Denitrification potential and occurrence of reactive minerals in the fractured carbonate aquifer of the Upper Muschelkalk, SW-Germany

2020 ◽  
Author(s):  
Hermann Rügner ◽  
Eva Blendinger ◽  
Karsten Osenbrück ◽  
Natalia Jakus ◽  
Peter Grathwohl
Keyword(s):  
Drinking Water ◽  
Pore Space ◽  
Effective Diffusion ◽  
Weight Percent ◽  
Fractured Aquifer ◽  
Thin Sections ◽  
Drinking Water Resources ◽  
Upper Muschelkalk ◽  
Facies Types ◽  
Matrix Rock

<p>Fractured or karstified carbonate rocks constitute major drinking water resources all over the world. Nitrate is one of the major threads for drinking water suppliers in regions with intensive agrucultural use. Field scale observations in the Upper Muschelkalk aquifer in the area “Oberes Gäu”, SW-Germany, suggest that denitrification due to oxidation of Fe<sup>(II)</sup> or sulfide-bearing minerals might be a relevant attentuation process at least in cases of extended mean residence times (> 5-40 years).</p><p>To identify reactive minerals within the rock matrix rock samples have been taken from major facies types within the Upper Muschelkalk from outcrops, drillings and carbonate quarries. Samples have been analysed in polished thin sections using transmitted & reflected light microscopy as well as electron microscopy including energy-dispersive elemental analysis.</p><p>Reactive Fe<sup>(II)</sup> and sulfide-bearing minearls are pyrite and marcasite as well as saddle dolomites (Fe-bearing dolomites). Concentrations of these minerals depend on facies types and amount to several weight percent iron. Porosities range from very low values (<1 %) up to 25 %.</p><p>In combination with a hydrogeological characterization, these investigations allowed to delineate reactive zones within the fractured aquifer. Denitrification within these reactive zones depends on the amount and dissolution of these minerals as well as effective diffusion in the pore space.</p>

Correlation of Pore Structure and Permeability by SEM-Image Analysis

1990 ◽  
Vol 48 (1) ◽  
pp. 428-429
Author(s):  
C. A. Callender ◽  
Wm. C. Dawson ◽  
J. J. Funk
Keyword(s):  
Image Analysis ◽  
Pore Structure ◽  
Imaging System ◽  
Pore Space ◽  
Simulation Models ◽  
Image Analyzer ◽  
Imaging Data ◽  
Sem Images ◽  
Thin Sections ◽  
Rock Types

The geometric structure of pore space in some carbonate rocks can be correlated with petrophysical measurements by quantitatively analyzing binaries generated from SEM images. Reservoirs with similar porosities can have markedly different permeabilities. Image analysis identifies which characteristics of a rock are responsible for the permeability differences. Imaging data can explain unusual fluid flow patterns which, in turn, can improve production simulation models.Analytical SchemeOur sample suite consists of 30 Middle East carbonates having porosities ranging from 21 to 28% and permeabilities from 92 to 2153 md. Engineering tests reveal the lack of a consistent (predictable) relationship between porosity and permeability (Fig. 1). Finely polished thin sections were studied petrographically to determine rock texture. The studied thin sections represent four petrographically distinct carbonate rock types ranging from compacted, poorly-sorted, dolomitized, intraclastic grainstones to well-sorted, foraminiferal,ooid, peloidal grainstones. The samples were analyzed for pore structure by a Tracor Northern 5500 IPP 5B/80 image analyzer and a 80386 microprocessor-based imaging system. Between 30 and 50 SEM-generated backscattered electron images (frames) were collected per thin section. Binaries were created from the gray level that represents the pore space. Calculated values were averaged and the data analyzed to determine which geological pore structure characteristics actually affect permeability.

scholarly journals Technologies Developing in Heavy Metals’ Removal from Water

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 860
Author(s):  
Konstantinos Simeonidis ◽  
Manassis Mitrakas
Keyword(s):  
Heavy Metals ◽  
Drinking Water ◽  
Water Resources ◽  
Human Health ◽  
Urban Wastewater ◽  
Heavy Metals Removal ◽  
Metals Removal ◽  
Drinking Water Resources

Elevated concentrations of heavy metals in drinking water resources and industrial or urban wastewater pose a serious threat to human health and the equilibrium of ecosystems [...]

scholarly journals Persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM) substances pose an equivalent level of concern to persistent, bioaccumulative and toxic (PBT) and very persistent and very bioaccumulative (vPvB) substances under REACH

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Sarah E. Hale ◽  
Hans Peter H. Arp ◽  
Ivo Schliebner ◽  
Michael Neumann
Keyword(s):  
Drinking Water ◽  
Human Health ◽  
Regulatory Decision ◽  
Drinking Water Resources ◽  
Trade Name ◽  
Chemicals Regulation ◽  
Range Transport ◽  
High Concern ◽  
Level Of Concern

Abstract Background Under the EU chemicals regulation REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals EC 1907/2006), registrants are not obliged to provide information related to intrinsic substance properties for substances that pose a threat to the drinking water resources. In 2019, perfluorobutane sulfonic acid (PFBS) and 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)-propanoic acid (HFPO-DA trade name GenX) were demonstrated to have an equivalent level of concern (ELoC) to persistent, bioaccumulative and toxic or very persistent and very bioaccumulative (PBT/vPvB) substances owing to their persistent, mobile and toxic (PMT) substance properties and very persistent and very mobile (vPvM) substance properties, respectively. They were both subsequently identified as substances of very high concern (SVHC) applying Article 57(f) in REACH. This work follows up on this regulatory decision by presenting a science based, conceptual level comparison that all PMT/vPvM substances pose an ELoC to PBT/vPvB substances. Using the two cases named above, as well as 1,4-dioxane, 16 categories were developed to evaluate a) serious effects on human health, b) serious effects on the environment and c) additional effects. 1,4-dioxane has recently been proposed to be classified as Carcinogenic 1B by the Committee for Risk Assessment (RAC). The aim was to enable an objective and scientifically justified conclusion that these classes of substances have an equivalent level of concern for the environment and human health. Results In all of the categories related to human health, the environment and other effects, the PMT/vPvM case study substances exhibited comparable effects to PBT/vPvB substances. A difference in the human and environmental exposure pathways of PMT/vPvM and PBT/vPvB substances exists as they vary temporally and spatially. However, effects and impacts are similar, with PMT/vPvM substances potentially accumulating in (semi-)closed drinking water cycles and pristine aquatic environments, and PBT/vPvB substances accumulating in humans and the food chain. Both PMT/vPvM and PBT/vPvB substances share the common difficulty that long term and long-range transport and risk of exposure is very difficult to determine in advance and with sufficient accuracy. Conclusion The registration process of substances under REACH should reflect that PMT/vPvM substances pose an equivalent level of concern to PBT/vPvB substances.

Permeability-porosity transforms from small sandstone fragments

Geophysics ◽  
2006 ◽  
Vol 71 (1) ◽  
pp. N11-N19 ◽  
Author(s):  
Ayako Kameda ◽  
Jack Dvorkin ◽  
Youngseuk Keehm ◽  
Amos Nur ◽  
William Bosl
Keyword(s):  
Pore Space ◽  
Petroleum Industry ◽  
Rock Physics ◽  
Three Dimensions ◽  
Absolute Permeability ◽  
High Porosity ◽  
Drill Cuttings ◽  
Thin Sections ◽  
Numerical Experimentation ◽  
The Absolute

Numerical simulation of laboratory experiments on rocks, or digital rock physics, is an emerging field that may eventually benefit the petroleum industry. For numerical experimentation to find its way into the mainstream, it must be practical and easily repeatable — i.e., implemented on standard hardware and in real time. This condition reduces the size of a digital sample to just a few grains across. Also, small physical fragments of rock, such as cuttings, may be the only material available to produce digital images. Will the results be meaningful for a larger rock volume? To address this question, we use a number of natural and artificial medium- to high-porosity, well-sorted sandstones. The 3D microtomography volumes are obtained from each physical sample. Then, analogous to making thin sections of drill cuttings, we select a large number of small 2D slices from a 3D scan. As a result, a single physical sample produces hundreds of 2D virtual-drill-cuttings images. Corresponding 3D pore-space realizations are generated statistically from these 2D images; fluid flow is simulated in three dimensions, and the absolute permeability is computed. The results show that small fragments of medium– to high-porosity sandstones that are statistically subrepresentative of a larger sample will not yield the exact porosity and permeability of the sample. However, a significant number of small fragments will yield a site-specific permeability-porosity trend that can then be used to estimate the absolute permeability from independent porosity data obtained in the well or inferred from seismic techniques.

scholarly journals Evaluation of Human Enteric Viruses in Surface Water and Drinking Water Resources in Southern Ghana

2011 ◽  
Vol 84 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Kristen E. Gibson ◽  
Yayi Guo ◽  
James T. Schissler ◽  
Melissa C. Opryszko ◽  
Kellogg J. Schwab
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Water Resources ◽  
Enteric Viruses ◽  
Drinking Water Resources ◽  
Human Enteric Viruses ◽  
Southern Ghana

Prospective environmental and economic assessment for biotreatment of micropollutants in drinking water resources in Denmark

2015 ◽  
Vol 15 (6) ◽  
pp. 1405-1413 ◽  
Author(s):  
Ivan Muñoz ◽  
Erik de Vries ◽  
Janneke Wittebol ◽  
Jens Aamand
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Economic Assessment ◽  
Pilot Scale ◽  
Impact Categories ◽  
Financial Cost ◽  
Sand Filters ◽  
Immobilized Bacteria ◽  
Drinking Water Resources ◽  
Scale Data

A prospective environmental life cycle assessment (LCA) and financial cost assessment is performed to the application of bioaugmentation to sand filters in Danish waterworks, to remove 2,6-dichlorobenzamide (BAM) from drinking water resources. Based on pilot-scale and laboratory-scale data, we compare bioaugmentation to current alternative strategies, namely granular activated carbon (GAC) adsorption, and well re-location. Both assessments identified well re-location as the least preferred option, however, this result is very sensitive to the distance from the waterworks to the new well. When bioaugmentation is compared to GAC, the former has a lower impact in 13 impact categories, but if immobilized bacteria are used, the impacts are higher than for GAC in all impact categories. On the other hand, from a cost perspective bioaugmentation appears to be preferable to GAC only if immobilized bacteria are used.

Micromorphology of soil structure - Description, quantification, application

Soil Research ◽  
1991 ◽  
Vol 29 (6) ◽  
pp. 777 ◽  
Author(s):  
AJ Ringrose-Voase
Keyword(s):  
Soil Structure ◽  
Pore Space ◽  
Structural Parameters ◽  
Thin Sections ◽  
Physical Measurements ◽  
Undisturbed Samples ◽  
Structure Description ◽  
Management Techniques ◽  
Pore Types ◽  
Soil Behaviour

Micromorphological observation can provide insights into soil structure and aid interpretation of soil behaviour. Undisturbed samples are taken in the field and impregnated. They are used to prepare thin sections or images of the macropore structure using fluorescent photography. Sections can also be obtained at macro, meso and submicroscopic scales. The various elements of soil structure observed micromorphologically can be classified into pore space, physical, distribution and orientation fabrics, and associated structures. Examples of the importance of features in each category are given. Image analysis, especially when computerized, provides a way of parameterizing micromorphological observations. To date it has been used primarily on images of macropore space at the meso and microscopic scales. Such images can be digitized and segmented to show pore space and solid. The pore space can be allocated to pore types. This aids the estimation of 3-D parameters from I-D and 2-D measurements made on the image using stereology. Various ways of using structural parameters to compare structures are discussed. Applications for micromorphological observations, especially when quantitative, include comparison of structures formed by different management techniques. Structural measurements can aid interpretation of soil behaviour as described by physical measurements. They also have a role in estimating the representative elementary volume, on which physical measurements should be made, and in calibrating field estimates of soil structure.

Sign in / Sign up

Export Citation Format

Share Document