulfadiazine C10H10N4O2S NN

O

O

SNH NH2 25027 249 650

Sulfamerazine C11H12N4O2S NN

3CH

O

O

SNH NH2

26430 mdash 700

Sulfamethoxazole C10H11N3O3SN

O

O

O

SNH NH2

H3C

25328 174 570

100mm

80mm

1

2

3

4

5

6

7

(1) Ultrasonic transducer(2) Stainless steel reactor(3) Water samples(4) Water bath

(7) Ultrasonic generator

(5) Cooling water inlet(6) Cooling water outlet

Figure 1 Schematic diagram of ultrasonic apparatus

diameter Φ = 100 cm H = 100 cm) the bottom of the cylin-der was directly connected with the ultrasound transducerand the joints were sealed with PTFE O-ring Stainless steelcylinder was placed in a thermostatic water bath system(Figure 1) with the reaction temperature controlled at 25 plusmn2∘C

The volume of reaction solution was 100mL in all exper-iments and the pH value was adjusted by buffer solutionReaction was conducted in the stainless steel reactor and thesamples were collected at predetermined time intervals forthe analysis of sulfa antibiotics When performing Fe(VI)-US samples taken should be added to a small amount of

01molsdotLminus1 sodium thiosulfate to terminate reaction with thesamples being analyzed after centrifugation

23 Analytical Methods and Detecting Instrument

231 Detection of Fe(VI) Concentration Fe(VI) exists in theform of FeO

4

2minus when dissolved in water the solution is pur-ple with a clear UV-visible spectrum the absorption curvehas been shown in appropriate concentration range (141 times10minus5ndash505 times 10minus4molsdotLminus1) [13] there is a linear relationshipbetween concentration and absorbance of Fe(VI) solutionthus the corresponding concentration can be obtained by


0

10

20

30

40

50

60

70

80

90

7 8 9pH

Rem

oval

()

(a) SD

Rem

oval

()

0

10

20

30

40

50

60

70

80

90

7 8 9pH

(b) SM

Rem

oval

()

0

20

40

60

80

100

USFe(VI)US-Fe(VI)

7 8 9pH

(c) SMX

Figure 2 The removal effect of sulfa antibiotics oxidized by Fe(VI)-US (a) sulfadiazine (b) sulfamerazine (c) sulfamethoxazole

measuring the absorbance of Fe(VI) solution In experimentabsorbance of Fe(VI) solution was measured by UVVISspectrophotometer instrument the concentration was calcu-lated according to Bill-Lambertrsquos law as follows

119860 = 120576bc (1)

where 120576 ismolar absorption coefficient reflecting the solutionabsorption capacity of a wavelength of light Lsdotmolminus1sdotcmminus1 119887is cuvette width cm 119888 is analyte concentration molsdotLminus1

When cuvette width 119887 is 1 cm Bill Lambertrsquos law isexpressed in

119860 = 120576c (2)

Absorbance of 025mmolsdotLminus1 and 051mmolsdotLminus1 ofpotassium ferrate solution reached maximum at 510 nmwavelength At the same time it was documented that

reaction products Fe(II) and Fe(III) phosphate would notinterfere with the detection at 510 nm wavelength thus wecan accurately track the Fe(VI) concentration change andadopt the wavelength of 510 nm as the determination ofFe(VI) solution [14] Molar absorption coefficient of Fe(VI)solution is 1150Mminus1sdotcmminus1 at 510 nm wavelength [15] Inaddition due to the Fe(VI) easily decomposed to Fe(OH)

3

interfering with the detection results samples weremeasuredafter centrifugation at 6000 rsdotminminus1 for 10min and thesupernatant was taken for spectrophotometry

232 Detection of Three Kinds of Sulfa Antibiotics by HPLCHigh performance liquid chromatography (HPLC) wasadopted on three kinds of sulfa antibiotics for quantitativeanalysis The concentrations of sulfadiazine sulfamerazineand sulfamethoxazole were measured by Waters e2695-2489


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a) SD

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b) SM

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

pH789

(c) SMX

Figure 3 Effect of pH values on degradation of sulfa antibiotics by Fe(VI)-US (a) sulfadiazine (b) sulfamerazine (c) sulfamethoxazole

HPLC (UV detector) and Waters Symmetry C18 column tocolumn (250mm times 46mm) Acetonitrile and mass fractionof 01 formic acid solution the volume ratio of 40 60were adopted for mobile phase with flow rate 08mLsdotminminus1column temperature 35∘C and detection wavelength 270 nmUnder these conditions sulfadiazine sulfamerazine and sul-famethoxazole peaked well and the peak time was 4081min4429min and 6015min respectively

233 Detection of Three Kinds of Sulfa Antibiotics and TheirDegradation Product by LC-MS-MS HPLC-MS (Waterse2695 Separation Module Thermo Finnigan TSQ Quantum)was adopted for qualitative analysis of sulfadiazine sulfam-erazine sulfamethoxazole and their products HPLC analysisconditions were as follows chromatographic columnwas C18column (Thermo Basic C18 150mm times 21mm) mobile phasewas acetonitrile and the mass fraction was 01 formic acid

Table 2 Mass spectrometric parameters in full scan mode

Parameter name Parameter valuesElectrospray voltage 3500VSheath gas N2 028MPa (40 psi)Auxiliary gas N2 007MPa (10 psi)Ion transport capillary temperature 270∘CScanning range 50sim500mz

solution using gradient elution mode Detection time lastedfor 30min mobile phase flow rate was 300120583Lsdotminminus1 thecolumn temperature was 35∘C and the injection volume was10 120583L


Table 3 Effect of Fe3+ on ultrasonic degradation of sulfa antibiotics

Substance name pH Ultrasound Fe3+-UltrasoundkLsdotmmolminus1sdotminminus1 119877

2 Fe3+ dosagemmolsdotLminus1 kLsdotmmolminus1sdotminminus1 1198772

Sulfadiazine7 56666 09992 005 62572 099548 69630 09922 005 76543 098829 82422 09906 005 97026 09623

Sulfamerazine7 78615 09961 005 93386 098108 82518 09913 005 10371 097449 99267 09874 005 11886 09628

Sulfamethoxazole

7 67640 09930 005 71840 098998 78218 09901 005 84047 098019 98719 09910 005 12358 098177 67640 09930 010 73010 098198 78218 09901 010 90281 098149 98719 09910 010 14884 096477 67640 09930 020 72641 099228 78218 09901 020 84559 097819 98719 09910 020 13590 09822

MS conditions were as follows full scan mode wasemployed for analysis of sulfadiazine sulfamerazine sul-famethoxazole and their products MS spectrometry ioniza-tion source was heating type electrospray ionization source(H-ESI) with specific parameters shown in Table 2

These three sulfa antibiotics could be separated andpeaked well in this full scale mode the peak time of sulfa-diazine sulfamerazine and sulfamethoxazole was 305min487min and 1313min respectively

3 Results and Analysis

31 Fe(VI)-US Synergy The initial concentrations of sul-fadiazine sulfamerazine and sulfamethoxazole were all002mmolsdotLminus1 the ultrasonic frequency was 800 kHz theoutput electric power was 100W reaction pH was controlledranging from 7 to 9 and 005mmolsdotLminus1 of potassium ferratewas added to the reaction solution studying the removaleffect of sulfa antibiotics by Fe(VI)-US Figure 2 presentedthe removal effect of sulfa antibiotics by ultrasound (US)potassium ferrate (Fe(VI)) and potassium ferrate-ultrasound(Fe(VI)-US) respectively at different pH values at the reac-tion time of 10min results showed that compared withthe degradation by US or Fe(VI) alone Fe(VI)-US had asignificant role in promoting degradation of sulfa antibioticsIt was demonstrated that ultrasonic irradiation had a goodeffect for degradation of oxidation of sulfadiazine sulfamer-azine and sulfamethoxazole and the common oxidation ofultrasonic irradiation and potassium ferrate greatly increasedthe removal rate of sulfa antibiotics whichmight be one of thereasons why Fe(VI)-US technology had synergistic effect

311 Promotion Effect of Fe3+ In the process of oxidizingsulfa antibiotics by potassium ferrate Fe(VI) turned to Fe(III)

finally the other reason why Fe(VI)-US had synergy mightbe that the existence of Fe(III) promoted the degradationof sulfa antibiotics Fe3+ was added into reaction solutionstudying the effect of Fe3+ on degradation of sulfa antibioticsby ultrasonic irradiation as shown in Table 3 Accordingto the experimental data Fe3+ had a promoted effect ondegradation of sulfa antibiotics by ultrasonic irradiation atthe pH of 7ndash9 The reaction rate increased continuously andthe removal effect was obvious with Fe3+ dosage increasingfrom 000mmolsdotLminus1 to 010mmolsdotLminus1 However this pro-motion decreased slightly when Fe3+ dosage reached up to020mmolsdotLminus1

Theremight be two reasons for Fe3+ promoting on degra-dation of sulfa antibiotics by ultrasonic irradiation First theaddition of Fe3+ increases the ionic strength Studies [16] haveshown that with the increase of ionic strength more andmore water molecules tend to be combined with anion andcation forming hydration film making water molecules dis-solving organic matters reduced which results in decrease ofthe solubility of organic matters in water more advantageousto head toward the cavitation bubble of gas-liquid interfacemigration in ultrasonic field Cavitation bubble of gas-liquidinterface is the active center of ultrasonic chemical reactionwith the presence of high concentrations of hydroxyl radicalsand supercritical water layer in this region [17] thus it ismore conducive for reaction However with the increaseof ionic strength in water the saturated vapor pressure ofwater decreases while the surface tension increases causingthe sound pressure for cavitation increasing the numberof cavitation bubbles formed within a unit time decreasescavitation weakens and the removal effect lowers

Second the water molecules under ultrasonic cavitationwill enter cavitation bubble then to form sdotOHand sdotHvia inter-nal thermal cracking A lot of sdotOH quickly recombine and


cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

Potassium ferrate dosage (mmolmiddotLminus1)

(c)

Figure 4 Effect of potassium ferrate dosages on degradation of sulfa antibiotics by Fe(VI)-US (a) sulfadiazine (b) sulfamerazine (c)sulfamethoxazole

generate H2

O2

at a relatively low temperature of cavitationbubbles of gas-liquid interface H

2

O2

eventually spreads intothe main body solution and performs class Fenton reactionwith Fe3+ ((3) and (4)) to generatemore sdotOH thus promotingthe removal of sulfa antibiotics as follows

Fe3+ +H2

O2

997888rarr Fe2+ +HO2

sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)

32 Effects of Degradation of Sulfa Antibiotics by Fe(VI)-US

321 Effect of pH The pH of reaction solution was adjustedby buffer solution pH value was ranging from 7 to 9The initial concentrations of sulfadiazine sulfamerazineand sulfamethoxazole were all 002mmolsdotLminus1 the ultrasonicfrequency was 800 kHz the output electric power was 100Wreaction pH was controlled at 7ndash9 and 005mmolsdotLminus1 of

potassium ferrate was added into the reaction solutionstudying the effect of pH on degradation of sulfa antibioticsby Fe(VI)-US Figure 3 showed the effect of different pHvalues on degradation of sulfadiazine sulfamerazine andsulfamethoxazole by Fe(VI)-US

As shown in Figure 3 the reaction rate declined withthe increasing pH value The degradation rate of these threesulfa antibiotics was the fastest at pH 7 and the removalrate reached a maximum at the first 10min As reactionextended when the reaction time was 30min the removalrate of all these three sulfa antibiotics reached maximum atpH 9 According to the study of sulfa antibiotics oxidizedby potassium ferrate oxidation rate was fast and reactionwas basically completed in the first 2min when the pHwas in neutral or acidic conditions Due to the oxidationof potassium ferrate dominated at the early stage of Fe(VI)-US the effect of pH on degradation of sulfa antibiotics by


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800

Ultrasonic frequency (kHz)

(c)

Figure 5 Effect of ultrasonic frequencies on degradation of sulfamethoxazole by Fe(VI)-US (a) pH = 7 (b) pH = 8 (c) pH = 9

Fe(VI)-US was consistent with that of potassium ferrate Theoxidation of ultrasonic irradiation took leading role at the latestage thus the effect of pH was consistent with degradationof sulfa antibiotics by ultrasonic irradiation

322 Effect of Potassium Ferrate Dosages Different concen-trations of potassium ferrate solution was added into thereaction solution studying the effect of potassium ferratedosages on degradation of sulfa antibiotics by Fe(VI)-US theexperimental results are shown in Figure 4

The potassium ferrate dosages ranged from000mmolsdotLminus1 to 020mmolsdotLminus1 the initial concentrationsof sulfadiazine sulfamerazine and sulfamethoxazole wereall 002mmolsdotLminus1 the ultrasonic frequency was 800 kHzthe output electric power was 100W and reaction pH wascontrolled at about 7 Figure 4 showed that potassium ferratedosages had a significant effect on degradation of sulfaantibiotics by Fe(VI)-US with the increase of potassium

ferrate dosages the degradation rate of sulfa antibiotics byFe(VI)-US increased When potassium ferrate dosage was020mmolsdotLminus1 all these three sulfa antibiotics were removedquickly with the degradation rate reaching up to more than98 at reaction time of 5min The increase of potassiumferrate dosages enhanced the leading role of oxidation ofpotassium ferrate in Fe(VI)-US thus the effect of potassiumferrate dosages on degradation of sulfa antibiotics wasconsistent with that of oxidized by potassium ferrate

323 Effect of Ultrasonic Frequencies Ultrasonic frequencyin experiments was 200 400 600 and 800 kHz respec-tively the initial concentration of sulfamethoxazole was002mmolsdotLminus1 and the output electric power was 100Wstudying the effect of ultrasonic frequency on degradation ofsulfa antibiotics by Fe(VI)-US Figure 5 showed the effect ofultrasonic frequency on degradation of sulfa antibiotics byFe(VI)-US in different pH conditions


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100

Ultrasonic power (W)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)

Figure 6 Effect of ultrasonic powers on degradation of sulfamethoxazole by Fe(VI)-US (a) pH = 7 (b) pH = 8 (c) pH = 9

In the study of degradation of sulfa antibiotics byultrasonic irradiation the removal rate of sulfa antibioticsincreased with the increase of ultrasonic frequency Theincrease of ultrasonic frequency increased the number ofhydroxyl radicals by ultrasonic cavitation and in returnstrengthens the Fe(VI)-US synergy promoting the reactionIn addition the oxidation rate of potassium ferrate decreasedas the pH value rose The higher the pH was the strongerFe(VI)-US the synergy was and the amplitude of degradationof sulfa antibiotics increased with the increase of ultrasonicfrequency

324 Effect of Ultrasonic Powers Ultrasonic power wasregulated respectively to 33 66 and 100W studying theeffect of ultrasonic powers on degradation of sulfa antibioticsby Fe(VI)-US The initial concentration of sulfamethoxazole

was 002mmolsdotLminus1 the ultrasonic frequency was 800 kHzthe effect of ultrasonic powers on degradation of sulfaantibiotics under different pH conditions was shown inFigure 6 According to the experimental data the effectof ultrasonic powers on degradation of sulfa antibiotics byFe(VI)-US was consistent with that of ultrasonic frequencyand the degradation rate of sulfamethoxazole increased withthe increase of ultrasonic powers Moreover the degradationrate increased more obviously at higher pH values

The number of cavitation bubbles produced increasedper unit with the increase of ultrasonic powers so did thecavitation effect and the Fe(VI)-US synergy was enhanced atthe same time Oxidation rate of potassium ferrate declinedwith the increase of pH and the synergy of Fe(VI)-US wasmore obviouswith higher pHvaluesThe larger the ultrasonicpower was themore significant the amplitude of degradationeffect was


Table 4 Main identified intermediates of sulfa antibiotics

Substance name 119898119911 Structure 119898119911 Structure

Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C

33 Mechanism of Degradation of Sulfa Antibiotics by Fe(VI)-US The main identified intermediates of sulfa antibioticsoxidized by Fe(VI)-US were analyzed by LC-HESI-MS-MS main products of sulfadiazine sulfamerazine and sul-famethoxazole were listed in Table 4 and the results showingthat degradation of these three sulfa antibiotics by Fe(VI)-US were all removed by hydroxyl radicals with oxidationAccording to the analysis of products the degradation path-way diagram of sulfa antibiotics oxidized by Fe(VI)-US was

made and the specific degradation process was shown inFigure 7

4 Conclusions

All of sulfadiazine sulfamerazine and sulfamethoxazolecould be degraded by ultrasound well and the reactionprocess was in accordance with pseudo-second order reac-tion kinetics As ultrasonic irradiation time extended the


R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C

Figure 7 Proposed degradation pathway of sulfa antibiotics oxidized by potassium ferrate combined with ultrasound

degradation rate of sulfa antibiotics increased continuouslyand the removal rate of sulfadiazine sulfamerazine andsulfamethoxazole reached 7746 8246 and 8246 afterreaction time 30min respectively

Compared with the degradation of sulfa antibiotics oxi-dized by potassium ferrate or ultrasonic irradiation Fe(VI)-US technology has a significant role in promoting thedegradation of sulfa antibiotics The synergy of Fe(VI)-USmainly includes two aspects one is the common oxidation ofpotassium ferrate and ultrasound and the other is that Fe(VI)finally turns into Fe(III) in the process of degradation of sulfaantibiotics oxidized by potassium ferrate and the existenceof Fe(III) promotes the removal effect of sulfa antibiotics byultrasound

Degradation of sulfa antibiotics by Fe(VI)-US are influ-enced by different sulfa antibiotics pH values potassiumferrate dosages ultrasonic frequencies and ultrasonic pow-ers and orthogonal experiments are performed to study theabove five factors on degradation of sulfa antibiotics and theinfluence of primary and secondary order of reaction rateThe effects of pH values potassium ferrate dosages and sulfaantibiotics type on the reaction rate are the most significantwith the pH values being the maximum Thus pH valuesand sulfa antibiotics dosages should be controlled reasonablyin experiments in order to ensure economy while achievingoptimal removal effect

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This project was supported jointly by National NaturalScience Foundation of China (51208456)TheNationalMajor

Science and Technology Project of China (2012ZX07403-001 2012ZX07403-003) and Foundation of Zhejiang LeadingTeam of Science and Technology Innovation (2010R50037)

References

[1] M S Diaz-Cruz M J Garcia-Galan and D Barcelo ldquoHighlysensitive simultaneous determination of sulfonamide antibi-otics and one metabolite in environmental waters by liquidchromatography-quadrupole linear ion trap-mass spectrome-tryrdquo Journal of Chromatography A vol 1193 no 1-2 pp 50ndash592008

[2] A J Watkinson E J Murby and S D Costanzo ldquoRemoval ofantibiotics in conventional and advancedwastewater treatmentimplications for environmental discharge and wastewater recy-clingrdquoWater Research vol 41 no 18 pp 4164ndash4176 2007

[3] D W Kolpin E T Furlong M T Meyer et al ldquoPharmaceuti-cals hormones and other organic wastewater contaminants inUS streams 1999-2000 a national reconnaissancerdquo Environ-mental Science and Technology vol 36 no 6 pp 1202ndash12112002

[4] O A Arikan C Rice and E Codling ldquoOccurrence ofantibiotics and hormones in a major agricultural watershedrdquoDesalination vol 226 no 1ndash3 pp 121ndash133 2008

[5] RHirsch T Ternes KHaberer andK L Kratz ldquoOccurrence ofantibiotics in the aquatic environmentrdquoThe Science of the TotalEnvironment vol 225 no 1-2 pp 109ndash118 1999

[6] H Liu G P Zhang and C Q Liu ldquoGuiyang reservoir fish areasand urban sewage antibiotics featurerdquo Bulletin of MineralogyPetrology and Geochemistry vol 26 no Z1 p 561 2007

[7] Y P Tai X D Luo and C H Mo ldquoResearch of Guangdongprovince livestock feces quinolone classes and sulfa antibioticscontent and distribution characteristicsrdquo Environmental Sci-ence vol 32 no 4 pp 1188ndash1193 2011

[8] M J Benotti R A Trenholm B J Vanderford J C Holady BD Stanford and S A Snyder ldquoPharmaceuticals and endocrine


disrupting compounds in US drinking waterrdquo EnvironmentalScience amp Technology vol 43 no 3 pp 597ndash603 2009

[9] W H Li Y L Shi L H Gao J M Liu and Y Q Cai ldquoOccur-rence of antibiotics in water sediments aquatic plants andanimals from Baiyangdian Lake in North Chinardquo Chemospherevol 89 no 11 pp 1307ndash1315 2012

[10] W H Xu Distribution Behavior and Fate of Typical Antibioticsin the Pearl River Water Guangzhou Institute of GeochemistryCAS Guangzhou China 2007

[11] R H Wood ldquoThe heat free energy and entropy of the fer-rate(VI) ionrdquo Journal of the American Chemical Society vol 80no 9 pp 2038ndash2041 1958

[12] J-Q Jiang and B Lloyd ldquoProgress in the development and useof ferrate(VI) salt as an oxidant and coagulant for water andwastewater treatmentrdquoWater Research vol 36 no 6 pp 1397ndash1408 2002

[13] Y C Liu H K Hu M X Luo and J L Xie ldquoDeterminationof disodium ferrate by spectrophotometryrdquo Chemical Researchand Application vol 14 no 3 pp 299ndash301 2002

[14] H Huang D Sommerfeld B C Dunn E M Eyring and C RLloyd ldquoFerrate(VI) oxidation of aqueous phenol kinetics andmechanismrdquo Journal of Physical Chemistry A vol 105 no 14pp 3536ndash3541 2001

[15] B H J Bielski andM JThomas ldquoStudies of hypervalent iron inaqueous solutions 1 Radiation-induced reduction of iron(VI)to iron(V) by CO2-rdquo Journal of the American Chemical Societyvol 109 no 25 pp 7761ndash7764 1987

[16] M R Hoffmann I Hua and R Hochemer ldquoApplication ofultrasonic irradiation for the degradation of chemical contami-nants in waterrdquoUltrasonics Sonochemistry vol 3 no 3 pp 163ndash172 1996

[17] E Manousaki E Psillakis N Kalogerakis and DMantzavinosldquoDegradation of sodium dodecylbenzene sulfonate in water byultrasonic irradiationrdquoWater Research vol 38 no 17 pp 3751ndash3759 2004

Submit your manuscripts athttpwwwhindawicom

PainResearch and TreatmentHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2014

ToxinsJournal of

VaccinesJournal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

AntibioticsInternational Journal of

ToxicologyJournal of


StrokeResearch and TreatmentHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Drug DeliveryJournal of



Advances in Pharmacological Sciences

Tropical MedicineJournal of


Medicinal ChemistryInternational Journal of


AddictionJournal of



BioMed Research International

Emergency Medicine InternationalHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Autoimmune Diseases


Anesthesiology Research and Practice

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Journal of


Pharmaceutics


MEDIATORSINFLAMMATION

of


the dung of 20 scale farms in Guangdong province (China)the results showed that sulfa compounds in dung was 19259ndash133995 120583gsdotkgminus1 mainly sulfamerazine and sulfamethoxazoleSulfa antibiotics detection rate in cow dung was more than90 the content ofwhichwas 10394ndash159303120583gsdotkgminus1mainlysulfamethoxazole and sulfamerazine [7] Sulfa antibiotics infarm manure discharged into waters with rainwater runoffand farm wastewater in abundance which have become oneof the most frequently detected antibiotics in water and theirdistributions in the environment were not optimistic [3]From 2006 to 2007 19 water companies in USA detectedraw water treated water and pipeline water the most com-monly detected compounds reached up to 11 kinds andsulfa antibiotics (sulfamethoxazole) was one of them [8]Twenty-two kinds of antibiotics were detected in the lakeof Baiyangdian (China) among which sulfa antibiotics werethe most widely distributed and were of the highest levelsthe concentration reached 086ndash1563 ngsdotLminus1 [9] Chinarsquos PearlRiver Basin was studied by Xu [10] which included theresidue of antibiotics both in Guangzhou and Shenzhenrivers the content of sulfamethoxazole in Shenzhen riverreaching 880 ngsdotLminus1 Typical broad-spectrum sulfa antibioticscan be detected both in surface water and drinking waterall over the world which not only explains the seriousmaterial pollution now but also declares the fact that theconventional treatment process cannot remove sulfa antibi-otics effectively Fortunately more and more attention hasbeen given to the research of degradation of antibiotics inwater environment Generally speaking there are physicalchemical and biological treatment methods for the removalof antibiotics in wastewaters all these methods can removeantibiotics effectively with high concentration of antibioticsHowever these methods cannot work well for drinking watersources with low levels of antibiotics Therefore much moreenergy should be devoted to study of the degradation of sulfaantibiotics in order to find out effective control methodsimproving water quantity and ensuring water security

The German chemical and physicist Georg Stahl firstdiscovered and reported the ferrate in 1702 since then theinternational research of ferrate has never stopped In recentyears potassium ferrate has gained widespread attention inthe field of water treatment for its strong oxidation It ishexavalent (Fe(VI)) for iron element of potassium ferratepotassium ferrate exists in the form of FeO

4

2minus in aque-ous solution having extremely strong oxidizing with redoxpotential +220V and +072V respectively in acidic andalkaline conditions [11] Potassium ferrate have strong oxi-dizing under acid condition the oxidation of which is muchstronger than the commonwater treatment disinfectants suchas chlorine ozone hydrogen peroxide and chlorine dioxide[12]

Potassium ferrate oxidation has a strong selectivity forpollutants and the oxidation rate and efficiency in differentcompounds are differentThe removal rate of some refractoryorganics is not high when potassium ferrate is used aloneand potassium ferrate itself is easily decomposed at low pHvalue affecting its oxidation efficiency Therefore there is aneed to research potassium ferrate coupling technique for

achieving better treatment effect Potassium ferrate couplingtechnique is a hot topic and application direction in the studyof potassium ferrate the existing techniques mainly includepotassium ferrate-aluminium potassium ferrate-ozone andpotassium ferrate-photocatalysis

This study took the typical broad-spectrum sulfa antibi-otics as target pollutants removed by Fe(VI)-US oxidationstudying different impacts of degradation effect of sulfadi-azine establishing the reaction kinetics model investigatingthe degradation mechanism of sulfa antibiotics and provid-ing certain theoretical basis and technical support for drugspolluted water treatment

2 Materials and Methods

21 Chemicals Sulfadiazine (purity gt 99) sulfamerazine(purity gt 99) and sulfamethoxazole (purity gt 99) wereall purchased from Sigma-Aldrich (USA) their physical andchemical properties (molecular formula structural formulamolecular weight ionization equilibrium constant pKa etc)were shown in Table 1 Oxidant potassium ferrate (purity gt90) was also purchased from Sigma-Aldrich (USA) Buffersolution used in the experiment was made up of analyt-ical grade of potassium hydroxide dipotassium hydrogenphosphate potassium dihydrogen phosphate and potassiumborate with sodium thiosulfate being reaction terminatorsMobile phases of formic acid purchased from Fluka (Switzer-land) and acetonitrile purchased from Sigma-Aldrich (USA)are chromatographic grade formic acid solution was pre-pared fromMilli-Q ultrapure water (182Ω) Other chemicalswere of analytical grade and above and all were purchasedfrom Sinopharm Chemical Reagent Co Ltd Water used inexperiment was deionized water

22 Experimental Apparatus and Methods

221 Apparatus and Methods of Ferrate Oxidation Degra-dation of sulfa antibiotics by Fe(VI) took place in 150mLconical flask The pH value of reaction solution was adjustedby buffer solution add a certain amount of Fe(VI) into thereaction solution under the condition of magnetic stirringtake samples at scheduled time and then add a smallamount of 01molsdotLminus1 sodium thiosulfate to terminate thereaction Samples taken were analyzed after centrifugationat 6000 rmin for 10min all experiments were performed atroom temperature (25 plusmn 2∘C)

222 Apparatus and Methods of Ultrasonic Reaction Ultra-sonic reactor used was purchased from Shanghai Poly FiberUltrasound Equipment Co Ltd consisting of ultrasonicgenerator ultrasonic transducer and reaction vessel Thereare four ultrasonic generators the models are respectivelyHF-200 (ultrasonic frequency f = 223 kHz) HF-400 (f =400 kHz) HF-600 (f = 600 kHz) and HF-800 (f = 800 kHz)ultrasonic power can be adjusted ranging from 30 to 100Wwith maximum power density 3Wsdotcmminus2 Ultrasonic reactionwas conducted in an open stainless steel cylinder (inner




pK1198861

pK1198862


O

O

SNH NH2 25027 249 650


3CH

O

O

SNH NH2

26430 mdash 700


O

O

O

SNH NH2

H3C

25328 174 570

100mm

80mm

1

2

3

4

5

6

7










4



0

10

20

30

40

50

60

70

80

90

7 8 9pH

Rem

oval

()

(a) SD

Rem

oval

()

0

10

20

30

40

50

60

70

80

90

7 8 9pH

(b) SM

Rem

oval

()

0

20

40

60

80

100

USFe(VI)US-Fe(VI)

7 8 9pH

(c) SMX



119860 = 120576bc (1)



119860 = 120576c (2)



3




00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a) SD

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b) SM

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

pH789

(c) SMX











Sulfadiazine7 56666 09992 005 62572 099548 69630 09922 005 76543 098829 82422 09906 005 97026 09623

Sulfamerazine7 78615 09961 005 93386 098108 82518 09913 005 10371 097449 99267 09874 005 11886 09628

Sulfamethoxazole

7 67640 09930 005 71840 098998 78218 09901 005 84047 098019 98719 09910 005 12358 098177 67640 09930 010 73010 098198 78218 09901 010 90281 098149 98719 09910 010 14884 096477 67640 09930 020 72641 099228 78218 09901 020 84559 097819 98719 09910 020 13590 09822










cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20


(c)


generate H2

O2


2

O2


Fe3+ +H2

O2


sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)






00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of




pK1198861

pK1198862


O

O

SNH NH2 25027 249 650


3CH

O

O

SNH NH2

26430 mdash 700


O

O

O

SNH NH2

H3C

25328 174 570

100mm

80mm

1

2

3

4

5

6

7










4



0

10

20

30

40

50

60

70

80

90

7 8 9pH

Rem

oval

()

(a) SD

Rem

oval

()

0

10

20

30

40

50

60

70

80

90

7 8 9pH

(b) SM

Rem

oval

()

0

20

40

60

80

100

USFe(VI)US-Fe(VI)

7 8 9pH

(c) SMX



119860 = 120576bc (1)



119860 = 120576c (2)



3




00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a) SD

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b) SM

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

pH789

(c) SMX











Sulfadiazine7 56666 09992 005 62572 099548 69630 09922 005 76543 098829 82422 09906 005 97026 09623

Sulfamerazine7 78615 09961 005 93386 098108 82518 09913 005 10371 097449 99267 09874 005 11886 09628

Sulfamethoxazole

7 67640 09930 005 71840 098998 78218 09901 005 84047 098019 98719 09910 005 12358 098177 67640 09930 010 73010 098198 78218 09901 010 90281 098149 98719 09910 010 14884 096477 67640 09930 020 72641 099228 78218 09901 020 84559 097819 98719 09910 020 13590 09822










cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20


(c)


generate H2

O2


2

O2


Fe3+ +H2

O2


sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)






00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of


0

10

20

30

40

50

60

70

80

90

7 8 9pH

Rem

oval

()

(a) SD

Rem

oval

()

0

10

20

30

40

50

60

70

80

90

7 8 9pH

(b) SM

Rem

oval

()

0

20

40

60

80

100

USFe(VI)US-Fe(VI)

7 8 9pH

(c) SMX



119860 = 120576bc (1)



119860 = 120576c (2)



3




00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a) SD

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b) SM

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

pH789

(c) SMX











Sulfadiazine7 56666 09992 005 62572 099548 69630 09922 005 76543 098829 82422 09906 005 97026 09623

Sulfamerazine7 78615 09961 005 93386 098108 82518 09913 005 10371 097449 99267 09874 005 11886 09628

Sulfamethoxazole

7 67640 09930 005 71840 098998 78218 09901 005 84047 098019 98719 09910 005 12358 098177 67640 09930 010 73010 098198 78218 09901 010 90281 098149 98719 09910 010 14884 096477 67640 09930 020 72641 099228 78218 09901 020 84559 097819 98719 09910 020 13590 09822










cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20


(c)


generate H2

O2


2

O2


Fe3+ +H2

O2


sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)






00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a) SD

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b) SM

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

pH789

(c) SMX











Sulfadiazine7 56666 09992 005 62572 099548 69630 09922 005 76543 098829 82422 09906 005 97026 09623

Sulfamerazine7 78615 09961 005 93386 098108 82518 09913 005 10371 097449 99267 09874 005 11886 09628

Sulfamethoxazole

7 67640 09930 005 71840 098998 78218 09901 005 84047 098019 98719 09910 005 12358 098177 67640 09930 010 73010 098198 78218 09901 010 90281 098149 98719 09910 010 14884 096477 67640 09930 020 72641 099228 78218 09901 020 84559 097819 98719 09910 020 13590 09822










cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20


(c)


generate H2

O2


2

O2


Fe3+ +H2

O2


sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)






00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of





Sulfadiazine7 56666 09992 005 62572 099548 69630 09922 005 76543 098829 82422 09906 005 97026 09623

Sulfamerazine7 78615 09961 005 93386 098108 82518 09913 005 10371 097449 99267 09874 005 11886 09628

Sulfamethoxazole

7 67640 09930 005 71840 098998 78218 09901 005 84047 098019 98719 09910 005 12358 098177 67640 09930 010 73010 098198 78218 09901 010 90281 098149 98719 09910 010 14884 096477 67640 09930 020 72641 099228 78218 09901 020 84559 097819 98719 09910 020 13590 09822










cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20


(c)


generate H2

O2


2

O2


Fe3+ +H2

O2


sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)






00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of


cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(a)

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20

(b)

0 0025005 01015 02

cc 0

t (min)

00

02

04

06

08

10

0 4 8 12 16 20


(c)


generate H2

O2


2

O2


Fe3+ +H2

O2


sdot +H+ (3)

HO2

sdot +H2

O2

997888rarr O2

+H2

O + sdotOH (4)






00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

200400

600800


(c)








00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(a)

00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(b)

3366100


00

02

04

06

08

10

0 5 10 15 20 25 30

cc 0

t (min)

(c)









Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of




Sulfadiazine

267N

N

NH O

SO

NH2

HO

267N

N

NH O

SO

NH2

OH

173OSO

NH2HO 96

N

NNH2

281 N

N

NH O

SO

NO2

Sulfamerazine

281

N

N

NH O

SO

NH2

OH

3CH

281

N

N

NH O

SO

NH2

HO3CH

173OSO

NH2HO 110 N

NNH2

H3C

295N

N

NH O

SO

NO2

3CH

Sulfamethoxazole

270N

N

H O

O

SO

NH2

OHH3C 270 N

N

H OSO

O

NH2

HO

H3C

288 N

N

H

O

OS

ONH2

HOHO

H3C

173OSO

NH2HO 99NO

NH2

H3C

284N

NH

O

OSOH3C

NO2 270N

NH O

SO

OO

NH2H3C



4 Conclusions



R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of


R

R

R R

R

R

R

R R

N NH

N

N

H HO

HO

HO

HO

HO

HO

HO Fe(VI)SO

OSO

OSO

OSO

OSO O

SO

NH O

SO

NH O

SO

O

OSO

NO2

NO2

NO2

NO2

NH2

NH2

NH2

NH2

NO2

∙OH

∙OH

∙OH

∙OH

∙OH

∙OH

OH

OH

OH

OH OH

OH

+

+ ++ +

H3C







Acknowledgments



References
























Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of
















Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of





Volume 2014

ToxinsJournal of

VaccinesJournal of















AddictionJournal of






Autoimmune Diseases




Journal of


Pharmaceutics



of

Documents

Research Article Degradation Effect of Sulfa Antibiotics by …downloads.hindawi.com/journals/bmri/2015/169215.pdf · 2019-07-31 · Research Article Degradation Effect of Sulfa Antibiotics