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Volumn 15, Issue 4, 2013, Pages

Reduction of hexavalent chromium with colloidal and supported palladium nanocatalysts

Author keywords

Catalytic reduction; Hexavalent chromium; Magnetic recycling; Palladium nanocatalyst

Indexed keywords

IRON OXIDES; MAGNETITE; NANOCATALYSTS; PALLADIUM; PALLADIUM COMPOUNDS; POLLUTION; RECYCLING; SYNTHESIS (CHEMICAL);

EID: 84875297733     PISSN: 13880764     EISSN: 1572896X     Source Type: Journal    
DOI: 10.1007/s11051-013-1593-6     Document Type: Article
Times cited : (19)

References (37)
  • 1
    • 0037201935 scopus 로고    scopus 로고
    • Cytotoxicity and oxidative mechanisms of different forms of chromium
    • DOI 10.1016/S0300-483X(02)00378-5, PII S0300483X02003785
    • Bagchi D, Stohs SJ, Downs BW, Bagchi M, Preuss HG (2002) Cytotoxicity and oxidative mechanisms of different forms of chromium. Toxicology 180:5-22. doi: 10.1016/S0300-483X(02)00378-5 (Pubitemid 35248089)
    • (2002) Toxicology , vol.180 , Issue.1 , pp. 5-22
    • Bagchi, D.1    Stohs, S.J.2    Downs, B.W.3    Bagchi, M.4    Preuss, H.G.5
  • 2
    • 73649129915 scopus 로고    scopus 로고
    • Pd supported on mesoporous activated carbons with high oxidation resistance as catalysts for toluene oxidation
    • 10.1016/j.apcatb.2009.10.015 1:CAS:528:DC%2BC3cXktVGmug%3D%3D 10.1016/j. apcatb.2009.10.015
    • Bedia J, Rosas J, Rodríguez-Mirasol J, Cordero T (2010) Pd supported on mesoporous activated carbons with high oxidation resistance as catalysts for toluene oxidation. Appl Catal B 94:8-18 10.1016/j. apcatb.2009.10.015
    • (2010) Appl Catal B , vol.94 , pp. 8-18
    • Bedia, J.1    Rosas, J.2    Rodríguez-Mirasol, J.3    Cordero, T.4
  • 3
    • 0031443113 scopus 로고    scopus 로고
    • In-situ remediation of Cr(VI)-contaminated groundwater using permeable reactive walls: Laboratory studies
    • DOI 10.1021/es960844b
    • Blowes DW, Ptacek CJ, Jambor JL (1997) In-situ remediation of Cr(VI)-contaminated groundwater using permeable reactive walls: laboratory studied. Environ Sci Technol 31:3348-3357. doi: 10.1021/es960844b (Pubitemid 28008181)
    • (1997) Environmental Science and Technology , vol.31 , Issue.12 , pp. 3348-3357
    • Blowes, D.W.1    Ptacek, C.J.2    Jambor, J.L.3
  • 4
    • 0033839580 scopus 로고    scopus 로고
    • Treatment of inorganic contaminants using permeable reactive barriers
    • 10.1016/S0169-7722(00)00122-4 10.1016/S0169-7722(00)00122-4 1:CAS:528:DC%2BD3cXmtVamsb8%3D
    • Blowes DW, Ptacek CJ, Benner SG, McRae CWT, Bennett TA, Puls RW (2000) Treatment of inorganic contaminants using permeable reactive barriers. J Contam Hydrol 45:123-137. doi: 10.1016/S0169-7722(00)00122-4
    • (2000) J Contam Hydrol , vol.45 , pp. 123-137
    • Blowes, D.W.1    Ptacek, C.J.2    Benner, S.G.3    McRae, C.W.T.4    Bennett, T.A.5    Puls, R.W.6
  • 5
    • 0042842458 scopus 로고    scopus 로고
    • Applications of surfactant-modified zeolites to environmental remediation
    • DOI 10.1016/S1387-1811(03)00354-8
    • Bowman RS (2003) Applications of surfactant-modified zeolites to environmental remediation. Microporous and Mesoporous Mater 61:43-56. doi: 10.1016/S1387-1811(03)00354-8 (Pubitemid 36911045)
    • (2003) Microporous and Mesoporous Materials , vol.61 , Issue.1-3 , pp. 43-56
    • Bowman, R.S.1
  • 6
    • 0030951489 scopus 로고    scopus 로고
    • Kinetics and pH dependence of chromium(VI) reduction by iron(II)
    • DOI 10.1021/es960672i
    • Buerge IJ, Hug SJ (1997) Kinetics and pH dependence of chromium(VI) reduction by Iron(II). Environ Sci Technol 31:1426-1432. doi: 10.1021/es960672i (Pubitemid 27194514)
    • (1997) Environmental Science and Technology , vol.31 , Issue.5 , pp. 1426-1432
    • Buerge, I.J.1    Hug, S.J.2
  • 7
    • 77950919866 scopus 로고    scopus 로고
    • 4/silica nanocomposite microspheres with embedded structures via a direct solution-based route
    • 10.1016/j.jallcom.2010.03.16 10.1016/j.jallcom.2010.03.016 1:CAS:528:DC%2BC3cXlt1Sgt70%3D
    • 4/silica nanocomposite microspheres with embedded structures via a direct solution-based route. J Alloys Compd 497:221-227. doi: 10.1016/j.jallcom.2010.03.16
    • (2010) J Alloys Compd , vol.497 , pp. 221-227
    • Chen, L.1    Xu, Z.2    Dai, H.3    Zhang, S.4
  • 8
    • 74249086661 scopus 로고    scopus 로고
    • Removal of Cr(VI) from simulative contaminated groundwater by iron metal
    • 10.1016/j.psep.2009.07.001 10.1016/j.psep.2009.07.001 1:CAS:528:DC%2BD1MXhsVSktbjN
    • Cissoko N, Zhang Z, Zhang J, Xu X (2009) Removal of Cr(VI) from simulative contaminated groundwater by iron metal. Proc Saf Environ Prot 87:395-400. doi: 10.1016/j.psep.2009.07.001
    • (2009) Proc Saf Environ Prot , vol.87 , pp. 395-400
    • Cissoko, N.1    Zhang, Z.2    Zhang, J.3    Xu, X.4
  • 9
    • 33644990108 scopus 로고    scopus 로고
    • Toxicity and carcinogenicity of chromium compounds in humans
    • 10.1080/10408440500534032 10.1080/10408440500534032 1:CAS:528: DC%2BD28XisVaku7k%3D
    • Costa M, Klein CB (2006) Toxicity and carcinogenicity of chromium compounds in humans. Crit Rev Toxicol 36:155-163. doi: 10.1080/10408440500534032
    • (2006) Crit Rev Toxicol , vol.36 , pp. 155-163
    • Costa, M.1    Klein, C.B.2
  • 10
    • 42149164892 scopus 로고    scopus 로고
    • Palladium-indium catalyzed reduction of N-nitrosodimethylamine: Indium as a promoter metal
    • DOI 10.1021/es7023115
    • Davie MG, Shih K, Pacheco FA, Leckie JO, Reinhard M (2008) Palladium-indium catalyzed reduction of N-nitrosodimethylamine: indium as a promoter metal. Environ Sci Technol 42:3040-3046. doi: 10.1021/es7023115 (Pubitemid 351536951)
    • (2008) Environmental Science and Technology , vol.42 , Issue.8 , pp. 3040-3046
    • Davie, M.G.1    Shih, K.2    Pacheco, F.A.3    Leckie, J.O.4    Reinhard, M.5
  • 11
    • 19944382223 scopus 로고    scopus 로고
    • Chromium(III) complexes as intermolecular probes
    • DOI 10.1016/j.jmr.2005.03.017, PII S109078070500114X
    • Diakova G, Fuller Z, Victor K, Fumino K, Bryant RG (2005) Chromium(III) complexes as intermolecular probes. J Magn Reson 175:65-72. doi: 10.1016/j.jmr.2005.03.017 (Pubitemid 40753508)
    • (2005) Journal of Magnetic Resonance , vol.175 , Issue.1 , pp. 65-72
    • Diakova, G.1    Fuller, Z.2    Victor, K.3    Fumino, K.4    Bryant, R.G.5
  • 12
    • 35448942612 scopus 로고    scopus 로고
    • Promoting effect of electroactive polymer supports on the catalytic performances of palladium-based catalysts for nitrite reduction in water
    • DOI 10.1016/j.apcatb.2007.06.002, PII S0926337307001786
    • Dodouche I, Epron F (2007) Promoting effect of electroactive polymer support on the catalytic performances of palladium-based catalysts for nitrite reduction in water. Appl Catal B 76:291-299. doi: 10.1016/j.apcatb.2007.06.002 (Pubitemid 47633914)
    • (2007) Applied Catalysis B: Environmental , vol.76 , Issue.3-4 , pp. 291-299
    • Dodouche, I.1    Epron, F.2
  • 13
    • 0037239866 scopus 로고    scopus 로고
    • Reduction of chromium (VI) by the indirect action of Thiobacillus thioparus
    • 10.1590/S0104-66322003000100013 10.1590/S0104-66322003000100013 1:CAS:528:DC%2BD3sXhtFGlu7g%3D
    • Donati E, Oliver C, Curutchet G (2003) Reduction of chromium (VI) by the indirect action of Thiobacillus thioparus. Braz J Chem Eng 20:69-73. doi: 10.1590/S0104-66322003000100013
    • (2003) Braz J Chem Eng , vol.20 , pp. 69-73
    • Donati, E.1    Oliver, C.2    Curutchet, G.3
  • 14
    • 0346457752 scopus 로고    scopus 로고
    • Cage effects upon light irradiation on azo compounds: Cis → trans isomerization in polymethyl methacrylate
    • 10.1016/S1010-6030(99)00022-2 10.1016/S1010-6030(99)00022-2 1:CAS:528:DyaK1MXis1aqtbY%3D
    • Grebenkin SY, Bolshakov B (1999) Cage effects upon light irradiation on azo compounds: cis → trans isomerization in polymethyl methacrylate. J Photochem Photobiol, A 122:205-209. doi: 10.1016/S1010-6030(99)00022-2
    • (1999) J Photochem Photobiol, A , vol.122 , pp. 205-209
    • Grebenkin, S.Y.1    Bolshakov, B.2
  • 15
    • 77951037862 scopus 로고    scopus 로고
    • Synthesis and characterization of colloidal-supported metal nanoparticles as potential intermediate nanocatalysts
    • 0.1021/jp100061a 10.1021/jp100061a 1:CAS:528:DC%2BC3cXjs1Oht70%3D
    • Gude K, Narayanan R (2010) Synthesis and characterization of colloidal-supported metal nanoparticles as potential intermediate nanocatalysts. J Phys Chem C 114:6356-6362. doi: 0.1021/jp100061a
    • (2010) J Phys Chem C , vol.114 , pp. 6356-6362
    • Gude, K.1    Narayanan, R.2
  • 16
    • 77952547189 scopus 로고    scopus 로고
    • Hexavalent chromium removal from near natural water by copper-iron bimetallic particles
    • 10.1016/j.waters.2010.02.037 10.1016/j.watres.2010.02.037 1:CAS:528:DC%2BC3cXlsVKhurY%3D
    • Hu CY, Lo SL, Liou YH, Hsu YW, Shih K, Lin CJ (2010) Hexavalent chromium removal from near natural water by copper-iron bimetallic particles. Water Res 44:3101-3108. doi: 10.1016/j.waters.2010.02.037
    • (2010) Water Res , vol.44 , pp. 3101-3108
    • Hu, C.Y.1    Lo, S.L.2    Liou, Y.H.3    Hsu, Y.W.4    Shih, K.5    Lin, C.J.6
  • 17
    • 0027241680 scopus 로고
    • The toxicology of chromium with respect to its chemical speciation: A review
    • DOI 10.1002/jat.2550130314
    • Katz SA, Salem H (1993) The toxicology of chromium with respect to its chemical speciation: a review. J Appl Toxicol 13:217-224. doi: 10.1002/jat.2550130314 (Pubitemid 23151262)
    • (1993) Journal of Applied Toxicology , vol.13 , Issue.3 , pp. 217-224
    • Katz, S.A.1    Salem, H.2
  • 18
    • 0033983874 scopus 로고    scopus 로고
    • Chromium occurrence in the environment and methods of its speciation
    • DOI 10.1016/S0269-7491(99)00168-2, PII S0269749199001682
    • KotaÅ J, Stasicka Z (2000) Chromium occurrence in the environment and methods of speciation. Environ Pollut 107:263-283. doi: 10.1016/S0269- 7491(99)00168-2 (Pubitemid 30050582)
    • (2000) Environmental Pollution , vol.107 , Issue.3 , pp. 263-283
    • Kotas, J.1    Stasicka, Z.2
  • 19
    • 39649123718 scopus 로고    scopus 로고
    • Removal of chromium (VI) by acid-washed zero-valent iron under various groundwater geochemistry conditions
    • DOI 10.1021/es071572n
    • Lai KCK, Lo IMC (2008) Removal of chromium (VI) by acid-washed zero-valent iron under various groundwater geochemistry conditions. Environ Sci Technol 2:1238-1244. doi: 10.1021/es071572n (Pubitemid 351287186)
    • (2008) Environmental Science and Technology , vol.42 , Issue.4 , pp. 1238-1244
    • Lai, K.C.K.1    Lo, I.M.C.2
  • 20
    • 39749134976 scopus 로고    scopus 로고
    • 6+ by citric acid
    • DOI 10.1016/j.chemosphere.2007.10.010, PII S0045653507012593
    • 6+ by citric acid. Chemosphere 71:781-787. doi: 10.1016/j.chemosphere.2007.10.010 (Pubitemid 351312207)
    • (2008) Chemosphere , vol.71 , Issue.4 , pp. 781-787
    • Lan, Y.1    Li, C.2    Mao, J.3    Sun, J.4
  • 21
    • 77956378520 scopus 로고    scopus 로고
    • 4 catalyst prepared by co-precipitation: Metal-support interaction and excellent intrinsic activity
    • 10.1016/j.jcat.2010.07.014 10.1016/j.jcat.2010.07.014 1:CAS:528:DC%2BC3cXhtV2gsb%2FK
    • 4 catalyst prepared by co-precipitation: metal-support interaction and excellent intrinsic activity. J Catal 274:287-295. doi: 10.1016/j.jcat.2010.07.014
    • (2010) J Catal , vol.274 , pp. 287-295
    • Liu, J.1    Sun, B.2    Hu, J.3    Pei, Y.4    Li, H.5    Qiao, M.6
  • 22
    • 0036827286 scopus 로고    scopus 로고
    • Sonolytic degradation of methyl tert-butyl ether: The role of coupled fenton process and persulphate ion
    • DOI 10.1016/S0043-1354(02)00211-7, PII S0043135402002117
    • Neppolian B, Jun Choi H, Lee JH, Kang JW (2002) Sonolytic degradation of methyl tert-butyl ether: the role of coupled fenton process and persulphate ion. Water Res 36:4699-4708. doi: 10.1016/S0043-1354(02)00211-7 (Pubitemid 35341101)
    • (2002) Water Research , vol.36 , Issue.19 , pp. 4699-4708
    • Neppolian, B.1    Jung, H.2    Choi, H.3    Lee, J.H.4    Kang, J.-W.5
  • 23
    • 34948878573 scopus 로고    scopus 로고
    • Palladium nanoparticles for catalytic reduction of Cr(VI) using formic acid
    • DOI 10.1016/j.apcatb.2007.05.018, PII S0926337307001580
    • Omole MA, K'Owino IO, Sadik OA (2007) Palladium nanoparticles for catalytic reduction of Cr(VI) using formic acid. Appl Catal B 76:158-167. doi: 10.1016/j.apcatb.2007.05.018 (Pubitemid 47532702)
    • (2007) Applied Catalysis B: Environmental , vol.76 , Issue.1-2 , pp. 158-167
    • Omole, M.A.1    K'Owino, I.O.2    Sadik, O.A.3
  • 24
    • 79955915482 scopus 로고    scopus 로고
    • Magnetically recoverable nanocatalysts
    • 10.1021/cr100230z 10.1021/cr100230z 1:CAS:528:DC%2BC3MXjtFektro%3D
    • Polshettiwar V, Luque R, Fihri A, Zhu H, Bouhrara M, Basset JM (2011) Magnetically recoverable nanocatalysts. Chem Rev 111:3036-3075. doi: 10.1021/cr100230z
    • (2011) Chem Rev , vol.111 , pp. 3036-3075
    • Polshettiwar, V.1    Luque, R.2    Fihri, A.3    Zhu, H.4    Bouhrara, M.5    Basset, J.M.6
  • 25
    • 0029412090 scopus 로고
    • Coupled iron corrosion and chromate reduction mechanisms for subsurface remediation
    • 10.1021/es00008a008 10.1021/es00008a008 1:CAS:528:DyaK2MXmsFClu7Y%3D
    • Powell RM, Puls RW, Hightower SK, Sabatini DA (1995) Coupled iron corrosion and chromate reduction mechanisms for subsurface remediation. Environ Sci Technol 29:1913-1922. doi: 10.1021/es00008a008
    • (1995) Environ Sci Technol , vol.29 , pp. 1913-1922
    • Powell, R.M.1    Puls, R.W.2    Hightower, S.K.3    Sabatini, D.A.4
  • 27
    • 0032076133 scopus 로고    scopus 로고
    • Mercury levels along the food chain and risk for exposed populations
    • DOI 10.1006/enrs.1998.3832
    • Renzoni A, Zino F, Franchi E (1998) Mercury levels along the food chain and risk for exposed populations. Environ Res 77:68-72. doi: 10.1006/enrs.1998.3832 (Pubitemid 28243878)
    • (1998) Environmental Research , vol.77 , Issue.2 , pp. 68-72
    • Renzoni, A.1    Zino, F.2    Franchi, E.3
  • 28
    • 67649771479 scopus 로고    scopus 로고
    • Reduction of hexavalent chromium mediated by micro- and nano-sized mixed metallic articles
    • 10.1016/j.jhazmat.2009.04.062 10.1016/j.jhazmat.2009.04.062 1:CAS:528:DC%2BD1MXotlOqsb8%3D
    • Rivero-Huguet M, Marshall WD (2009) Reduction of hexavalent chromium mediated by micro- and nano-sized mixed metallic articles. J Hazard Mater 169:1081-1087. doi: 10.1016/j.jhazmat.2009.04.062
    • (2009) J Hazard Mater , vol.169 , pp. 1081-1087
    • Rivero-Huguet, M.1    Marshall, W.D.2
  • 29
    • 0029394792 scopus 로고
    • Hexavalent chromium removal in two-stage bioreactor system
    • 10.1061/(ASCE)0733-9372(1995)121:11(798 10.1061/(ASCE)0733-9372(1995)121: 11(798) 1:CAS:528:DyaK2MXoslegurk%3D
    • Shen H, Wang YT (1995) Hexavalent chromium removal in two-stage bioreactor system. J Environ Eng 121:798-804. doi: 10.1061/(ASCE)0733-9372(1995) 121:11(798
    • (1995) J Environ Eng , vol.121 , pp. 798-804
    • Shen, H.1    Wang, Y.T.2
  • 30
    • 0034665927 scopus 로고    scopus 로고
    • Preparation and catalytic properties of amphiphilic copolymer-stabilized platinum metals colloids
    • 10.1006/jcis.2000.7041 10.1006/jcis.2000.7041 1:CAS:528: DC%2BD3cXmtlOrsL8%3D
    • Tu W, Liu H, Liew KY (2000) Preparation and catalytic properties of amphiphilic copolymer-stabilized platinum metals colloids. J Colloid Interface Sci 229:453-461. doi: 10.1006/jcis.2000.7041
    • (2000) J Colloid Interface Sci , vol.229 , pp. 453-461
    • Tu, W.1    Liu, H.2    Liew, K.Y.3
  • 31
    • 0033808379 scopus 로고    scopus 로고
    • Preparation of tractable platinum, rhodium, and ruthenium nanoclusters with small particles size in organic media
    • 10.1021/cm0000853 10.1021/cm0000853
    • Wang Y, Ren J, Deng K, Gui L, Tang Y (2000) Preparation of tractable platinum, rhodium, and ruthenium nanoclusters with small particles size in organic media. Chem Mater 12:1622-1627. doi: 10.1021/cm0000853
    • (2000) Chem Mater , vol.12 , pp. 1622-1627
    • Wang, Y.1    Ren, J.2    Deng, K.3    Gui, L.4    Tang, Y.5
  • 32
    • 74249087038 scopus 로고    scopus 로고
    • Preparation and characterization of Au-In/APTMS-SBA-15 catalyst for chemoselective hydrogenation of crotonaldehyde to crotyl alcohol
    • 10.1016/j.apcata.2009.08.032 10.1016/j.apcata.2009.08.032 1:CAS:528:DC%2BD1MXht1OrurbE
    • Yang QY, Zhu Y, Tian L, Xie SH, Pei Y, Li H, Li HX, Qiao MH, Fan KN (2009) Preparation and characterization of Au-In/APTMS-SBA-15 catalyst for chemoselective hydrogenation of crotonaldehyde to crotyl alcohol. Appl Catal A 369:67-76. doi: 10.1016/j.apcata.2009.08.032
    • (2009) Appl Catal A , vol.369 , pp. 67-76
    • Yang, Q.Y.1    Zhu, Y.2    Tian, L.3    Xie, S.H.4    Pei, Y.5    Li, H.6    Li, H.X.7    Qiao, M.H.8    Fan, K.N.9
  • 33
    • 72649085598 scopus 로고    scopus 로고
    • Viral templated palladium nanocatalysts for dichromate reduction
    • 10.1016/j.apcatb.2009.10.001 10.1016/j.apcatb.2009.10.001 1:CAS:528:DC%2BD1MXhs1Witr3F
    • Yang C, Manocchi AK, Lee B, Yi H (2010) Viral templated palladium nanocatalysts for dichromate reduction. Appl Catal B 93:282-291. doi: 10.1016/j.apcatb.2009.10.001
    • (2010) Appl Catal B , vol.93 , pp. 282-291
    • Yang, C.1    Manocchi, A.K.2    Lee, B.3    Yi, H.4
  • 34
    • 0036853734 scopus 로고    scopus 로고
    • Adsorption of chromate and arsenate by amino-functionalized MCM-41 and SBA-1
    • 10.1021/cm0202355 10.1021/cm0202355 1:CAS:528:DC%2BD38Xns1CqsL0%3D
    • Yoshitake H, Yokoi T, Tatsumi T (2002) Adsorption of chromate and arsenate by amino-functionalized MCM-41 and SBA-1. Chem Mater 14:4603-4610. doi: 10.1021/cm0202355
    • (2002) Chem Mater , vol.14 , pp. 4603-4610
    • Yoshitake, H.1    Yokoi, T.2    Tatsumi, T.3
  • 35
    • 0033080515 scopus 로고    scopus 로고
    • Preparation of polymer-stabilized noble metal colloids
    • DOI 10.1006/jcis.1998.5938
    • Yu W, Liu M, Liu H, Zheng J (1999a) Preparation of polymer-stabilized noble metal colloids. J Colloid Interface Sci 201:218-221. doi: 10.1006/jcis.1998.5938 (Pubitemid 29394499)
    • (1999) Journal of Colloid and Interface Science , vol.210 , Issue.1 , pp. 218-221
    • Yu, W.1    Liu, M.2    Liu, H.3    Zheng, J.4
  • 36
    • 0033524296 scopus 로고    scopus 로고
    • Synthesis of nanoscale platinum colloids by microwave dielectric heating
    • 10.1021/la9806505 10.1021/la9806505 1:CAS:528:DyaK1cXnslOhu78%3D
    • Yu W, Tu W, Liu H (1999b) Synthesis of nanoscale platinum colloids by microwave dielectric heating. Langmuir 15:6-9. doi: 10.1021/la9806505
    • (1999) Langmuir , vol.15 , pp. 6-9
    • Yu, W.1    Tu, W.2    Liu, H.3
  • 37
    • 0033542373 scopus 로고    scopus 로고
    • Immobilization of polymer-stabilized metal colloids by a modified coordination capture: Preparation of supported metal colloids with singular catalytic properties
    • 10.1016/S1381-1169(98)00282-9 10.1016/S1381-1169(98)00282-9 1:CAS:528:DyaK1MXisV2nurY%3D
    • Yu W, Liu H, Liu M, An X, Liu Z, Ma X (1999c) Immobilization of polymer-stabilized metal colloids by a modified coordination capture: preparation of supported metal colloids with singular catalytic properties. J Mol Catal A 142:201-211. doi: 10.1016/S1381-1169(98)00282-9
    • (1999) J Mol Catal A , vol.142 , pp. 201-211
    • Yu, W.1    Liu, H.2    Liu, M.3    An, X.4    Liu, Z.5    Ma, X.6


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