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  • EuropeanJournalofChemistry3(4)(2012)480484

    EuropeanJournalofChemistryISSN21532249(Print)/ISSN21532257(Online)2012EURJCHEM

    DOI:10.5155/eurjchem.3.4.480484.698

    EuropeanJournalofChemistryJournalhomepage:www.eurjchem.com

    Thefateofleachateofpharmaceuticalslikeamoxicillin,ibuprofenandcaffeineinthesoilusingsoilcolumnsShehdehJodeha,*,HalimehStaitib,MarwanHaddadb,TamaraRennoc,AbdelnaserZaidc,NidalJaradatcandMaherKharoafdaChemistryDepartment,AnNajahNationalUniversity,Nablus,11347,PalestinebWaterandEnvironmentalInstitute,AnNajahNationalUniversity,Nablus,11347,PalestinecPharmacyDepartment,AnNajahNationalUniversity,Nablus,11347,PalestinedJerusalemPharmaceuticalCompany,Ramallah,11347,Palestine*Correspondingauthorat:ChemistryDepartment,AnNajahNationalUniversity,Nablus,11347,Palestine.Tel.:+970.59.959049;Fax:+970.59.2345982.Emailaddress:sjodeh@najah.edu(S.Jodeh).

    ARTICLEINFORMATION ABSTRACTReceived:30October2012Accepted:07November2012Online:31December2012

    KEYWORDS

    Fromanenvironmentalengineeringpointofview,pharmaceuticalssuchasantibioticsareagroup of manmade chemicals of concern entering the environment in concentrations atwhich,thehealtheffectsareunknown.Theproblemthatmaybecreatedbythepresenceofantibioticsatlowconcentrationsintheenvironmentisthedevelopmentofantibioticresistantmicroorganisms. In this study, three pharmaceutical drugsmanufactured in Palestinewerestudiedinwastewaterandtheiradsorptioninagriculturesoilwasstudiedusingsoilcolumns.During thestudyofsoil columns, itwasnoted that theconcentrationof caffeine in leachatewashigher than thatof ibuprofenandamoxicillin,ascaffeinehashigheraqueoussolubility.Ibuprofen and amoxicillinwere present in leachatewith very small concentrations, due totheir degradationanddecomposition into other substances thatmaybeharmful, andaffectthenaturalpropertiesofsoil,groundwaterandhumanhealth.Thedecompositionpercentagesof the pharmaceuticals in the soil columns were 97.82, 97.88 and 86.52% for amoxicillin,ibuprofen and caffeine for one years study, respectively. For the fifteen years, thedecomposition percentages were 94.04, 96.60 and 93.70% for amoxicillin, ibuprofen andcaffeine,respectively.

    KineticsLeachateAdsorptionPharmaceuticalsChemicaloxygendemand(COD)Biochemicaloxygendemand(BOD)

    1.Introduction

    Landfillleachatesareheavilyloadedwithdifferenttypesoforganic and inorganic contaminants and present amajor riskwithrespecttocontaminationofnaturalwaterresources[1].Inunprotectedlandfills,leachatesinfiltrateverticallythroughthevadose soil zone below the landfill and eventually reach thegroundwater aquifer, forming anaerobic plumes [2], that canpose a serious threat to drinking water resources [3]. Inlandfills, which include a leachate collection system, it ismandatorytotreatthecollectedleachatebeforeitsreleaseintoambientsurfacewaters.

    Newpharmaceuticalresiduesintheenvironment,andtheirpotential toxic effects, already have been recognized as anemerging research area in environmental chemistry [4]. Abetterknowledgeoftheoccurrenceandfateofpharmaceuticalsreleasetotheenvironmentwillattainaproperriskassessmentforriverbasins;wetlandsandothersrelatedecosystems[5].Itis nowwell established that pharmaceuticals are widespreadcontaminants of wastewater effluents [67], surface anddrinking waters, but limited publications are concerned withtheiroccurrenceinterrestrialecosystems[4].

    Drinking water for major areas in the world is producedfrom surface as well as groundwater. Filtering cannot beachieved for all pollutants, neither from surface to groundwater, nor from soils to streams or wells. Soil infiltration isbecomingmorecommonforwastewatereffluentsindevelopedcountriesasatertiarytreatmentprocessandawayofreusing

    waterasresourcesbecomescarcer[8].Theuseofwastewater,often untreated, to irrigate soils occurs widely in lessdevelopedcountriesandhasdonesoformanyyears[9].

    In different countries including Palestine, drugs and theirmetabolites have been repeatedly detected in ground andsurface waters and occasionally in drinking water [1012].After intake, the drugs ormetabolites are excreted and reachthe sewage plant through the sewage system. Because of theabsence of any specific absorption or degradation system,drugsandtheirmetabolitesreachthepondwaterandgroundwater [1012]. Further sources include the improper disposalof residual or outdated drugs through the sewage systems ofprivate households, and the improper disposal on dumps,whichpossiblybypassesthesewageplant.

    In general, most pharmaceuticals in the environment aretheresultofhumanexcretionbutalsopharmaceuticalsmaybefound in lowconcentrations in landfill leachate,discharged towastewater treatment plants. Although the science is limited,thismightsuggestthatlandfilldisposalofpharmaceuticalsmaybe a lowrisk practice. Wastewater treatment plants are notdesignedtoremovepharmaceuticals,sothisalsocanbeviewedas a minor pathway by which pharmaceuticals reach theenvironment.Accordingtoa2007report[13]preparedfortheOregonAssociationofCleanWaterAgencies,onlyafewstudiesprior to that date had examined concentrations of pharmaceutical compounds in leachate from lined landfills and all ofthose studies focused on landfills in countries other than theU.S.[14].Thereportconcludedthattheoreticalcalculationsand

  • Jodehetal./EuropeanJournalofChemistry3(4)(2012)480484 481

    field data suggest that drugs disposed of in municipal solidwaste landfills contribute only a small fraction (< 1%) of thetotal loadofpharmaceuticalcompoundsdischargedtosurfacewater viamunicipalwastewater treatment plants and landfillleachate treatment systems. In most developed countries,landfillsarenowequippedwithengineeredlinersandleachatecollectionsystemsinordertominimizetheadverseimpactsofleachateonthesurroundingenvironment[15].

    In this study three selected pharmaceutical productsmanufactured by major drug companies in Palestine werechosen, to study their presence in the wastewater of thosecompanies and to study their leachate in soil using a plasticpipescolumnsfilledwithagriculturesoil.Theobjectiveofthisstudy is to understand the fate of those drugs, wastepenetrating groundwater through soil using soil columns andadddifferentconcentrationsofthosedrugsinthecolumnsandcollect the leachates out of those columns. This will beexplainedindetailsinthemethodsandmaterialssection.2.Experimental

    The research experimental work basically depends ondetermining the concentration of residues of amoxicillin,ibuprofen, and caffeine (Scheme 1) versus time in soil, andleachate,whichisconsideredbythreeterms,Zeroterm,shortterm (one year), and longterm concentration (fifteen years)whichallofwhichwillbeexplainedlater.

    Amoxicillin

    (2S,5R,6R)6{[(2R)2amino2(4hydroxyphenyl)acetyl]amino}3,3dimethyl7oxo4thia1azabicyclo[3.2.0]heptane2carboxylicacid

    Ibuprofen

    (RS)2(4(2methylpropyl)phenyl)propanoicacid

    Caffeine

    1,3,7trimethyl1Hpurine2,6(3H,7H)dione

    Scheme12.1.Instrumentation

    HighPerformance Liquid Chromatography (HPLC)consisted of a Waters Millipore (Bedford, MA) 6000A pump,SpectraPhysics (San Jose, CA) 3000A automatic injector withcolumnheater,Waters/Millipore440dualfixedwavelengthUVdetector, Spectra PhysicsWinner data collection systemwith4270integratorandacolumnofWhatman10cmPartishere5

    C18mpacking. Theinjectionvolumeusedwas10Lwithaflowrateof1mL/min.Datawascollectedat254,230and256nmfor ibuprofen, amoxicillin, andcaffeine, respectively at2.5points/second.Column temperaturewas regulatedat30 oC, afewdegreesaboveambient temperature tostabilize retentiontime.2.2.Soilcolumnpreparation

    Seven columnsof Polyvinyl chloride (PVC) (15 x 100 cm)werepreparedafterfillingthemwithsievedsoil63mm.Allofthecolumnswerepreparedbyaddingdistilledwater throughthem to insure that there are no gaps or spaces between thesoilpieces.Thefirstcolumnwasusedasblankwhichhadonlysoil and distilled water. The second column represented oneyearsexpectationtoseewhatwillhappento thedrugafter itwas adsorbed by soil. The second and third columns werepolluted using amoxicillin contained at 50 mg/L, solutioncontaining0.2034 g for oneyear and3.054 g in4.0L for 15years.Usuallyweadd4litersof50mg/Lofamoxicillintothesoil in the column to study the adsorption and leachate. Thethird columnwasused for the studyof the adsorption for 15years, which is basically adding 4 liters of 750 mg/L ofamoxicillin and studying the adsorption and leachate. Thefourth column was polluted with Ibuprofen; a solutioncontaining0.2034gof Ibuprofen ina4.0L containerwith50mg/Lwaspreparedandaddedtothecolumn,thereforeitwaslabeled(ibuprofenoneyear).Thefifthcolumncontained3.054g of Ibuprofen powder in 4.0 L, contained 150 mg/L ofibuprofen and labeled ibuprofen 15 years. These labels arerelated with the study of the fate of pharmaceuticals in oneyearand15years,respectively.Thesixthandseventhcolumnswere polluted using caffeine of 50mg/L solutions containing0.2034 g for one year, and 3.054 g for 15years. After theadditionofpharmaceuticalstothecolumns,soilcolumnswereleftfor24hrstoensureacompleteadsorptionprocessonsoil.Ofcourseeachcolumnwaspreparedbyaddingdistilledwaterbeforeadditiondrugs towet thecolumnsandmakesure thattherewasnoairbetweensoilgranulesandthewaterrunningsmoothlyinthecolumns.

    In Palestine it rains an average of 43 days a year andweusedthisnumbertoaddthedrugstocolumn43timesandwecollected the leachate every 72 hours for HPLC analysis. Theleachateswerecentrifugedat1100gfor20min,andthen,thesupernatant solution was decanted, filtered through 0.45 mAcrodiskfilters,andstoredat4oCbeforeanalysisusingHPLC.At the end of the experiment, each soil columnwas cut intoeight parts (025, 2550, 5075, 75100, 100125, 125150,150175,175200cm).

    Thesoilwastakenoutandextractedwithdoubledeionizedwater (DDW) at 18 M resistivity. All pharmaceuticals andchemicalswerepurchasedfromtheSunCompanyinPalestineand all chemicals with of very high purity. The otherpharmaceutical materials (samples for studies) weremanufactured in Palestine (Beir Zeit, Dar Elshefa andJerusalemPharmaceuticalCompanies).

    All standard solutions used in the experiment wereanalytical reagent grade or of extra pure quality unlessotherwiseindicated.Allglasswareandplasticcontainersweresoaked overnight in 10% nitric acid and rinsed with DDWbeforetheywereusedforanalysis.2.3.HPLCscanningofamoxicillin

    FordetectionthewavelengthofpharmaceuticalsusingUVdetector, chemicals and reagents like acetonitrile solution,monobasic potassium phosphate, sodium hydroxide, distilledwater,and thepharmaceuticalswereused. In thisexperimentthreesolutionswereprepared:

    Mobile phase solution prepared from a diluent andacetonitrile (96:4), the diluent was a mixture of 6.9 g of

  • 482 Jodehetal./EuropeanJournalofChemistry3(4)(2012)480484monobasicpotassiumphosphatewith1000mLdistilledwater,adjustedwith45%NaOHsolutiontoapHof5.00.1.

    The standard solution was prepared by dissolving anaccurately weighed quantity of the pharmaceuticals to bestudied in diluents to obtain a solution having a knownconcentrationofabout1.2mg/mL(degassedbyultrasonicationbeforeuse).The retention timeandwavelength foreachdrugareshowninTable1.

    Table 1. Wavelengths and retention times for the pharmaceuticals usingHPLC.Drugname Wavelength(nm) Retentiontime(min)Amoxicillin 230 9.16Ibuprofen 254 2.00Caffeine 256 20.712.4.Calibrationcurves

    Standardcalibrationcurves foramoxicillin, ibuprofen,andcaffeine weremade by preparing a stock solution containing500 mg/L of ibuprofen, amoxicillin and caffeine as referencestandardsand then transferred into100mLvolumetric flasksof10,30,40,50and60mg/Lofeachcompound.Absorbancereadingswere recorded at 254nm for ibuprofen, 230nm foramoxicillin,andat256nmforcaffeine.3.Resultsanddiscussion3.1.Soiltests

    Samplesofredsoilwereanalyzedinordertoevaluatethesoil texture, moisture, pH value, and specific gravity. Table 2showstheresultsobtainedfromthesetests.

    From the table it was noticed that the silt percentage islarger than the clay and both organic carbon and organicmatterwere highwhich increased the adsorption capacity ofdrugs.

    Table 2. Soil specific gravity, pH, texture, and moisture for soil beforepollution.Soilproperties ResultSpecificgravity 2.34pH 7.14Clay,% 41Silt,% 71Moisturecontent,% 29Organiccarbon,% 7.34Organicmatter,% 10.363.2.Pollutedleachatewaterfromibuprofen,amoxicillin,andcaffeineanalysis

    Theleachatewaterthatflowedfromeachsoilcolumnwaskept in well closed High Density Polyethylene (HDPE)containersandstoredinrefrigeratorat7oCandthenanalyzedby HPLC. The absorbance readings were recorded, andconvertedtoconcentrations(mg/L)usingstandardcalibrationcurves.TheresultsareshowninFigure13forthethreedrugsand this data represents the kinetic study for the leachate inoneand15years,respectively.

    Fromtheresultsthathavebeenobtained,thespeedofflowofwaterinblankcolumnsismuchhigherthaninothercolumnswith added medications because of the lack soil correlationwithanyotheradditives.

    Hydrolysis of ibuprofen, amoxicillin, and caffeine inpollutedwaterfollowedfirstorderkineticsasprescribedintheplottedgraphs(Figure1,2and3).StraightlineswereobtainedafterplottingLn[A]vs.timeanditagreeswithpreviousstudies[1821].

    Asprescribed in Figure2. The concentrationmeasuredofibuprofeninpollutedwaterwasdecreasedamongtheoneyearand 15years columns, due to the limited mobility of thecompoundandrapiddegradation,andbecausethesoilusedin

    theexperimenthasapHof7.41.Ibuprofendissolvedinacidicmediamorethananyotherpharmaceuticals[18].

    Itwasnotedthatamoxicillinconcentrationsdecreasedlessdramaticallyandrapidlythanibuprofenduetoitsnature,asitdecomposesduringthefirst6hoursoftime[22].Whileitwasobserved that the concentrations of caffeine were obviouslylarger than both ibuprofen and amoxicillin, this is becausecaffeineisamorewatersolublecompound[23].

    Figure 1. Ln [A] versus time for polluted water flowed from amoxicillincolumnforoneandfifteenyears.

    Figure2. Ln[A]versustimeforpollutedwaterflowedfromibuprofen(oneyearandfifteenyears).

    Figure3. Ln [A]versus time forpollutedwater flowed fromcaffeine (oneyearandfifteenyears).

  • Jodehetal./EuropeanJournalofChemistry3(4)(2012)480484 483

    Table3.Massbalanceforamoxicillin,ibuprofenandcaffeine.

    Totalconcentrationinleachate(mg/L)/43days

    Totalconcentrationadsorbedonsoil(mg/L)/43days

    Decomposed(%)

    Amoxicillinoneyear2150(mg/L) 40.42 9.90 97.66Amoxicillin15year32,250(3.23%) 1213.46 706.92 94.04Ibuprofenoneyear2150(mg/L) 11.18 34.3 97.88Ibuprofen15year32,250(3.23%) 258.00 1161.00 96.60Caffeineoneyear2150(mg/L) 96.75 38.70 93.70Caffeine15year32,250(3.23%) 3010.00 1400 86.323.3.Distributionofpharmaceuticalinsoilcolumnsafterfinishingtheleachatestudy

    Afterfinishingtheleachatestudiesfromthecolumnsinoneyear and fifteen year studies, the columns were cutoff for 8equalpartsandarepresentativesampleofsoilwastakenfromeachpartasdescribedinSection2.2toseethedistributionofadsorptionineachlayerofthecolumns.

    Fromtheresultsofthispartofstudy, thepharmaceuticalswere distributed along the columns. Amoxicillin in one andfifteenyearssoilcolumns(Figure4and5),showedthehighestconcentrations in the region of 025 cm, and the amount ofamoxicillinwas rapidly decreased a...