Korean Chemical Engineering Research

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(1)Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005, pp. 153-160. Modified Fenton ReactionG Fenton-like Reaction ¿ô§ È£ oG ëÜ/ £?£ ã÷ K§ ;·. <ü g / (|S. †. K¬H/ dHàHê ÖQ C }¢ 17 ¸ ö ³ [¤, 2004¸ 12ö 30³ >). 133-791 (2004 8 25. A Study on Remediation of Explosives-Contaminated Soil/Ground Water using Modified Fenton Reaction and Fenton-like Reaction Jung-Wook Hur, Seung-Won Seo, Min-Kyoung Kim and Sung-Ho Kong† Department of Chemical Engineering, Hanyang University, 17, Haengdang-dong, Seongdong-gu, Seoul 133-791, Korea (Received 25 August 2004; accepted 30 December 2004). ß È. á Y×o TNT 1 ÁSJ fMõ .K dHJ s-,¬ íès IJk³ K Fenton reaction JÄ Ñ îg ÊûG. ,Ê Fenton reactiono o pH ®C s Í(2 Y« ÀÊ wõo pHÑ ¬K buffering capacityõ Í(Ê Àk³ JÄ « ÂuG. «Ñ O pHÑ ÁSJk³ Fenton reactions KO ¤ À 2 modified Fenton reactions á Y×Ñ JÄG. K, wõ K { s {«5 ¬U ÄWk³ {16( è@ Mdõ .K Fenton-like reaction JÄ ÍD Ñ ¬Gñ ]Gñ ÝI. Y×ê2 1 ,Ê Fenton reaction fMÁSo u 20QÑ á pH 3Ñ 93%« ä

(2) pH 7Ñ2 21%»s Ý. KI, TNT 1 ¤ÄU s-Ñ {«5ê 5Ü chelating agentõ ·½K Y×Ñ2 24QÑ ä á pH 7Ñ NTA-Fe Î Í 87%³ ÁS« Íß Î¤GÊ citrate-Fe 46%, EDTA-Fe 71%, oxalate-Fe 64%, acetate-Fe 37% ÎÎ fM ÁSs ÷É. K, TNT 1 ¤ÄU s-Ñ 3Ü { k³ Fenton-like reactions JÄK Î, pH 3Ñ 24QÑ á goethite 33%, hematite 40%, magnetite 40% s-ÁSs ÝÊ. pH 7¯ Î goethite 28%, hematite 34%, magnetiteÑ2 36% s-ÁSs Ý. jÍ, D« Î¤K chelating agent 3Üê 2Ü { s «Ä K ÞYs- Y×Ñ2 magenetite Î pH 7Ñ NTA 79%, oxalate 59%, EDTA 14% fMÁS« +_æÉÊ, hematite Î NTA 73%, oxalate 25% -Ê EDTA 19% s-ÁSs »É. ·Jk³ { ê modified fenton reaction ÞYs- Î s- ,Ñ Ù Ò¯Éõ eÝO Î ÁSJk³ TNT 1Ñ JÄî ¤ Às a k³ ,¬ê. Abstract − There have been large areas of soil contaminated with high levels of explosives. For this experimental work, 2,4,6-trinitrotoluene (TNT) was tested as a representative explosive contaminant of concern in both aqueous and soil samples and its removal was evaluated using three different chemical treatment methods: 1) the classical Fenton reaction which utilizes hydrogen peroxide (H2O2) and soluble iron at pH less than 3; 2) a modified Fenton reaction which utilizes chelating agents, H2O2, and soluble iron at pH 7; and 3) a Fenton-like process which utilizes iron minerals instead of soluble iron and H2O2, generating a hydroxyl radical. Using classic Fenton reaction, 93% of TNT was removed in 20 h at pH 3 (soil spiked with 300 mg/L of TNT, 3% H2O2 and 1mM Fe(III)), whereas 21% removed at pH 7. The modified Fenton reaction, using nitrilotriacetic acid (NTA), oxalate, ethylenediaminetetraacetic acid (EDTA), acetate and citrate as representative chelating agents, was tested with 3% H2O2 at pH 7 for 24 h. Results showed the TNT removal in the order of NTA, EDTA, oxalate, citrate and acetate, with the removal efficiency of 87%, 71%, 64%, 46%, and 37%, respectively, suggesting NTA as the most effective chelating agent. The Fenton-like reaction was performed with water contaminated with 100 mg/L TNT and soil contaminated with 300 mg/L TNT, respectively, using 3% H2O2 and such iron minerals as goethite, magnetite, and hematite. In the goethite-water system, 33% of TNT was removed at pH 3 whereas 28% removed at pH 7. In the magnetite-water system, 40% of TNT was removed at pH 3 whereas 36% † To. whom correspondence should be addressed. E-mail: [email protected]. ‡. « øéo K¬H/ é§, /¤ _¸s ,ÄGñ ·ÊæÉ5n. 153.

(3) Ç_Ïö9òö6Æ öà ,. 154. removed at pH 7. In the hematite-water system, 40% of TNT was removed at pH 3 whereas 34% removed at pH 7. For further experiments combining the modified Fenton reaction with the Fenton-like reaction, NTA, EDTA, and oxalate were selected with the natural iron minerals, magnetite and hematite at pH 7, based on the results from the modified Fenton reaction. As results, in case magnetite was used, 79%, 59%, and 14% of TNT was removed when NTA, oxalate, and EDTA used, respectively, whereas 73%, 25%, and 19% removed in case of hematite, when NTA, oxalate, and EDTA used, respectively. Key words: Modified Fenton Reaction, Fenton-Like Reaction, TNT, Chelating Agents, Neutral pH. 1.. C «. nT³ª öÇ dYí(nitroaromatic compounds, NACs)o °u, 0, yY Íf, u, u\ Ù K Ä³ ÄæÊ À´ ÆJk³ y® « ¿j ¬&æÊ À. U¾, duÍ fÆÑ À´ 2 «Q ço nT³ª öÇ dYí« cê é0³ ÄæÉk, ñ6 ÷¶Ñ K «K³ è@K h@J Mÿk³ ¯Gñ Éõª ³ KæÉÊ, ÉhÝDõ .K k åw Ù IJk³ L¬K « åQfGj Äæ´ @G¤ Ú s 1QE f. jÍ, f 2ó §ª¬M« ³û áÑ ñ6 hÍÑ ¤]O ÄO ¤ Ç 2 duÍÍ h Ñ Âj2 « Êsæ@ :o g·D, @G kß, 2 ôwÎ Ùk³ Dök³ 1« [dæÉ. nT³ª öÇ dYío dH gÆJk³ û~g íH³ O 4n¶, É « ãGñ Éõª³ öî Î ¯Ñ Ú @=ªÑ jJ¯ s k ÍD « À. ¬,J¯ duÍ³ ~ Íæ´ À2 2,4,6-trinitrotoluene(TNT)o Íß dê = nT³ ª öÇ dYí G÷«, É o Âh EPAÑ class c Ù èDíH³ ä_GÊ À. « íHo Â@í Eo ¯KÍ §¯Ñ ¬Gñ §¯ dHJ Ú KM « À2 frame-shift ¡«í H³ ÝÊæÊ Àk ³ 24íö 8 k³ 2 mg « TNT Í ·ñê jÍÑ Uß +wJí ÍQ Ò¤ KÆA êR(bone marrow fibrosis), y Ý, 9_ J¯ §¯~ù Ùs KèK2 õgêÍ ÝÊæ´ Àk[1], K, TNT @ àßÑ )z Ú DDõ 0Gñ TNTÑ ôê àß³É

(4) U Ñ hemoglobin ¡« è@G2 Ù 1)g Y« ÝÊê à À [2].

(5) g÷ TNT yÑ ~gíH É s @nÊ À´

(6) k³ Gw, D¤ Ú @=ªÑ 5s Ân[3]. «Q ço @=ªÑ ¬K Áê³ ¯Gñ Âh EPA(U.S. environmental protection agency)Ñ2 TNTõ Îs-¬ dYí(priority pollutants)³ ~Íg î-g 1Ê Àk[4], {Ä¤ TNT ¤HD go 0.002 mg/L «G³ ÄGj äfæÊ À. !¶ ÆË Qãê 8Ms .g TNT³ 1ê , @,¤Q @G¤õ _d O 1® « ¬&æÊ À. TNT2 PD ´sÒ dYí«³ « UK ~gõ .g *³Ò s- D¬« ½« ®gê. !¶ Ês-dD¬ (advanced oxidation processes, AOPs) «Äo DÑ Ñ TNT õ ~gO ¤ À2 *³Ò ¤«. «M õgÑ Ês- dD¬o catalytic ozonation[5], UV/ozone system[6], titanium dioxide (TiO )-mediated photocatalysis system[4,7]Q Fenton’s reagent[8] Ù õgÍ ¤}æÉ. á õgÑ2 TNTQ a yÑ@ íËs KíÊ ÁêJk ³ ~gGD .K örk³ AOPs Dr y G÷¯ Fenton’s reagent Äs JÄGñ ÝI. «2 in-situ injectionê pump and treat 2. ¤@¤ C43× C1 2005 2. D¬s ÄGñ 1ê @,¤Q @G¤õ s-G2) «Ä ÍD O O 4n¶ D AOPs Ëê2 - A[ 1ê s s -O ¤ À2 UVs Í@Ê À@O, DÊ Fenton äÑ o f Ml K@õ .g ®gæ´D o pH2 ßÑ @Jk³ JÄGD ´sÒ Y« À. !¶, y pHÑ o fMl s JÄQÿD .g chelating agentsõ ·½Gñ {«5 8_ s Q modified Fenton reaction JÄ ¤}G. j Í, DÊ Fenton ä JÄQ ás-ª¯ ydê_Ñ {« 5«

(7) {16@³ è@æ´@2 Ys Í@Ê À. !¶, á õgÑ2 ñ6 Í@ ÜÍ { s «ÄGñ Fenton-like reactions JÄWk³ {«5s ¬O ¤ À2 ÍD s 9Gg ÝI. «³, DÑ Y×ê 3Í@ ÜÍ dHJ s-Drs J ÄGñ ê êõ ¬³ Gñ ÎÎ ßYËs H& JÄQÿ Ê, ßÑ Íß ÁSJk³ JÄO ¤ À2 Drs íèGD . Gñ ÞYJ¯ Fenton reaction Y×s ¤}G. 2,4,6-Trinitrotolueneo h k³z ÉõJk³ è@æ@ :Ê f Æê ôº+ å+ Ê dYí«. TNT2 sulfuric acidQ nitric acid HYíê toluene ÆYk³ ¯g OË´D. «6K 2,4,6trinirotoluene ñ «ýk³2 symtrinitrotoluene, TNTQ 1-methyl2,4,6-trinitrotoluene« À. 2,4,6-trinirotoluene2 ÆJk³ ÄO ¤ Çk, du fÆ , ³D , ³D D Ú ß Ùk³ Ä ÄÍ fKJ«. Table 1o TNT í-,dHJ U s ÷. 1-1. Classic Fenton reaction Fenton[9]. «Â ñ ¸M Ñ g èê Fenton reactiono é b@ dà_Ñ Äæ´@Ê À. 1930¸¬Ñ HaberQ Weiss[10] Table 1. Summary of Physical-Chemical Properties of TNT CAS No. Molecular weight Color State. Melting point Boiling point Odor Solubility. 118-96-7 227.13 yellow-white Monoclinic needles 80.1 oC 240 oC Odorless 130 mg/L in water at 20 oC; soluble in aceton, benzene, alcohol and ether. Partition coefficients Log Kow 1.60; 2.2(measured), 2.7(estimated) Koc 300(estimated), 1,100(measured) Vapor pressure (at 20 oC) 1.99E-04 mmHg Henry’s Law constant (at 20 oC)4.57E-07 atm m3/mole Conversion factors 1 ppm=9.28 mg/m3 1 mg/m3=0.108 ppm Source: ATSDR (1995).

(8) Fenton. äs «ÄK @uÍ 1 /(G¤ I-. Ñ g Fenton reaction cdf³ fQê hydroxyl radical(OH·) o DáJk³ {ê ço RÑ è@æ´D.. 3. Fe2++H2O2. Fe3++OH·+OH−. (1). 2 4c ãtK df yÑ G÷«, standard 2 «Ê OH· ñ KD dYíê ä 2 u «[11]. KD dYí« ç« Êé O A OH·o ¤òÉ fM ä(H abstraction reaction) Eo MÉ ndJ Í ä(electrophilic addition reaction)s D}Q ¤ À. !¶ OH·2 «·Jk³ TNTQ ço nitro-substituted aromatics O 4n¶ chlorinated aromatic, alkeneê aliphaticsõ ¯WK K gK KD dYís dQÿ2 Dts Í@Ê À. Hydroxyl radical. redox potential(Eo) -2.8 Volts 109-1010 mol−1sec−1. s ÂK. !¶ { ,

(9) J«÷ [ñQÑ Ù« ä õ _G2 y®K ®Í ê. «6K Fenton-like reactiono DÊ M0J¯ s-DrÑ t Dæ´@2 Y¯

(10) { 16@ è@s Ls ¤ Àk, { ägJ¯ Ä« ÍDWÑ !¶ s-9Äs k«j O ¤ À. 2.. o ~gÁS« Íß Î¤GD2 G@O, ê d¤Ñ hydroxyl radicals è@QÿD .K ñkf¯ {«5 « 8_dæ2 pH2 3-4«Ê pH 5 « Ñ2 {« @ æ´ z Mæ³ d ät« ¿j ©´D. !¶ {«5s y pH òÑ 8_dQÿD .K örk³ {«5ê Wÿ ôf l [20]Ñ à3s &´ _ê EDTA, NTA, Oxalate Ù Ligandõ c½Gñ 9GJ 8_K {ôõ Gj GÊ, « {ô2 ¤ ÄU Ñ {«5ê ço ñk òOs ¤}Wk³ Fenton reaction lÄp.õ y pH(6-9) 2 « b@ Æ ¤ À [12]. ñ M õgÑ2 modified Fenton reaction à_ y df¯ hydroxyl radical(OH·)« k³ ÄæÉs ÎÝ, « ê_ yÑ @ æ2 hòf(superoxide anion(O ), hydroperoxide anion(HO ) Ù)Í QÑ ÊéG «Ë ÿäÑ g 1 ò fMÁSÑ s Âr ¤ À{s éÉ. Modified Fenton systemÑ2 «M R (1)Ñ hydroxyl radicals @ G2 ä «Ñ {ê ço ä« Ídê. H O +OH·3HO · +H O HO ·4H +O pKa=4.8 HO ·+O 3HO +O − 2. − 2. 2. 2. 2. +. 2 2. − 2. 2. − 2. − 2. 2. 1-3. Fenton-like reaction Fenton reaction. á Y×Ñ2 s 1ê Ñ JÄQ Î ³äJk³ 3-5% { « Äê. «õ «ÄG

(11) { 16@ è@s k³ ¤ Às ak³ D¬æ, fJk³ Þ« î ¤ Às ak³ D¬ê. { s {«5 ¬U ·½. ÄG2 örs ]GD .Gñ ¤ÄU Ñ goethite, hematite, magenetiteõ ÄK Fenton-like reactions ¤}G. «6K { s ÄK ñ6 Y×Ñ2 dä 2Í@ mechanism« f Qæ´ À. ~2 { {« õ4 «5 =³ äK 2 a«Ê, .~³2 { ,

(12) Ñ MÉGhÑ K Fentonlike reactionÑ g ä« D}ê2 Î«. Watts Ù[13]o ,

(13) ä« Î§GÊ GÊ, Kitajima Ù[14]o { äR s f8G. H O +S3OH· +OH +S ñD, S2 { ,

(14) «, S 2 { ,

(15) y dê @ò 2. 2. −. +. +. / ÷ Z tà. / ÷ á õgÑ Äê 2,4,6-trinitrotolueneo h z Þk³ hö z gk9¯s »´ (c)KdÑ g½GÊ, FeSO , FeCl , Fe (SO ) Q modified Fenton reaction Y×Ñ chelating agents³. Äê ethylenediaminetetraacetic acid(EDTA, 99%)2 Aldrich Co. (Milwaukee, USA) Ñ g½Gk, nitrilotriacetic acid(NTA, 99%)2 Acros , goethite(α-FeOOH), magnetite(Fe O ), hematite (Fe O ), 2-methyl-2-propanol(99.5%), chloroformo Aldrich Co.(Milwaukee, USA)Ñ g½G. K, hydrogen peroxide(35%), hexane (95%), sodium oxalate(99%)2 Junsei. Co.(Tokyo, Japan) Ñ g ½æÉÊ, sodium acetate trihydrate(98%)2 Shinyo Pure Chemical Co.(Osaka, Japan)³z g½ ÄæÉ. 2-2. / tà 2-2-1. ¯àk³ 1ê ¤ÄU Ú fÆ 2,4,6-trinitrotoluene íÑ ¬K ÄgÍ ¬Jk³ k³ 1s .g Äê Äk2 acetones ÄGk, _eK 1. õ b´cD .Gñ 10,000 mg-TNT/L-acetone stock solution s fÆGñ ÄGk, ¯à1 ¤ÄU Î stock solution s ð¨¤³ Gñ 100 mg-TNT/L-waterõ fÆG. ¯à 1 Î, òQ acetoneÑ TNTõ õ¯ á §tê HÖ Ñ 1Q á acetones ÉõQÆ QE 300 mg-TNT/kg-soils fÆ G. ¯à1s fÆQ ¬D yk³ 1í« Aèæ2 Î õ Æ Gñ ÝIk÷ Ñ ÍÍê TNT2 95% « «É. HÇ Y×Ñ Äê ¤ÄU fÆ2 millipore systems Ä Gñ 18 mΩ-cmb@ _dê Í¤õ ÄG. á Y×Ñ y®K ¡¤ y G÷¯ pH ÆQs .K ÄUo 1 N H SO Q 1 N NaOHõ ÄG. Î Y×o ¡~R äDÑ Y×Þk, jartesterõ «ÄGñ ÄUs èÙGj stirring Gñ cÉ. ¬Ækk³ HÇ control Y× ÄUo _dê Í¤Os ÄGñ fÆG . ³äJk³ ä« QÊê «á, ³_K ä QÑÑ b´ Î äD³z 5 ml samples »o á ã¯ H SO 50 µlõ ÍWk³ pHõ 2 «G³ Æ_Gñ H O õ ÄU Ñ 8_dQ k³ êd¤~g äs IGQZ. Sampleê ³K 5 ml f(hexane)õ ÍK á 2~Ñ vortex-mixerõ ÄGñ fQ ÄU« £~¾ [ñG´ G. «Rj ê TNT2 GC-ECDõ «Ä ~G. K, Äê y ~o ICP-MS õ «ÄG. 2-2-2. Classical Fenton reaction TNT M0J¯ Fenton äÑ .K ~g ÍD s e¯GD . K á Y×Ñ2 TNT³ 1ê ¤ÄU ÎQ ÎÑ ¬g ÎÎ Y×G. 2-1.. 4. 2. 1-2. Modified Fenton reaction Classical Fenton reaction. 155. 3. 4 3. 3. 4. 2 3. 2. 2. 4. 4. 2 2. Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(16) Ç_Ïö9òö6Æ öà ,. 156. Ë ¤ÄU¯ Î: TNT(100 mg-TNT/L-water)³ 1ê ¤ÄU Ñ Fe(II)Q Fe(III) s- ÁSs 9GGD .g 3 mM Fe(II) Q Fe(III)s ÎÎ 3 wt% H O Q c½Gñ pH 3ê 7Ñ Fenton äs D}QZ. Sampling QÑo ä QÊ á, ðDÑ2 Gj ä« D}æ³ 30~ .³ GÊ «á 1, 2, 3QÑ Ñ k³ Gk, HÇ Y×Ñ è³Gj Æ_æÉ. Ì ¯ Î: TNT(300 mg-TNT/kg-soil)³ 1ê Î K÷Í@³ 1ê 100 gÑ Fenton reagents(1 mM Fe(III)+3 wt% H O ) 400 mLõ c½Gñ äs QÊK á ³K QÑÑ b´ samples »´ ço örk³ G. 1ê Î Fe(III)2 ¯à1Ñ ôê 1í %ôÑ Áê Í À{« f8æÉk³ Fe(II) ¬U Fe(III)s ÄG[12]. 2-2-3. Modified Fenton reaction TNT(100 mg TNT/L water)³ 1ê ¤ÄUÑ Fe(II)ê «P2 chelating agents³ nitrilotriacetic acid(NTA), ethylenediaminetetraacetic acid(EDTA), sodium oxalate, sodium acetate, sodium citrateõ Ä G. ÎÎ chelating agents s- ÁSs <4ÝD .g pH 3, 7³ Æ_Gk, HÇ äQÑo 24QÑk³ G. ÎÎ {«5ê ligand Y92 3 mol : 9 mol³ Æ_G. 2-2-4. Fenton-like reaction Éõ Ñ2 u 5% { [15]« WKæ´ À2 ak³ <s À{k³ Fenton reactionÑ 1®K iron ion ¬U Ê 5% { (goethite, magnetite, hematite)k³ ·½Gk, H O 3 wt%õ c½Gñ Fenton-like reactions KG. 1ê ¤Ä U(100 mg-TNT/L-water) Î pH 3, 7Ñ 24QÑ 8 äQ E sampling QÑÑ !¶ samples Gñ ~G. 1ê (300 mg-TNT/kg-soil) Î pH 3Ñ 24QÑ 8 äQE samples »´ Gñ ~G. 2-2-5. Combining Fenton-like reaction and modified Fenton reaction á Y×Ñ2 Fenton-like reaction, modified Fenton reaction ßYs ÆYGñ ßÑ JÄ ÍDK s- Dr íès .Gñ { Y×s ¤}Gj æÉ. « Y×Ñ pH2 7³ Æ_Gk , {ñk2 5% { (magnetite, Hematite)s ÄGk, chelating agents2 NTA, EDTA -Ê oxalateõ ÄGk « A { ê ligand P92 1 : 3k³ ·½G. 1. 2 300 mg-TNT/kg-soils ÄGk, H O 2 3 wt%³ Gñ 24QÑ 8 äQZ. 2 2. 2. 2. 2. 2. Gñ ~g ÍD s e¯GD .g Y×G. Fig. 1(a)2 3 w/v% H O Q 3 mM ferrous ion(Fe(II))Q ferric ion(Fe(III))s ÎÎ { ñk³ Ä|s Î classical Fenton äÑ K TNT fM ÁSs ÷ a«. Fe(II) systemÑ2 pH 3Ñ 24Q Ñ 8 95% « TNT fM ÁSs Ý. Fe(III) systemÑ 2 ço QÑê ÆQÑ 83% ~gSs ÷É. Burbano Ù[16]o MTBE ~gÑ «Q 97K êõ îûG. 2 1QÑ «Ñ Fe(II) systemÑ MTBE fM ÁSo 97%¶Ê ÝÊG. Fe(II) systemê Fe(III) systemÑ pH 3Ñ 7³ Æ_Gs Î(Fig. 1(b)), TNT fM ÁSo 10% ÂOk³ IGj 4 . á Y×Ñ äD Ñ äo control äDÑQ ¿ j ó«Í ÇÉ. «2 pH 4 « Ñ ÄUk³z { ñkÍ z 2. 2. 2. 2. 2-3. Chemical analysis. ¤ÄUê Ñ 1ê TNT2 EPA Method 8330Ñ MGñ k³ G. TNT ~o EPA Method 8095Ñ g MÉ¯¢ ]D(electron capture detecter, ECD)Í ßôê HP-6890 Gas Chromatographyõ ÄGk, 0.53 µm(i.d)-6 m RTX-TNT columns ÄGÊ, oven ðD52 80 C« 9 5 2 180 Cb@2 10 C/min«Ê «á 30 C/mink³ 95 QE MÜ5õ 300 C³ G. hexane. o. o. o. o. o. 3.. / ûG Z +{. 3-1. Classical Fenton reaction. á Y×o TNT³ 1ê ¤ÄUÑ classical Fenton reactionÑ. ¤@¤ C43× C1 2005 2. Fig. 1. (a). The effect of Fe2+ or Fe3+ on degradation of TNT by Classical Fenton reagent. Initial TNT concentration of water was 100 mg-TNT/L-water. Reactions were conducted with 3% H2O2, and 3 mM Fe2+, or Fe3+ at pH 3, (b) The effect of Fe2+ or Fe3+ on degradation of TNT by classical Fenton reagent. Initial TNT concentration of water was 100 mg-TNT/L-water. Reactions were conducted with 3% H2O2, and 3 mM Fe2+, or Fe3+ at pH 7..

(17) Fenton. äs «ÄK @uÍ 1 /(G¤ I-. 157. Fig. 2. Effect of pHs on classical fenton degradation of TNT contaminated sand. Initial TNT concentration of sand was 300 mgTNT/kg-soil. Reactions were conducted with 3% H2O2, and 1 mM Fe3+ at pH 3 and 7.. Mæ´ H O Q äGñ OH·s @ Q ¤ ÇD AéÑ 1í Ñ ¬K fM ÁSs 4c ÝGj ê. TNT³ 1ê Î 3% H O Q 1 mM Fe(III)s pH 3 ê 7Ñ 21QÑ 8 äQ as Fig. 2Ñ ÷É. pH 3Ñ 2 93% fM ÁSs ÝÊ, pH 7Ñ2 41% ~gSs ÷ É. «2 Watts Ù[17] õgÑ 1ê PCP f MÍ pH 2-3Ñ { «5s «ÄK Fenton reagentÑ g ³´ û2 aê ³jK. K, Watts Ù[18]o batch Y×Ñ ôê hexachlorobenzene ~gõ DQÿD .g { «5ê H O õ «Ä ÍDG2 as éÉ. «6K Watts Ù[17-18] õg³z 1ê Ñ Fenton’s reagent JÄo Yf³ ÍD « Qo s- D¬»s ÷. 6÷ á Y×Ñ2 pH 3Ñ fM ÁSo | ÁSs Ý @O pH 7Ñ2 ÁS« Q« ÝG. «2 Yf Ñ pHõ 3 «G³ ©´X-2 ao ¬z~ buffering capacity AéÑ 4c ´sÒ ³«. K, pHõ c2 ao ñ ÞA «@ :2 Ë« KJk³ î ÍD « À´ «6K Ë @G¤³ «k³ ¯Gñ y éfÍ ¬&î ¤ À. «6 K «K³ g classical Fenton reagent in-situ s-2 YJk ³ ÍD « áG. 2. 2. 2 2. 2. 2. 3-2. Modified Fenton reaction. M0J¯ Fenton reaction pH Ê s ÞGD .Gñ ¤} ê modified Fenton reaction Y×s ¤}K ê2 { Fig. 3(a) Q Fig. 3(b)Ñ ÷É. Fig. 3(b)Ñ NTA-Fe ÎÑ2 pH 7 Ñ 87% fM ÁSs ÷ÉÊ, EDTA-Fe2 71%, oxalate-Fe 2 64%, citrate-Fe Î 46%, acetate-Fe2 37% fM ÁSs Ý. pH 3(Fig. 3(a))Ñ «Q 97K êõ ÷ ao ô dê { =2

(18) o pH p.Ñ l « ´÷2 as ÂK. !¶ { ê³z { ôdYí³ Ä ÍDK systemo NTAQ EDTA, oxalates ÄK Î«, «õ M0J¯. Fig. 3. (a) Degradation of TNT contaminated water with modified Fenton reaction as effected by chelator (NTA, citrate, EDTA, oxalate, acetate). Initial TNT concentration was 100 mg TNT/Lwater. Reactions were conducted with 3% H2O2, 3 mM Fe3+, and 9 mM chelator at pH 3, (b) Degradation of TNT contaminated water with modified Fenton reaction as effected by chelator (NTA, citrate, EDTA, oxalate, acetate). Initial TNT concentration was 100 mg TNT/L-water. Reactions were conducted with 3% H2O2,3 mM Fe3+, and 9 mM chelator at pH 7.. Ñ fMÁSê 9Gg Ý

(19) , Fig. 1Ñ Ý¯ ÁSJ¯ è@s y pH sb@ KO ¤ À{s e¯O ¤ ÀÉ. , y pH òÑ ÁêJ¯ TNT ~gÍ «P´H ¤ À{k³ DÊ Fenton ä Yk³ @Jê o pHÑ s- ÁSs Q ¤ À. Fenton reaction pH 7 hydroxyl radical. 3-3. Fenton-like reaction Fig. 4((a), (b)). 2 1ê ¤ÄU Î goethite-H O systemÑ pH 3¯ Î 33%, pH 7¯ Î 28% fMÁSs Ýk, hematite-H O system¯ Î pH 3³ A 40%, pH 7¯ Î 34%« . K, magnetite-H O systemÑ2 pH 3Ñ 40%, pH 7Ñ 2 2. 2 2. 2 2. Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(20) Ç_Ïö9òö6Æ öà ,. 158. Fig. 5. Destruction of TNT in soil by Fenton-like reaction using iron minerals (goethite, hematite, magnetite). Reactions were performed with 3% H2O2 and 5% iron minerals (goethite, magnetite, hematite) at pH 3.. «ÄGñ Fenton reactions KO ¤ À{k³ ßÑ Ý fJ¯ örk³ TNT fMÍ ÍDO ak³ e¯æÉ. 3-4. Combining Fenton-like reaction and modified Fenton reaction. ê modified Fenton reactions YK á D ro 1í s-Ñ À´ *³Ò [ öR«. DÊ Y×Ñ ÁêÍ e¯ê NTA, EDTA, oxalateõ chelating agents³ «Ä GÊ, { y ¤ÄUÑ TNT s-ÁS« I magnetiteQ hematiteõ «ÄGñ 1ê Ñ TNT s-Áêõ Æ G ñ ÝI. ÏI, { magnetiteõ «ÄK fMÁS Y×ê2 { Fig. 6(a)Ñ ÷É. ÎÎ pH 7Ñ NTA Î 79%, oxalate Î 59%, EDTA Î 14% TNT fMÍ ÍDW« e¯æÉ . K, Fig. 6(b)Ñ2 hematiteõ { ñk³ ÄK Î«, NTA 73%, oxalate 25% -Ê EDTA 19% s-ÁSs »É. !¶ á Y× ê2 Yf TNT³ 1ê ¤ÄU Ú Ñ À ´ êd¤Q chelating agents c½Ok³ DÊ Fenton ä Ñ o fMl K@õ .g ®gæ´D o pHõ ßÑ @Jk³ JÄGD ´sÒ Ys ÞGÊ y pHÑ o fMl s JÄO ¤ Àk, K Éõ Ñ ÊéG2 { s «ÄWk³ o TNT fMÁSs »s ÍD s e¯G . Fenton-like reaction. Fig. 4. (a) Destruction of TNT in water by Fenton-like reaction using iron minerals (goethite, hematite, magnetite). Reactions were performed with 3% H2O2 and 5% iron minerals (goethite, magnetite, hematite) at pH 3, (b) Destruction of TNT in water by Fenton-like reaction using iron minerals (goethite, hematite, magnetite). Reactions were performed with 3% H2O2 and 5% iron minerals (goethite, magnetite, hematite) at pH 7.. TNTÍ fMæÉ. Valentineê Miller[19]Ñ G

(21) goethite Î êd¤Q äÑ ¬K 2ó ¤2 0.0016M s « Kitajima Ù[14]Ñ G

(22) Hematite Î2 2ó ¤Í 0.037M s ¯ ak³ ÝÊGÊ À. G@O, á Y×Ñ goethiteH O system TNT s-ÁS« hematite-H O system Ý ©´@2 ao hematite Ú magnetite-H O systemsms ä ¤Q

(23) ´ ä _ªÑ s c2 ñ ®¯« À 2 ak³ ¶æ, á «Ñ ¬K Y×« D}î ª¢«. TNT³ 1ê Ñ2 pH 3³ A s-ÁSo goethite/H O systemÑ 28%, hematite/H O systemÑ 50%, magnetite/H O systemÑ 31% fM ÁSs Ý(Fig. 5). á Y× ê2 { (goethite, hematite, magnetite)ê êd ¤Q o ä AéÑ U {«5 Ä ÎÝ 1ò fM ÁS« ÂG@O, wõ Ñ ÊéG2 { s 36%. −1 −1. −1 −1. 2. 2. 2. 2. 2 2. 2 2. ¤@¤ C43× C1 2005 2. 2. 2. 2. 2. 4.. û «. Fenton reactions «ÄK duÍQ yk³ 1ê Ú @G¤õ s-G2 aÑ ¬g ¡~R Y×s K ê {ê ç o ·s »s ¤ ÀÉ. (1) Classic Fenton reactionÑ K ¤ÄUÑ 1ê TNT sÁSo pH 3Ñ 24QÑ Ñ 99%b@ fM ÁSs ÷,k 1ê ÎÑ2 93% fMÁSs Ý. «6K ê2.

(24) Fenton. äs «ÄK @uÍ 1 /(G¤ I-. 159. ê Fenton-like reactionÑ ê³z «Ës ÆYK õg2 Ñ {ñk³ magnetiteõ «ÄG Ê chelating agent³ NTAõ Ä|s Î TNT³ 1ê o 79% fM ÁSs Ýk hematiteõ {ñk³ ÄG s ÎÑ2 73% fMÁSs ÷,. !¶ á õg2 TNT ³ 1ê ¤ÄU Ú s ÁêJk³ s-GD .g Éõ Ê éæ´@2 { s ÄG Éõ pH buffering capacity õ ÞG o pH³ ¯K Éõ )gõ MKk³ G2 insitu treatmentÑ JÄ ÍDO ak³ D¬ê. (4) Modified Fenton reaction pH 7. +S. Fig. 6. (a) Combining Fenton-like reaction and modified Fenton reaction of contaminated soil. Initial TNT concentration was 300 mgTNT/kg-soil. Reactions were conducted with 3% H2O2, 3 mM magnetite and 9 mM chelating agents (NTA, oxalate, and EDTA) at pH 7 during 24 h, (b) Combining Fenton-like reaction and modified Fenton reaction of contaminated soil. Initial TNT concentration was 300 mg-TNT/kg-soil. Reactions were conducted with 3% H2O2, 3 mM hematite and 9 mM chelating agents (NTA, oxalate, and EDTA) at pH 7 during 24 h.. Ñ g duÍ s-ÍD s e¯QE c@O «2 Yf Ñ pHõ 3 «G³ ©´X-2 ao ¬z ~ buffering capacity AéÑ 4c ´sÒ ³«. (2) Modified Fenton reactionÑ K ¤ÄUÑ 1ê TNT2 chelating agent³ NTAõ Ä|s Î pH 7Ñ 24QÑ Ñ 87%b@ fM ÁSs ÷,. !¶ y pH òÑ Á êJ¯ TNT ~gÍ «P´H ¤ À{k³ DÊ Fenton ä Yk³ @Jê o pHÑ s- ÁSs Q ¤ À. (3) { (goethite, magnetite, hematite)s «ÄK Fenton-like reaction Î TNT³ 1ê Ñ pH 3Ñ 24QÑ 8 ä QZs A 9GJ o s- ÁSs Ý»s < ¤ ÀÉ. classic Fenton reaction. 1. Lachance, B., Robidoux, P. Y., Hawari, J., Ampleman, G., Thiboutot, S. and Sunahara, G. I., “Cytotoxic and Genotoxic Effects of Energetic Compounds on Bacterial and Mammalian Cells in Vitro,” Mutation Research., 444(1), 25-39(1999). 2. Sabbioni, G., Wei, J. and Liu, Y. Y., “Determination of Hemoglobin Adducts in Workers Exposed to 2,4,6-trinitrotoluene,” Journal of Chromatography B., 682(2), 243-248(1996). 3. Smock, L. A., Stoneburner, D. L. and Clark, J. R. “The Toxic Effects of Trinitrotoluene(TNT) and its Primary Degradation Products on two Species of Algae and the Fathead Minnow,” Water Res., 10(6), 537-543(1982). 4. Schmelling, D. C. and Gray, K. A., “Photocatalytic Transformation and Mineralization of 2,4,6-trinitrotoluene(TNT) in TiO2 Slurries,” Water Res., 29(1-2), 2651-2662(1995). 5. Lang, P. S., Ching, W. K., Willberg, D. M. and Hoffman, M. R., “Oxidative Degradation of 2,4,6-trinitrotoluene bt Ozone in an Electrohydraulic Discharge Reactor,” Environ. Sci. Tech., 32(20), 3142-3148(1998). 6. Peyton, G. R., Huang, F. Y., Burleson, J. L. and Glaze, W. H., “Destruction of Pollutions in Water with Ozone in Combination with Ultraviolet Radiation. 1. General Principles and Oxidation of Tetrachloroethlene,” Environ. Sci. Tech., 16(8), 448-453(1982). 7. Hess, T. F., Lewis, T. A., Crawford, R. L., Katamneni, S., Wells, J. H. and Watts, R. J., “Combined Photocatalytic and Fungal Treatment for the Destruction of 2,4,6-trinitrotoluene(TNT),” Water Res., 32(5), 1481-1491(1998). 8. Li, Z. M., Comfort, S. D. and Shea, P. J., “Destruction of 2,4,6Trinitrotoluene by Fenton Oxidation,” J. Environ. Qual., 26(2), 480-487(1997). 9. Fenton, H. J. H. “Oxidation of Tartatic Acid in Presence of Iron,” J. Chem. Soc., 65, 899-910(1894). 10. Haber, F. and Weiss, J., “The Catalytic Decomposition of Hydrogen Peroxide by Iron Salts,” Proc. Roy. Sot., London. Series A, 147, 332-351(1934). 11. Haag, W. R. and Yao, C. D. D., “Rate Constants for the Reaction of Hydroxyl Radicals with Several Drinking Water Contaminants,” Environ. Sci. Tech., 26(5), 1005-1013(1992). 12. Watts, R. J., Bottenberg, B. C., Hess, T. F., Jensen, M. D. and Teel, A. L., “Role of Reductants in the Enhanced Desorption and Transformation of Chloroaliphatic Compounds by Modified Fenton’s Reactions,” Environ. Sci. Technol., 33(19), 3432-3437(1999). 13. Watts, R. J., Jones, A. P., Chen, P. and Kenny, A., “Mineral-Catalyed Fenton-Like Oxidation of Sorbed Chlorobenzenes,” Water Environ. Res., 69(3), 269-275(1997). Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(25) 160. Ç_Ïö9òö6Æ öà ,. 14. Kitajima, N., Fukuzumi, S. and Ono, Y., “Formation of Superoxide ion During the Decomposition of Hydrogen Peroxide on Supported Metal Oxides,” J. Phys. Chem., 82(13), 1505-1510(1978). 15. Watts, R. J., Udell, M. D., Kong, S. H. and Leung, S. W., “Fenton-Like Soil Remediation Catalyzed by Naturally Occurring Iron Minerals,” Environ. Eng. Sci., 16(1), 93-103(1999). 16. Burbano, A. A., Dionysios, D. D., Richardson, T. L. and Suidan, M. T., “Degradation of MTBE Intermediates using Fentons Reagent,” J. Environ. Eng., 128(7), 799-805(2002). 17. Watts, R. J., Udell, M. D. and Rauch, P. A., “Treatment of Pentachlorophenol-Contaminated Soils using Fentons Reagent,”. ¤@¤ C43× C1 2005 2. Hazard. Waste. Hazard. Mater., 7(4), 335-345(1990). 18. Watts, R. J., Kong, S. H., Dippre, M. and Barnes, W. T., “Oxidation of Sorbed Hexachloroenzene in Soils using Catalyzed Hydrogen Peroxide,” J. Hazard. Mater., 39(1), 33-47(1994). 19. Valentine, R. L. and Miller, C. M., “Hydrogen Peroxide Decomposition and Quinoline Degradation in the Presence of Aquifer Material,” Water Res., 29(10), 2353(1995). 20. Sun, Y. and Pignatello, J. J., “Chemical Treatment of Pesticide Wastes. Evaluation of Fe(III) Chelates for Catalytic Hydrogen Peroxide Oxidation of 2,4-D at Circumneutral,” J. Agric. Food. Chem., 40(2), 322-327(1992)..

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