scispace - formally typeset
Open AccessBook

Geochemical Processes: Water and Sediment Environments

Reads0
Chats0
TLDR
The approach of this book to geochemistry can be summarized in the question: What happens, and how fast does it happen, when waters, solids, and gases interact in the earth's surface environment? The environment of the earths surface is made of solids and fluids, and the interactions among them are responsible for much of what is taking place in the physical world around us as mentioned in this paper.
Abstract
The approach of this book to geochemistry can be summarized in the question: What happens, and how fast does it happen, when waters, solids, and gases interact in the earths surface environment? The environment of the earths surface is made of solids and fluids, and theinteractions among them are responsible for much of what is taking place in the physical world around us. The dissolved load of natural waters and the materials of which sediments are made are the products of reactions taking place practically everywhere on land, in the atmosphere, and in the hydrosphere. Thus the term water and sediment environments applies effectivelly to much of the surface environment of the earth, including the zone of up to a few kilometers above and below the land and ocean surface. Evolution present itself to us as a more or less complex variety of processes-geological, physical, chemical, and biological. To this end, the inclusive title Geochemical Processes was chosen for the book, to introduce a text that emphasizes processes and time-dependent phenomena.

read more

Citations
More filters
Journal ArticleDOI

Effective reactive surface area: An anisotropic property of physically and chemically heterogeneous porous media

Abstract: Although transport calculations are often formulated in terms of mass-based isotropic distribution coefficients, it is the abundance of reactive surface areas of subsurface materials that controls contaminant adsorption. In water-saturated homogeneous systems devoid of advective fluxes (e.g., batch experiments), the available reactive surface area is similar to the total surface area (as measured by conventional methods such as BET gas adsorption). However, in physically and chemically heterogeneous systems with advective fluxes, the effective reactive surface area (i.e., the surface area that a packet of advecting water interacts with) is smaller than the laboratory measured surface area and is a complex function of advective velocity and the correlation structures of the physical and chemical heterogeneities. Theoretical derivations for an important but simple type of heterogeneity (fine-scale horizontal layering) suggest that the effective reactive surface area is an anisotropic property of the medium and is inversely correlated with the anisotropy in hydraulic conductivity. The implications of reactive transport anisotropy include the concept that the retardation factor should be treated as a directional property rather than being treated as a constant. Furthermore, because of the inverse relationship between effective reactive surface area and hydraulic conductivity, batch adsorption experiments tend to overestimate the retention of contaminants relative to intact natural materials.
Journal ArticleDOI

Modeling Non-Stationary Processes of Diffusion of Solute Substances in the Near-Bottom Layer ofWater Reservoirs: Variation of the Direction of Flows and Assessment of Admissible Biogenic Load

TL;DR: In this article, a non-stationary free boundary problem is modeled and numerical computations of the problem are performed to estimate the potentials of the biogenic load on the water reservoir.
Journal ArticleDOI

岩石-流体反応プロセスのt-h-c連成モデルによる岩石及び土壌変質シミュレーション

TL;DR: In this paper, the T(thermo)-H(hydro)-C(chemical) coupled mathematical model is used to simulate the chemical reaction and dynamic function of the solid-liquid interface and overall systems.
Journal ArticleDOI

Geochemical control of [H+] in lakes receiving acidic deposition

TL;DR: In this paper, bottom sediments were collected from seven lakes and tested for aluminosilicates and nine geochemical weathering models were written and examined for their ability to predict pH values in agreement with measured pH values.
Related Papers (5)