MICROBIAL PARTICIPATION IN IODIDE REMOVAL FROM SOLUTION BY ORGANIC SOILS

1989 ◽  
Vol 69 (1) ◽  
pp. 127-135 ◽  
Author(s):  
J. T. KOCH ◽  
D. B. RACHAR ◽  
B. D. KAY
Keyword(s):  
Gamma Irradiation ◽  
Key Words ◽  
Microbial Activity ◽  
Nuclear Fuel ◽  
Organic Soil ◽  
Organic Soils ◽  
Γ Radiation ◽  
Precambrian Shield ◽  
Biological Removal ◽  
Nuclear Fuel Waste

The migration of the long-lived nuclide 129I in the biosphere may be changed if the nuclide passes through an organic soil (organic soils often occur in topographical depressions where groundwater generally enters the biosphere). The reactivity of I and, hence, its transportability may be altered in organic soils by processes in which microorganisms participate. The aim of this study, therefore, was to test for microbial participation in these processes. Twelve samples of nine organic soils, varying widely in degree of humification and in parent vegetation, were used in this study and were collected mainly on the Precambrian Shield of Ontario. Experiments were conducted using glucose, thymol, and γ radiation (60Co) to stimulate or suppress microbial activity in the soils. The presence of glucose generally increased I− removal from solution whereas thymol depressed removal. Gamma irradiation of the soils decreased I− removal from solution in all samples, but 100 kGy terminated I− removal in only one sample. If the removal of I− from solution after exposing the soils to 100 kGy of γ radiation is termed nonbiological, the biological removal of I− from solution exceeded the non-biological in all samples but one. The natural I content of the soils was directly related to both the biologically and the nonbiologically mediated processes of I− removal from solution. We conclude that microorganisms play an important role in the processes of I− removal from solution in organic soils of the Precambrian Shield of Ontario. Key words: Nuclear fuel waste, 129I, groundwater, microorganisms, enzymes, mobility

Workshop on Stress Partitioning in Engineered Clay Barriers, Duke University, Durham, NC., U.S.A., May 29–31, 1992: Overview

1992 ◽  
Vol 29 (6) ◽  
pp. 1011-1012 ◽  
Author(s):  
Malcolm N. Gray
Keyword(s):  
Key Words ◽  
Nuclear Fuel ◽  
Stress Partitioning ◽  
Duke University ◽  
Nuclear Fuel Waste ◽  
Clay Barriers

The accompanying text introduces a series of papers on various aspects of the use of bentonites for the storage and disposal of nuclear fuel waste. The papers were initially presented by a group of international researchers at a workshop on "Stress partitioning on engineered clay barriers" held at Duke University, Durham, N.C., in May 1991. The papers provide an excellent overview of current research on the properties and behaviour of dense, clay-rich bentonitic barriers. Key words : bentonites, nuclear fuel waste, workshop.

TRANSPORTABILITY OF IODIDE IN SOME ORGANIC SOIL MATERIALS FROM THE PRECAMBRIAN SHIELD OF ONTARIO

1987 ◽  
Vol 67 (2) ◽  
pp. 353-366 ◽  
Author(s):  
J. T. KOCH ◽  
B. D. KAY
Keyword(s):  
Rate Constant ◽  
Nuclear Power ◽  
Power Plants ◽  
Organic Soil ◽  
Zero Order ◽  
Organic Soils ◽  
Order Kinetic ◽  
Precambrian Shield ◽  
Zero Order Kinetics ◽  
Order Kinetic Model

Knowledge of the transportability of the long-lived and potentially hazardous nuclide 129I in organic soils is important for evaluating the concept of safely disposing of radioactive fuel waste from Canadian nuclear power plants. The current concept for the disposal of nuclear fuel waste in Canada involves its emplacement in a vault mined 500–1000 m deep in a stable plutonic rock formation in the Canadian Shield. Degradation over time of components of the vault could lead to the entry of 129I to organic soils from contaminated groundwater. Twelve samples from nine organic soils, widely different in degree of humification and in parent vegetation, were collected from the Precambrian Shield of Ontario. Batch reaction techniques were used to measure the kinetics of iodide loss from solution in the presence of the organic soil materials. All soil materials exhibited an initial constant rate of iodide loss from solution (zero-order kinetics). The rate constants for iodide loss for the different soil materials ranged from 1.44 to 36.0 mg iodide per kilogram soil per day. The natural I content for the organic soil samples was positively correlated to the measured rate constant. It is concluded that the rate constant for iodide, as measured in the laboratory, is related to the processes that operate in the field to immobilize I under natural conditions, and that a zero-order kinetic model is appropriate for describing the loss of iodide from the solution phase in an organic soil. Key words: Organic soils, iodide-129, groundwater, transport kinetics, immobilization

MEASUREMENT AND SIGNIFICANCE OF CELLULOSE IN PEAT SOILS

1988 ◽  
Vol 68 (4) ◽  
pp. 681-685 ◽  
Author(s):  
ANN BROWN ◽  
TIIU KAURI ◽  
D. J. KUSHNER ◽  
S. P. MATHUR
Keyword(s):  
Carbon Dioxide ◽  
Key Words ◽  
Respiration Rate ◽  
Aerobic Respiration ◽  
Organic Soils ◽  
Peat Soils ◽  
Precambrian Shield ◽  
Acid Hydrolysate ◽  
Operator Error ◽  
Cellulose Component

The degree of decomposition of 30 organic soils from southern Superior Province of the Precambrian Shield was investigated by comparing the cellulose component, measured as glucose in the acid hydrolysate, with the aerobic respiration rate and with the rubbed fiber content of the soils. Bivarient analyses of these parameters show reasonable correlation. It is suggested, therefore, that cellulose determination is suitable for assessing the biodegradation potential of organic soils. The method is quantitative and less subject to operator error and variability than the fiber determinations, and more rapid and reproducible than measurement of carbon dioxide produced by respiration. Key words: Cellulose, peatlands, organic soils, respiration rate, degree of decomposition

THE EFFECT OF GAMMA STERILIZATION AND ITS EFFECT ON MICROSCOPIC STRUCTURE OF DEEP FROZEN DOG SKULL

2018 ◽  
pp. 37-40
Author(s):  
Phuong Thao Tien Nguyen ◽  
Anh Hung Tran ◽  
Van Tam Le ◽  
Huu Thao Phung ◽  
Phan Quynh Anh Nguyen
Keyword(s):  
Structural Change ◽  
Gamma Radiation ◽  
Gamma Irradiation ◽  
Key Words ◽  
Bone Matrix ◽  
Infected Tissue ◽  
Microscopic Structure ◽  
Bacteriological Examination ◽  
Microscopic Scale

Objective: To evaluate the effect of gamma sterilization and its effect on microscopic structure of deeply frozen dog skull. Subjects and methods: 50 pairs of dog skull fragments have the same size,which were taken symmetrically through the midline of the skull, were divided into two lots. Evident lot consisting of 50 pieces are just deeply frozen, not irradicated. Experimental lot which was composed of 50 pieces were deeply frozen and exposed to 25kGy of gamma radiation. Afterwards, to evaluate the effect of gamma sterilization and compare the alter of bone matrix between lot groups. Results: After gamma irradiation, all dog skull fragments were negative with bacteriological examination. In microscopic scale, no difference was found between the two lots and there was no structural change in the irradiated fragments of all dog skull. Conclusion: Gamma irradiation with 25 kGy: (i) It has the ability to kill bacteria completely in the type of bacteria commonly infected tissue. (ii) It does not alter the structure of dog skull in microstructures. Key words: dog skull, gamma, sterilize

scholarly journals Modelling of solute transport and microbial activity in diffusion cells simulating a bentonite barrier of a spent nuclear fuel repository

2021 ◽  
Vol 211 ◽  
pp. 106193
Author(s):  
Mirjam Kiczka ◽  
Marek Pekala ◽  
Susanna Maanoja ◽  
Eveliina Muuri ◽  
Paul Wersin
Keyword(s):  
Solute Transport ◽  
Microbial Activity ◽  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Diffusion Cells

RELATIONSHIPS BETWEEN SOME PROPERTIES OF ORGANIC SOILS FROM THE SOUTHERN CANADIAN SHIELD

1990 ◽  
Vol 70 (3) ◽  
pp. 363-377 ◽  
Author(s):  
D. ANN BROWN ◽  
S. P. MATHUR ◽  
ANTON BROWN ◽  
D. J. KUSHNER
Keyword(s):  
Principal Component Analysis ◽  
Acid Leaching ◽  
Principal Component ◽  
Organic Soil ◽  
Component Analysis ◽  
Soil Types ◽  
Organic Soils ◽  
Mining Districts ◽  
Two Populations ◽  
Inorganic Components

Different numerical methods used to distinguish between organic soil types are evaluated. The research was initiated by the suggestion that acid leaching from mining wastes could be prevented by capping the tailings with a self-renewing methane-producing muskeg bog, in order to prevent the penetration of oxygen to the wastes. Thirty organic soils from bogs in the mining districts of Elliot Lake, Sudbury, and Timmins, Ontario, and Noranda, Quebec, were sampled and 28 soil characteristics were measured. These characteristics, whose values are normally or lognormally distributed, were analyzed by several different statistical methods. Some characteristics indicate the existence of two populations, and others are bivariantly correlated. Canonical discriminant analysis was more successful than cluster analysis in separating the bogs into well-defined geographical groups. However, principal component analysis proved best at grouping the organic soils according to their organic and inorganic components, and we suggest that this is a suitable method for the general discrimination of organic soil types. Methane was present in all the 17 bogs tested for it, and in two very wet bogs more than 2 mmol of methane per liter were extracted. Key words: Muskeg bog, organic soils, soil characterization, principal component analysis

scholarly journals A Novel Approach to the Analysis of the Soil Consolidation Problem by Using Non-Classical Rheological Schemes

2021 ◽  
Vol 11 (5) ◽  
pp. 1980
Author(s):  
Kazimierz Józefiak ◽  
Artur Zbiciak ◽  
Karol Brzeziński ◽  
Maciej Maślakowski
Keyword(s):  
Constitutive Models ◽  
Organic Soil ◽  
Organic Soils ◽  
Soil Consolidation ◽  
Flexible Tool ◽  
One Dimensional ◽  
Novel Approach ◽  
Soil Skeleton ◽  
The One ◽  
The Relationship

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil.

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