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Chemical Engineering Journal 180 (2012) 99– 105

Contents lists available at SciVerse ScienceDirect

Chemical Engineering Journal

j ourna l ho mepage: www.elsev ier .com/ locate /ce j

emediation of chloramphenicol-contaminated soil by atmospheric pressureielectric barrier discharge

ing Loua,b, Na Lua,b, Jie Lia,b,∗, Tiecheng Wanga, Yan Wua,b

Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024, PR ChinaKey Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education of the People’s Republic of China, Dalian 116024, PR China

r t i c l e i n f o

rticle history:eceived 17 August 2011eceived in revised form 4 November 2011ccepted 4 November 2011

eywords:BD plasma

a b s t r a c t

The remediation of antibiotics-contaminated soil using dielectric barrier discharge (DBD) plasma atatmospheric pressure was investigated in this study. Experimental results showed that the degradationefficiency of chloramphenicol (CAP) approached 81% after 20 min of plasma treatment. Increasing appliedvoltage was beneficial for CAP decomposition, due to higher production of active species. Experimentsconducted under different gas atmospheres (O2, air, N2, Ar) indicated that O3 made a major contributionto CAP degradation. Large oxygen flow rate favored the abatement of CAP in soil and the optimal soil

0

oil remediationntibioticshloramphenicol

moisture content was found as 10%. As iron element abounded in soil, the effect of Fe with differentlevels was examined and the improvement on CAP degradation was obtained. The system of DBD plasmaperformed a high level decomposition with initial CAP concentration between 200 and 1000 mg kg−1. CAPmolecules experienced O–H, phenyl–N bonds rupture and dechlorination, oxidation reactions throughidentifying intermediates of CAP degradation using HPLC/MS. Based on HPLC/MS analysis, a possible

ion in

pathway of CAP degradat

. Introduction

During the past decades, the point-source unloading in chemi-al and pharmaceutical industry has led to serious sites pollutionnd solution for soil remediation is an urgent assignment to beolved. A large number of toxic contaminants have been contin-ally entered into plant sites including petroleum hydrocarbon,eavy metals, pharmaceuticals (such as antibiotics) and persistentrganic pollutants (such as organochlorine pesticides, nitroben-ene compounds). Among the contaminants, antibiotics have beenighly overused and misused in veterinary and human medicine,esulting in the accumulation in soil and other environmental com-artments. Antibiotics residuals are shed into the soil mainly viaanure, pharmaceutical wastewater and medical solid waste [1].

wide variety of antibiotics in the environment had been detected.he range of residual concentrations in soil varied from a few �g upo g kg−1 [2]. Chlortetracycline and oxytetracycline were measuredn pig liquid manure at concentrations up to 46 and 29 mg kg−1,

espectively [3]. Antibiotics dissipated slowly in soil and their per-istence depended primarily on the temperature and the chemicaltructure of the antibiotics [4,5]. The residues of antibiotics in soil

∗ Corresponding author at: Institute of Electrostatics and Special Power, Dalianniversity of Technology, Dalian 116024, PR China. Tel.: +86 411 84708576;

ax: +86 411 84709869.E-mail address: lijie@dlut.edu.cn (J. Li).

385-8947/$ – see front matter © 2011 Elsevier B.V. All rights reserved.oi:10.1016/j.cej.2011.11.013

soil in this system was also proposed.© 2011 Elsevier B.V. All rights reserved.

are of potential environmental concern due to their adverse effects,resulting in disturbing soil microbial communities and affectingplant growth [6], thereby giving rise to ecological risks.

Research on antibiotics degradation in environment has mainlyconcerned about wastewater treatment processes [7–9], while onlyfew investigations have been published related to the antibiotics-contaminated soil remediation so far. Lin et al. [10] investigated theremoval of chloramphenicol in diatomite with microwave treat-ment, and better results were achieved when a certain amount ofgranular activated carbon was combined. The degradation of sul-fadiazine in three soils was studied by Yang et al. [11] and thebest performance was obtained under the aerobic nonsterile con-dition. In view of the complicated chemical structure of antibiotics,convenient operation and economical efficiency of treatment pro-cess, it is essential to develop an alternative method to decomposeantibiotics in soil.

In recent years, Low-Temperature Plasma (LTP) technology hasbeen widely investigated because of its high removal efficiencyand potential applications in various industrial and technologicalprocesses. It is extensively used in the field of pollution controlincluding water purification [12,13] and gas conversion [14,15].Previous studies have demonstrated that LTP generated by the dis-charge initiates a variety of chemical and physical effects involving

electric field, ultraviolet radiation, shock waves and, of partic-ular importance, formation of various chemically active species(O3, OH•, H• and O• radicals). Besides the capability for contam-inated water and exhaust gas treatment, LTP has given rise to

1 eering

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nterest in the application of soil remediation. When the dischargeegins, high energy electrons generated in discharge area collisionsith atoms, molecules and ions, which initiate many important

hemical reactions [16]. The generated reactive species can reactith pollutants in soil and produce new reaction products by

urther collisions. Wang et al. [17,18] reported the remediationf pentachlorophenol contaminated soil using pulsed corona dis-harge plasma from soil characteristics and influencing factors, andhe promising results were obtained. Dielectric barrier dischargeDBD) has been widely used in various technical applications, dueo its homogeneous stable discharge features and highly plasmaroduction in a controllable way at atmospheric pressure and tem-erature. Until recently, the oxidation of kerosene-contaminatedoil in a cylinder-to-plane DBD reactor was studied by Redolfi et al.19] with a high-frequency alternating current (AC) power sup-ly, and a better biodegradability of soil was achieved. It is wellnown that flat plate structure is a simple configuration to achieveBD without additional complex disposal. Therefore, DBD with flatlate configuration was carried out to remediate chlorampheni-ol (CAP)-contaminated soil in the present work. CAP was selecteds the target pollutant in soil, which was found to exist in envi-onment, although the use has been limited in human medicineor many years due to its toxic effects such as aplastic anemia20]. Experiments under various conditions were conducted tonvestigate the effects of applied voltage, gas atmosphere, oxygenow rate, soil moisture content and Fe0 dosage on CAP degrada-ion. To examine the treatment capacity of this DBD system, theesults were obtained under different initial CAP concentrations.he intermediates were also identified, and a possible pathwayf CAP degradation in soil in this system was proposed. The pur-ose of this research is to determine the feasibility for treatingntibiotics-contaminated soil by DBD plasma and provide an alter-ative method with the basic data for the removal of antibiotics inoil.

. Experimental

.1. Materials and methods

Chloramphenicol (>98%) was purchased from TCI (Shanghai)evelopment Co., Ltd. (Shanghai, China). Its structure is shown inig. 1. Iron powder (>98%) was a product of Tianjin Bodi Chem-cal Co. (Tianjin, China). All other reagents were analytical gradeurchased through commercial companies and were used withouturther purification.

The soil used in this study was collected from the campusf Dalian University of Technology, China. The soil propertiesere as follows: the contents of sand, silt, clay and organic mat-

ers were 2.5%, 75.3%, 22.2% and 2.71%, respectively; bulk density.07 g cm−3; porosity 59.62%; pH 5.4. According to the USDA Soilextural Triangle, the soil was characterized as silt loam.

The pretreated 50 g soil was mixed with 50 mL CAP methanol−1

olution (200 mg L ) thoroughly to achieve the uniform distribu-

ion of 200 mg CAP kg−1. The CAP-contaminated soil was dried inume hood for 24 h until the methanol evaporated completely. Theater content of the contaminated soil was 0.19%.

Fig. 1. Structure of chloramphenicol (C11H12O5N2Cl2).

Journal 180 (2012) 99– 105

2.2. Experimental apparatus

The experimental schematic diagram is shown in Fig. 2. The sys-tem consisted of two main components: an AC high-voltage powersupply and a DBD reactor made of PlexiglasTM cylinder (inner diam-eter 69 mm). In this work applied voltage of the power supply inthe range 0–20.4 kV with a fixed frequency of 500 Hz was used.The high voltage disc electrode attached to a shaft 115 mm longwas made of stainless steel (thickness 2.5 mm, diameter 44.5 mm),which was placed onto the foursquare quartz dielectric (thickness2 mm, side length 150 mm). The ground electrode was composedof dense metal net and iron panel with holes. The gap between thequartz dielectric and ground electrode was maintained at 6 mm.

In each experiment, approximately 2.5 g CAP-contaminated soilsamples were exposed to the ground net electrode, with the thick-ness of approximate 0.9 mm. The reactant gas was impregnatedinto the reactor to generate various active species, penetrated intothe soil layers, finally exhausted from the gas outlet.

2.3. Extraction and analysis

In order to determine the concentration changes of CAP in thesoil, 50 mL deionized water used as extractant was added into soilafter each discharge treatment. The mixture shaken for 4 h was cen-trifuged for 10 min at 4500 rpm and the extract was filtered through0.45 �m filter to measure. The recoveries of CAP in soil were about98% in this study.

The concentration of CAP in the filtrate was measured usingHPLC system (SCL-10ACP, Shimadzu, Japan) equipped with Hyper-sil ODS (25 �m, 4.6 mm × 250 mm) reverse phase column and UVdetector (276 nm). The mobile phase was combined 50% methanolwith 50% water, and the flow rate was 0.6 mL min−1.

The identification of CAP and its decomposition products in soilwas performed by HPLC–MS (MS, 6410B series, Agilent, USA). HPLCsystem employed was Agilent 1200 series and mass spectrome-try was carried out using electrospray ionization in the negativeion (NI) mode. Nitrogen was served as dry gas at the flow rate of10 L min−1 with temperature 350 ◦C. The nebulizer pressure was40 psi. The range of m/z was 50–500 in the full-scan mode.

3. Results and discussion

3.1. Effect of applied voltage

Since the applied voltage was an important parameter in thetreatment process, its effect on the degradation of CAP was illus-trated in Fig. 3(a). Experiments were carried out for three values ofapplied voltage: 16.4, 18.4 and 20.4 kV. It was obvious that increas-ing applied voltage improved the degradation efficiency of CAP, dueto a higher energy input introduced in the discharge. After 10 minof plasma treatment, the degradation efficiency of CAP increasedfrom 47% to 65% when applied voltage was varied from 16.4 to20.4 kV. A higher voltage resulted in enhancement of electric field,which made electrons more energetic and induce reactions for alarger amount of active species generation [21], leading to a higherdegradation of the CAP in soil. In addition, the degradation effi-ciency increased rapidly in the initial 5 min of plasma treatment,and then tended to increase slowly. This phenomenon might indi-cate that a competition occurred between the degradation of CAPmolecules and the decomposition of intermediate products.

The energy efficiency was used as an indicator to evaluate the

energy consumption of the system, which was shown in Fig. 3(b) asa function of degradation efficiency for the three applied voltages.As degradation efficiency increased, less CAP molecules were resid-ual in soil for decomposition and a competition with intermediates

J. Lou et al. / Chemical Engineering Journal 180 (2012) 99– 105 101

ental s

esiafta

3

aood(wdaatrsotNttt

Fe12

After 20 min of plasma treatment, the degradation efficiency of CAP−1

Fig. 2. Schematic diagram of the experim

xisted, thus the energy efficiency decreased. Furthermore, for theame degradation efficiency, the energy efficiency increased withncreasing applied voltage. At 63% of CAP degradation efficiency,n energy efficiency of about 0.17 and 0.53 g kW h−1 was obtainedor applied voltage of 18.4 and 20.4 kV. The observations suggestedhat energy consumption could be reduced at a higher voltage with

shorter treatment time.

.2. Effect of gas atmosphere

The process of soil remediation by DBD plasma is very complexs it involves various active species such as O3, OH•, excited atomsf oxygen and nitrogen, all of which play a role in the process. Inrder to investigate the roles of different free radicals in CAP degra-ation, the soil samples were exposed to different gas atmospheresnitrogen, argon, oxygen and air atmospheres), the results of whichere shown in Fig. 4. After 20 min of plasma treatment, the degra-ation efficiency of CAP reached 41% and 26% under oxygen and airtmospheres, respectively; while only 7.8% and 17.6% of CAP werechieved under argon and nitrogen atmospheres, respectively. Inhe case of oxygen atmosphere, the generation density of oxygenicadicals in the discharge was larger than those under air atmo-phere, resulting in the higher degradation efficiency in the casef oxygen atmosphere than air atmosphere. The oxidative poten-ials of oxygenic radicals was much stronger than those atomic

+ +

, N2 and N generated by N2 dissociation [18], so the degrada-ion efficiency of CAP was much higher under air atmosphere thanhat under N2 atmosphere. In the present conditions, the degrada-ion efficiency under argon atmosphere was much lower than that

0 5 10 15 200

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20 30 40 50 60 70

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U=20.4 kV U=18.4 kV U=16.4 kVD

egra

datio

n ef

ficie

ncy

(%)

Treatment time (min)

a b

Ene

rgy

effic

ienc

y (g

kw

h)-1

Degradation efficiency (%)

ig. 3. CAP degradation efficiency as a function of treatment time (a); CAP energyfficiency as a function of degradation efficiency and (b) for applied voltage of6.4, 18.4 and 20.4 kV (conditions: O2 flow rate 0.5 L min−1; CAP concentration00 mg kg−1; soil moisture 4%).

ystem (a: flow chart and b: DBD reactor).

under oxygen atmosphere. The experimental results suggested thatoxygen atmosphere was more favorable for CAP decompositioncompared to argon atmosphere.

The O• and O3 are produced only under atmospheres containingoxygen. In order to investigate the contribution of O3 to CAP degra-dation, pure O3 (without discharge) was impregnated into the DBDreactor to decompose CAP, and the corresponding result was shownin Fig. 4. Herein, the concentration of O3 was equal to that generatedby discharge under O2 atmosphere. After 20 min of O3 treatment,37% of CAP was degraded, which was about 4% lower than thatobtained by the discharge treatment under O2 atmosphere. Theseresults indicated that O3 made the major contribution to CAP degra-dation. According to previous reports, O3 was also used as the mainreactant for agricultural materials sterilization [22], and affectedthe properties of soil and plant growth.

3.3. Effect of oxygen flow rate

The oxygen flow rate has significantly influence on oxygenicradicals production (such as O3, O•) in the gas-phase discharge,which may in return affect the oxidation of CAP. Fig. 5 shows thedegradation efficiency of CAP under various oxygen flow rates for20 min of plasma treatment. The results suggested that the moreO2 molecules in DBD reactor, the higher decomposition of CAP.

reached 44% at the flow rate of 0.15 L min and up to 71% with theflow rate increasing to 1.5 L min−1

. In the case of 1.5 L min−1, 67%of CAP was decomposed within 5 min of plasma treatment, while

N2 Ar O2 air O30

10

20

30

40

50

Deg

rada

tion

effic

ienc

y (%

)

Gas atmosphere

Fig. 4. CAP degradation efficiency as a function of gas atmosphere (conditions:applied voltage 18.4 kV; gas flow rate 0.5 L min−1; CAP concentration 200 mg kg−1;soil moisture 0.19%; treatment time 20 min).

102 J. Lou et al. / Chemical Engineering Journal 180 (2012) 99– 105

0 5 10 15 200

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Treatment time (min)

Fo2

2otatatt

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assfrrtOmt

Fd4c

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tion

effic

ienc

y (%

)

Treatment time (min)

DBD alone

1% Fe 0

2% Fe 0

4% Fe 0

Fig. 7. CAP degradation efficiency as a function of treatment time for Fe0 dosage of

ig. 5. CAP degradation efficiency as a function of treatment time for O2 flow ratef 0.15, 0.5 and 1.0 L min−1 (conditions: applied voltage 18.4 kV; CAP concentration00 mg kg−1; soil moisture 4%).

0 min was needed for 1.0 L min−1 to achieve the similar result. Thebservations indicated that higher oxygen flow rate with shorterreatment time can obtain a high level of CAP decomposition. For

higher O2 flow rate, more O2 molecules will be impregnated intohe reactor and break down by collision with energetic electrons,nd then generate higher quantity of active species within the sameime span [23], which can be reached in the soil layers and benefithe degradation of CAP.

.4. Effect of soil moisture content

Soil moisture content was directly related to the formation ofctive radicals, and then affected the degradation of pollutants inoil [24], so its influence on CAP degradation was examined. Theoil moisture content was adjusted to specific values in the rangerom 0.19% to 40%. After 20 min of plasma treatment, experimentalesults were performed in Fig. 6. There existed a moisture contentange for high level CAP degradation between 4% and 16%, and

he optimal case is 10%, as insert in Fig. 6. Active radicals (such asH•, O2

•−, etc.) would be produced through the oxidation of waterolecules and reaction between O2 and electrons [25]. Because of

he rising amount of produced active radicals, these active radicals

0 5 10 15 20010203040506070

0 10 20 30 400

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4%10%16%

ba

ig. 6. CAP degradation efficiency as a function of soil moisture content; insert: CAPegradation efficiency as a function of treatment time for soil moisture content of%, 10% and 16% (conditions: applied voltage 18.4 kV; O2 flow rate 0.5 L min−1; CAPoncentration 200 mg kg−1; treatment time 20 min).

0, 0.25, 0.5 and 0.1 g (conditions: applied voltage 18.4 kV; O2 flow rate 0.5 L min−1;CAP concentration 200 mg kg−1; soil moisture 10%).

may be responsible for the enhancement of CAP degradation insoil. When the moisture content was risen up to 10%, the amountof active radicals was increased by dissociation of water moleculeswith high energy electron impacts. On the contrary, the status ofsoil would become to be sludge when the moisture content washigher than 16%. Excess water content would adsorb high energyelectron that should be reacted with gas to produce active species,and meanwhile hinder active gas from penetrating into the soil todecompose CAP molecules. It was indicated that the CAP moleculesmight contact with active gases inadequately, thereby providingthem with lower transfer efficiency, so this effect resulted in asignificant decrease for CAP degradation. Therefore, the moisturecontent in subsequent experiments was set at 10%.

3.5. Effect of Fe0 dosage

As iron element abounded in soil, four dosages of Fe0 amount(0–0.1 g) were added to soil samples, and the corresponding resultsfor CAP degradation were presented in Fig. 7. In the presence ofFe0 was helpful to increase CAP decomposition. Degradation ofCAP in soil increased from 71% to 79% when the Fe0 amount wasvaried from 0% to 2%. Fe0 is a strong reductant, which can berapidly oxidized under oxygen atmosphere and generate its oxi-dation products in the course of plasma treatment (Eqs. (1) and(2)). Fe3O4, which is the main oxidation products, is characterizedby good magnetic properties and excellent electrical conductivitycreating bridges between both electrodes, resulting in increasingdischarge channels. The gas entered into the soil, containing morehigh energy electrons that might generate a larger number of activespecies by direct dissociation of water molecules in soil [26], andthereby decompose CAP efficiently. Nevertheless, further additionof Fe0 led to a slight improvement. Excess Fe0 not only enhances thedischarge channels, but also may consume a part of reactive speciesto generate its oxidation products (Eqs. (3) and (4)), as reactivespecies are nonselective.

4Fe0 + 3O2 → 2Fe2O3 (1)

3Fe0 + 2O2 → Fe3O4 (2)

3Fe0 + 2O3 → Fe3O4 + O2 (3)

3Fe2O3 + O3 → 2Fe3O4 + 2O2 (4)

J. Lou et al. / Chemical Engineering

0 5 10 15 200

20

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20 40 60 800

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a

200 mg kg-1

1000 mg kg-1

2000 mg kg-1

b

200 mg kg-1

1000 mg kg-1

2000 mg kg-1

Ene

rgy

effic

ienc

y (g

kWh -1 )

Degradation efficiency (%)

Fig. 8. CAP degradation efficiency as a function of treatment time (a); CAP energyefficiency as a function of degradation efficiency and (b) for initial concentrationso0

3

fti

f 200, 1000 and 2000 mg kg−1 (conditions: applied voltage 18.4 kV; O2 flow rate.5 L min−1; soil moisture 4%; Fe0/soil 2%).

.6. Effect of initial CAP concentration

In order to investigate the treatment capacity of DBD plasmaor CAP-contaminated soil, the effect of initial CAP concentra-ions on the degradation and energy consumption was illustratedn Fig. 8. Presented results in Fig. 8(a) showed that the CAP

Fig. 9. Possible degradation pathway

Journal 180 (2012) 99– 105 103

degradation was directly related to the initial concentration. 79%of CAP was removed after 20 min of plasma treatment for ini-tial concentration 200 mg kg−1, whereas the degradation efficiencywas reduced to 65% when the initial concentration increasedto 2000 mg kg−1. Higher initial concentration meant more CAPmolecules present in soil while the amount of reactive radicalsremained the same. Therefore, CAP molecules and its intermediatesmay have a more intensive competition for the reactive species.Accordingly, higher initial concentrations led to lower degrada-tion efficiency. In addition, when the initial concentrations of CAPincreased to 1000 mg kg−1, the degradation efficiency was similarto the results of 200 mg kg−1. The phenomenon demonstrated thatDBD plasma technique could perform a high level decompositionwith initial CAP concentration between 200 and 1000 mg kg−1.

Fig. 8(b) showed that energy efficiency decreased withthe rising degradation efficiency. For initial concentration1000 mg kg−1, maximum energy efficiency reached 4.29 g kW h−1,while 3.05 g kW h−1 was obtained for 2000 mg kg−1. The obser-vation indicated that when initial concentration was higher than1000 mg kg−1, the experimental conditions were insufficient togenerate enough active species to remove the CAP molecules insoil. For a high CAP initial concentration, larger applied voltageand O2 flow rate were supposed to be needed to get higher energyefficiency.

3.7. CAP degradation mechanism

To investigate the degradation mechanisms of CAP and in soil,the intermediates of CAP degradation after 5 min of plasma treat-ment were analyzed using HPLC/MS. Four intermediates werededuced, as shown in Table 1. Compound A, with an [M−H]− of319, resulted from the O–H bonds rupture. Compound B at [M−H]−

275 mass units could be attributed to the removal of the nitrogroup by active species attack on the nitrobenzene ring. In addi-

tion, CAP molecules experienced dechlorination reactions due tothe detection of Compound C with [M−H]− of 253. Compound D at[M−H]− 166 mass units produced by oxidation corresponded wellwith the structure of 4-nitrobenzoic acid, which was consistent

s of CAP in soil by DBD plasma.

104 J. Lou et al. / Chemical Engineering

Table 1Identified intermediates.

Compound tr (min) [M−H]− Chemical structure

A 23.653 319

O

HN

O

O

Cl

ClO2N

B 31.97 275

OH

HN

OH

O

Cl

Cl

C 38.472 253

OH

HN

OH

OO2N

D 5.309 166

OH

O

O2N

CAP 20.394 321

OH

HN

OH

Cl

ClO2N

wpNgtol[ddo

lldwerda

4

ritipt

[

[

[

[

[

[

[

[

[

[

O

ith previous results [10]. Chemical structure of CAP includes threearts: nitrobenzene ring, propylene glycol and dichloro-acetamide.itrobenzene ring is the main functional group of CAP and its nitroroup could cause both hemotoxicity and hypotension in suscep-ible individuals [27]. CAP containing chlorine atoms is one of therganochlorine compounds, which could cause environmental pol-ution and severe health effects to humans after chronic exposure28]. Since CAP molecules experienced phenyl-nitryl rupture andechlorination reaction, it could be expected that the toxicity of theegradation products was less than that of CAP. Overall, the toxicityf antibiotics in soil decreased greatly after DBD treatment.

According to the bond dissociation energies (BDEs) theory, theower BDE makes the chemical bond more active [29], where easilyosing electrons and being attacked by reactive species [30]. Theissociation energies of O–H, phenyl–nitryl and C–Cl bonds wereeaker than the others in CAP molecules, so these bonds can be

asily cleaved by reactive species [31]. Based on the experimentalesults above combined with the BDEs theory, the possible degra-ation pathways of CAP in soil by DBD plasma had been proposed,s shown in Fig. 9.

. Conclusions

The application of atmospheric pressure DBD technique for theemediation of soil contaminated by antibiotics was investigatedn this study. Increasing applied voltage favored CAP degrada-

ion, due to the enhancement of active species production. Thenvestigation of contributions of different radicals to CAP decom-osition indicated that O3 played a more important role during thereatment process. Improving oxygen flow rate and soil moisture

[

Journal 180 (2012) 99– 105

content (up to 10%) gained more active species such as O3 and OH•

in DBD reactor, and then benefited CAP degradation. The additionof Fe0 had a positive influence on the process of CAP oxidationthrough providing the DBD reactor with more discharge channels.The system of DBD plasma performed a high level decompositionwith initial CAP concentration between 200 and 1000 mg kg−1.The identification of intermediates by HPLC/MS showed thatCAP molecules experienced phenyl–N, O–H bonds rupture anddechlorination, oxidation reactions during DBD plasma treatment.

The good performance was showed for removing CAP from soilin DBD reactor, demonstrating that the application of DBD plasmafor antibiotics-contaminated soil treatment was a reasonable alter-native to traditional solution.

Acknowledgements

The authors thank the National Natural Science Foundation,P.R. China (Project No. 40901150), the Ministry of Science andTechnology, P.R. China (Project No. 2008AA06Z308), and Programfor Liaoning Excellent Talents in University, China (Project No.2009R09) for their financial supports to this research.

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