Hexavalent chromium review, part 2: Chemistry, occurrence, and treatment

Journal - American Water Works Association

Volumn 104, Issue 7, 2012, Pages

  McNeill, Laurie S ^a   McLean, Joan E ^a   Parks, Jeffrey L ^b   Edwards, Marc A ^b  

^a UTAH STATE UNIVERSITY   (United States)

^b VIRGINIA POLYTECHNIC INSTITUTE AND STATE UNIVERSITY   (United States)

Author keywords

Chromium; Drinking water; Occurrence; Redox

Indexed keywords

ANTHROPOGENIC CONTAMINATION; CHROMIUM OXIDATION; DISTRIBUTION SYSTEMS; DRINKING WATER SOURCES; HEALTH EFFECTS; HEXAVALENT CHROMIUM; HUMAN HEALTH EFFECTS; LIMITED DATA; NATURALLY OCCURRING; OCCURRENCE; POTENTIAL SOURCES; REDOX; REDUCTANTS; TREATMENT METHODS; TREATMENT PLANTS; TRIVALENT CHROMIUM;

CHROMIUM COMPOUNDS; POTABLE WATER;

CHROMIUM;

EID: 84865594151     PISSN: 0003150X     EISSN: None     Source Type: Journal    
DOI: 10.5942/jawwa.2012.104.0092     Document Type: Review

References (143)

1. Alowitz, M.J. & Scherer, M.M., 2002. Kinetics of Nitrate, Nitrite, and Cr(VI) Reduction by Iron Metal. Envir. Sci. & Technol., 36:3:299.
2. Anderson, N.J.; Bolto, B.A.; & Pawlowski, L., 1984. A Method for Chromate Removal From Cooling Tower Blowdown Water. Nuclear & Chemical Waste Mngmnt., 5:125. http://dx.doi.org/10.1016/0191-815X(84)90042-1.
3. Astrup, T.; Stipp, S.L.S.; & Christensen, T.H., 2000. Immobilization of Chromate From Coal Fly Ash Leachate Using an Attenuating Barrier Containing Zero-Valent Iron. Envir. Sci. & Technol., 34:19:4163.
4. Ball, J.W. & Izbicki, J.A., 2004. Occurrence of Hexavalent Chromium in Ground Water in the Western Mojave Desert, California. Applied Geochemistry, 19:7:1123.
5. Bartlett, L.B., 1997. Aqueous Cr(III) Oxidation by Free Chlorine in the Presence of Model Organic Ligands: Chemistry in the Context of Environmental Regulations. Doctoral dissertation, Civil and Environmental Engineering, Duke University, Durham N.C.
6. Bartlett, R.J. & Kimble, J.M., 1976. Behavior of Chromium in Soils: II. Hexavalent Forms. Jour. Envir. Quality, 5:4:383.
7. Becquer, T.; Quantin, C.; Sicot, M.; & Boudot, J.P., 2003. Chromium Availability in Ultramafic Soils From New Caledonia. Sci. Total Envir., 301:1-3:251.
8. Blowes, D.W.; Ptacek, C.J.; & Jambor, J.L., 1997. In-Situ Remediation of Cr(VI)-Contaminated Groundwater Using Permeable Reactive Walls: Laboratory Studies. Envir. Sci. & Technol., 31:12:3348.
9. Blute, N.K. & Wu, Y., 2012. Chromium Research Effort by the City of Glendale California (Interim Report), Arcadis U.S. Inc., Los Angeles, Calif.
10. Blute, N.K., 2010. Optimization Studies to Assist in Cr(VI) Treatment Design. Proc. AWWA 2010 Annual Conference and Exposition, Chicago, Ill.
11. Blute, N.; Porter, K.; & Kuhnel, B., 2010. Cost Estimates for Two Hexavalent Chromium Treatment Processes. Proc. AWWA 2010 Annual Conference and Exposition, Chicago, Ill.
12. Blute, N.K.; McGuire, M.J.; Qin, G.; Brabander, D.J.; Newville, M.; & Kavounas, P., 2007. State of the Art Geochemical Techniques in Evaluating Drinking Water Treatment Contaminant Removal Processes. Proc. AWWA 2007 WQTC, Charlotte, N.C.
13. Bobrowski, A.; Gawlicki, M.; & Malolepszy, J., 1997. Analytical Evaluation of Immobilization of Heavy Metals in Cement Matrices. Envir. Sci. & Technol., 31:3:745.
14. Boni, M.R. & Sbaffoni, S., 2009. The Potential of Compost-Based Biobarriers for Cr(VI) Removal From Contaminated Groundwater: Column Test. Jour. Hazardous Materials, 166:2-3:1087.
15. Bourotte, C.; Bertolo, R.; Almodovar, M.; & Hirata, R., 2009. Natural Occurrence of Hexavalent Chromium in a Sedimentary Aquifer in Urania, State of Sao Paolo, Brazil. Anais da Acad. Brasileira de Ciencias, 81:227. http://dx.doi. org/10.1590/S0001-37652009000200009.
16. Brandhuber, P.; Frey, M.M.; McGuire, M.J.; Chao, P.-F.; Seidel, C.; Amy, G.; Yoon, J.; McNeill, L.S.; & Banerjee, K., 2004. Low-Level Hexavalent Chromium Treatment Options: Bench-Scale Evaluation. AwwaRF, Denver.
17. Brewster, M.D. & Passmore, R.J., 1994. Use of Electrochemical Iron Generation for Removing Heavy Metals From Contaminated Groundwater. Envir. Progress, 13:2:143.
18. Buerge, I.J. & Hug, S.J., 1999. Influence of Mineral Surfaces on Chromium(VI) Reduction by Iron(II). Envir. Sci. & Technol., 33:23:4285.
19. Buerge, I.J. & Hug, S.J., 1998. Influence of Organic Ligands on Chromium(VI) Reduction by Iron(II). Envir. Sci. & Technol., 32:14:2092.
20. Buerge, I.J. & Hug, S.J., 1997. Kinetics and pH Dependence of Chromium(VI) Reduction by Iron(II). Envir. Sci. & Technol., 31:5:1426.
21. Burgess, C.O. & Briggs, H.K., 1956. Chromium in Cast Iron. Chromium, Volume II: Metallurgy of Chromium and Its Alloys (M.J. Udy, editor). Reinhold, New York.
22. Butler, J.N., 1967. Ionic Equilbrium. Addison-Wesley, New York.
23. CDPH (California Department of Public Health), 2012. Chromium-6 in Drinking Water: MCL Update. www.cdph.ca.gov/certlic/drinkingwater/Pages/ Chromium6.aspx (accessed May 7, 2012).
24. Chen, H.-W.; Frey, M.M.; Clifford, D.; McNeill, L.S.; & Edwards, M., 1999. Arsenic Treatment Considerations. Jour. AWWA, 91:3:74.
25. Chen, J.M. & Hao, O.J., 1998. Microbial Chromium (VI) Reduction. Critical Rev. Envir. Sci. & Technol., 28:3:219.
26. Chung, J.-B.; Burau, R.G.; & Zasoski, R.J., 2001. Chromate Generation by Chromate Depleted Subsurface Materials. Water, Air, & Soil Pollution, 128:3:407.
27. Clifford, D. & Chau, J.M., 1988. The Fate of Chromium (III) in Chlorinated Water, Project Summary. EPA/600/S2-87/100. USEPA, Cincinnati, Ohio.
28. Clifford, D.; Subramonian, S.; & Sorg, T.J., 1986. Water Treatment Processes. III. Removing Dissolved Inorganic Contaminants From Water. Envir. Sci. & Technol., 20:11:1072.
29. Craun, G.F. & McCabe, L.J., 1975. Problems Associated With Metals in Drinking Water. Jour. AWWA, 67:11:593.
30. Dawson, B.J.M.; Bennett, G.L.; & Belitz, K., 2008. Ground-Water Quality Data in the Southern Sacramento Valley, California, 2005-Results From the California GAMA Program. US Geological Survey Data Series 285, US Geological Survey, Reston, Va.
31. Deng, B. & Stone, A.T., 1996. Surface-Catalyzed Chromium(VI) Reduction Reactivity Comparisons of Different Organic Reductants and Different Oxide Surfaces. Envir. Sci. & Technol., 30:8:2484.
32. Dionex, 2011. Sensitive Determination of Hexavalent Chromium in Drinking Water: Application Update 179. Dionex Corp., Sunnyvale, Calif.
33. Dionex, 2003. Determination of Hexavalent Chromium in Drinking Water Using Ion Chromatography: Application Update 144, Dionex Corp., Sunnyvale, Calif.
34. Døssing, L.N.; Dideriksen, K.; Stipp, S.L.S.; & Frei, R., 2011. Reduction of Hexavalent Chromium by Ferrous Iron: A Process of Chromium Isotope Fractionation and Its Relevance to Natural Environments. Chemical Geol., 285:1-4:157.
35. Drago, J.A., 2001. Technology and Cost Analysis for Hexavalent Chromium Removal From Drinking Water Supplies. Proc. AWWA 2001 WQTC, Nashville, Tenn.
36. Durfor, C.N. & Becker, E., 1962. Public Water Supplies of the 100 Largest Cities in the United States, 1962, US Geological Survey, Reston, Va.
37. Dzombak, D.A. & Morel, F.M.M., 1990. Surface Complexation Modeling: Hydrous Ferric Oxide. Wiley-Interscience, New York.
38. Eary, L.E. & Rai, D., 1989. Kinetics of Chromate Reduction by Ferrous Ions Derived From Hematite and Biotite at 25C. Amer. Jour. Sci., 289:2:180.
39. Eary, L.E. & Rai, D., 1988. Chromate Removal From Aqueous Wastes by Reduction with Ferrous Iron. Envir. Sci. & Technol., 22:8:972.
40. Eary, L.E. & Rai, D., 1987. Kinetics of Chromium(III) Oxidation to Chromium(VI) by Reaction With Manganese Dioxide. Envir. Sci. & Technol., 21:12:1187.
41. Edwards, M.; Patel, S.; McNeill, L.S.; Chen, H.-W.; Frey, M.M.; Eaton, A.D.; Antweiler, R.C.; & Taylor, H., 1998. Considerations in As Analysis and Speciation. Jour. AWWA, 90:3:103.
42. Edwards, M. & Benjamin, M.M., 1989. Adsorptive Filtration Using Coated Sand: A New Approach for Treatment of Metal-Bearing Wastes. Jour. Water Pollution Control Federation, 61:9:1523.
43. El-Shoubary, Y.; Speizer, N.; Seth, S.; & Savoia, H., 1998. A Pilot Plant to Treat Chromium-Contaminated Groundwater. Envir. Progr., 17:3:209.
44. EWG (Environmental Working Group), 2010. Chromium-6 Is Widespread in US Tap Water. www.ewg.org/chromium6-in-tap-water (accessed July 7, 2011).
45. Eyring, A.M.; Weinberg, H.S.; & Singer, P.C., 2002. Measurement and Effect of Trace Element Contaminants in Alum. Jour. AWWA, 94:5:135.
46. Fantoni, D.; Brozzo, G.; Canepa, M.; Cipolli, F.; Marini, L.; Ottonello, G.; & Zuccolini, M.V., 2002. Natural Hexavalent Chromium in Groundwaters Interacting With Ophiolitic Rocks. Envir. Geol., 42:8:871.
47. Faust, S.D. & Aly, O.M., 1998 (2nd ed.). Chemistry of Water Treatment. Ann Arbor Press, Chelsea, Mich.
48. Fendorf, S.E. & Li, G., 1996. Kinetics of Chromate Reduction by Ferrous Iron. Envir. Sci. & Technol., 30:5:1614.
49. 2. Jour. Colloid & Interface Sci., 153:1:37.
50. 2. 1. Characterization. Envir. Sci. & Technol., 26:1:79.
51. Frey, M.M.; Seidel, C.; Edwards, M.; Parks, J.; & McNeill, L.S., 2004. Occurrence Survey of Boron and Hexavalent Chromium. AwwaRF, Denver.
52. Fruchter, J., 2002. In-Situ Treatment of Chromium-Contaminated Groundwater. Envir. Sci. & Technol., 36:23:464A.
53. Gandhi, S.; Oh, B.T.; Schnoor, J.L.; & Alvarez, P.J.J., 2002. Degradation of TCE, Cr(VI), Sulfate, and Nitrate Mixtures by Granular Iron in Flow-through Columns Under Different Microbial Conditions. Water Res., 36:1973. http://dx.doi.org/10.1016/S0043-1354(01)00409-2.
54. Geld, I. & McCaul, C., 1975. Corrosion in Potable Water. Jour. AWWA, 67:10:549.
55. Gonzalez, A.R.; Ndungu, K.; & Flegal, A.R., 2005. Natural Occurrence of Hexavalent Chromium in the Aromas Red Sands Aquifer, California. Envir. Sci. & Technol., 39:15:5505.
56. Gould, J.P., 1982. The Kinetics of Hexavalent Chromium Reduction by Metallic Iron. Water Res., 16:871. http://dx.doi.org/10.1016/0043-1354(82)90016- 1.
57. Gray, D.J., 2003. Naturally Occurring Cr+6 in Shallow Groundwaters of the Yilgarn Craton, Western Australia. Geochemistry Exploration Envir., Analysis 3:359. http://dx.doi.org/10.1144/1467-7873/03-012.
58. Guo, Q.; Toomuluri, P.J.; & Eckert Jr., J.O., 1998. Leachability of Regulated Metals From Cement-Mortar Linings. Jour. AWWA, 90:3:62.
59. Guo, Q., 1997. Increases of Lead and Chromium in Drinking Water From Using Cement-Mortar-Lined Pipes: Initial Modeling and Assessment. Jour. Hazardous Materials, 56:1-2:181.
60. He, Y.T.; Chen, C.C.; & Traina, S.J., 2004. Inhibited Cr(VI) Reduction by Aqueous Fe(II) Under Hyperalkaline Conditions. Envir. Sci. & Technol., 38:21:5535.
61. Hem, J.D., 1977. Reactions of Metal Ions at Surfaces of Hydrous Iron Oxide. Geochimica et Cosmochimica Acta, 41:527. http://dx.doi.org/10.1016/0016- 7037(77)90290-3.
62. Henderson, T., 1994. Geochemical Reduction of Hexavalent Chromium in the Trinity Sand Aquifer. Ground Water, 32:3:477.
63. Henrie, T.; Steinpress, M.; Simion, V.; Auckly, C.; & Weber, J.V., 2004. Naturally Occurring Chromium(VI) in Groundwater. Chromium(VI) Handbook (J. Guertin, J.A. Jacobs, & C.P. Avakian, eds.). CRC Press, Boca Raton, Fla.
64. Hering, J.G. & Harmon, T.C., 2004. Geochemical Controls on Chromium Occurrence, Speciation, and Treatability. AwwaRF, Denver.
65. Hills, L.M. & Johansen, V.C., 2007. Hexavalent Chromium in Cement Manufacturing: Literature Review. Portland Cement Association, Skokie, Ill.
66. Hug, S.J.; Laubscher, H.-U.; & James, B.R., 1997. Iron(III) Catalyzed Photochemical Reduction of Chromium(VI) by Oxalate and Citrate in Aqueous Solutions. Envir. Sci. & Technol., 31:1:160.
67. Icopini, G.A. & Long, D.T., 2002. Speciation of Aqueous Chromium by Use of SolidPhase Extractions in the Field. Envir. Sci. & Technol., 36:13:2994.
68. Izbicki, J.A.; Ball, J.W.; Bullen, T.D.; & Sutley, S.J., 2008. Chromium, Chromium Isotopes and Selected Trace Elements, Western Mojave Desert, USA. Applied Geochemistry, 23:5:1325.
69. James, B.R. & Bartlett, R.J., 1983. Behavior of Chromium in Soils: VII. Adsorption and Reduction of Hexavalent Forms. Jour. Envir. Quality, 12:2:177.
70. Johnson, C.A. & Xyla, A.G., 1991. The Oxidation of Chromium(III) to Chromium(VI) on the Surface of Manganite (Gamma-MnOOH). Geochimica et Cosmochimica Acta, 55:10:2861.
71. Kayhanian, M.; Vichare, A.; Green, P.G.; & Harvey, J., 2009. Leachability of Dissolved Chromium in Asphalt and Concrete Surfacing Materials. Jour. Envir. Mngmnt., 90:11:3574.
72. Khaodhiar, S., 1997. Removal of Chromium, Copper, and Arsenic From Contaminated Groundwater Using Iron-Oxide Composite Adsorbents. Doctoral dissertation, Oregon State University, Corvallis, Ore.
73. Kharkar, D.P.; Turekian, K.K.; & Bertine, K.K., 1968. Stream Supply of Dissolved Silver, Molybdenum, Antimony, Selenium, Chromium, Cobalt, Rubidium and Cesium to the Oceans. Geochimica et Cosmochimica Acta, 32:3:285.
74. Kim, C.; Zhou, Q.; Deng, B.; Thornton, E.C.; & Xu, H., 2001. Chromium(VI) Reduction by Hydrogen Sulfide in Aqueous Media: Stoichiometry and Kinetics. Envir. Sci. & Technol., 35:11:2219.
75. Kimbrough, D.E.; Cohen, Y.; Winer, A.M.; Creelman, L.; & Mabuni, C., 1999. A Critical Assessment of Chromium in the Environment. Critical Rev. Envir. Sci. & Technol., 29:1:1.
76. Kiyak, B.; Ozer, A.; Altundogan, H.S.; Erdem, M.; & Tumen, F., 1999. Cr(VI) Reduction in Aqueous Solutions by Using Copper Smelter Slag. Waste Mngmnt., 19:5:333.
77. Lai, H. & McNeill, L.S., 2006. Chromium Redox Chemistry in Drinking Water Systems. Jour. Envir. Engrg., 132:8:842.
78. Lee, G.H. & Hering, J.G., 2005. Oxidative Dissolution of Chromium(III) Hydroxide at pH 9, 3, and 2 With Product Inhibition at pH 2. Envir. Sci. & Technol., 39:13:4921.
79. Lee, G. & Hering, J.G., 2003. Removal of Chromium(VI) From Drinking Water by Redox-Assisted Coagulation With Iron(II). Jour. Water Supply Res. Technol.-AQUA, 52:5:319.
80. Lin, C.F.; Rou, W.; & Lo, K.S., 1992. Treatment Strategy for Cr(VI)-Bearing Wastes. Water Sci. & Technol., 26:9-11:2301.
81. Liu, T.; Tsang, D.C.W.; & Lo, I.M.C., 2008. Chromium(VI) Reduction Kinetics by Zero-Valent Iron in Moderately Hard Water With Humic Acid: Iron Dissolution and Humic Acid Adsorption. Envir. Sci. & Technol., 42:6:2092.
82. Loyaux-Lawniczak, S.; Refait, P. ; Ehrhardt, J.-J.; Lecomte, P. ; & Genin, J.-M.R., 2000. Trapping of Cr by Formation of Ferrihydrite During the Reduction of Chromate Ions by Fe(II)-Fe(III) Hydroxysalt Green Rusts. Envir. Sci. & Technol., 34:3:438.
83. Lytle, D.A.; Sorg, T.J.; Muhlen, C.; & Wang, L., 2010. Particulate Arsenic Release in a Drinking Water Distribution System. Jour. AWWA, 102:3:87.
84. Mayer, K.U.; Blowes, D.W.; & Frind, E.O., 2001. Reactive Transport Modeling of an in Situ Reactive Barrier for the Treatment of Hexavalent Chromium and Trichloroethylene in Groundwater. Water Resources Res., 37:12:3091.
85. McGuire, M.J., 2010. Scientific Underpinnings: Hexavalent Chromium Treatment Basic Research and Pilot Testing. Proc. AWWA 2010 Annual Conference and Exhibition, Chicago, Ill.
86. McGuire, M.J.; Blute, N.K.; Qin, G.; Kavounas, P.; Froelich, D.; & Fong, L., 2007. Hexavalent Chromium Removal Using Anion Exchange and Reduction with Coagulation and Filtration. AwwaRF, Denver.
87. McGuire, M.J.; Blute, N.K.; Seidel, C.; Qin, G.; & Fong, L., 2006. Pilot-Scale Studies of Hexavalent Chromium Removal From Drinking Water. Jour. AWWA, 98:2:134.
88. Meranger, J.C.; Subramanian, K.S.; & Chalifoux, C., 1979. A National Survey for Cadmium, Chromium, Copper, Lead, Zinc, Calcium, and Magnesium in Canadian Drinking Water Supplies. Envir. Sci. & Technol., 13:6:707.
89. MDNR (Missouri Department of Natural Resources), 2010. News Release 38-006: Trace Levels of Hexavalent Chromium Found in Two Cities' Drinking Water. http://dnr.mo.gov/newsrel/2010/nr10-006.htm (accessed July 7, 2011).
90. Mohan, D. & Pittman Jr, C.U., 2006. Activated Carbons and Low Cost Adsorbents for Remediation of Tri-and Hexavalent Chromium From Water. Jour. Hazardous Materials, 137:2:762.
91. 2. Envir. Sci. & Technol., 34:16:3363.
92. Nriagu, J.O. & Nieboer, E., 1988. Chromium in the Natural and Human Environments. John Wiley & Sons, New York.
93. Oze, C.; Bird, D.K.; & Fendorf, S., 2007. Genesis of Hexavalent Chromium From Natural Sources in Soil and Groundwater. Proc. Natl. Acad. Sci., 104:6544. http://dx.doi.org/10.1073/pnas.0701085104.
94. Oze, C.; Fendorf, S.; Bird, D.K.; & Coleman, R.G., 2004. Chromium Geochemistry of Serpentine Soils. Intl. Geology Review, 46:2:97.
95. Patterson, R.R.; Fendorf, S.; & Fendorf, M., 1997. Reduction of Hexavalent Chromium by Amorphous Iron Sulfide. Envir. Sci. & Technol., 31:7:2039.
96. Patterson, J.W.; Gasca, E.; & Wang, Y., 1994. Optimization for Reduction/Precipitation Treatment of Hexavalent Chromium. Water Sci. & Technol., 29:9:275.
97. Peterson, M.L.; Brown Jr., G.E.; Parks, G.A.; & Stein, C.L., 1997a. Differential Redox and Sorption of Cr(III/VI) on Natural Silicate and Oxide Minerals: EXAFS and XANES Results. Geochimica et Cosmochimica Acta, 61:16:3399.
98. Peterson, M.L.; White, A.F.; Brown Jr., G.E.; & Parks, G.A., 1997b. Surface Passivation of Magnetite by Reaction With Aqueous Cr(VI): XAFS and TEM Results. Envir. Sci. & Technol., 31:5:1573.
99. Peterson, M.L., 1996. Chromium(VI) Reduction by Magnetite: Spectroscopic Evidence of Sorption, Precipitation, and Heterogeneous Oxidation-Reduction Reactions. Doctoral dissertation, Department of Geological and Environmental Sciences, Stanford University, Stanford, Calif.
100. 2 in Acidic Solution. Envir. Sci. & Technol., 36:5:901.
101. Pettine, M.; Barra, I.; Campanella, L.; & Millero, F.J., 1998a. Effect of Metals on the Reduction of Chromium (VI) With Hydrogen Sulfide. Water Res., 32:9:2807.
102. Pettine, M.; D'Ottone, L.; Campanella, L.; Millero, F.J.; & Passino, R., 1998b. The Reduction of Chromium(VI) by Iron (II) in Aqueous Solutions. Geochimica et Cosmochimica Acta, 62:9:1509.
103. Philipot, J.M.; Chaffange, F.; & Sibony, J., 1984. Hexavalent Chromium Removal From Drinking Water. Water Sci. & Technol., 17:1121.
104. Ponder, S.M.; Darab, J.G.; & Mallouk, T.E., 2000. Remediation of Cr(VI) and Pb(II) Aqueous Solutions Using Supported, Nanoscale Zero-Valent Iron. Envir. Sci. & Technol., 34:12:2564.
105. Popov, B.N.; White, R.E.; Slavkov, D.; & Koneska, Z., 1992. Reduction of Chromium(VI) When Solar Selective Black Chromium Is Deposited in the Presence of Organic Additive. Jour. Electrochemical Soc., 139:1:91.
106. Powell, R.M.; Puls, R.W.; Hightower, S.K.; & Sabatini, D.A., 1995. Coupled Iron Corrosion and Chromate Reduction: Mechanisms for Subsurface Remediation. Envir. Sci. & Technol., 29:8:1913.
107. Pratt, A.R.; Blowes, D.W.; & Ptacek, C.J., 1997. Products of Chromate Reduction on Proposed Subsurface Remediation Material. Envir. Sci. & Technol., 31:9:2492.
108. Qin, G.; McGuire, M.J.; Blute, N.K.; Seidel, C.; & Fong, L., 2005. Hexavalent Chromium Removal by Reduction With Ferrous Sulfate, Coagulation, and Filtration: A Pilot-Scale Study. Envir. Sci. & Technol., 39:16:6321.
109. Raddatz, A.L.; Johnson, T.M.; & McLing, T.L., 2011. Cr Stable Isotopes in Snake River Plain Aquifer Groundwater: Evidence for Natural Reduction of Dissolved Cr(VI). Envir. Sci. & Technol., 45:2:502.
110. Rai, D.; Saas, B.M.; & Moore, D.A., 1987. Chromium(III) Hydrolysis Constants and Solubility of Chromium(III) Hydroxide. Inorganic Chemistry, 26:3:345.
111. Reiber, S. & Dostal, G., 2000. Arsenic and Old Pipes-A Mysterious Liaison. Opflow, 26:3:1.
112. Richard, F.C. & Bourg, A.C.M., 1991. Aqueous Geochemistry of Chromium: A Review. Water Res., 25:7:807.
113. Robertson, F.N., 1975. Hexavalent Chromium in the Ground Water in Paradise Valley, Arizona. Ground Water, 13:6:516.
114. Robles-Camacho, J. & Armienta, M.A., 2000. Natural Chromium Contamination of Groundwater at León Valley, México. Jour. Geochemical Exploration, 68:3:167.
115. Rock, M.L.; James, B.R.; & Helz, G.R., 2001. Hydrogen Peroxide Effects on Chromium Oxidation State and Solubility in Four Diverse, Chromium-Enriched Soils. Envir. Sci. & Technol., 35:20:4054.
116. Rock, M.L., 1999. Chromium Oxidation and Reduction by Hydrogen Peroxide in Diverse Soils and Simple Aqueous Systems. Doctoral dissertation, Chemistry, University of Maryland at College Park.
117. Saputro, S.; Yoshimura, K.; Takehara, K.; Matsuoka, S.; & Narsito, 2011. Oxidation of Chromium(III) by Free Chlorine in Tap Water During the Chlorination Process Studied by an Improved Solid-Phase Spectrometry. Analytical Sciences, 27:6:649.
118. Schlautman, M.A. & Han, I., 2001. Effects of pH and Dissolved Oxygen on the Reduction of Hexavalent Chromium by Dissolved Ferrous Iron in Poorly Buffered Aqueous Systems. Water Res., 35:6:1534.
119. Schroeder, D.C. & Lee, G.F., 1975. Potential Transformations of Chromium in Natural Waters. Water, Air, & Soil Pollution, 4:355. http://dx.doi.org/10.1007/BF00280721.
120. Sedlak, D.L. & Chan, P.G., 1997. Reduction of Hexavalent Chromium by Ferrous Iron. Geochimica et Cosmochimica Acta, 61:11:2185.
121. Sharma, S.K., Petrusevski, B. & Amy, G., 2008. Chromium Removal From Water: A Review. Jour. Water Supply Res. Technol.-AQUA, 57:8:541.
122. Somasundaram, V.; Philip, L.; & Bhallamudi, S.M., 2009. Experimental and Mathematical Modeling Studies on Cr(VI) Reduction by CRB, SRB and IRB, Individually and in Combination. Jour. Hazardous Materials, 172:2-3:606.
123. Sorg, T.J., 1979. Treatment Technology to Meet the Interim Primary Drinking Water Regulations for Organics: Part 4. Jour. AWWA, 71:8:454.
124. Szulczewski, M.D.; Helmke, P.A.; & Bleam, W.F., 2001. XANES Spectroscopy Studies of Cr(VI) Reduction by Thiols in Organosulfur Compounds and Humic Substances. Envir. Sci. & Technol., 35:6:1134.
125. Thomas, D.H.; Rohrer, J.S.; Jackson, P.E.; Pak, T.; & Scott, J.N., 2002. Determination of Hexavalent Chromium at the Level of the California Public Health Goal by Ion Chromatography. Jour. Chromatography A, 956:1-2:255.
126. Tong, J.Y.-p. & King, E.L., 1953. A Spectrophotometric Investigation of the Equilibria Existing in Acidic Solutions of Chromium(VI). Jour. Amer. Chemical Soc., 75:24:6180.
127. Tuthill, A.H., 1994. Stainless-Steel Piping. Jour. AWWA, 86:6:67.
128. USEPA (US Environmental Protection Agency), 2011. Method 218.7: Determination of Hexavalent Chromium in Drinking Water by Ion Chromatography With Post-Column Derivatization and UV-Visible Spectroscopic Detection, USEPA Ofce. of Ground Water and Drinking Water, Cincinnati.
129. USEPA, 2010. The Analysis of Regulated Contaminant Occurrence Data From Public Water Systems in Support of the Second Six-Year Review of National Primary Drinking Water Regulations. USEPA Ofce. of Water, Washington.
130. USEPA, 2005. Cost and Performance Summary Report in Situ Chemical Reduction at the Frontier Hard Chrome Superfund Site Vancouver, Washington. http://costperformance.org/pdf/fhc-final-7-26-05.pdf (accesssed August 5, 2011).
131. Ulmer, N.S., 1986. Effect of Chlorine on Chromium Speciation in Tap Water. EPA/600/M-86/015, USEPA Water Engineering Research Laboratory, Cincinnati, Ohion.
132. Vainshtein, M.; Kuschk, P. ; Mattusch, J.; Vatsourina, A.; & Wiessner, A., 2003. Model Experiments on the Microbial Removal of Chromium From Contaminated Groundwater. Water Res., 37:6:1401.
133. Webster, M.T. & Loehr, R.C., 1996. Long-Term Leaching of Metals From Concrete Products. Jour. Envir. Engrg., 122:8:714.
134. White, A.F. & Peterson, M.L., 1996. Reduction of Aqueous Transition Metal Species on the Surfaces of Fe(II)-Containing Oxides. Geochimica et Cosmochimica Acta, 60:20:3799.
135. Wielinga, B.; Mizuba, M.M.; Hansel, C.M.; & Fendorf, S., 2001. Iron Promoted Reduction of Chromate by Dissimilatory Iron-Reducing Bacteria. Envir. Sci. & Technol., 35:3:522.
136. Wittbrodt, P.R. & Palmer, C.D., 1996. Effect of Temperature, Ionic Strength, Background Electrolytes, and Fe(III) on the Reduction of Hexavalent Chromium by Soil Humic Substances. Envir. Sci. & Technol., 30:8:2470.
137. Wittbrodt, P.R. & Palmer, C.D., 1995. Reduction of Cr(VI) in the Presence of Excess Soil Fulvic Acid. Envir. Sci. & Technol., 29:1:255.
138. Xu, X.-R.; Li, H.-B.; Li, X.-Y.; & Gu, J.-D., 2004. Reduction of Hexavalent Chromium by Ascorbic Acid in Aqueous Solutions. Chemosphere, 57:7:609.
139. Yang, C.-L. & Kravets, G., 2000. Removal of Chromium From Abrasive Blast Media by Leaching and Electrochemical Precipitation. Jour. Air & Waste Mngmnt. Assn., 50:4:536.
140. Yoon, J.; Amy, G.; Chung, J.; Sohn, J.; & Yoon, Y., 2009. Removal of Toxic Ions (Chromate, Arsenate, and Perchlorate) Using Reverse Osmosis, Nanofiltration, and Ultrafiltration Membranes. Chemosphere, 77:2:228.
141. Yoon, J.; Amy, G.; & Yoon, Y., 2002. Transport of Chromium (Cr(VI)) Through Reverse Osmosis (RO), Nanofiltration (NF) and Ultrafiltration (UF) Membranes. Proc. AWWA 2002 Annual Conference and Exposition, New Orleans, La.
142. Zhang, H., 2000. Light and Iron(III)-Induced Oxidation of Chromium(III) in the Presence of Organic Acids and Manganese(II) in Simulated Atmospheric Water. Atmospheric Envir., 34:10:1633.
143. Zouboulis, A.I.; Kydros, K.A.; & Matis, K.A., 1995. Removal of Hexavalent Chromium Anions From Solutions by Pyrite Fines. Water Res., 29:7:1755.