Applied Geochemistry 24 (2009) 52–61
Contents lists available at ScienceDirect
Applied Geochemistry journal homepage: www.elsevier.com/locate/apgeochem
Particle size and mineralogical composition of inorganic colloids in waters draining the adit of an abandoned mine, Goesdorf, Luxembourg Montserrat Filella a,b,*, Vincent Chanudet a,c, Simon Philippo d, François Quentel e a
Department of Inorganic, Analytical and Applied Chemistry, University of Geneva, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland SCHEMA, Rue Principale 92, L-6990 Rameldange, Luxembourg c Institut F.-A. Forel, University of Geneva, 10 route de Suisse, CH-1290 Versoix, Switzerland d Musée National d’Histoire Naturelle, 25 rue Münster, L-2160 Luxembourg, Luxembourg e Laboratoire de Chimie Analytique, UMR-CNRS 6521, Université de Bretagne Occidentale, 6 avenue V. Le Gorgeu, F-29238 Brest Cedex 3, France b
a r t i c l e
i n f o
Article history: Received 29 April 2008 Accepted 1 November 2008 Available online 24 November 2008 Editorial handling by R. Fuge
a b s t r a c t Particle size distributions and the mineralogy of inorganic colloids in waters draining the adit of an abandoned mine (Goesdorf, Luxembourg) were quantified by single particle counting based on light scattering (100 nm–2 lm) combined with transmission electronic microscopy coupled with energy dispersive spectroscopy and selected area electron diffraction. This water system was chosen as a surrogate for groundwaters. The dependence of the colloid number concentration on colloid diameters can be described by a power-law distribution in all cases. Power-law slopes ranged from 3.30 to 4.44, depending on water ionic strength and flow conditions. The same main mineral types were found in the different samples: 2:1 phyllosilicates (illite and mica), chlorite, feldspars (albite and orthoclase), calcite and quartz; with a variable number of Fe oxide particles. The colloid mineralogical composition closely resembles the composition of the parent rock. Spatial variations in the structure and composition of the rock in contact with the waters, i.e. fissured rock versus shear joints, are reflected in the colloid composition. The properties of the study colloids, as well as the processes influencing them, can be considered as representative of the colloids present in groundwaters. Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction The transport and fate of contaminants in soils and groundwater are closely related to the nature and relative abundance of the reactive mineral phases. Since particles in the colloidal size range have a high specific surface, colloids moving through soils, regolith, fractured rock systems and aquifers have been the subject of much interest in a number of pollutant-related studies over many years (McDowell-Boyer et al., 1986; Buddemeier and Hunt, 1988; McCarthy and Zachara, 1989; Puls and Powell, 1992; McCarthy and Degueldre, 1993; Kaplan et al., 1994; Ledin et al., 1994; Honeyman, 1999; Ryan et al., 1999; Geckeis et al., 2003). Consequently, colloids have been studied in a variety of groundwaters from various geological formations ranging from crystalline (Degueldre, 1990; Laaksoharju, 1995; Billon et al., 1991; Vilks et al., 1991; Turrero et al., 1995; Degueldre et al., 1996; Düker and Ledin, 1998) to sedimentary (Longworth et al., 1990; Kim et al., 1992; Vilks et al., 1993) systems, including karstic aquifers (Atteia and Kozel, 1997; Atteia et al., 1998). However, for colloidal material in subsurface
* Corresponding author. Address: Department of Inorganic, Analytical and Applied Chemistry, University of Geneva, 30 quai Ernest-Ansermet, CH-1211 Geneva 4, Switzerland. Fax: +41 22 3796069. E-mail address: montserrat.fi
[email protected] (M. Filella). 0883-2927/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.apgeochem.2008.11.010
waters, particle size distributions and a quantitative classification of their mineralogical composition have rarely been published together. One of the main reasons for this is the difficulty in quantitatively assessing both the size and the composition of colloidal materials in natural waters. In order to overcome this problem, a non-perturbing approach that combines a size measuring technique (single particle counting) with the quantification of the size and mineralogical composition of inorganic colloids by transmission electron microscopy (TEM) coupled with energy dispersive spectroscopy (EDS) and selected area electron diffraction (SAED), after the non-perturbing on site preparation of specimen TEM grids, has been developed (Chanudet and Filella, 2006a). This approach has recently been used successfully in the study of a variety of surface waters (Chanudet and Filella, 2006b, 2008). However, in the case of subsurface waters, an additional factor that must be taken into account is the difficulty involved in sampling colloids without causing significant disturbance (McCarthy and Degueldre, 1993). In this study this problem was overcome by sampling water that either percolates through the ceiling of the adit of an abandoned mine or flows along the bottom of the adit. The colloids present in such waters can be considered as being very close to the ones existing in groundwaters, while avoiding sampling artefacts. Along with the ease of sampling, a further advantage is that it makes it possible to study, within a small area, waters with a
M. Filella et al. / Applied Geochemistry 24 (2009) 52–61
different history and chemical composition while maintaining a constant background rock composition, thus allowing the study of the effect of these factors on colloid size and composition.
53
The main inorganic soil constituents, which come from the weathering of the bedrock (shale), are (starting with the highest concentration): quartz, albite, sericite, illite, chlorite, kaolinite and montmorillonite (Verstraten, 1977). The proportion of each mineral essentially remains constant with depth.
2. Experimental 2.2. Sampling 2.1. Site description 2.1.1. Site location The mine is located 1 km east of the village of Goesdorf on a hill called Weissenstein. According to old maps, Weissenstein means ‘white stone’ and probably refers to quartz veins forming the mineral lode. The village of Goesdorf is located in the Eisleck (490 m asl), north of the Grand Duchy of Luxembourg. The name of the village comes from Giessdorf which etymologically means ‘‘village of smelters”. Mining in the area dates back to Roman times. The mine was exploited until 1944. It consists of a main shaft (70 m deep), 450 m of drift split into five levels, a drain adit at the base of the main shaft, and three smaller extraction shafts. The upper part of the mine (entrance to the shafts and dumps) is at the top of a hill covered in meadowland. The drain adit is located in a valley covered by a deciduous forest (oak and beech trees). The adit is 2 lm) are being lost in samples C and D, which is not happening in samples F and H. It is important to mention, however, that measurements in the higher size range should be considered with caution because they are based on extremely low particle counts, particularly in waters which contain a very low particle charge, as is the case with Goesdorf waters. 4. Discussion The composition of the colloids in the different samples (2:1 phyllosilicates, feldspars, quartz) is quite similar and fairly accurately reflects the composition of the solid matrix. Mobile colloids are generated in soils and groundwaters by a number of mechanisms including (i) erosion and mechanical resuspension of noncemented small sized grains and (ii) dissolution of cementation agents composed of fine-grained crystalline and poorly-crystalline secondary minerals. Thus the predominance of illite colloids (the largest proportion of the 2:1 phyllosilicates) in most samples is easily explained by the predominance of this mineral in the rock shear joints; because of its fragmented structure, small, solid components of such joints will be mobilized more easily than the components of unaltered rocks. The different composition of sample H (a higher concentration of feldspars) would therefore suggest that waters at this point do not percolate through a shear joint but through fissured rocks (richer in feldspars). It is interesting to note that waters in close physical proximity (points G and H) can have different colloid compositions which just reflect the heterogeneity of the solid matrix. A third mechanism by which colloids are generated in subsurface systems is the precipitation of colloidal size phases. Dolomite, calcite and Fe oxides are examples of this colloid formation process in the system studied. As shown by speciation calculations, both calcite and dolomite are oversaturated in the waters that have
been in contact with the mineralised vein and their formation could therefore be expected, if kinetic factors are ignored. Iron oxides are present in all samples. They have a variety of morphological aspects; many were sorbed onto other mineral and organic phases. The diversity of amorphous Fe oxides formed in natural waters is well-known (Davison and De Vitre, 1992; Perret et al., 2000). Ferrihydrite, the most widespread poorly crystalline Fe oxide, is ambiguous in its identity and often consists of a mixture of particles with varying degrees of ordered structures and hydration (Majzlan et al., 2004). Moreover, even if crystalline forms were present, as discussed in detail in Chanudet and Filella (2006a), the measuring method would not allow for assigning crystallographic structures to these oxides (e.g., hematite, goethite, lepidocrocite, etc.). The abundance of fresh Fe oxyhydroxides in sample H merits particular mention. Morphologically they looked different from the Fe oxides observed in the other samples. It is not possible to ascertain whether these colloids were formed before, during or after sampling but they were absent in other waters with apparently similar chemical characteristics and origin (samples F and G) when the same sampling and conservation procedures were used. Although colloids in all samples show a common log–log linear number versus size relationship, different slope values have been measured. They show that the proportion of bigger versus smaller particles is not constant among the samples. A number of different factors need to be considered in combination in order to understand the differences observed. First, two different types of water sample have been measured: waters that come directly from the ‘‘rock” (points C, F, H and G) and waters that flow along the floor of the adit (samples B, D and E). For the first group of water samples, different slope values may be due to the effect of: (i) water flow rate: higher flow rates may modify mobilization, transport and coagulation processes; (ii) mineralogical composition: different types of material may erode in different ways or precipitate in different sizes; (iii) the solid matrix structure: the presence of material that is more or less fractured or porous and physical factors related to the relative size of the colloids
60
M. Filella et al. / Applied Geochemistry 24 (2009) 52–61
and pores and pore throats; (iv) differences in water chemistry: a higher ionic strength favours coagulation and attachment between colloids and between colloids and matrix minerals. Sample C is characterised by a higher SPC b value, the absence of aggregates (TEM) and the presence of smaller TEM-sized illites as compared to sample F. Considering that there are no significant differences in factor (ii), the different features can be explained by the combined effect of a higher water flow and a lower ionic strength at point C. The effect of the slightly higher ROM level (compared to other samples) at point C could also be cited, but the well-known colloid stabilising effect of ROM compounds (Filella, 2007) is probably negligible in this case because ROM concentration in C is still very low in absolute terms. Waters at G and H share very similar conductivities (high) and flows (very low) but, as discussed above, they differ significantly in terms of their colloidal composition (presence of feldspars and fresh Fe oxides in H). Unfortunately, their b values cannot be compared because PSD was not measured at point G by SPC. However, it is important to mention that, as shown by TEM images, the total number of colloids in this sample is extremely low while the composition is still typical of the other samples, although with bigger illite particles. Thus, the combination of high ionic strength and very slow flow conditions would favour the retention of smaller particles in the porous media while bigger particles flow through preferential paths. For the second group of samples (B, D and E), slope values remain relatively constant in the waters flowing through the adit prior to the input of water at C (points D and E) while water in B shows a distinctively higher b value. Colloid PSD in any surface water is the result of the combined effect of the PSD of the incoming waters, entrainment of colloids previously settled in the colluvial sediments, losses through aggregation–sedimentation and aggregate breakage. In the samples studied, although a possible disaggregating effect brought about by a decrease in the ionic strength after the input of waters at point C cannot be disregarded, variations in b values seem to very closely reflect the PSD of the incoming waters. 5. Conclusions Coupling particle size determination by light scattering with mineralogical characterization and quantification by TEM-EDSSAED has recently proved to be a powerful tool in the study of colloids in surface waters (Chanudet and Filella, 2008) and ice (Chanudet and Filella, 2006b). In this study, the same approach has been applied to the study of waters draining the adit of an old mine. This system was chosen as a close surrogate of groundwater media. While variations in PSD of these subsurface waters are mostly due to variations in water ionic strength and flow rates, the colloid mineralogical composition reflects the composition and structure of the parent rock. Similar factors can be expected to influence the size and mineralogical composition of groundwater colloids. Acknowledgements We would like to thank Dina Andriamahady (ROM), Isabelle Bihannic (XRD) and Odile Barres (IR) for laboratory assistance. References ASTM, 2005. D1067-02 Test Methods for Acidity or Alkalinity of Water, vol. 11.01. ASTM Book of Standards. Atteia, O., Kozel, R., 1997. Particle size distributions in waters from a karstic aquifer: from particles to colloids. J. Hydrol. 201, 102–119. Atteia, O., Perret, D., Adatte, T., Kozel, R., Rossi, P., 1998. Characterization of natural colloids from a river and spring in a karstic basin. Environ. Geol. 34, 257–269. Billon, A., Caceci, M., Della Mea, G., Dellis, T., Dran, J. C., Moulin, V., Nicholson, S., Petit, J. C., Ramsay, J., Russel, P., Theyssier, M., 1991. The role of colloids in the
transport of radionuclides in geological formations. Commission of the European Communities, Luxembourg. Report EUR 13506 en. Buddemeier, R.W., Hunt, J.R., 1988. Transport of colloidal contaminants in groundwater: radionuclide migration at the Nevada test site. Appl. Geochem. 3, 535–548. Chanudet, V., Filella, M., 2006a. A non-perturbing scheme for the mineralogical characterization and quantification of inorganic colloids in natural waters. Environ. Sci. Technol. 40, 5045–5051. Chanudet, V., Filella, M., 2006b. Particle size and mineralogical composition of inorganic colloids in glacier-melting water and overlying ice in an Alpine glacier, the Oberaargletscher, Switzerland. J. Glaciol. 52, 473–475. Chanudet, V., Filella, M., 2007a. Submicron organic matter in a peri-alpine, ultraoligotrophic lake. Org. Geochem. 38, 1146–1160. Chanudet, V., Filella, M., 2007b. The fate of inorganic colloidal particles in Lake Brienz. Aquat. Sci. 69, 199–211. Chanudet, V., Filella, M., 2008. Size and composition of inorganic colloids in a perialpine, glacial flour-rich lake. Geochim. Cosmochim. Acta 72, 1466–1479. Chanudet, V., Filella, M., Quentel, F., 2006. Application of a simple voltammetric method to the determination of refractory organic substances in freshwaters. Anal. Chim. Acta 569, 244–249. Davison, W., De Vitre, R., 1992. Iron particles in freshwater. In: Buffle, J., van Leeuwen, H.P. (Eds.), Environmental Particles I. Lewis, Chelsea, MI, pp. 315–355. Degueldre, C., 1990. Grimsel colloid exercise – an international intercomparison exercise on the sampling and characterisation of groundwater colloids. Commission of the European Communities, Luxembourg, Report EUR 12660 en. Degueldre, C., Grauer, R., Laube, A., Oess, A., Silby, H., 1996. Colloid properties in granitic groundwater systems. II: Stability and transport study. Appl. Geochem. 11, 697–710. Düker, A., Ledin, A., 1998. Properties of the particulate phase in deep saline groundwater in Laxemar, Sweden. Water Res. 32, 186–192. Filella, M., 2007. Colloidal properties of submicron particles in natural waters. In: Wilkinson, K.W., Lead, J. (Eds.), Environmental Colloids and Particles: Behaviour, Separation and Characterisation. Wiley, New York, pp. 17–93. Filella, M., Barres, O., Belzile, N., Bihannic, I., Chanudet, V., Chen, Y.-W., Philippo, S., Quentel, F., Webb, S., 2008. Solubility and adsorption in antimony environmental fate: the case of the Goesdorf mine, Luxembourg. Presented at XIII ISSP, Dublin, Ireland. Geckeis, H., Ngo Manh, Th., Bouby, M., Kim, J.I., 2003. Aquatic colloids relevant to radionuclide migration: characterization by size fractionation and ICP-mass spectrometric detection. Colloids Surf. A 217, 101–108. Honeyman, B.D., 1999. Colloidal culprits in contamination. Nature 397, 23–24. Kaplan, D.I., Bertsch, P.M., Adriano, D.C., Orlandini, K.A., 1994. Actinide association with groundwater colloids in a coastal plain aquifer. Radiochim. Acta 66/67, 181–187. Kim, J., Zeh, P., Delakovitz, B., 1992. Chemical interactions of actinide ions with groundwater colloids in Gorleben aquifer systems. Radiochim. Acta 58/59, 147– 154. Klein, C., 2002. Manual of Mineral Science, 22nd ed. John Wiley and Sons, New York. Knollenberg, R.G., Veal D.L., 1991. Optical particle monitors, counters, and spectrometers: performance characterization, comparison and use. In: Proceedings of the 37th Annual Technical Meeting of the Institute of Environmental Sciences, San Diego, CA, pp. 750–771. Laaksoharju, M., 1995. Colloidal particles in deep Swedish granitic groundwater. SKB Technical Report AR-90-37, SKB, Stockholm, Sweden. Ledin, A., Karlsson, S., Düker, A., Allard, B., 1994. Measurements in situ of concentration and size distribution of colloidal matter in deep groundwaters by photon correlation spectroscopy. Water Res. 28, 1539–1545. Lienemann, C.-P., Heissenberger, A., Leppard, G.G., Perret, D., 1998. Optimal preparation of water samples for the examination of colloidal material by transmission electron microscopy. Aquat. Microb. Ecol. 14, 205–213. Longworth, G., Ross, C.A.M., Degueldre, C., Ivanovich, M., 1990. Interlaboratory study of sampling and characterization techniques for groundwater colloids: the Markham Clinton exercise. Commission of the European Communities, Luxembourg. Report EUR 12843 en. Lucius, M., 1950. Das Oesling. Publication du Service Géologique de Luxembourg, Band VI. Majzlan, J., Navrotsky, A., Schwertmann, U., 2004. Thermodynamics of iron oxides: Part III. Enthalpies of formation and stability of ferrihydrite (Fe(OH)3), schwertmannite (FeO(OH)3/4(SO4)1/8), and e-Fe2O3. Geochim. Cosmochim. Acta 68, 1049–1059. May, P.M., Murray, K., 2001. Database of chemical reactions designed to achieve thermodynamic consistency automatically. J. Chem. Eng. Data 46, 1035–1040. McCarthy, J.F., Degueldre, C., 1993. Sampling and characterization of colloids and particles in groundwater for studying their role in contaminant transport. In: Buffle, J., van Leeuwen, H.P. (Eds.), Environmental Particles II. Lewis, Chelsea, MI, pp. 247–315. McCarthy, J.F., Zachara, J.M., 1989. Subsurface transport of contaminants. Environ. Sci. Technol. 23, 496–502. McDowell-Boyer, L.M., Hunt, J.R., Sitar, N., 1986. Particle transport through porous media. Water Resour. Res. 22, 1901–1921. Perret, D., Gaillard, J.-F., Dominik, J., Atteia, O., 2000. The diversity of natural hydrous iron oxides. Environ. Sci. Technol. 34, 3540–3546. Perret, D., Leppard, G.G., Muller, M., Belzile, N., De Vitre, R., Buffle, J., 1991. Electron microscopy of aquatic colloids: Non-perturbing preparation of specimens in the field. Water Res. 25, 1333–1343. Philippo, S., Hanson, A., 2007. La minéralisation en antimoine de Goesdorf. Ferrantia 49, 111–146.
M. Filella et al. / Applied Geochemistry 24 (2009) 52–61 Puls, R.W., Powell, R.M., 1992. Transport of inorganic colloids through natural aquifer material: implications for contaminant transport. Environ. Sci. Technol. 26, 614–621. Roduit, N., 2006. JMicroVision, Department of Geology, University of Geneva. (accessed 06.02.08). Rossé, P., Loizeau, J.-L., 2003. Use of single particle counters for the determination of the number and size distribution of colloids in natural surface waters. Colloids Surf. A 217, 109–120. Ryan, J.N., Elimelech, M., Ard, R.A., Harvey, R.W., Johnson, P.R., 1999. Colloid mobilization and transport in groundwater. Environ. Sci. Technol. 33, 63–73. Turrero, M.-J., Gómez, P., Pérez del Villar, L., Moulin, V., Magonthier, M.-C., Menager, M.-T., 1995. Relation between colloid composition and the environment of their
61
formation: application to the El Berrocal site (Spain). Appl. Geochem. 10, 119– 131. Verstraten, J.M., 1977. Chemical erosion in a forested watershed in the Oesling, Luxembourg. Earth Surf. Process 2, 175–184. Vilks, P., Cramer, J.J., Bachinski, D.B., Doern, D.C., Miller, H.G., 1993. Studies of colloids and suspended particles, Cigar Lake uranium deposit, Saskatchewan, Canada. Appl. Geochem. 8, 605–616. Vilks, P., Miller, H.G., Doern, D.C., 1991. Natural colloids and suspended particles in the Whiteshell Research Area, Manitoba, Canada, and their potential effect on radiocolloid formation. Appl. Geochem. 6, 565–574. Wieland, E., Spieler, P., 2001. Colloids in the mortar backfill of a cementitious repository for radioactive waste. Waste Manage. 21, 511–523.
