Geochemical processes

Lerman, A. (1979). "Geochemical Processes Water and Sediment Environments." Wiley, New York. 

Eberl, D. D., Srodon, J., and Northrop, H. R. (1986). Potassium fixation in smectite by wetting and drying. In "Geochemical Processes at Mineral Surfaces," pp. 296-325. American Chemical Society, Washington, DC, ACS Symposium Series 323. 

Lasaga, A. C. (1981). Dynamic treatment of geochemical cycles global kinetics. In "Kinetics of Geochemical Processes" (A. C. Lasaga and R. J. Kirkpatrick, eds), pp. 69-110. Mineral. Soc. Amer., Washington, DC. 

The complex interactions amongst geological, biological, and geochemical processes at the land-sea margin control the delivery and fate of radionuclides, contaminants, and other natural elements in coastal environments (Swarzenski et al. 2003). For many such constituents, there is at least a fundamental understanding of major source and sink functions and their potential estuarine transformation reactions. For example, rivers can be monitored quite easily for discharge rates into estuaries as well as for elemental... 

DeMaster DJ, Kuehl SA, Nittrouer CA (1986) Effects of suspended sediments on geochemical processes near the mouth of the Amazon river - examination of biological silica uptake and the fate of particle-reactive elements. Cont Shelf Res 6 107-125... 

Environmental Factors Affecting Deep-Well-Injection Geochemical Processes.806... 

Table 20.4 presents the partition and transformation processes known to occur in the near-surface environment along with the special factors that should be considered when evaluating data in the context of the deep-well environment. Geochemical processes affecting hazardous wastes in deep-well environments have been studied much less than those occurring in near-surface environments (such as soils and shallow aquifers). Consequently, laboratory data and field studies for a particular substance may be available for near-surface conditions, but not for deep-well conditions. 

Near-Surface Geochemical Processes and Their Relevance to the Deep-Well Environment... 

ENVIRONMENTAL FACTORS AFFECTING DEEP-WELL-INJECTION GEOCHEMICAL PROCESSES... 

The previous chapter examined the geochemical processes that can occur in the deep-well environment. The type and outcome of reactions that will actually occur when a waste is injected, however, depend on its chemical characteristics and on injection-zone conditions. This chapter examines six major environmental factors that must be taken into consideration. 

Effects of pH on Deep-Well Geochemical Processes and Other Environmental Factors... 

This section relates the chemical characteristics of inorganic and organic hazardous wastes to the important fate-influencing geochemical processes occurring in the deep-well environment. 

Table 20.19 summarizes information about each study, including the location of the well, the lithology of the injection zone, waste characteristics, and the major geochemical processes observed. Current commercial-hazardous-waste, deep-well-injection facilities can be found on the Environment, Health and Safety Online (EHSO) web site.163... 

Messineva, M.A., The geological activity of bacteria and its effect on geochemical processes, in Geologic Activity of Microorganisms, Kuznetsov, S.I., Ed., Transactions of the Institute of Microbiology No. IX (trans. from Russian), Consultants Bureau, New York, 1962, pp. 6-24. 

Sposito, G. Distinguish adsorption from surface precipitation. In Geochemical Processes at Mineral Surfaces. J.A. Davis, K.F. Hayes, eds. Washington D.C. Americal Chemical Society Symposium Series No. 323,1986. 

Figure 1. Schematic illustration of factors influencing the production and migration of radon in soils and into buildings. Geochemical processes affect the radium concentration in the soil. The emanating fraction is principally dependent upon soil moisture (1 0) and the size distribution of the soil grains (d). Diffusion of radon through the soil is affected primarily by soil porosity ( ) and moisture content, while convective flow of radon-bearing soil gas depends mainly upon the air permeability (k) of the soil and the pressure gradient (VP) established by the building.

Manganese is of particular interest because of its central role in many marine geochemical processes and involvement in biological systems. 

In recent years, there has been an increasing level of interest in the use of 234Th/238U disequilibrium in the marine environment to study geochemical processes with short time scales (up to 100 days), particularly those associated with carbon cycling in the oceans [34-36] and the partitioning of pollutants between the dissolved and particulate phases [37,38]. However, the analysis of 234thorium is constrained by its short half-life and its low concentration in seawater, so appropriate analytical techniques must be rapid and sensitive and preferably should allow shipboard analysis. 

Reaction models, despite their simple conceptual basis (Fig. 2.1), can be configured in a number of ways to represent a variety of geochemical processes. Each type of model imposes on the system some variant of equilibrium, as described in the previous section, but differs from others in the manner in which mass and heat transfer are specified. This section summarizes the configurations that are commonly applied in geochemical modeling. 

Many geochemical processes occur in which a fluid remains in contact with a gaseous phase. The gas, which could be the Earth s atmosphere or a subsurface gas reservoir, acts to buffer the system s chemistry. By dissolving gas species from the buffer or exsolving gas into it, the fluid will, if reaction proceeds slowly enough, maintain equilibrium with the buffer. 

Helgeson, H. C., 1968, Evaluation of irreversible reactions in geochemical processes involving minerals and aqueous solutions, I. Thermodynamic relations. Geochimica et Cosmochimica Acta 32, 853-877. 

Environmental assessments of open-pit mines include an understanding of geochemical processes, which control production of acidity and migration of metals (Davis Ashenberg 1998, MEND 1991). 

This study describes the results of the formation water monitoring and the interpretation of the physical and geochemical processes from that data,... 

The distribution of Al and a number of other elements in soil profiles across the W-E transect appears to be strongly dependant on climate gradients rather than significant changes in soil parent materials and soil age. This observation provides important information about the relative importance of a number of geochemical processes that are not revealed in studies at more detailed (local) scales. 

Green, W.J., Stage, B.R., Preston, A., Wagers, S., Shacat, J. Newell, S. 2005. Geochemical processes in the Onyx River, Wright Valley, Antarctica major ions, nutrients, trace metals. Geochemica et Cosmochimica Acta, 69, 839-850. 

The rare earth elements (REE) form a group of elements that have coherent geochemical behaviour due to their trivalent charge and similar ionic radii. They can, however, be fractionated from one another as a result of geochemical processes operating under specific physico-chemical conditions. In order to outline general trends within and differences between the individual REE, concentrations are usually normalized to a reference system (e.g. to shale). Deviations of individual elements from the generally smooth trend are referred to as anomalies. 

Nordstrom, D.K. 2004. Modeling low-temperature geochemical processes. In Drever, J.l. (ed.) Surface and Ground Water, Weathering, and Soils 5, Holland, H.D. Turekian, K.K. (ed.) Treatise on Geochemistry, Elsevier, 37-72. 

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