research article preparation of cathode-anode integrated...

Research ArticlePreparation of Cathode-Anode Integrated Ceramic Filler andApplication in a Coupled ME-EGSB-SBR System forChlortetracycline Industrial Wastewater Systematic Treatment

Yuanfeng Qi12 Suqing Wu1 Fei Xi2 Shengbing He1 Chunzhen Fan1 Bibo Dai2

Jungchen Huang1 Meng Meng2 Xiangguo Zhu23 and Lei Wang24

1School of Environmental Science and Engineering Shanghai Jiaotong University Shanghai 200240 China2Shandong ATK Environmental Engineering Company Limited Jinan 250101 China3Shandong Kenli Petrochemical Group Dongying 257500 China4Shandong Wonfull Petrochemical Group Co Ltd Zibo 256410 China

Correspondence should be addressed to Shengbing He shengbing he163com

Received 28 June 2016 Revised 6 September 2016 Accepted 20 September 2016

Academic Editor Manuel A R Rodrigo

Copyright copy 2016 Yuanfeng Qi 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

Chlortetracycline (CTC) contamination of aquatic systems has seriously threatened the environmental and human healththroughout the world Conventional biological treatments could not effectively treat the CTC industrial wastewater and few studieshave been focused on the wastewater systematic treatment Firstly 400 wt of clay 300 wt of dewatered sewage sludge (DSS)and 300 wt of scrap iron (SI) were added to sinter the newmedia (cathode-anode integrated ceramic filler CAICF) Subsequentlythe nontoxic CAICF with rough surface and porous interior packed into ME reactor severing as a pretreatment step was effectivein removing CTC residue and improving the wastewater biodegradability Secondly expanded granular sludge bed (EGSB) andsequencing batch reactor (SBR) serving as the secondary biological treatment were mainly focusing on chemical oxygen demand(COD) and ammonia nitrogen (NH3-N) removal The coupled ME-EGSB-SBR system removed about 980 of CODcr and 950of NH3-N and the final effluent met the national discharged standard (C standard of CJ 343-2010 China) Therefore the CTCindustrial wastewater could be effectively treated by the coupled ME-EGSB-SBR system which has significant implications for acost-efficient system in CTC industrial systematic treatment and solid wastes (DSS and SI) treatment

1 Introduction

As a biological wastewater treatment process activated sludgetechnology has been widely used in municipal and industrialwastewater treatment However large amounts of excesssludge generated as by-product during the process usuallycontain organic and mineral components [1] and pathogenicand toxic substances [2 3] which has hindered application ofactivated sludge process Generally disposal of excess sludgemight account for more than 60 of the total operatingexpenditure in a wastewater treatment plant [4] Variousmethods have been applied in excess sludge treatmentincluding incineration land application land filling roadsurfacing and conversion to fertilizer [5] Although thesestudies achieved some desired effect in treating excess sludge

these methods were uneconomical unsafe or insanitaryTherefore eco-friendly and economical methods for safehandling disposal and recycling of excess sludge are of greatsignificance

As a kind of solid waste large quantity of scrap ironmight be generated and discarded by machinery plantsresulting in waste of resources In recent years scrap iron hasbeen utilized in many manners mainly including hexavalentchromium reduction [6] sulfur dioxide removal [7] azodyes wastewater pretreatment [8] and antibiotics residueremoval [9] These methods are insufficient for scrap ironreusing therefore more economical and effective methodsare essential for recycling scrap iron

In the past several decades excess sewage sludge andscrap iron have been utilized to prepare ceramics which have

Hindawi Publishing CorporationJournal of ChemistryVolume 2016 Article ID 2391576 11 pageshttpdxdoiorg10115520162391576

2 Journal of Chemistry

beenwidely used in construction industry chemical industrymetallurgy agriculture and environmental protection [10]resulting in reusing these solid wastes and reducing clayconsumption during ceramics production

CTC as a broad-spectrum antibiotic has been widelyused in disease control and animal growth [11 12] Largeamounts of wastewater are generated from fermentationprocess during CTC production mainly containing fermen-tation medium residue mycelium and various complicatedmetabolites (carbohydrates proteins organic acids etc)In addition CTC extraction process also generates somewastewater mainly containing organic solvent acid alkaliand antibiotic residue Therefore CTC industrial wastewateris difficultly degraded by biological methods and it willaccumulate constantly [13] So far lots of methods havebeen utilized to treat the CTC industrial wastewater includ-ing photodegradation [14ndash17] advanced oxidationreduction[18 19] manganese oxidation [20] and sorption [21ndash24]Although these studies obtained some desired effect veryfew of them could be applied in practical project due totheir rigorous reaction conditions and expensive operatingcost Consequently it is important to develop economical andeasily applicable methods for real CTC industrial wastewatertreatment

In our previous study [25] a coupled ME-EGSB-AOsystem was utilized for oxytetracycline (OTC) productionwastewater treatment In this study a similar coupled sys-tem (ME-EGSB-SBR) was applied to treat CTC productionwastewater Although similar treatment system was used inthe two studies different fillers were prepared and appliedin ME reactor cathode fillers (CCF) and anode fillers (ACF)in different particle bodies were sintered separately in theprevious study while cathode and anode fillers were incor-porated in the same particle body and the incorporate fillers(CAICF) were prepared in the present study which couldsimplify preparation process of the fillers and enhance thetreatment efficiency of the ME reactor Therefore in thisstudy a coupled ME-EGSB-SBR system was utilized for CTCindustrial wastewater treatment

Firstly new media (CAICF) were prepared from DSSSI and clay and subsequently applied as fillers for MEreactor Microelectrolysis technology developed on the basisof electrochemistry was first applied in Europe during the1960s [26] Its principles are very similar to electrochemicalmethods and the electrons are supplied from the galvaniccorrosion of many microscale sacrificial anodes withoutexternal power supply Numerous microscopic galvanic cellsare formed between the iron and carbon particles whencontactedwithwastewater (electrolyte solution)Thehalf-cellreactions can be represented as follows [27 28]

Anode (oxidation) 2Fe 997888rarr 2Fe2+ + 4eminus

119864120579 (Fe2+Fe) = minus044V

Cathode (reduction) Acidic 2H+ + 2eminus 997888rarr H2 uarr

119864120579 (H+H2) = 0V

O2 + 4H+ + 4eminus 997888rarr 2H2O 119864

120579 (O2H2O) = +123V

Neutral to alkaline O2 + 2H2O + 4eminus 997888rarr 4OHminus

119864120579 (O2OHminus) = +040V

(1)

In recent years ME has been widely used to treat refractorywastewaters including landfill leachate [29] pharmaceuticalwastewater [30] palm oil mill wastewater [31] ionic liquidswastewater [32] coking wastewater [33] and dyeing wastew-ater [26 34] In this research ME was used as the wastewaterpretreatment mainly focusing on CTC residue removaland improvement of the wastewater biodegradability whichcould facilitate subsequent biological treatments

Secondly EGSB followed by SBR was utilized as thesecondary biological treatment for the CTC wastewaterEGSB as a representative kind of anaerobic bioreactors wasmainly based on the mechanisms about anaerobic biolog-ical degradation of organic contaminants When influentwastewater flowed through the anaerobic bioreactor the con-tained organic contaminants were biologically degraded bythe anaerobic microorganisms in granule sludge with CODremoval and methane generation Therefore EGSB has beenapplied to disposal of high concentrated organic wastewa-ters including brewing industry wastewater [35 36] starchextracting wastewater [37] trichloroethylene-contaminatedwastewater [38] and industrial oil wastewater [39] SBRsystems have been remarkably employed in industrial andmunicipal wastewater treatment for many years [40] suchas wastewater containing p-nitrophenol [41] dairy effluents[42] and soybean-processingwastewater [43]The secondarytreatment wasmainly used to removemajority of CODcr andNH3-N in the wastewater

2 Materials and Methods

21 Materials DSS SI and clay utilized as raw materialsto prepare CAICF were obtained from Jinan wastewatertreatment plant a machinery plant in Jinan city (ShandongProvince China) and a brickyard in Zibo city (ShandongProvince China) respectively The components of DSS andclay were shown in Table 1 and the raw materials were driedat 105∘C for 4 h crushed in a ball mill sieved through a0154mm mesh and then stored in polyethylene vessels toavoid humidification before utilization

The utilized CTC industrial wastewater obtained from aCTC manufacturing factory in Hohhot city (Inner MongoliaAutonomous Region China) was mainly generated fromseparation and extraction processes of CTC equipmentrinsing processThemain water quality of the rawwastewaterand the national discharged standard (wastewater qualitystandards for discharge to municipal sewers C standard ofCJ 343-2010 China) are shown in Table 2 revealing thatthe wastewater quality was not stable and all indexes of thewastewater did not meet the national discharged standard Inthe wastewater treatment plant of this enterprise the utilizedwastewater treatment system mainly contained flocculationand precipitation upflow anaerobic sludge blanket (UASB)(two anaerobic reactors were connected in series) cyclicactivated sludge system (CASS) anoxicoxic activated sludge

Journal of Chemistry 3

Table 1 Chemical components of clay and DSS (wt)

SiO2 Al2O3 Fe2O3 CaO K2O Na2O Sulfate Phosphate OthersDSS 2994 1850 948 2142 178 mdash 943 537 408Clay 6328 1875 772 123 214 207 mdash mdash 481

Table 2 The components of the raw CTC industrial wastewater and the national standard

Indexes Unit Concentration range CJ 343-2010 C standardCODcr mg Lminus1 10474ndash16855 le300NH3-N mgLminus1 3585ndash8402 le25Suspended solid (SS) mg Lminus1 8475ndash1049 le300Chroma mdash 2105ndash3323 le60pH mdash 460ndash652 650ndash950CTC residue mg Lminus1 728ndash1026 mdashBOD5 mgLminus1 11243ndash15325 le150

process (AO) and Fenton oxidation However this com-plicated system had several problems (1) the two anaerobicreactors could not operate stably and granule sludge in thereactors disintegrated greatly and must be renewed everythree months (2) the system required high operating costmainly resulting from the renewal of granule sludge andoperation of the Fenton process (3) the final effluent ofthe system (CODcr of 586ndash673mg Lminus1 NH3-N of 215ndash268mg Lminus1 SS of 975ndash1138mg Lminus1 chroma of 200ndash300)did not meet the discharged national standard (CODcr le300mg Lminus1 NH3-N le 25mg Lminus1 SS le 300mg Lminus1 chromale 60) Therefore it is necessary to improve the system ordevelop new system for the CTC wastewater treatment

According to our previous study [28] CAICF was pre-pared according to the following three steps

Step 1 (dosing mixing pelleting screening and drying)Clay DSS and SI (4 3 3 www) were completely mixedand poured into a pelletizer (DZ-20) to produce raw pellets(about 700wt of water was added) Then the raw pelletswere sieved (the diameters were 50ndash60mm) and stored indraught cupboard at room temperature (22∘C) for about 24 hbefore thermal treatment

Step 2 (sintering treatment) The dried raw pellets wererapidly transferred into electric tube rotary furnace (KSY-4D-16) and sintered at 400∘C for 20min in anoxic conditions

Step 3 (cooling treatment) After the sintering treatmentthe pellets were transferred to draught cupboard until theycooled down to room temperature (22∘C)

22 Starting and Operating of the Wastewater TreatmentSystem In this study a coupled ME-EGSB-SBR system wasutilized for the CTC industrial wastewater treatment A pilot-scale experiment was set up for the wastewater treatmentas shown Figure 1 all units were made of stainless steel toprevent possible corrosion caused by the wastewater and toeliminate potential photodegradation by the light

Firstly flocculation and precipitation processes were usedto remove SS in the raw wastewater and prevent blockage of

the ME reactor Then the wastewater was introduced into theregulating reservoir 1 (cylinder 10m in diameter and 15mtall) to adjust pH of the wastewater by adding hydrochloricacid (HCl) solution Seven initial pH values (10 20 30 4050 60 and 70) and eight hydraulic retention times (HRTs10 20 30 40 50 60 70 and 80 h) were selected todetermine the optimum conditions of ME reactor accordingto the removal rate of CTC residue and CODcr 30 cm ofcobble stone was packed as supporting layer at the bottom ofME reactor (cylinder 10m diameter and 20m height) with10m of CAICF as media layer on the top leaving a bottomspace of 20 cm for water and air distribution and a headspaceof 30 cm to retain fillers during backwashingThe wastewaterwas pumped into the reactor through the inlet at the bottomand discharged to the regulating reservoir 2 (cylinder 10min diameter and 15m tall) from the upper outlet

Secondly calcium hydroxide (Ca(OH)2) solution wasadded to adjust and keep pH of the wastewater to about 70before being introduced into EGSB tank At start-up stagethe up-flow EGSB tank (cylinder 12m in diameter and 50mtall) with an effective volume of approximately 396m3 wasinoculated with granule sludge (approximately 12m3) froma local starch factory at a concentration of approximately159 g VSS Lminus1 and the starting organic loading rate (OLR)was about 05 kgmminus3 dminus1 During the operation OLR wasincreased gradually until the optimum OLR was determinedby the CODcr removal efficiency Other conditions includingtemperature and pHwere kept at about 350∘Cand 70 respec-tively The effluent was discharged into sludge precipitationreservoir (cylinder 10m in diameter and 15m tall) andexcess sludge was returned to the EGSB tank via a refluxsludge pump

Thirdly the supernatant of sludge precipitating reservoirwas pumped into SBR reactor (cuboid 12m times 06m times065m)with an effective volume of approximately 043m3 Atthe start-up stage the reactor was inoculated with activatedsludge obtained from the same starch factory at a solidsconcentration of approximately 54 g MLSS Lminus1 During theoperation the time for influent feeding aerating precipi-tating and effluent discharging was 10 h 40 h 20 h and10 h respectively Additionally temperature and pH of the


Influent Regulatingreservoir 1

ME reactor

Regulatingreservoir 2

EGSB tank Effluent

SBR reactorPrecipitation

reservoir

Figure 1 The treatment system of CTC wastewater

wastewater were controlled at about 300∘C and 70 by addingNaHCO3 solution Finally the effluent was discharged fromthe wastewater treatment system into urban sewage pipenetwork

All pumping and mixing cycles in the system wereoperated via four metering pumps (JsbasenGM50003 Bei-jing China) and a sludge pump (LanshenQJB-W4 NanjingChina)The dissolved oxygen (DO) concentration in the SBRreactor was controlled at 20ndash40mg Lminus1 using a Roots blower(FengyuanFRMG350 Shandong China)

23 Analytical Methods

231 Properties of CAICF According to our previous study[44] water absorption and bulk density were measuredby the national standard (lightweight aggregates and thetest methods-part 2 test methods for lightweight aggregateGBT 174312-2010 China) and grain density was calculatedaccording to Archimedesrsquo principle The above-mentionedphysical properties were calculated as follows

Bulk density = mass of ceramic bodiesbulk volume of ceramic bodies

kgsdotmminus3

Grain density = mass of ceramic bodiesvolume of ceramic bodies

kgsdotmminus3

Water absorption =1 h saturated mass of ceramic bodies minusmass dry of ceramic bodies

mass of dry ceramic bodiestimes 100

(2)

Structural and morphological analysis was conducted byscanning electron microscopy (SEM Hitachi S-520 Japan)both in the surface and in the cross section (Au coated)

100000 g of CAICF was soaked into 100 L of HCl(020mol Lminus1) for 24 h 100mL of leach solution obtainedfrom the supernatant was collected for leaching test of thetoxicmetal elements Toxicmetal concentrations (Cu Zn PbCr Cd Hg Ba Ni and As) of 100000 g of CAICFwere deter-mined by ICP-AES (IRIS Intrepid II XSP equipmentThermoElectron USA) and were compared with national standard(identification standards for hazardous wastes identificationfor extraction toxicity GB 50853-2007 China)

232 Characterization of Wastewater CODcr NH3-N SSBOD5 chroma and pH of the wastewater were measuredaccording to national standard methods (State Environmen-tal Protection Administration of China Monitoring andAnalysis Methods of Water and Wastewater fourth edChina Environmental Science Press Beijing) and volatilefatty acid (VFA) of the wastewater in the EGSB tank wasmeasured by titrimetry [45] CTC residue in the wastewaterwas detected by High Performance Liquid Chromatography(HPLC) analysis (Shimadzu LC-2010A Japan) equipped with

a UV absorbance detector and the analytical method for theCTC analysis was shown in Table 3 Dissolved oxygen (DO)and temperature were monitored with DO meter (HQ 30d53LED HACH USA) All measurements were conductedin five replicates

3 Results and Discussion

31 Properties of CAICF Firstly physical properties ofCAICF as shown in Table 4 revealed that the fillers hadlow bulk density and grain density The low bulk densityimplied abundant void which could enhance mass transferand prevent short-circuiting The low grain density mightimprove backwashing process and SS intercepted by thefillers could be easily removed during backwashing processTherefore utilization of CAICF as fillers could ensure thereliability of ME reactor

Secondly Figure 2 showed the appearance and micro-structure of CAICF ((a) surface (b) fracture surface) Fig-ure 2(a) demonstrated a few small and large aperturesdistributed on the rough surface of CAICF mainly caused bythe escaped gas from interior of CAICF during the sinteringtreatment As mentioned in our previous study [28] the


Table 3 Analytical methods for CTC analysis with a HPLC

Columnstationary phase

Injection volume(120583L)

Flow rate(mLminminus1) UV detection (nm) Eluent

CTC C8b 50 10 355 001M oxalic acid methanol acetonitrile (72 8 20)bLuna 5120583 C8(2) 100 A (Phenomenex Torrance CA USA) 150mm (L) times 46mm (120601)

Table 4 Physical properties of CAICF

Ceramics Bulk density (kgmminus3) Grain density (kgmminus3) Water absorption (wt)CAICF 9185 13182 136

Table 5 Toxic metal leaching tests of CAICF

Toxic metal Contents(mg kgminus1 of CAICF)

Threshold(mg kgminus1 of hazardous

waste)Total Cu 008 10000Total Zn 002 10000Total Cd 001 100Total Pb 006 500Total Cr 002 1500Total Hg mdash 010Total Ba 005 10000Total Ni mdash 500Total As 002 500

rough surface could make fillers contact with wastewatermore easily and the apertures on surface could promotethe wastewater flow into the interior of CAICF resultingin enhancement of treating effect Figure 2(b) revealed lotsof small and large apertures distributed inside of CAICFmeaning that the wastewater could flow through inside ofthe fillers Consequently the wastewater could be treatedsufficiently inside of the fillers and the interior might notbe easily blocked by SS Therefore utilization of CAICF asfillers might be satisfactory according to the microstructureanalysis

Thirdly results of the toxic metal leaching test of CAICFwere shown in Table 5 revealing that all the nine metalconcentrations (Cu Zn Pb Cr Cd Hg Ba Ni and As) inlixivium were much lower than the limits of the nationalstandard (GB 50853-2007)The results suggested that CAICFutilized as fillers would not lead to secondary pollution towater environment Additionally comparing with the detec-tion for DSS [44] all the toxic metal leaching concentrationsof CAICFwere far lower than those ofDSS especially for totalCu Zn Cr Pb and Ba This result showed that utilization ofDSS to prepare CAICF could immobilize the toxic metals inDSS and consequently decrease the pollution of DSS

Overall it could be deduced that CAICF used as fillers ofME reactor might be feasible safe and reasonable accordingto the properties test

32 CTCWastewater Pretreatment Effect by ME321 Initial pH of the Wastewater pH is an importantparameter forME reaction andmay affect the treatment effect

of ME reactor Therefore seven pH values were selected tostudy the influence of initial pH on ME reactor During thisexperiment CAICF was applied as fillers in the ME reactorHRT was kept at 80 h under aerating condition

The influence of initial pH on CTC and CODcr removalwas shown in Figure 3(a) The results revealed that theremoval efficiency of CODcr and CTC decreased rapidlywhen initial pH increased from about 30 to 70 and theremoval efficiency decreased slightly as initial pH increasedfrom about 10 to 30 It was likely that corrosion anddissolution of Fe0 in the fillers were more easily proceededunder acidic condition therefore more reducing agents (Fe0Fe2+ and active radical ([H])) could be generated resultingin destruction and reduction of CTC in the wastewater [2846] Moreover hydroxyl radical (∙OH) as a strong oxidizingagent might be easily generated during ME reactions underaerating conditions resulting in oxidation of CTC and CODresidue in the wastewater However when the wastewaterreached neutral and alkaline condition iron oxides andhydroxides were easily formed on the surface of the fillersresulting in slow iron corrosion and surface passivationconsequently leading to the weakening of reduction andoxidation effect by the ME reactor Therefore higher CTCremoval efficiency by the ME reactor was obtained on acidiccondition than that on neutral and alkaline condition andthe CTC removal efficiency increased when pH decreasedgradually probably due to the acceleration of Fe corrosionwhich could strengthen the reduction and oxidation effect bytheME reactor However when pH in the wastewater was toolow dissolution of Fewas accelerated drastically whichwouldgreatly decrease service life of the sintered fillers Therefore30 should be the optimum pH for the ME reactor in order toobtain high CTC removal efficiency and long service life ofthe sintered fillers

322 HRT of theWastewater HRT is also a crucial parameterforME reactionTherefore eight HRTs were selected to studythe influence of HRT on CODcr and CTC removal of MEreactor During this experiment initial pH was kept at about30 under aerating condition

Figure 3(b) showed the influence of HRT on the removalefficiency of CODcr and CTC by ME reactor revealingthat the removal efficiency increased quickly when HRTwas increased from 10 h to 40 h and it varied slightly asHRT was increased from 40 h to 80 h It could be deducedthat ME reaction could not be accomplished with shortHRT which might be confirmed by abnormally low pH in


(a) (b)

Figure 2 The appearance and microstructure of CAICF (SEM) (a) surface (b) fracture surface

1 7654320

10

20

30

40

50

CODcr removal efficiencyCTC removal efficiency

pH

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

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50

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70

80

90

100

CTC

rem

oval

effici

ency

()

(a)

1 2 3 4 5 6 7 810

15

20

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30

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50


HRT (h)

COD

cr re

mov

al effi

cien

cy (

)

0

10

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60

70

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100

CTC

rem

oval

effici

ency

()

(b)

Figure 3 Influence of initial pH and HRT on ME treatment effect ((a) pH (b) HRT)

effluent resulting in low removal efficiency of CODcr andCTC Consequently the removal efficiency increased quicklywhen HRT was increased from 10 h to 40 h Howeverwhen HRT exceeded 40 h the reaction time was enough foraccomplishing ME reaction sufficiently Additionally pH inthe effluent (about 650) varied slightly as HRTwas increasedfrom 40 h to 80 h probably leading to the slight variationof removal efficiency In all the optimum HRT for the MEreactor should be 40 h determined by the CODcr and CTCremoval efficiency

323 Mechanisms for CTC and CODcr Removal In MEreactor several reaction mechanisms are involved in MEreactions for CTC removal Firstly the residual CTC mightbe reduced by the reduction effect which was derived fromactive radical ([H]) Fe0 and Fe2+ under acidic conditions

[47] It was known that when contacted with wastewaterunder acidic conditions Fe0 could react with H+ and gener-ated active radical ([H]) which was a strong reducing agentto reduce CTC Additionally Fe0 and its corrosion product(Fe2+) were also reducing agents which could also reduceCTC Secondly H+ was consumed during ME reactionsand pH reached neutral and alkaline conditions graduallyresulting in the generation of iron hydroxide (Fe(OH)2 andFe(OH)3) which could remove the residual CTC and CODcrby flocculation effect [48 49] Thirdly the electrode voltageunder acidic and aerating conditions (+167V) was higherthan that under acidic and anaerobic conditions (+040V)which could enhance ME reactions and accelerate corrosionof Fe resulting in the improvement of CTC removal [46]Additionally as a strong oxidizing agent hydroxyl radi-cal (∙OH) might be generated during ME reactions under


30

25

35

40

45

50

55

60


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

50

55

60

65

70

75

80

85

90

95

100

CTC

rem

oval

effici

ency

()

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

Figure 4 Operating effect of the ME reactor

aerating conditions which has been demonstrated by someresearchers [50 51] ∙OHmight oxidize the residual CTC andremove some CODcr in the wastewater Overall CTC andCODcr in the wastewater were mainly removed by reducingoxidizing and flocculation effects

324 Operating Effect of ME Reactor According to the aboveexperiments the optimum initial pH (about 30) and HRT(40 h) were applied in the pilot-scale experiment and theMEreactor was packed with CAICF

Figure 4 showed the operating results of the ME reac-tor in the whole experiment It could be seen that theME reactor could get stable CODcr and CTC removalefficiency (400 and 900 resp) It was noted that theremoval efficiency decreased appreciably (about 50) from15 d to 29 d probably due to the blockage of the reactorby SS in the wastewater Consequently the mass trans-fer of wastewater was inhibited resulting in the decreaseof removal efficiency After the backwash for the reactorthe removal efficiency was recovered Therefore the reac-tor was backwashed regularly (the backwashing cycle wasabout 15 d) and the reactor operated stably during the laterexperiment

From the operating effect it could be deduced that themolecular structure of CTC might be destroyed by the MEreactor and the majority of CTC residue in the wastewatermight be decomposed or inactivated and biotoxicity of thewastewatermight be decreased according to the high removalefficiency of the ME reactor and the operating effect oflater biological treatment Therefore it could be deducedthat utilization of this ME reactor for CTC wastewaterpretreatment was feasible and satisfactory

33 Anaerobic Biological Treatment by EGSB After the MEpretreatment EGSB tank was used as the following anaerobicbiological treatment for the wastewater in order to removethemajority of CODcr in thewastewater and further enhancebiodegradability of the wastewater

20253035404550556065707580859095

100

CODcr removal efficiencyOLR

Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

00

05

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

OLR

(kgm

minus3dminus1)

Figure 5 The effect of EGSB tank

CODcr removal efficiency of the EGSB tank was shownin Figure 5 The results showed that the operating effectfluctuated occasionally during the microbial acclimationstage and CODcr removal efficiency could reach 850 to900 after microbial acclimation was accomplished Duringthe whole experiment it could be observed that CODcrremoval efficiency decreased obviously on two stages Thefirst stage appeared from 17 d to 25 d it was likely thatdominant bacteria in the EGSB tank have not been greatlyreproduced and it could not bear high OLR (20 kgmminus3 dminus1)resulting in insufficient degradation of organic substances bydominant bacteria Meanwhile granule sludge in the tankwas recombined and some bacteria that could not adapt to thewastewater would be eliminated resulting in the dischargeof some eliminated flocculent sludge When the tank wasoperated after 25 d the CODcr removal efficiency trended tostability suggesting that dominant bacteria might reproducegradually in the tank

On the second stage (43 to 47 d) when OLR reachedabout 45 kgmminus3 dminus1 the CODcr removal efficiency de-creased rapidly with the rapid increase of VFA (from 259to 1008mmol Lminus1) It was likely that the present OLR hasexceeded endurance limit of dominant bacteria resultingin insufficient degradation of organic substances It couldbe deduced that CTC loading rate was enhanced as OLRincreased due to small amount of CTC residue in thewastewater resulting in the inhibition of dominant bacteriaIt is well known that methane and carbon dioxide are theend-products of anaerobic biological treatment Two groupsof bacteria play the major roles in this process acetoclas-tic methanogens and hydrogenotrophic methanogens theformer transform acetate to methane and carbon dioxideand the latter can produce methane and carbon dioxideby utilizing hydrogen produced during anaerobic oxidationof soluble organics Moreover about 75 of the methaneproduced during anaerobic biological treatment is caused bythe acetoclastic methanogen activity [52] CTC could inhibitboth homoacetogenic bacteria and acetoclasticmethanogens


100

200

300

400

500

600

700

800

900

1000

CODcr in effluentCODcr removal efficiency

Operating time (d)

30

35

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55

60

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70

75

80

COD

cr re

mov

al effi

cien

cy (

)

0 5 10 15 20 25 30 35 40

COD

cr in

efflue

nt (m

gLminus1)

Figure 6 The effect of SBR reactor

which could utilize acetate and consequently affect methaneproduction by these microorganisms [53] Moreover ace-togenic bacteria could also be inhibited by CTC resultingin accumulation of VFA in the tank After this stage OLRwas reduced to 40 kgmminus3 dminus1 and the tank was recovered tonormal stage gradually resulting in the increase of theCODcrremoval efficiency

To sum up the optimum OLR of the EGSB tank wasabout 40 kgmminus3 dminus1 with 850 to 900 of CODcr removalefficiency and the anaerobic treatment effect demonstratedthat biotoxicity of the wastewater could be reduced by theMEreactor

34 Aerobic Biological Treatment by SBR Subsequently SBRwas utilized for the aerobic biological treatment mainlyfocusing on CODcr residue and majority of NH3-N removaland SBR reactor was started after EGSB has been operated for30 d

CODcr removal efficiency of SBR reactor was shown inFigure 6 revealing that the reactor could reach stable stageeasily (about 23 d) and it operated stably after 23 d withthe stable CODcr removal efficiency (about 750) From1 to 13 d it could be observed that CODcr in effluent wasdecreased gradually with the increase of CODcr removalefficiency suggesting that quantity of aerobic heterotrophicbacteria might grow and reproduce gradually From 13 to18 d CODcr in the effluent increased rapidly probably dueto the increase of influent CODcr in SBR mainly caused bythe overload operating of EGSB tank However the CODcrremoval was affected slightly in this stage mainly due tothe sufficient aerobic heterotrophic bacteria and effectivedegradation of organic substance resulting in high CODcrremoval efficiency Meanwhile the results suggested that theSBR reactor had strong shock resistance ability After 18 dCODcr in effluent decreased gradually and subsequentlytrended to stability and the reactor entered into the stablestage on 23 d

Overall after the SBR reactor reached stability about750 of influent CODcr could be removed and the effluent

0 18 20 22 24161412108642200250300350400450500550600650700750800850900

Ammonia nitrogen in influentAmmonia nitrogen in effluent

Operating time (d)

81012141618202224262830323436384042444648

Am

mon

ia n

itrog

en in

influ

ent (

mg L

minus1)

Am

mon

ia n

itrog

en in

efflue

nt (m

g Lminus1)

Figure 7 NH3-N removal effect of the system

CODcr could be always lower than 300mg Lminus1 on the basisof stable operation of EGSB tank Moreover this SBR reactorhad strong shock resistance ability

35 Nitrogen Removal Effect by the Whole System NH3-Nremoval effect by the whole system was investigated whenthe SBR reactor has been operated for about 16 d The resultswere shown in Figure 7 It could be observed that the effluentNH3-N was higher in the first three days than that in latertime mainly caused by the high influent NH3-N of thesystem From 1 to 7 d the effluent NH3-N was decreasedgradually mainly due to the growth and reproduction ofnitrifying bacteria in the SBR reactor After this stage thesystem entered into the stable stage resulting in the stableNH3-N in the effluent of the system Additionally NH3-Nin the wastewater was mainly removed by the SBR reactordemonstrating the great NH3-N removal ability of SBRreactor [54ndash56]

Finally it could be concluded that the whole system couldremove about 950 ofNH3-N in thewastewater andNH3-Nin the final effluent of the system could be always lower than250mg Lminus1

4 Conclusions

In this study conclusions were shown as follows

(1) Utilization of solid waste (DSS and SI) to prepare newmedia CAICF was feasible and satisfactory accordingto the physical properties microstructure analysisand toxic metal leaching test of CAICF

(2) CAICF applied as filler in ME reactor for CTCwastewater pretreatment was effective approximately400 of CODcr and 900 of CTC residue in thewastewater were removed and biodegradability of theraw wastewater was enhanced effectively

(3) The coupled ME-EGSB-SBR system could treat theCTC wastewater effectively approximately 980 of


CODcr and 950 of NH3-N could be removed andthe final effluent met the requirement of nationalstandard (CODcrle 300mg Lminus1 NH3-Nle 25mg Lminus1)

Nomenclature

CTC ChlortetracyclineOTC OxytetracyclineDSS Dewatered sewage sludgeSI Scrap ironCAICF Cathode-anode integrated ceramic fillerCCF Cathode fillersACF Anode fillersEGSB Expanded granular sludge bedME MicroelectrolysisSBR Sequencing batch reactorUASB Upflow anaerobic sludge blanketCASS Cyclic activated sludge systemAO Anoxicoxic activated sludge processSS Suspended solid (mg Lminus1)COD Chemical oxygen demand (mg Lminus1)NH3-N Ammonia nitrogen (mg Lminus1)BOD Biochemical oxygen demand (mg Lminus1)VFA Volatile fatty acid (mg Lminus1)OLR Organic loading rate (kg mminus3 dminus1)HRT Hydraulic retention time (h)DO Dissolved oxygen (mg Lminus1)

Competing Interests

The authors declare that they have no competing interests

Acknowledgments

The study was supported by Program for New CenturyExcellent Talents in University (NCET-11-0320) the NationalNatural Science Foundation of China (51378306) ShanghaiJiaotong University ldquoChenxing Plan (SMC-B)rdquo and Shan-dong Provincial Environmental Protection Industry Projectsfor Technology Research and Development (SDHBYF-2012-12)

References

[1] ENeyens J BaeyensMWeemaes andBDeHeyder ldquoHot acidhydrolysis as a potential treatment of thickened sewage sludgerdquoJournal of Hazardous Materials vol 98 no 1ndash3 pp 275ndash2932003

[2] S Werle and R K Wilk ldquoA review of methods for the thermalutilization of sewage sludge the Polish perspectiverdquo RenewableEnergy vol 35 no 9 pp 1914ndash1919 2010

[3] J Werthera and T Ogadab ldquoSewage sludge combustionrdquoProgress in Energy and Combustion Science vol 25 no 1 pp55ndash116 1999

[4] S-T Yan H Zheng A Li et al ldquoSystematic analysis ofbiochemical performance and the microbial community of anactivated sludge process using ozone-treated sludge for sludgereductionrdquo Bioresource Technology vol 100 no 21 pp 5002ndash5009 2009

[5] M R Salsabil J Laurent M Casellas and C Dagot ldquoTechno-economic evaluation of thermal treatment ozonation andsonication for the reduction of wastewater biomass volumebefore aerobic or anaerobic digestionrdquo Journal of HazardousMaterials vol 174 no 1ndash3 pp 323ndash333 2010

[6] M Gheju and I Balcu ldquoRemoval of chromium from Cr(VI)polluted wastewaters by reduction with scrap iron and subse-quent precipitation of resulted cationsrdquo Journal of HazardousMaterials vol 196 pp 131ndash138 2011

[7] J-H Jiang Y-H Li and W-M Cai ldquoExperimental andmechanism research of SO2removal by cast iron scraps in amagnetically fixed bedrdquo Journal ofHazardousMaterials vol 153no 1-2 pp 508ndash513 2008

[8] J R Perey P C Chiu C-P Huang and D K Cha ldquoZero-valentiron pretreatment for enhancing the biodegradabilityrdquo WaterEnvironment Research vol 74 no 3 pp 221ndash225 2002

[9] O Hanay B Yildiz S Aslan and H Hasar ldquoRemoval oftetracycline and oxytetracycline by microscale zerovalent ironand formation of transformation productsrdquo EnvironmentalScience and Pollution Research vol 21 no 5 pp 3774ndash37822014

[10] S Wu Q Yue Y Qi B Gao S Han and M Yue ldquoPreparationof ultra-lightweight sludge ceramics (ULSC) and application forpharmaceutical advanced wastewater treatment in a biologicalaerobic filter (BAF)rdquo Bioresource Technology vol 102 no 3 pp2296ndash2300 2011

[11] W-R Chen and C-H Huang ldquoAdsorption and transformationof tetracycline antibiotics with aluminum oxiderdquo Chemospherevol 79 no 8 pp 779ndash785 2010

[12] Z R Hopkins and L Blaney ldquoA novel approach to modelingthe reaction kinetics of tetracycline antibiotics with aqueousozonerdquo Science of the Total Environment vol 468-469 pp 337ndash344 2013

[13] N Kemper ldquoVeterinary antibiotics in the aquatic and terrestrialenvironmentrdquo Ecological Indicators vol 8 no 1 pp 1ndash13 2008

[14] M Hammad Khan H-S JungW Lee and J-Y Jung ldquoChlorte-tracycline degradation by photocatalytic ozonation in the aque-ous phase mineralization and the effects on biodegradabilityrdquoEnvironmental Technology vol 34 no 4 pp 495ndash502 2013

[15] I Kim and H Tanaka ldquoPhotodegradation characteristics ofPPCPs in water withUV treatmentrdquo Environment Internationalvol 35 no 5 pp 793ndash802 2009

[16] R Daghrir P Drogui and M A El Khakani ldquoPhotoelectrocat-alytic oxidation of chlortetracycline using TiTiO2 photo-anodewith simultaneous H2O2 productionrdquo Electrochimica Acta vol87 pp 18ndash31 2013

[17] J J Lopez-Penalver M Sanchez-Polo C V Gomez-Pachecoand J Rivera-Utrilla ldquoPhotodegradation of tetracyclines inaqueous solution by using UV and UVH2O2 oxidation pro-cessesrdquo Journal of Chemical Technology and Biotechnology vol85 no 10 pp 1325ndash1333 2010

[18] J J Lopez Penalver C V Gomez Pacheco M Sanchez Poloand J Rivera Utrilla ldquoDegradation of tetracyclines in differentwater matrices by advanced oxidationreduction processesbased on gamma radiationrdquo Journal of Chemical Technology andBiotechnology vol 88 no 6 pp 1096ndash1108 2013

[19] J Jeong W Song W J Cooper J Jung and J Greaves ldquoDegra-dation of tetracycline antibiotics mechanisms and kinetic stud-ies for advanced oxidationreduction processesrdquo Chemospherevol 78 no 5 pp 533ndash540 2010

[20] H C Zhang W-R Chen and C-H Huang ldquoKinetic modelingof oxidation of antibacterial agents by manganese oxiderdquo


Environmental Science and Technology vol 42 no 15 pp 5548ndash5554 2008

[21] X L Bao Z M Qiang W C Ling and J-H Chang ldquoSono-hydrothermal synthesis of MFe2O4 magnetic nanoparticles foradsorptive removal of tetracyclines from waterrdquo Separation andPurification Technology vol 117 pp 104ndash110 2013

[22] S E Allaire J Del Castillo and V Juneau ldquoSorption kineticsof chlortetracyline and tylosin on sandy loam and heavy claysoilsrdquo Journal of Environmental Quality vol 35 no 4 pp 969ndash972 2006

[23] R V P Jutta and L David ldquoSorption of tetracycline andchlortetracycline onKminus andCaminus saturated soil clays humic sub-stances and clay-humic complexesrdquo Environmental Science ampTechnology vol 41 no 6 pp 1928ndash1933 2007

[24] J Rivera-Utrilla C V Gomez-Pacheco M Sanchez-Polo J JLopez-Penalver and R Ocampo-Perez ldquoTetracycline removalfrom water by adsorptionbioadsorption on activated carbonsand sludge-derived adsorbentsrdquo Journal of Environmental Man-agement vol 131 pp 16ndash24 2013

[25] Y Qi S Wu F Xi et al ldquoPerformance of a coupled micro-electrolysis anaerobic and aerobic system for oxytetracycline(OTC) production wastewater treatmentrdquo Journal of ChemicalTechnology amp Biotechnology vol 91 no 5 pp 1290ndash1298 2016

[26] X-C Ruan M-Y Liu Q-F Zeng and Y-H Ding ldquoDegrada-tion and decolorization of reactive red X-3B aqueous solutionby ozone integrated with internal micro-electrolysisrdquo Separa-tion and Purification Technology vol 74 no 2 pp 195ndash201 2010

[27] H Cheng W Xu J Liu H Wang Y He and G ChenldquoPretreatment of wastewater from triazine manufacturing bycoagulation electrolysis and internal microelectrolysisrdquo Jour-nal of Hazardous Materials vol 146 no 1-2 pp 385ndash392 2007

[28] S Wu Y Qi Y Gao et al ldquoPreparation of ceramic-corrosion-cell fillers and application for cyclohexanone industry wastew-ater treatment in electrobath reactorrdquo Journal of HazardousMaterials vol 196 pp 139ndash144 2011

[29] D Ying J Peng X Xu K Li Y Wang and J Jia ldquoTreat-ment of mature landfill leachate by internal micro-electrolysisintegrated with coagulation a comparative study on a novelsequencing batch reactor based on zero valent ironrdquo Journal ofHazardous Materials vol 229-230 pp 426ndash433 2012

[30] I Sires and E Brillas ldquoRemediation ofwater pollution caused bypharmaceutical residues based on electrochemical separationand degradation technologies a reviewrdquo Environment Interna-tional vol 40 no 1 pp 212ndash229 2012

[31] J Cheng X Zhu J Ni and A Borthwick ldquoPalm oil mill effluenttreatment using a two-stage microbial fuel cells system inte-grated with immobilized biological aerated filtersrdquo BioresourceTechnology vol 101 no 8 pp 2729ndash2734 2010

[32] H Zhou P Lv Y Shen J Wang and J Fan ldquoIdentification ofdegradation products of ionic liquids in an ultrasound assistedzero-valent iron activated carbonmicro-electrolysis system andtheir degradation mechanismrdquo Water Research vol 47 no 10pp 3514ndash3522 2013

[33] W-W Liu X-Y Tu X-P Wang F-Q Wang and W Li ldquoPre-treatment of coking wastewater by acid out micro-electrolysisprocess with in situ electrochemical peroxidation reactionrdquoChemical Engineering Journal vol 200ndash202 pp 720ndash728 2012

[34] L Huang G Sun T Yang B Zhang Y He and X Wang ldquoApreliminary study of anaerobic treatment coupled with micro-electrolysis for anthraquinone dye wastewaterrdquo Desalinationvol 309 pp 91ndash96 2013

[35] I Colussi A Cortesi L D Vedova V Gallo and F K C RoblesldquoStart-up procedures and analysis of heavymetals inhibition onmethanogenic activity in EGSB reactorrdquoBioresource Technologyvol 100 no 24 pp 6290ndash6294 2009

[36] S Connaughton G Collins and V OrsquoFlaherty ldquoPsychrophilicand mesophilic anaerobic digestion of brewery effluent acomparative studyrdquo Water Research vol 40 no 13 pp 2503ndash2510 2006

[37] W-Q Guo N-Q Ren Z-B Chen et al ldquoSimultaneous bio-hydrogen production and starch wastewater treatment in anacidogenic expanded granular sludge bed reactor by mixed cul-ture for long-term operationrdquo International Journal of HydrogenEnergy vol 33 no 24 pp 7397ndash7404 2008

[38] A Siggins A-M Enright and V OrsquoFlaherty ldquoMethanogeniccommunity development in anaerobic granular bioreactorstreating trichloroethylene (TCE)-contaminated wastewater at37∘C and 15∘Crdquo Water Research vol 45 no 8 pp 2452ndash24622011

[39] N Garcia-Mancha D Puyol V M Monsalvo H Rajhi AF Mohedano and J J Rodriguez ldquoAnaerobic treatment ofwastewater from used industrial oil recoveryrdquo Journal of Chem-ical Technology and Biotechnology vol 87 no 9 pp 1320ndash13282012

[40] Y J Chan M F Chong C L Law and D G Hassell ldquoA reviewon anaerobicndashaerobic treatment of industrial and municipalwastewaterrdquo Chemical Engineering Journal vol 155 no 1-2 pp1ndash18 2009

[41] S Yi W-Q Zhuang B Wu S T-L Tay and J-H TayldquoBiodegradation of p-nitrophenol by aerobic granules in asequencing batch reactorrdquo Environmental Science and Technol-ogy vol 40 no 7 pp 2396ndash2401 2006

[42] N Schwarzenbeck J M Borges and P AWilderer ldquoTreatmentof dairy effluents in an aerobic granular sludge sequencing batchreactorrdquo Applied Microbiology and Biotechnology vol 66 no 6pp 711ndash718 2005

[43] K-Z Su and H-Q Yu ldquoFormation and characterization ofaerobic granules in a sequencing batch reactor treating soybean-processing wastewaterrdquo Environmental Science and Technologyvol 39 no 8 pp 2818ndash2827 2005

[44] Y Qi Q Yue S Han et al ldquoPreparation and mechanismof ultra-lightweight ceramics produced from sewage sludgerdquoJournal ofHazardousMaterials vol 176 no 1ndash3 pp 76ndash84 2010

[45] Y L He Anaerobic Biological Treatment of Wastewater ChinaLight Industry Press Beijing China 1998

[46] F Ju and Y Hu ldquoRemoval of EDTA-chelated copper fromaqueous solution by interior microelectrolysisrdquo Separation andPurification Technology vol 78 no 1 pp 33ndash41 2011

[47] M Stieber A Putschew and M Jekel ldquoTreatment of phar-maceuticals and diagnostic agents using zero-valent ironmdashkinetic studies and assessment of transformation productsassayrdquo Environmental Science and Technology vol 45 no 11 pp4944ndash4950 2011

[48] J-H Fan and L-MMa ldquoThepretreatment by the Fe-Cu processfor enhancing biological degradability of themixedwastewaterrdquoJournal of Hazardous Materials vol 164 no 2-3 pp 1392ndash13972009

[49] T B Hofstetter C G Heijman S B Haderlein C Holligerand R P Schwarzenbach ldquoComplete reduction of TNT andother (poly)nitroaromatic compounds under iron-reducingsubsurface conditionsrdquo Environmental Science and Technologyvol 33 no 9 pp 1479ndash1487 1999


[50] Y Segura F Martınez and J A Melero ldquoEffective pharmaceu-tical wastewater degradation by Fenton oxidation with zero-valent ironrdquoApplied Catalysis B Environmental vol 136-137 pp64ndash69 2013

[51] R C Martins D V Lopes M J Quina and R M Quinta-Ferreira ldquoTreatment improvement of urban landfill leachates byFenton-like process using ZVIrdquo Chemical Engineering Journalvol 192 pp 219ndash225 2012

[52] J J Stone S A Clay Z Zhu K L Wong L R Porath andG M Spellman ldquoEffect of antimicrobial compounds tylosinand chlortetracycline during batch anaerobic swine manuredigestionrdquoWater Research vol 43 no 18 pp 4740ndash4750 2009

[53] T M Dreher H V Mott C D Lupo A S Oswald S AClay and J J Stone ldquoEffects of chlortetracycline amended feedon anaerobic sequencing batch reactor performance of swinemanure digestionrdquo Bioresource Technology vol 125 pp 65ndash742012

[54] J Adriano S David E Jack et al ldquoFull-scale nitrogen removalfrom digester liquid with partial nitritation and anammox inone SBRrdquo Environmental Science amp Technology vol 43 no 14pp 5301ndash5306 2009

[55] M K De Kreuk J J Heijnen and M C M Van LoosdrechtldquoSimultaneous COD nitrogen and phosphate removal byaerobic granular sludgerdquo Biotechnology and Bioengineering vol90 no 6 pp 761ndash769 2005

[56] S Tsuneda T Ohno K Soejima and A Hirata ldquoSimulta-neous nitrogen and phosphorus removal using denitrifyingphosphate-accumulating organisms in a sequencing batch reac-torrdquo Biochemical Engineering Journal vol 27 no 3 pp 191ndash1962006

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


beenwidely used in construction industry chemical industrymetallurgy agriculture and environmental protection [10]resulting in reusing these solid wastes and reducing clayconsumption during ceramics production

CTC as a broad-spectrum antibiotic has been widelyused in disease control and animal growth [11 12] Largeamounts of wastewater are generated from fermentationprocess during CTC production mainly containing fermen-tation medium residue mycelium and various complicatedmetabolites (carbohydrates proteins organic acids etc)In addition CTC extraction process also generates somewastewater mainly containing organic solvent acid alkaliand antibiotic residue Therefore CTC industrial wastewateris difficultly degraded by biological methods and it willaccumulate constantly [13] So far lots of methods havebeen utilized to treat the CTC industrial wastewater includ-ing photodegradation [14ndash17] advanced oxidationreduction[18 19] manganese oxidation [20] and sorption [21ndash24]Although these studies obtained some desired effect veryfew of them could be applied in practical project due totheir rigorous reaction conditions and expensive operatingcost Consequently it is important to develop economical andeasily applicable methods for real CTC industrial wastewatertreatment

In our previous study [25] a coupled ME-EGSB-AOsystem was utilized for oxytetracycline (OTC) productionwastewater treatment In this study a similar coupled sys-tem (ME-EGSB-SBR) was applied to treat CTC productionwastewater Although similar treatment system was used inthe two studies different fillers were prepared and appliedin ME reactor cathode fillers (CCF) and anode fillers (ACF)in different particle bodies were sintered separately in theprevious study while cathode and anode fillers were incor-porated in the same particle body and the incorporate fillers(CAICF) were prepared in the present study which couldsimplify preparation process of the fillers and enhance thetreatment efficiency of the ME reactor Therefore in thisstudy a coupled ME-EGSB-SBR system was utilized for CTCindustrial wastewater treatment

Firstly new media (CAICF) were prepared from DSSSI and clay and subsequently applied as fillers for MEreactor Microelectrolysis technology developed on the basisof electrochemistry was first applied in Europe during the1960s [26] Its principles are very similar to electrochemicalmethods and the electrons are supplied from the galvaniccorrosion of many microscale sacrificial anodes withoutexternal power supply Numerous microscopic galvanic cellsare formed between the iron and carbon particles whencontactedwithwastewater (electrolyte solution)Thehalf-cellreactions can be represented as follows [27 28]

Anode (oxidation) 2Fe 997888rarr 2Fe2+ + 4eminus

119864120579 (Fe2+Fe) = minus044V

Cathode (reduction) Acidic 2H+ + 2eminus 997888rarr H2 uarr

119864120579 (H+H2) = 0V

O2 + 4H+ + 4eminus 997888rarr 2H2O 119864

120579 (O2H2O) = +123V

Neutral to alkaline O2 + 2H2O + 4eminus 997888rarr 4OHminus

119864120579 (O2OHminus) = +040V

(1)

In recent years ME has been widely used to treat refractorywastewaters including landfill leachate [29] pharmaceuticalwastewater [30] palm oil mill wastewater [31] ionic liquidswastewater [32] coking wastewater [33] and dyeing wastew-ater [26 34] In this research ME was used as the wastewaterpretreatment mainly focusing on CTC residue removaland improvement of the wastewater biodegradability whichcould facilitate subsequent biological treatments

Secondly EGSB followed by SBR was utilized as thesecondary biological treatment for the CTC wastewaterEGSB as a representative kind of anaerobic bioreactors wasmainly based on the mechanisms about anaerobic biolog-ical degradation of organic contaminants When influentwastewater flowed through the anaerobic bioreactor the con-tained organic contaminants were biologically degraded bythe anaerobic microorganisms in granule sludge with CODremoval and methane generation Therefore EGSB has beenapplied to disposal of high concentrated organic wastewa-ters including brewing industry wastewater [35 36] starchextracting wastewater [37] trichloroethylene-contaminatedwastewater [38] and industrial oil wastewater [39] SBRsystems have been remarkably employed in industrial andmunicipal wastewater treatment for many years [40] suchas wastewater containing p-nitrophenol [41] dairy effluents[42] and soybean-processingwastewater [43]The secondarytreatment wasmainly used to removemajority of CODcr andNH3-N in the wastewater

2 Materials and Methods

21 Materials DSS SI and clay utilized as raw materialsto prepare CAICF were obtained from Jinan wastewatertreatment plant a machinery plant in Jinan city (ShandongProvince China) and a brickyard in Zibo city (ShandongProvince China) respectively The components of DSS andclay were shown in Table 1 and the raw materials were driedat 105∘C for 4 h crushed in a ball mill sieved through a0154mm mesh and then stored in polyethylene vessels toavoid humidification before utilization

The utilized CTC industrial wastewater obtained from aCTC manufacturing factory in Hohhot city (Inner MongoliaAutonomous Region China) was mainly generated fromseparation and extraction processes of CTC equipmentrinsing processThemain water quality of the rawwastewaterand the national discharged standard (wastewater qualitystandards for discharge to municipal sewers C standard ofCJ 343-2010 China) are shown in Table 2 revealing thatthe wastewater quality was not stable and all indexes of thewastewater did not meet the national discharged standard Inthe wastewater treatment plant of this enterprise the utilizedwastewater treatment system mainly contained flocculationand precipitation upflow anaerobic sludge blanket (UASB)(two anaerobic reactors were connected in series) cyclicactivated sludge system (CASS) anoxicoxic activated sludge


















ME reactor


EGSB tank Effluent


reservoir







kgsdotmminus3


kgsdotmminus3



(2)





























(a) (b)


1 7654320

10

20

30

40

50


pH

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

40

50

60

70

80

90

100

CTC

rem

oval

effici

ency

()

(a)

1 2 3 4 5 6 7 810

15

20

25

30

35

40

45

50


HRT (h)

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

40

50

60

70

80

90

100

CTC

rem

oval

effici

ency

()

(b)






30

25

35

40

45

50

55

60


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

50

55

60

65

70

75

80

85

90

95

100

CTC

rem

oval

effici

ency

()

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70







20253035404550556065707580859095

100


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

00

05

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

OLR

(kgm

minus3dminus1)





100

200

300

400

500

600

700

800

900

1000


Operating time (d)

30

35

40

45

50

55

60

65

70

75

80

COD

cr re

mov

al effi

cien

cy (

)

0 5 10 15 20 25 30 35 40

COD

cr in

efflue

nt (m

gLminus1)







0 18 20 22 24161412108642200250300350400450500550600650700750800850900


Operating time (d)

81012141618202224262830323436384042444648

Am

mon

ia n

itrog

en in

influ

ent (

mg L

minus1)

Am

mon

ia n

itrog

en in

efflue

nt (m

g Lminus1)





4 Conclusions







Nomenclature


Competing Interests


Acknowledgments


References





































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


















ME reactor


EGSB tank Effluent


reservoir







kgsdotmminus3


kgsdotmminus3



(2)





























(a) (b)


1 7654320

10

20

30

40

50


pH

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

40

50

60

70

80

90

100

CTC

rem

oval

effici

ency

()

(a)

1 2 3 4 5 6 7 810

15

20

25

30

35

40

45

50


HRT (h)

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

40

50

60

70

80

90

100

CTC

rem

oval

effici

ency

()

(b)






30

25

35

40

45

50

55

60


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

50

55

60

65

70

75

80

85

90

95

100

CTC

rem

oval

effici

ency

()

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70







20253035404550556065707580859095

100


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

00

05

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

OLR

(kgm

minus3dminus1)





100

200

300

400

500

600

700

800

900

1000


Operating time (d)

30

35

40

45

50

55

60

65

70

75

80

COD

cr re

mov

al effi

cien

cy (

)

0 5 10 15 20 25 30 35 40

COD

cr in

efflue

nt (m

gLminus1)







0 18 20 22 24161412108642200250300350400450500550600650700750800850900


Operating time (d)

81012141618202224262830323436384042444648

Am

mon

ia n

itrog

en in

influ

ent (

mg L

minus1)

Am

mon

ia n

itrog

en in

efflue

nt (m

g Lminus1)





4 Conclusions







Nomenclature


Competing Interests


Acknowledgments


References





































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of






















(a) (b)


1 7654320

10

20

30

40

50


pH

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

40

50

60

70

80

90

100

CTC

rem

oval

effici

ency

()

(a)

1 2 3 4 5 6 7 810

15

20

25

30

35

40

45

50


HRT (h)

COD

cr re

mov

al effi

cien

cy (

)

0

10

20

30

40

50

60

70

80

90

100

CTC

rem

oval

effici

ency

()

(b)






30

25

35

40

45

50

55

60


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

50

55

60

65

70

75

80

85

90

95

100

CTC

rem

oval

effici

ency

()

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70







20253035404550556065707580859095

100


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

00

05

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

OLR

(kgm

minus3dminus1)





100

200

300

400

500

600

700

800

900

1000


Operating time (d)

30

35

40

45

50

55

60

65

70

75

80

COD

cr re

mov

al effi

cien

cy (

)

0 5 10 15 20 25 30 35 40

COD

cr in

efflue

nt (m

gLminus1)







0 18 20 22 24161412108642200250300350400450500550600650700750800850900


Operating time (d)

81012141618202224262830323436384042444648

Am

mon

ia n

itrog

en in

influ

ent (

mg L

minus1)

Am

mon

ia n

itrog

en in

efflue

nt (m

g Lminus1)





4 Conclusions







Nomenclature


Competing Interests


Acknowledgments


References





































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


30

25

35

40

45

50

55

60


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

50

55

60

65

70

75

80

85

90

95

100

CTC

rem

oval

effici

ency

()

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70







20253035404550556065707580859095

100


Operating time (d)

COD

cr re

mov

al effi

cien

cy (

)

00

05

10

15

20

25

30

35

40

45

50

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

OLR

(kgm

minus3dminus1)





100

200

300

400

500

600

700

800

900

1000


Operating time (d)

30

35

40

45

50

55

60

65

70

75

80

COD

cr re

mov

al effi

cien

cy (

)

0 5 10 15 20 25 30 35 40

COD

cr in

efflue

nt (m

gLminus1)







0 18 20 22 24161412108642200250300350400450500550600650700750800850900


Operating time (d)

81012141618202224262830323436384042444648

Am

mon

ia n

itrog

en in

influ

ent (

mg L

minus1)

Am

mon

ia n

itrog

en in

efflue

nt (m

g Lminus1)





4 Conclusions







Nomenclature


Competing Interests


Acknowledgments


References





































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


100

200

300

400

500

600

700

800

900

1000


Operating time (d)

30

35

40

45

50

55

60

65

70

75

80

COD

cr re

mov

al effi

cien

cy (

)

0 5 10 15 20 25 30 35 40

COD

cr in

efflue

nt (m

gLminus1)







0 18 20 22 24161412108642200250300350400450500550600650700750800850900


Operating time (d)

81012141618202224262830323436384042444648

Am

mon

ia n

itrog

en in

influ

ent (

mg L

minus1)

Am

mon

ia n

itrog

en in

efflue

nt (m

g Lminus1)





4 Conclusions







Nomenclature


Competing Interests


Acknowledgments


References





































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



Nomenclature


Competing Interests


Acknowledgments


References





































































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

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