Characteristics and Rates of Microbial Processes in Clays of Different Mineral and Elemental Composition in Relation to Safety Prediction for ESB Clay Materials

Abstract

Microbial activity in clay barrier materials during radioactive waste disposal can lead to a violation of important physicochemical properties of the barrier system as a whole, thereby reducing the safety of the storage facility. This work evaluates the activity of the microbial complex of five bentonite and two kaolin clays. All clay materials were found to contain microorganisms, mostly with organotrophic aerobic and anaerobic metabolism capable of forming hydrogen sulfide and transforming basic and impurity clay minerals. The activity of microorganisms can increase with the ingress of degradation products of aluminophosphate matrices and cement barriers, as well as radiolysis products. For all clay the rates of microbial processes were shown to exhibit a direct correlation with the content of organic matter, kaolinite, and potassium feldspar, and an inverse correlation with montmorillonite content. A systematic methodological approach is proposed for clay materials and their susceptibility to microbial processes. The approach makes it possible, based on the content of organic matter, biophilic elements in the samples, parameters of the respiratory activity of the microbial complex, the formation of hydrogen sulfide, and other parameters, to assess in advance the possibility of using them in barriers.

Effect of Mineral Carriers on Biofilm Formation and Nitrogen Removal Activity by an Indigenous Anammox Community from Cold Groundwater Ecosystem Alone and Bioaugmented with Biomass from a “Warm” Anammox Reactor

“…In the current study, the natural clays of the bentonite and kaolin types from various deposits on the territory of the Russian Federation were used ( Figure S1 ). The composition of the clays was studied in detail previously [ 40 ].…”

An Overview of Recent Developments and Understandings of Unconventionals in the Vaca Muerta Formation, Argentina

“…The prolonged exposure of the lateral section (exceeding 48 h) due to slow tripping operations resulted in alterations to fluid properties and rheology, triggering the emergence of cavings and gas influxes that required management. To address these issues, the team deployed a specialized mining rig in order to install deeper conductor casings at depths between 40 and 50 feet, a significant departure from the previous 9-12 foot depths in Pad A. Fluid specifications were also re-evaluated, leading to the introduction of potassium sulfate as a clay stabilizer to enhance wellbore integrity [45,46].…”

Structural Study of Nano-Clay and Its Effectiveness in Radiation Protection against X-rays

“…When he observed a glowing fluorescent screen, Roentgen discovered the mysterious penetrating radiation called X-rays [2,3]. Nowadays, X-rays offer wide range of applications covering medical [4], military [5], space [6], security [7], and industrial [8] fields and in scientific research [9,10].…”