Degradation of Paracetamol in Aqueous Solution by ... - Cafet Innova

International Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-11101103Degradation of Paracetamol in Aqueous Solution byFenton Oxidation and Photo-Fenton OxidationProcesses using Iron from Laterite Soil as CatalystBASAVARAJU MANU and MAHAMOODDepartment of Civil Engineering, National Institute of Technology Karnataka-NITK,Surathkal, P.O. Srinivasanagar– 575025, Mangalore-D.K, INDIAEmail: bmanu@nitk.ac.in; riazmahamood@gmail.comAbstract: For the treatment of paracetamol in water, the photo-Fenton Oxidation processand Classic Fenton oxidation process have been demonstrated and found effective. An ironcatalyst extracted from lateritic soil is used to exhibit the degradation and mineralization ofparacetamol. Paracetamol reduction and chemical oxygen demand (COD) removal aremeasured as the objective functions to be maximized. The experimental conditions of thedegradation of paracetamol are optimized by Fenton process. the optimum conditionsobserved for 10 mg/L initial paracetamol concentration are influent pH 3, initial H 2 O 2 dosage30 mg/L, [paracetamol]/[H 2 O 2 ] ratio 1:3 (w/w) and [H 2 O 2 ] / [Laterite iron] ratio 30:0.75(w/w). At the optimum conditions, for 10 mg/L of initial paracetamol concentration , 76%paracetamol reduction and 69% COD removal by Fenton oxidation and 79% paracetamolreduction and 77% COD removal by UV-C Fenton process are observed in 120 minutesreaction time. At the above optimum conditions, HPLC analysis has demonstrated 100%removal of paracetamol for Fenton oxidation process in 240 minutes and for UV-C photo-Fenton process in 120 minutes. The methods are effective and they may be used in theparacetamol industry.Keywords: Degradation of paracetamol; Fenton oxidation; Laterite soil; Photo-Fentonoxidation; UV-C lightIntroduction:Many chemical treatment techniques havebeen emerged in the last few decades todegrade non-biodegradable organicpollutants. Among these treatmenttechniques, the advanced oxidationprocesses appear to be promising andreported to be effective for the degradationof pharmaceuticals in waters. AdvancedOxidation Processes (AOPs) have provedcapable of completely degrading thepharmaceuticals from aqueous solutions(Klavarioti et al. 2009). These Processes arebased on the generation of hydroxyl radical,which is a powerful oxidant. Among AOPs,Fenton and Photo-Fenton Oxidationprocesses have emerged as the mostpromising methods for the treatment oforganic non-biodegradable pollutants. In acomprehensive review, Neyens and Baeyens(2003) have indicated that the Fenton’sOxidation is very effective in the removal ofmany hazardous organic pollutants fromwater and wastewaters. The photo-Fentonreaction involves irradiation with solar or UVlight which significantly increases the rate ofpollutant degradation by photo reduction ofFe 3+ to Fe 2+ . Fenton’s reaction generateshydroxyl radicals and photo-Fentonreactions reduce the Fe 3+ to Fe 2+ , thusleading to production of additional OHradicals and continuous regeneration of Fe 2+in a catalytic way (Sun and Pignatello 1993).It is also observed that the additionalamounts of OH radicals are also producedfrom the direct photolysis of H 2 O 2 (Laat etal. 1999).Laterite soils are porous soil, coarse intexture and rich in minerals like iron,aluminum, manganese and titanium butpoor in nitrogen, phosphoric acid, potashand lime. These soils are composed of ironoxides and hydrated aluminum with smallquantities of silica, manganese and titaniumoxides. This soil is common in India andmany other parts of the world.#02041220 Copyright © 2011 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.

1104BASAVARAJU MANU and MAHAMOODParacetamol (4-hydroxyacetanilide or 4-acetamidephenol or acetaminophen orTylenol) is extensively used as analgesic andantipyretic drug. Paracetamol is found to bepresent in sewage treatment plant (STP)effluents up to a concentration of 6 µg/L(Ternes 1998), up to 10 µg/L in watersamples from natural sources in USA(Buxton and Kolpin 2002) and more than 65µg/L in the Tyne River, UK (Roberts andThomas 2006). However, consequent to thesteep increase in the usage, the productionof paracetamol has also been increasedmanifold all over the world and hence theconcentration of paracetamol may increasein the waters.The aim of the present investigation is tostudy the paracetamol degradation andchemical oxygen demand (COD) removalefficiencies by Fenton and Photo-Fentonprocesses using the iron extracted fromlaterite soil as catalyst. It is observed thatthe UV-C light enhanced both thedegradation and mineralization ofparacetamol in water over Fenton oxidationand laterite soil may be used as an alternatesource of iron in Fenton reagent.Materials and Methods:Materials:Paracetamol Extra pure (98% assay) ispurchased from SD Fine Chem. Ltd. (India).Hydrogen Peroxide (H 2 O 2 ) (50% w/w) andFerrous Sulfate (FeSO 4 .7H 2 O) are purchasedfrom Merck (India). The chemicals are usedas received in the Fenton’s OxidationProcess. Hydrochloric acid (HCl, Merck,India, 35% purity), Sulfuric acid (H 2 SO 4 ,Merck, India, 98% purity), Sodiumhydroxide (NaOH, Merck, India, 98%purity), are also used in the experiments.Methanol AR grade (Merck, India), SodiumPentanesulfonate AR grade (Merck, India)and Formic acid AR grade (Merck, India) areused in HPLC analysis. The iron from lateritesoil is extracted using procedure given byOlanipekun (2000). The simulatedparacetamol aqueous stock solution of 1000mg/L concentration is prepared every weekwith Millipore Elix-3 deionized water andstored in the dark at 4 o C.Experimental Procedure:The oxidation experiments are carried out atambient temperature (27±3 o C) in batchreactors. Initially, the reaction conditionslike pH, H 2 O 2 dosage, and [H 2 O 2 ] / [Fe 2+ ]ratio are optimized in the Fenton oxidationof paracetamol and the further Fenton andphoto-Fenton experiments are conductedwith the optimum conditions. The effect ofinitial paracetamol concentration on thedegradation and mineralization ofparacetamol by both Fenton oxidation andUV-C Fenton oxidation are evaluated andthe results are compared. Paracetamolsamples are analyzed using UV-Vis doublebeam spectrophotometer and highperformanceliquid chromatography (HPLC).All the Fenton and photo-Fentonexperiments are carried out in batchreactors. Figure 1 shows the photo-reactorconsists of enclosed chamber comprising areactor (2L volume), 8W UV-C Philips lampcovered with a quartz jacket and connectedto AC power, magnetic stirrer. A 1000 mLsolution of required paracetamolconcentration is prepared from the stockparacetamol solution and is taken in the 2-liter reactor. Appropriate amount of ironconcentration from the 1000 mg/L stocksolution, which has been freshly preparedfrom the extract of laterite soil, is added tothe reactor bath and stirred with magneticstirrer. The intrinsic pH of the wastewater is6.32 and the Initial pH 3 of the solutions ismaintained using 0.1 N H 2 S0 4 and 0.1NNaOH. Required amount of H 2 O 2 is added tothe reactor bath to initiate the reaction. Themixture of paracetamol solution andFenton’s reagent is stirred with magneticstirrer during treatment. The paracetamolsolution samples are taken out for analysisat pre-defined time intervals, filteredthrough 0.45-µm Millipore filter membranefor COD analysis, and filtered through a0.45-µm Millipore Syringe filter fordetermination of paracetamol concentrationby using UV-VIS Spectrophotometer andHPLC analysis.International Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-1110

Degradation of Paracetamol in Aqueous Solution by Fenton Oxidation andPhoto-Fenton Oxidation Processes using Iron from Laterite Soil as Catalyst1105Figure 1: Schematic Representationof the Photochemical ReactorAnalytical Methods:UV-VIS spectrum is recorded from 190 to500 nm using UV-VIS spectrophotometerand the absorbance peak of paracetamol isobserved to be at wavelength 243 nm. Theconcentration of paracetamol in the aqueoussolution at wavelength 243 nm is measuredimmediately after removal of samples fromthe reactor using the standard curve, whichhas already been calibrated with UV-VISdouble beam spectrophotometer. The pH ismeasured with a digital pH meter (Lovibond– pH 100). The COD of the samples isdetermined by closed reflux titrimetricmethod as per the procedure outlined in theStandard Methods (APHA 2005). The initialCOD before treatment is due to paracetamolin synthetic wastewater and the COD aftertreatment is due to residual paracetamol ifpresent and other reaction intermediates, ifany, present in the aqueous solution. FinalCOD is quantitatively corrected for hydrogenperoxide interference according to thecorrelation equation given by Kang et al.(1999). The Iron concentration is measuredby Thiocynate-colorimetric Method usingSpectrocolorimeter (PC Spectroll, Lovibond).The H 2 O 2 concentration is determined byiodometric titration method (Kolthoff 1920).HPLC analysis is carried out with reversedphaseJasco High Performance LiquidChromatograph fitted with Microbonda 5µm, 300 x 4.6 mm column at a temperatureof 30 o C and coupled with a Jasco UV-2075plus intelligent UV-VIS Photodiode arraydetector selected at 243 nm, controlledthrough Jasco Chromatography data system.The mobile phase employed for paracetamolis 0.1 mg/mL of Sodium Pentanesulfonate atflow rate of 1.5 mL/minute. Theparacetamol solution samples are injected atthe rate of 15 µL and acquisition time is setas 30 minutes.Results and Discussion:Fenton Oxidation Process:Effect of pH:The experiments are conducted at differentpH values varying from 2 to 5.5 with initialparacetamol concentration of 10 mg/L,[H 2 O 2 ] o 20 mg/L and [Fe 2+ ] o 2 mg/L. Theferrous sulfate is used as source of iron inthese experiments. The maximumparacetamol reduction and COD removal arefound to be 78% and 75% respectively atpH 3. The paracetamol removal efficienciesare less for the other values of pH.At pH 3, Paracetamol removal is maximumand it may be due to the formation of moreFe(OH) + which has much higher activitythan Fe 2+ in Fenton’s oxidation (Badawy andAli 2006). When pH > 3, oxidationefficiency rapidly decreases due to autodecompositionof H 2 O 2 affecting theproduction of OH radicals (Badawy and Ali2006) and deactivation of ferrous catalystwith the formation of ferric hydroxideprecipitates (Luis et al. 2009). When pH

1106BASAVARAJU MANU and MAHAMOODFigure 2: Variations in (a) Percent Paracetamol Reduction, (b) Percent COD Removal forvarying H 2 O 2 Dosage from 10-50 mg/L and varying [Laterite Iron] from0.25 to 1.25 mg/L, (pH 3, [Paracetamol] o 10 mg/L)The reaction (1) given below describes thecomplete mineralization of paracetamol inthe Fenton’s Oxidation process.C8H9NO2+ 21H2O2+ Fe(II ) → 8CO2+ 25H2O+ HNO3+ Fe(II ) (1)The quantity of hydrogen peroxide required,based on Stoichiometric conditions, for thecomplete mineralization of paracetamol is4.72 mg of H 2 O 2 per 1 mg of paracetamol.Stoichiometrically, 47.2 mg/L H 2 O 2 isrequired for the complete oxidation of 10mg/L of paracetamol. However, in thisFenton treatment with H 2 O 2 concentration of30 mg/L, the maximum paracetamolreduction and COD removal are observed.The results obtained for the removalefficiencies may be related to the incompletemineralization and the presence ofintermediates in the aqueous solution.Initially, the removal efficiency is increasedwith increase in H 2 O 2 concentration andfurther increase in the H 2 O 2 concentrationresults in increase of the residual H 2 O 2concentration. This is because of thescavenging of OH radicals with increase inthe H 2 O 2 concentration. It can be explainedby the fact that the very reactive OHradicals are consumed by H 2 O 2 that resultsin the generation of less reactive OOHradical and the hydroxyl radical is scavengedby the OH radical reaction with another OHradical to form water.The paracetamol reduction and CODremoval are increased up to 80% and 75%respectively with the addition of laterite ironto the solution. Figure 2(a) -2(b) shows thevariations in percent paracetamol reductionand COD removal under the differentconditions of the laterite iron and H 2 O 2maintaining pH of 3, reaction time of 24hours. The max paracetamol reduction andCOD removal are observed to be 80% and75% respectively at 0.75 mg/L laterite ironconcentration. These results are inagreement with the literature, where in anincrease in ferrous ion concentration ofFenton’s reagent increases OH radicalproduction and hence the degradation andmineralization (Yilmaz et al. 2010). It hasalso been observed that at higher lateriteiron concentrations the paracetamol andCOD removals are reduced. This may bedue to the iron ion inhibition that occurswhen high concentration of laterite iron ionsis present in the system and laterite ironions itself can react with OH radicalsresulting the scavenging of OH radical.International Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-1110

Degradation of Paracetamol in Aqueous Solution by Fenton Oxidation andPhoto-Fenton Oxidation Processes using Iron from Laterite Soil as Catalyst1107Effect of Initial Paracetamol Concentration:Figure 3: Variations in (a) Percent Paracetamol (PCM) Reduction and (b) Percent CODRemoval at [Paracetamol] o : [H 2 O 2 ] o : [Laterite Iron] o = 10:30:0.75 (w/w) , Fenton ProcessExperiments are conducted to study theeffect of initial paracetamol concentrationson the Fenton’s oxidation process by varyinginitial concentration from 10 - 50 mg/L for areaction time of 240 minutes. Theparacetamol reduction is increased and CODremoval is decreased with the increase ininitial concentration of paracetamol. Thisresult is comparable with the literature,where COD removal of pharmaceuticalwastewater by Fenton’s Oxidation is morefor the lower initial concentrations of drugsUV-C Fenton Oxidation Process:(Yilmaz et al. 2010). Figure 3 (a)-3(b)shows the variations in percent paracetamolreduction and COD removals at[paracetamol] o /[H 2 O 2 ] o ratio 1:3 (w/w)[H 2 O 2 ] o /[Laterite iron] o ratio 30:0.75 (w/w),pH 3 for 240 minutes of reaction time. 77%of paracetamol reduction and 71% of CODremoval are observed for 10 mg/L initialconcentration of paracetamol, at H 2 O 2 of 30mg/L, laterite iron of 0.75 mg/L in 240minutes of reaction time.Figure 4: Variations in (a) Percent Paracetamol (PCM) Removal and (b) Percent CODRemoval, UV-C Photo-Fenton Process, [PCM]: 10 – 50 mg/L [Paracetamol]o: [H 2 O 2 ] o: [Fe 2+ ] o= 10:30:0.75 (w/w), pH 3UV-Fenton experiments for the effect ofinitial paracetamol concentrations areconducted with paracetamol concentrationvarying from 10 mg/L to 50 mg/L, optimumratio of [paracetamol] o :[H 2 O 2 ] o :[lateriteiron] o ::10:30:0.75 (w/w), which has beenobserved in our studies with Fenton’soxidation, pH 3 and the UV irradiation timeInternational Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-1110

1108BASAVARAJU MANU and MAHAMOOD120 minutes. Figure 4 shows the variationsin percent paracetamol reduction and CODremovals at [paracetamol] o /[H 2 O 2 ] o ratio 1:3(w/w) [H 2 O 2 ] o /[Laterite iron] o ratio 30:0.75(w/w, pH 3 and 120 minutes of reactiontime. The paracetamol reduction and CODremoval are observed as 73% and 58%respectively in 5 minutes UV irradiationtime, whereas 79% of Paracetamolreduction and 77% of COD removal areobserved in 120 minutes of UV irradiationtime for 10 mg/L initial concentration ofparacetamol. With the increase inparacetamol concentration from 10 to 50mg/L, the drug degradation is increasedfrom 79% to 90% and the COD removal isdecreased to 42% from 77%. This result isin accordance with the literature, whereCOD removal of pharmaceutical wastewaterby UV-Fenton Oxidation is more for thelower initial concentrations of pollutant (Deviet al. 2009). This phenomenon of decreasein COD removal with increase in initialparacetamol concentration is associated withthe characteristics of UV visible absorptionspectrum of the paracetamol (λ max =243 nm)that is significant near 254 nm (UV-C light isused) and hence the solution with higherdrug concentration absorbs a moresignificant fraction of the emitted UV light at254 nm than that with a lower initialconcentration, as a result the number ofavailable photons decreases leading to adecrease in the formation of OH radicals(Feng et al. 2003).Comparison between Fenton and Photo-Fenton Process:By analyzing the results, it is observed thatthe paracetamol degradation efficiencies aremore in the case of UV-Fenton oxidationover the Fenton oxidation. Figure 5 showsthe comparison of (a) percent paracetamolreduction and (b) percent COD removalbetween Fenton oxidation and UV-Fentonoxidation. 3% more paracetamol reductionand 8% more COD removal are observed forUV-C photo-Fenton over Fenton oxidationfor 10 mg/L of initial paracetamolconcentration in 120 minutes reaction time.The reason for more degradation andmineralization of paracetamol may be due toregeneration of Fe 2+ ions in photo-Fentonoxidation and in turn production of more OHradicals which has mineralized moreamounts of parent drug and theintermediates formed in the reaction.Table 1: Comparison of the Literature Results with the Present StudyReferenceMethodResultsDegradation Mineralization Reaction timeAndreozzi et al. Ozonation 30% 120 min(2003)H 2 O 2 / UV 40% 120 minSires et al. (2006) Electrochemical98% 360 minSkoumal et al. (2006)83% 240 minDalmazio et al. (2008)90% 160 minTiO 2 /UVYang, et al., (2008) 95% 80 minIsariebel et al.(2009) Sonolysis 100% 39% 480 minPresent studyH 2 O 2 /lateriteiron100% 71% 240 minH 2 O 2 /lateriteiron/UV-C100% 77% 120 minThere are limited number of works reportedon the advanced oxidation of paracetamolby different methods (Andreozzi et al. 2003;Sires et al. 2006; Skoumal et al. 2006;Dalmazio et al. 2008; Yang et al. 2008;Isriebel et al. 2009) . The Table 1 consistsof the comparison of present study withsome important results in literature. In thepresent study, HPLC analysis hasdemonstrated 100% degradation ofparacetamol for photo-Fenton process in120minutes and for Fenton process in 240minutes. The corresponding COD removalsare observed to be 71% for Fenton processInternational Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-1110

Degradation of Paracetamol in Aqueous Solution by Fenton Oxidation andPhoto-Fenton Oxidation Processes using Iron from Laterite Soil as Catalyst1109in 240 minutes and 77% for photo-Fentonprocess in 120 minutes. As compared withprevious studies, the extent of thedegradation and mineralization in 120 minobtained in the present study are greaterthan the most of the literature studies dueto optimized conditions and UV-C lighteffectiveness in photo-Fenton oxidation.Figure 5: Comparison for (a) Percent Paracetamol (PCM) Removal and (b) Percent CODRemoval between Fenton and Photo-Fenton Processes, [Paracetamol]o: [H 2 O 2 ] o: [Fe 2+ ] o= 10:30:0.75 (w/w), [PCM] 10 mg/L, pH 3Conclusions:UV-C light enhanced the photo-Fentonoxidation of paracetamol and the process ismore efficient over Fenton oxidation. It isdemonstrated by the Fenton process thatthe optimum conditions to treat 10 mg/Lparacetamol concentration are pH 3, [H 2 O 2 ]30 mg/L, [laterite iron] 0.75 mg/L. At theoptimum conditions, for 10 mg/L of initialparacetamol concentration , 76%paracetamol reduction and 69% CODremoval by Fenton oxidation and 79%paracetamol reduction and 77% CODremoval by UV-C Fenton process areobserved in 120 minutes reaction time.HPLC analysis has demonstrated completedegradation of paracetamol for photo-Fenton process in 120minutes and forFenton process in 240 minutes. Ascompared to the works in literature, thepresent study is most effective indegradation and mineralization ofparacetamol. UV-Fenton process is observedto be an effective treatment method overFenton process for the removal ofparacetamol in aqueous solutions. Fenton’soxidation process may be applied in-situ forthe treatment of paracetamol in surfacewater, ground water and lateritic soils.Acknowledgements:The authors gratefully acknowledge theesteemed pharmaceutical company,SeQuent Scientific Limited, 120 A&B,Industrial area, Baikampady, NewMangalore, India, for their HPLC analyticalservices.References:[1] Andreozzi, R., Caprio, V., Marotta, R. &Vogna, D. (2003). Paracetamol oxidationfrom aqueous solutions by means ofozonation and H 2 O 2 /UV system. WaterRes. 37, 993-1004.[2] APHA, AWWA, WEF.(2005). Standardmethods for the Examination of Waterand Wastewater, 21 st ed., Washington,DC USA.[3] Badawy, M. I. & Ali, M. E. M. (2006).Fenton’s peroxidation and coagulationprocesses for the treatment of combinedindustrial and domestic wastewater. J.Hazard. Mater. 136, 961-966.[4] Buxton, H. & Kolpin, D.W. (2002).Pharmaceuticals, Hormones, and OtherOrganic Wastewater Contaminants inU.S. Streams, Fact Sheet FS-027-02,United States Geological Surveyhttp://toxics.usgs.gov/pubs/FS-027-02,(Accessed on April 22, 2010).International Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-1110

1110BASAVARAJU MANU and MAHAMOOD[5] Dalmazio, I., Alves, T.M.A. & Augusti, R.(2008). An Appraisal on the Degradationof Paracetamol by TiO 2 /UV System inAqueous Medium, Product Identificationby Gas Chromatography-MassSpectrometry (GC-MS). J. Braz. Chem.Soc. 19(1), 81-88.[6] Devi, G.L., Kumar, G.S. & Reddy, M.K.(2009). Photo Fenton like processFe 3+ /(NH 4 ) 2 S 2 O 8 /UV for the degradationof Di azo dye Congo red using low ironconcentration. Cent. Eur. J. Chem. 7,468-477.[7] Feng, J., Hu, X., Yue, P.L., Zhu, H.Y. &Lu, G.Q. (2003). Discoloration andmineralization of Reactive Red HE-3B byheterogeneous photo-Fenton reaction.Water Res. 37, 3776-3784.[8] Isariebel, Q.P., Carine, J.L., Javier,J.H.U., Marie, W.A. & Henri, D. (2009).Sonolysis of levodopa and Paracetamolin aqueous solutions. Ultrason.Sonochem. 16, 610-616.[9] Kang, Y.W., Cho, M.J. & Hwang, K.Y.(1999). Correction of Hydrogen Peroxideinterference on Standard ChemicalOxygen demand test. Water Res. 33(5),1247-1251.[10] Klavarioti, M., Mantzavinos, D. &Kassinos, D. (2009). Removal ofresidual pharmaceuticals from aqueoussystems by advanced oxidationprocesses - Review article. Environ. Int.35, 402-417.[11] Kolthoff, I.M. (1920). Chem Weekblad17: 197.[12] Laat, D.J., Gallard, H., Ancelin, S. &Legube, B. (1999). Comparative studyof the oxidation of atrazine and acetoneby H 2 O 2 /UV, Fe(III)/UV, Fe(III)/H 2 O 2 /UV and Fe(II) or Fe(III)/H 2 O 2 .Chemosphere. 39, 2693-2706.[13] Lucas, M. S. & Peres, J. A. (2006).Decolorization of the azo dye ReactiveBlack 5 by Fenton and photo-Fentonoxidation. Dyes and Pigm. 71, 236-244.[14] Luis, A. D., Lombranda, J. I., Varona, F.& Menendez, A. (2009). Kinetic Studyand hydrogen peroxide consumption ofphenolic compounds oxidation byFenton’s reagent. Korean. J. Chem.Eng. 26(1), 48-56.[15] Neyens, E. & Baeyens, J. (2003). Areview of classic Fenton’s peroxidationas an advanced oxidation technique. J.Hazard. Mater. 98, 33-50.[16] Olanipekun EO (2000) Kinetics ofleaching laterite. Int J Miner Process 60:9-14.[17] Roberts, P.H. & Thomas, K.V. (2006).Occurrence of selected pharmaceuticalsin wastewater effluent and surfacewaters of the lower Tyne catchment.Sci. Total Environ. 356(1-3), 143-153.[18] Sires, I., Garrido, J.A., Rodriguez, R.M.,Cabot, P.L., Centellas, F., Arias, C. &Brillas, E. (2006). ElectrochemicalDegradation of Paracetamol from Waterby Catalytic Action of Fe 2+ , Cu 2+ , andUVA Light on Electro generatedHydrogen Peroxide. J. Electrochem.Soc. 153(1), D1-D9.[19] Skoumal, M., Cabot, PL., Centellas, F.,Arias, C., Roderiguez, R.M., Garrio, J.A.& Brillas, E. (2006). Mineralization ofparacetamol by ozonation catalyzedwith Fe 2+ , Cu 2+ and UVA light. J. appl.Catal. 66, 228-240.[20] Sun, Y. & Pignatello, J.J. (1993).Photochemical reactions involved in thetotal mineralization of 2, 4-D byFe 3+ /H 2 O 2 /UV. Environ. Sci. Technol.27, 304-310.[21] Ternes, T.A. (1998). Occurrence ofdrugs in German Sewage TreatmentPlants and Rivers. Water Res. 32, 3245-3260.[22] Ternes, T.A., Joss, A. & Siegrist, H. (2004).Scrutinizing pharmaceuticals and PersonalCare Products in Wastewater Treatment.Environ. Sci. Technol. 392A-399A.[23] Troung, G.L., Laat, D.J. & Legue, B.(2004). Effect of chloride and sulfate onthe rate of oxidation of ferrous ion byH 2 O 2 . Water Res. 38, 2383.[24] Yang, L., Yu, L.E. & Ray. M.B. (2008).Degradation of paracetamol in aqueoussolutions by TiO 2 photo catalysis. WaterRes. 42, 3480-3488.[25] Yilmaz, T., Aygun, A., Berktay A. & Nas,B. (2010). Removal of COD and colourfrom young municipal landfill leachateby Fenton process. Environ. Technol.31(14), 1635-1640.International Journal of Earth Sciences and EngineeringISSN 0974-5904, Vol. 04, No. 06, December 2011, pp. 1103-1110