[1]   Dorfner, K. (1972) Ion exchangers: Properties and applications. Ann Arbor Science, Newton, 177.

[2]   Pajunen, P. (1995) Hard chrome bath purification and recovery using ion exchange. Metal Finishing, 93, 40-45. doi:10.1016/S0026-0576(05)80048-0

[3]   Schiewer, S. and Volesky, B. (1997) Ionic strength and electrostatic effects in biosorption of protons. Environmental Science and Technology, 31, 1863-1871. doi:10.1021/es960434n

[4]   Fourest, E. and Volesky, B. (1996) Contribution of sulphonate groups and alginate to heavy metal biosorption by the dry biomass of Sargassum fluitans. Environmental Science and Technology, 30, 277-282. doi:10.1021/es950315s

[5]   Barba, D., Beolchini, F. and Vegliò, F. (2001) A simulation study on biosorption of heavy metals by confined biomass in UF/MF membrane reactors. Environmental Science and Technology, 35, 3048.

[6]   Truong, P. and Hart, B. (2001) Vetiver system for wastewater treatment. Technical Bulletin No. 2001/21, Pacific Rim Vetiver Network, Office of the Royal Development Projects Board, Bangkok.

[7]   Ash, R. and Truong, P. (2004) The use of vetiver grass for sewerage treatment. Proceedings of Sewage Management Queensland EPA Conference: Risk Assessment and Triple Bottom Line, Cairns, 5-7 April 2004.

[8]   Roongtanakiat, N. and Chairoj, P. (2001a) Uptake potential of some heavy metals by vetiver grass. Kasetsart Journal (Natural Science), 35, 46-50.

[9]   Roongtanakiat, N. and Chairoj, P. (2001b) Vetiver grass for the remediation of soil contaminated with heavy metals. Kasetsart Journal (Natural Science), 35, 433-440.

[10]   Roongtanakiat, N. (2009) Vetiver phytoremediation for heavy metal decontamination. PRVN Technical Bulletins No. 2009/1. ORDPB, Pacific Rim Vetiver Network, Office of the Royal Development Projects Board, Bangkok.

[11]   Hart, B., Cody, R. and Truong, P. (2003) Efficacy of vetiver grass in the hydroponic treatment of post septic tank effluent. Proceedings of the 3rd International Conference on Vetiver and Exhibition, Guangzhou, 6-9 October 2003.

[12]   Roongtanakiat, N., Tangruangkiat, S. and Meesat, R. (2007) Utilization of vetiver grass (Vetiveria zizanioides) for removal of heavy metals from industrial wastewaters. Science Asia, 33, 397-403. doi:10.2306/scienceasia1513-1874.2007.33.397

[13]   Percy, I. and Truong, P. (2005) Landfill leachate disposal with irrigated vetiver grass. Proceedings of 2005 National Conference on Landfill, Brisbane.

[14]   Kong, X.H., Lin, W.W. and Wang, B.Q. (2003) Study on vetiver’s purification for wastewater from pig farm. Proceedings of the 3rd International Conference on Vetiver and Exhibition, Guangzhou, 6-9 October 2003.

[15]   Figueira, M.M., Volesky, B., Ciminelli, V.S.T. and Roddick, F.A. (2000) Biosorption of metals in brown seaweed biomass. Water Research, 34, 196-204. doi:10.1016/S0043-1354(99)00120-7

[16]   Kumar, J.I.N., Oommen, C. and Kumar, R.N. (2009) Biosorption of heavy metals from aqueous solution by green marine macroalgae from Okha Port, Gulf of Kutch, India. American-Eurasian Journal of Agricultural & Environmental Sciences, 6, 317-323.

[17]   Khorramabadi, G.S. and Soltani, R.D.C. (2008) Evaluation of the marine algae Gracilaria salicornia and Sargassum sp. for the biosorption of Cr(VI) from aqueous solutions. Journal of Applied Sciences, 8, 2163-2167. doi:10.3923/jas.2008.2163.2167

[18]   Huang, C.P. and Wu, M.H. (1977) The removal of chromium(VI) from dilute aqueous solution by activated carbon. Water Research, 11, 673-679. doi:10.1016/0043-1354(77)90106-3

[19]   APHA (American Public Health Association) (2005) Standard methods for the examination of water and wastewater. 21st Edition, American Public Health Association, Washington DC.

[20]   APHA (American Public Health Association) (1985) American health association standards for examination of waste waters. 18th Edition, American Public Health Association, New York.

[21]   Mabbett, A.N., Lloyd, J.R. and Macaskie, L.E. (2002) Effect of complexing agents on reduction of Cr(VI) by Desulfovibrio vulgaris ATCC 29579. Biotechnology and Bioengineering, 79, 389-397. doi:10.1002/bit.10361

[22]   Seidel-Morgenstern, A. (2004) Experimental determination of single solute and competitive adsorption isotherms. Journal of Chromatography A, 1037, 255-272. doi:10.1016/j.chroma.2003.11.108

[23]   Gao, H., Liu, Y., Zeng, G., Xu, W., Li, T. and Xia, W. (2008) Characterization of Cr (VI) removal from aqueous solutions by a surplus agricultural waste-Rice straw. Journal of Hazardous Materials, 150, 446-452. doi:10.1016/j.jhazmat.2007.04.126

[24]   Basha, S., Murthy, Z.V.P. and Jha, B. (2008) Biosorption of hexavalent chromium by chemically modified seaweed, Cystoseira indica. Chemical Engineering Journal, 137, 480-488. doi:10.1016/j.cej.2007.04.038

[25]   Al-Asheh, S., Banat, F., Al-Omari, R. and Duvnjak, Z. (2000) Predictions of binary sorption isotherms for the sorption of heavy metals by pine bark using single isotherm data. Chemosphere, 41, 659-665. doi:10.1016/S0045-6535(99)00497-X

[26]   Pagnanelli, F., Esposito, A., Toro, L. and Veglio, F. (2003) Metal speciation and pH effect on Pb, Cu, Zn and Cd biosorption onto Sphaerotilus natans: Langmuir-type empirical model. Water Research, 37, 627-633. doi:10.1016/S0043-1354(02)00358-5

[27]   Moussavi, G. and Barikbin, B. (2010) Biosorption of chromium(VI) from industrial wastewater onto pistachio hull waste biomass. Chemical Engineering Journal, 162, 893-900. doi:10.1016/j.cej.2010.06.032

[28]   Sahranavard, M., Ahmadpour, A. and Doosti, M.R. (2011) Biosorption of hexavalent chromium ions from aqueous solutions using almond green hull as a low-cost biosorbent. European Journal of Scientific Research, 58, 392- 400.

[29]   Stephen, B., Inbaraj, B. and Sulochana, N. (2002) Basic dye adsorption on a low cost carbonaceous sorbent-kinetic and equilibrium studies. Indian Journal of Chemical Technology, 9, 201-208.

[30]   Basu, A., Kumar, S. and Mukherjee, S. (2003) Arsenic reduction from aqueous environment by water lettuce (Pistia stratiotes L.). Indian Journal of Environmental Health, 45, 143-150.

[31]   Pokhrel, D. and Viraraghavan, T. (2006) Arsenic removal from an aqueous solution by a modified fungal biomass. Water Research, 40, 549-552. doi:10.1016/j.watres.2005.11.040

[32]   Esmaeili, A., Ghasemi, S. and Rustaiyan, A. (2008) Evaluation of the activated carbon prepared from the algae Gracilaria for the biosorption of Cu(II) from aqueous solutions. African Journal of Biotechnology, 7, 2034-2037.

[33]   Ahmady-Asbchin, S., Omran, A.N. and Jafari, N. (2012) Potential of Azolla filiculoides in the removal of Ni and Cu from wastewaters. African Journal of Biotechnology, 11, 16158-16164.

[34]   Alpat, S., Alpat, S.K., Cadirci, B.H., Ozbayrak, O. and Yasa, I. (2010) Effects of biosorption parameter: Kinetics, isotherm and thermodynamics for Ni(II) biosorption from aqueous solution by Circinella sp. Electronic Journal of Biotechnology, 13, 5.