Arsenic mobility in groundwater

Flow and diffusion transport dissolved and mobile particulate arsenic in groundwater. The flow velocity (speed and direction) of groundwater is largely controlled by changes in the elevation of the water table with lateral distance, water pressure and density, and the permeability and other properties of the aquifer. In some circumstances, temperature gradients may also affect groundwater flow (Freeze and Cherry, 1979), 25. 

Diffusion involves the movement of dissolved chemical species in liquids or gases because of a concentration gradient. That is, the dissolved species will migrate from areas of high concentration to areas of 

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Risk assessment of arsenic mobility in groundwaters in Langley, British Columbia using geochemical indicators... 

Szramek, K Walter, L.M. and McCall, P. (2004) Arsenic mobility in groundwater/surface water systems in carbonate-rich Pleistocene glacial drift aquifers (Michigan). Applied Geochemistry, 19(7), 1137-55. 

Acharyya, S.K. (2002) Arsenic contamination in groundwater affecting major parts of southern West Bengal and parts of western Chhattisgarh source and mobilization process. Current Science, 82(6), 740-44. 

Klump, S., Kipfer, R., Cirpka, O.A. et al. (2006) Groundwater dynamics and arsenic mobilization in Bangladesh assessed using noble gases and tritium. Environmental Science and Technology, 40(1), 243-50. 

Stiiben, D Berner, Z Chandrasekharam, D. and Karmakar, J. (2003) Arsenic enrichment in groundwater of West Bengal, India geochemical evidence for mobilization of As under reducing conditions. Applied Geochemistry, 18(9), 1417-34. 

Zheng, Y., Stute, M., van Geen, A. et al. (2004) Redox control of arsenic mobilization in Bangladesh groundwater. Applied Geochemistry, 19(2), 201-14. 

There is much speculation about the reasons for the high arsenic concentrations in groundwaters in Bangladesh and elsewhere. It is useful in these discussions to consider three aspects of the problem the source of the arsenic, its mobilization and the extent of its present and past transport or movement in the groundwater flow. 

Despite this, a substantial proportion of U.S. groundwaters [42% in the Frey and Edwards (31) study] have arsenic concentrations below 0.5 [tg/L. In addition, the variability of arsenic concentrations in groundwaters suggests that arsenic is differentially mobilized from various source materials under different environmental conditions. Thus the speciation of arsenic in the solid phase and its susceptibility to leaching by contacting porewater as well as mechanisms for the sequestration of arsenic from the aqueous to solid phases must be considered. 

Prakash Maity, J., Nath, B., Chen, C.-Y., Bhattacharya, R, Sracek, O., Bundschuh, J., Thunvik, R., Kar, S., Chatteijee, D. Jean, J.-S. (2011 a) Arsenic enrichment in groundwaters of Bengal Basin (India, Bangladesh) and Chianan Plain (Taiwan) comparison of hydrochemical characteristics and mobility constraints. Journal of Environmental Sciences Health A, 46 (11), 1163—1176. 

Welch A. H., Westjohn D. B., Helsel D. R., and Wanty R. B. (2000) Arsenic in ground water of the United States occurrence and geochemistry. Ground Water 38, 589-604. White A. and Dubrovsky N. (1994) Chemical oxidation-reduction controls on selenium mobility in groundwater systems. In Selenium in the Environment (eds. W. T. Frankenberger and S. Benson). Dekker, New York, chap. 8, pp. 185-221. 

Anawar, H.M., Akai, J. and Sakugawa, H. (2004) Mobilization of arsenic from subsurface sediments by effect of bicarbonate ions in groundwater. Chemosphere, 54(6), 753-62. 

Anawar, H.M., Akai, J., Komaki, K. et al. (2003) Geochemical occurrence of arsenic in groundwater of Bangladesh Sources and mobilization processes. Journal of Geochemical Exploration, 77(2-3), 109-31. 

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