Arsenic retention

Jia, Y. Demopoulos, G. 2008. Coprecipitation of arsenate with iron(lll) in aqueous sulfate media Effect of time, lime as base and co-ions on arsenic retention. Water Research, 42, 661-668. 

Rubinos, D., Barral, M.T., Ruiz, B. et al. (2003) Phosphate and arsenate retention in sediments of the Anll6ns River (northwest Spain). Water Science and Technology, 48(10), 159-66. 

Dhoum, R.T. and Evans, G. J. (1998) Evaluation of uranium and arsenic retention by soils from a low level radioactive waste management site using sequential extraction. Appl. Geochem., 13, 415—420. 

The concentration of arsenic in charcoal increased linearly with temperature before leveling off at 400 °C. The concentration of arsenic in pyrolysis oil increased markedly at low temperature and at long pyrolysis times. It is therefore concluded that the optinol temperature and duration of pyrolysis is 4S0 C and 80 a. respectively. The fast pyrolysis technique has potential for the treatment of CCA-impregnated wood because of minimized secondary reactions and maximum arsenic retention are expected. 

Vithanage. M. et al.. Mechanistic modeling of arsenic retention on natural red earth in simulated environmental systems, J. Colloid Interf. Sci., 294, 265, 2006. 

Ouvrard, S. et al.. Natural manganese oxide Combined analytical approach for solid characterization and arsenic retention, Geochim. Cosmochim. Acta, 69, 2715, 2005. 

Generally, precipitation contributes only a small portion of the arsenic retention except in highly contaminated soils (e.g., soils around acid mines). If present at very high concentrations, direct precipitation or coprecipitation of arsenic with solid-phase Al, Fe, Mn, Mg, and Ca can occur. For example, Masscheleyn et al. (1991a) indicated that under reduced conditions, the formation of Mn3(As04)2 may control dissolved As(V). Under highly reduced conditions and in the presence of sulhdes, arsenic sulhde precipitation may occur. 

Horner has extended this reaction to the electrochemical reduction of optically active arsonium salts (68, X = As), which also undergo cleavage with retention of stereochemical configuration at arsenic M 65). This is a convenient synthetic route of optically active arsines of known configuration. 

Fendorf S, Eich MJ, Grossl P, Sparks DL (1997) Arsenate and chromate retention mechanisms on goethite. 1. Surface structure. Environ Sci Technol 31 315—320 Francesconi KA, Kuehnelt D (2002) Arsenic compounds in the environment. In Environmental chemistry of arsenic. In Frankenberger WT Jr (ed) Marcel Dekker, New York, Chapter 3, pp 51-94... 

Cleavage reactions are best carried out in aqueous solution. In aprotic solvents, electrogenerated bases lead to the conversion of onium salts to the ylids which are not reducible [49]. The sequence of reactions shown in Scheme 5.2 shows that the bond cleavage process for phosphonium salts proceeds with retention of configuration around the phosphorus atom [50]. Retention of configuration at arsenic is also observed [51]. This electrochemical process is a route to asymmetric trisub-stituted phosphorus and arsenic centres. 

Feltz, A. Martin, A. (1987) Solid-state reactivity and mechanisms in oxide systems. 11 Inhibition of zinc ferrite formation in zinc oxide - a-iron(lll) oxide mixtures with a large excess of a-iron(lll) oxide. In Schwab, G.M. (ed.) Reactivity of solids. Elsevier, 2 307—313 Fendorf, S. Fendorf, M. (1996) Sorption mechanisms of lanthanum on oxide minerals. Clays Clay Miner. 44 220-227 Fendorf, S.E. Sparks, D.L. (1996) X-ray absorption fine structure spectroscopy. In Methods of Soil Analysis. Part 3 Chemical Methods. Soil Sd. Soc. Am., 377-416 Fendorf, S.E. Eick, M.J. Grossl, P. Sparks, D.L. (1997) Arsenate and chromate retention mechanisms on goethite. 1. Surface structure. Environ. Sci. Techn. 31 315-320 Fendorf, S.E. Li,V. Gunter, M.E. (1996) Micromorphologies and stabilities of chromiu-m(III) surface precipitates elucidated by scanning force microscopy. Soil Sci. Soc. Am. J. 60 99-106... 

S. Ainsworth, C.C. (1997). Arsenate and chromate retention mechanism on goethite. 2 Kinetic evaluation using a pressure-jump relaxation technique. Envir. Sci. Techn. 31 321-326... 

The distillation separation procedure was the principal method used for the arsenic determinations, but more recently Santoliquido (24) has developed a method for the carrier-free separation of arsenic from low-temperature coal ash involving retention on an inorganic exchanger column. 

Erdalith Preservative shall be used to treat redwood lumber by the pressure treating process. The waterborne salts are, by weight, 33% copper sulfate, 56% potassium dichromate and 11% arsenic pen-toxide. Lumber treatment shall be to an average retention at shipment of 0.75 lb/ft3. 

Arienzo, M., Adamo, P., Chiarenzelli, J. et al. (2002) Retention of arsenic on hydrous ferric oxides generated by electrochemical peroxidation. Chemosphere, 48(10), 1009-18. 

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