The Rôle of Inorganic Agencies in the Deposition of Calcium Carbonate

1916 ◽  
Vol 24 (8) ◽  
pp. 729-750 ◽  
Author(s):  
John Johnston ◽  
E. D. Williamson
Keyword(s):  
Calcium Carbonate

scholarly journals The role of bacterial urease activity on the uniformity of carbonate precipitation profiles of bio-treated coarse sand specimens

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charalampos Konstantinou ◽  
Yuze Wang ◽  
Giovanna Biscontin ◽  
Kenichi Soga
Keyword(s):  
Calcium Carbonate ◽  
Calcium Chloride ◽  
Urease Activity ◽  
Coarse Sand ◽  
Carbonate Precipitation ◽  
Population Densities ◽  
Carbonate Cements ◽  
Microbially Induced Carbonate Precipitation

AbstractProtocols for microbially induced carbonate precipitation (MICP) have been extensively studied in the literature to optimise the process with regard to the amount of injected chemicals, the ratio of urea to calcium chloride, the method of injection and injection intervals, and the population of the bacteria, usually using fine- to medium-grained poorly graded sands. This study assesses the effect of varying urease activities, which have not been studied systematically, and population densities of the bacteria on the uniformity of cementation in very coarse sands (considered poor candidates for treatment). A procedure for producing bacteria with the desired urease activities was developed and qPCR tests were conducted to measure the counts of the RNA of the Ure-C genes. Sand biocementaton experiments followed, showing that slower rates of MICP reactions promote more effective and uniform cementation. Lowering urease activity, in particular, results in progressively more uniformly cemented samples and it is proven to be effective enough when its value is less than 10 mmol/L/h. The work presented highlights the importance of urease activity in controlling the quality and quantity of calcium carbonate cements.

scholarly journals Deposition of calcium carbonate in karst caves: role of bacteria in Stiffe's Cave

2001 ◽  
Vol 30A (1/4) ◽  
pp. 69-79 ◽  
Author(s):  
Claudia Ercole ◽  
Paola Cacchio ◽  
Georgio Cappuccio ◽  
Aldo Lepidi
Keyword(s):  
Calcium Carbonate ◽  
Karst Caves

Isolation and characterization of calcifying bacteria from “living rocks”: a possible carbon sink

2021 ◽  
Author(s):  
Maddalena del Gallo ◽  
Amedeo Mignini ◽  
Giulio Moretti ◽  
Marika Pellegrini ◽  
Paola Cacchio
Keyword(s):  
Calcium Carbonate ◽  
Carbon Sink ◽  
In Vitro Regeneration ◽  
Scientific Basis ◽  
16S Rrna Analysis ◽  
Environmental Threats ◽  
Isolation And Characterization ◽  
Definition Of

<p>CO<sub>2</sub> emissions triggered by anthropogenic and natural activities contribute to climate change, one of the current environmental threats of public and scientific concern. At present, microbially-induced biomineralization of CO<sub>2</sub> by calcium carbonate (CaCO<sub>3</sub>) is one of the highly topical study subjects as carbon stabilization process. In the present study we focused our attention on the calcifying bacteria of “living rocks”. The origin of these concretions, composed by a silicate skeleton of quartz and feldspars, merged by massive carbonate concrete, has so far been recognized as abiotic. Within this study we investigated the role of calcifying bacteria in their formation of these concretions and we isolated and characterized the species with CaCO<sub>3</sub> precipitation abilities. Concretions were sampled in Romania (Trovant) and Italy (Sibari and Rome). Samples were first analyzed for their culturable microflora (i.e. isolation, CaCO<sub>3 </sub>precipitation capability and molecular characterization). Then, in vitro regeneration tests were carried out to confirm the contribution of bacteria in the formation of these erratic masses. Moreover, natural samples and bioliths regenerated in vitro were (i) observed and analyzed by scanning electron microscopy (SEM-EDS) and (ii) characterized at molecular level by DNA extraction and 16S rRNA analysis (V3-V4 regions). By isolating and characterizing the culturable microflora, we obtained 19 calcifying isolates, with different morphological, bacteriological and mineral precipitation properties. These evidences have given a first relevant contribution for the definition of the biotic role to the formation of these concretions. These evidences were confirmed by the efficient in vitro regeneration and SEM-EDS analysis. The molecular identification of the isolates and the comparison of the data obtained from the Illumina sequencing with those present in the literature, allowed us to hypothesize the genera that most likely contributed to the formation of these concretions. The results obtained provide a good scientific basis for further studies, which should be directed towards the use of isolates in studies of environmental and socio-economic relevance. Several studies demonstrate that microbially mediated biomineralization has the potential to capture and sequester carbon. Calcium carbonate, is a stable pool of carbon and is an effective sealant to prevent CO<sub>2</sub> release back into the atmosphere.</p>

The Role of Fungal Biofilm and Networks in the Terrestrial Calcium Carbonate Cycle

2003 ◽  
pp. 363-369 ◽  
Author(s):  
Eric P. Verrecchia ◽  
Corinne Loisy ◽  
Olivier Braissant ◽  
Anna A. Gorbushina
Keyword(s):  
Calcium Carbonate

Non-stoichiometric hydrated magnesium-doped calcium carbonate precipitation in ethanol

2019 ◽  
Vol 55 (86) ◽  
pp. 12944-12947 ◽  
Author(s):  
Giulia Magnabosco ◽  
Andrea M. M. Condorelli ◽  
Rose Rosenberg ◽  
Iryna Polishchuk ◽  
Boaz Pokroy ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Crystallization Process ◽  
Ion Solvation ◽  
Absolute Ethanol ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation

The effect of Mg2+ on the precipitation pathway of CaCO3 in absolute ethanol has been studied to investigate the role of ion solvation in the crystallization process.

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