River acid mine drainage

Clark Fork River, an important tributary of the Columbia River. Acid mine drainage seriously degrades water quality and threatens the existence of animal and plant populations. The average pH is 2.5, an acidity level toxic to most life forms, both macrobial and microbial. Many cations reach levels well above drinking water standards set by the EPA. A sample of Berkeley Pit lake water analyzed by Inductively Coupled Plasma (ICP) has high levels of Fe+2/Fe+3, Al+, Cu+2, and many other cations. It is also very rich in sulfates, the predominant anionic species present (8500 ppm). Some typical cation levels in Pit water (24) and EPA drinking water standards for these same cations are shown below in Table 1 [48],... 

Turner, A., Rawling, M.C. (2002) Sorption of benzo[a]pyrene to sediment contaminated by acid mine drainage contrasting particle concentration-dependencies in river water and seawater. Water Res. 36, 2011-2019. 

Johnson, C. A., 1986, The regulation of trace element concentrations in river and estuarine waters with acid mine drainage, the adsorption of Cu and Zn on amorphous Fe oxyhydroxides. Geochimica et Cosmochimica Acta 50, 2433-2438. 

A number of methods have been devised to reduce acid mine drainage (AMD) and, therefore, the harmful environmental effects it may cause. One of the simplest approaches (at least in theory) is to divert the flow of water that would normally pass through or over a mine. The principle is that in the absence of water much less sulfuric acid forms and what little is produced is not likely to he carried into lakes, rivers, and other bodies of water. 

Upper Colorado River Basin Colorado USA 37 streambed sediment samples (8 from nonmined areas) USA Alabama northern impacted by acid mine drainage 25 sites USA Alaska Cook Inlet Basin streams 47 sites USA Black Hills Spearfish, Whitewood, and Bear Butte creeks watersheds USA (conterminous) (541 stream bed samples)... 

Kimball, B.A., Callender, E. and Axtmann, E.V. (1995) Effects of colloids on metal transport in a river receiving acid mine drainage, Upper Arkansas River, Colorado, U.S.A. Applied Geochemistry, 10(3), 285-306. 

Figure 8.10 Sorption constants for Cu, Zn and Cd on natural oxyhydroxides as a function of pH obtained from field measurements. The points were obtained in the Carnon River, UK (V, Johnson, 1986) in 40 sites in Canadian lakes representing a variety of geological settings, lake pH values, and trace element concentrations in the sediments and in the overlying waters (O, Tessier, 1992) and in streams affected by acid mine drainage (A, Chapman et at., 1983). Log= Fe-M / Fe-ox [Mz+] (adapted from Tessier, 1992).

Diamond, J. M., W. Bower, and D. Gruber. 1993. Use of man-made impoundment in mitigating acid mine drainage in the North Branch Potomac River. Environ. Management 17 225-238. 

Brake S. S., Connors K. A., and Romberger S. B. (2001) A river runs through it impact of acid mine drainage on the geochemistry of West Little Sugar Creek pre- and postreclamation at the Green Valley coal mine, Indiana, USA. Environ. Geol. 40, 1471-1481. 

Therefore in general, Eh measurements in natural systems are quite often of only qualitative significance (Morris and 8tumra, 1967 Nordstrom and Munoz, 1985 Drever, 1988), although there are systems where Eh can be quantitatively related to independently determined redox couples, such as Fe-rich river waters or acid-mine drainage waters (Crerar et al., 1981 Kleinmann et al., 1981 see also Nordstrom et al., 1979). Field Eh measurements can be very useful in systems where one redox couple (such as Fe /Fe ) predominates, but the chemical composition of the solution should be well characterized before such data are used quantitatively. And in spite of the difficulties of measurement in natural systems, we will always need some way of discussing such systems theoretically, and Eh is much used in this way. 

Nieto JM, Sarmiento AM, Ohas M, Canovas CR, Riba I, Kalman J, Delvalls TA (2007) Acid mine drainage pollution in the Tinto and Odiel rivers (Iberian Pyrite Belt, SW Spain) and bioavail-abflity of the transported metals to the Huelva Estuary. Environ Int 33 445-455 Nordstrom KD (1982) Aqueous pyrite oxidation and the consequent formation of secondary minerals. In Kittrick JA, Fanning DS, Hossner LR (eds) Acid sulfate weathering pedogeochemistry and relationship to manipulation of soil materials. Soil Science Society, America Press, Madison, WI, pp 37-56... 

Paper mill on the Potomac River near Westernport, Maryland, neutralizes acid mine drainage in the water. Upstream of the mitt, the river is acidic and lifeless below the mitt, the river teems with life. 

The results of a detailed investigation of the Carnon River system (south-west England) have shown high concentrations of Fe, Cu, Zn, As and Cl" in the river water (Johnson and Thornton 1987), with the Cl" subjected to strong seasonal variations. Over 80% of Fe, Zn and As, and about 40% of Cu is derived from acid mine drainage. The binding of Cu and Zn depends on the pH and Fe concentration, whereas, only little pH dependence is observed for As. About 80% of arsenic was found in the particulate phase. 

Johnson CA, Thornton I (1987) Hydrological and chemical factors controlling the concentrations of Fe, Cu, Zn and As in a river system contaminated by acid mine drainage. Wat. Res. 21 3. 

With rare exception all source waters have relatively low lead. Ground-waters generally have very low lead and river waters sometimes contain detectable lead from industrial discharges or acidic mine drainage. However, even in these cases, much of the lead is removed by water treatment. 

This sensor approach has also been employed in the analysis of several relevant and contrasting water samples such as river water, acid mine drainage, and treated urban water, thus covering a wide spectnun of matrices and absolute and relative heavy metal concentrations. Residts were shown to be in good agreement with those obtained with the standard inductively coupled plasma mass spectroscopy technique [36]. Moreover, this sol-gel nanocomposite has been successfully employed for the construction of screen-printed electrochemical sensors. 

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