Calcium Carbonate Precipitation Process Research Articles

The optimized microbial-induced calcium carbonate precipitation process to fabricate underwater superoleophobic mesh for efficient oil-water separation

Microbial-induced calcium carbonate precipitation (MICP) is an environmentally-friendly and easy operation technique for separating oil-water mixtures. However, the effect of environmental factors on the wettability and oil-water separation performance of MICP remains unclear. In this study, three primary factors including mineralization solution (MS) concentration, bacterial suspension (BS) concentration, and temperature were carefully investigated. Under these varying conditions, stainless steel meshes (SSM) were chosen as the substrates for the growth of CaCO3 precipitations. Experimental results demonstrate a strong dependence of the morphology and wettability of CaCO3 precipitations on these factors. Higher MS concentration and temperature contribute to enhanced hydrophilicity of CaCO3 coatings due to the increased surface roughness. The water flux of MICP-coated SSMs decreases with the increase of BS concentration, MS concentration, and temperature. The MICP-coated SSM obtained with MS concentration of 0.15 M, BS concentration of 0.1 × 108 cells/mL, and mineralization reaction at 25 ℃ for 24 hours demonstrated the optimal comprehensive performance, exhibiting underwater superoleophobicity with an underwater oil contact angle (UWOCA) exceeding 151°, an ultra-high oil intrusion pressure (> 3.0 kPa), ultrahigh flux (28,644 L m−2 h−1), and a preferable oil rejection rate (> 99.9%). Additionally, the as-prepared mesh exhibited superior anti-oil-fouling property and reusability, while concurrently demonstrating excellent chemical and thermal stability. This work contributes to advancing our knowledge of the influence of various environmental factors on the wetting characteristics of MICP and provides a feasible solution for the highly efficient and low-cost preparation of oil-water separation membranes based on the MICP process.

ADDITION OF BACTERIOLOGICAL ADDITIVES IN THE PRODUCTION OF SELFHEALING CONCRETE

Self-repairing concrete is a product in which microorganisms will be used to produce limestone to fill cracks appearing on the surface of concrete structures. It is presented by the author that specially selected types of bacteria of the genus Bacillus, a calcium-based nutrient known as calcium lactate, and nitrogen and phosphorus are added to the ingredients of concrete when it is mixed. These self-healing agents can remain dormant within concrete for up to 200 years. Self-repairing materials are a special type of materials that regenerate their strength properties after minor damage caused to the material during its service life. Self-repair technology is particularly useful in the case of composite materials because composites have low damage detection capability and are susceptible to sudden and brittle failure. Modern man-made materials have excellent mechanical properties. However, they lack the ability to self-repair. Therefore, in the event of damage, there is the possibility of loss of mechanical strength and, over time, a gradual loss of functional strength in the absence of human intervention.Different bacterial species along with abiotic factors such as salinity, ambient pH value, temperature, nutrient availability and habitat composition play a significant role in the calcium carbonate precipitation process in a wide range of different environments. There are four key factors that determine the MICP process: (I) calcium concentration, (II) dissolved inorganic carbon concentration, (III) pH value and (IV) presence of nucleation centres.

Observation of Calcium Carbonate Precipitation Process and the Permeability Experiments by EICP using Microfluidic Chip

Observation of Calcium Carbonate Precipitation Process and the Permeability Experiments by EICP using Microfluidic Chip

Advances of enzymes related to microbial cement

Microbial induced calcium carbonate precipitation (MICP) refers to the natural biological process of calcium carbonate precipitation induced by microbial metabolism in its surrounding environment. Based on the principles of MICP, microbial cement has been developed and has received widespread attention in the field of biology, civil engineering, and environment owing to the merits of environmental friendliness and economic competence. Urease and carbonic anhydrase are the key enzymes closely related to microbial cement. This review summarizes the genes, protein structures, regulatory mechanisms, engineering strains and mutual synergistic relationship of these two enzymes. The application of bioinformatics and synthetic biology is expected to develop biocement with a wide range of environmental adaptability and high performance, and will bring the MICP research to a new height.

Metagenomic Insights Into Ecosystem Function in the Microbial Mats of a Large Hypersaline Coastal Lagoon System

The hypersaline lagoon system of Araruama (HLSA) is one of the largest in the world and one of the most important sources of evaporative salt in Brazil. The biogeochemical characteristics of this lagoon system led it to be considered a Precambrian relic. The HLSA also harbors extensive microbial mats, but the taxonomic and metabolic attributes of these mats are poorly understood. Our high-throughput metagenomics analyses demonstrated that the HLSA microbial mats are dominated by Proteobacteria, Cyanobacteria, and Bacteroidetes. Among Proteobacteria, Deltaproteobacteria comprises approximately 40% of the total population and it includes sulfate-reducing bacteria such as Desulfobacterales, Desulfuromonadales, and Desulfovibrionales. Differing in composition and function of their reaction centers, other phylogenetic diverse anoxygenic phototrophic bacteria were detected in the HLSA microbial mats metagenomes. The presence of photolithoautotrophs, sulfate reducers, sulfide oxidizers, and aerobic heterotrophs suggests the existence of numerous cooperative niches that are coupled and regulated by microbial interactions. We suggest that the HLSA microbial mats hold microorganisms and the necessary machinery (genomic repertoire to sustain metabolic pathways) to promote favorable conditions (i.e., create an alkaline pH microenvironment) for microbially mediated calcium carbonate precipitation process. Metagenome-assembled genomes (Ca. Thiohalocapsa araruaensisHLSAbin6 sp. nov. andCa. Araruabacter turfaeHLSAbin9 gen. nov. sp. nov.) obtained support the relevance of Sulfur metabolism and they are enriched with genes involved in the osmoadaptive networks, hinting at possible strategies to withstand osmotic stress. Metabolically versatile bacteria populations, able to use multiple nutrient sources and osmolytes, seem to be a relevant attribute to survive under such stressful conditions.

Crack repairing of high strength engineered cementitious composites using bacteria-free waste medium

High strength engineered cementitious composites (ECC) that fracture under tensile stress present cracks with the width over 100 μm, which may not be easily repaired by autogenous healing. Herein, this study investigated the healing efficiency of high strength ECC after being immersed in bacteria-free medium which is waste medium during spore cultivation. During incubation of bacteria, concentration of carbonate ions in the medium could rise to 0.30 mol/L approximately. These carbonate ions can be leveraged in calcium carbonate precipitation process for crack healing, which contributed to greater reduction of crack width of ECC specimens in waste medium than that in water. The superior crack closure led to the recovery of water tightness by lowering down the water absorption of cracked specimens and the restoration of tensile properties including both tensile strength and ultimate strain even after final failure of specimens. Therefore, it can be concluded that bacteria-free waste medium is promising to promote healing of concrete cracks.

Influence of direct urease source incorporation on mechanical properties of concrete

Strength augmentation of cementitious materials is a highly studied research area and incorporation of microbes in cementitious materials has drawn attention of many researchers worldwide recently. While most of the research work has been performed by using microbes, the cost and maintenance of involved microbes causes significant increase in overall cost. Moreover, involvement of microbes makes it difficult to implement the technique as it requires expert supervision. Many researchers have tried to minimize the cost by using various innovative ways to grow and maintain microbes. However, no study has been performed to completely replace the microbes to achieve comparable enhancement in the properties of the cementitious materials. Generally, ureolytic bacteria are used as a source of urease enzyme (EC 3.5.1.5) to perform the biocementation process. However, the involvement of bacteria makes the on field application of the process difficult. The present study, for the very first time demonstrates the direct utilization of plant-based urease for the process of calcium carbonate precipitation. Various urease rich seeds of plants such as watermelon seeds, soya beans and pumpkin seeds were directly added to the concrete mix in powdered form along with urea and calcium hydroxide in measured quantities. Results showed a noteworthy improvement in the properties of treated concrete specimens as compared to control specimens.

A Bioinspired Technique for Improving the Interaction Between Cohesive Soil and Geotextile Reinforcements

Reinforced soil structures often cannot perform properly when there is a weak interface which is not capable of mobilizing the required shear strength between fine-grained soils and the reinforcing elements. The calcium carbonate precipitation (CCP) technique adopted in this research has proved to be extremely useful in removing this deficiency. In this study, plant-derived urease-induced calcium carbonate precipitation (PDUICCP) was used as a novel method to improve the performance of the interface. Instead of using commercial-grade purified urease, the extract of soybean seeds was mixed with calcium chloride and urea to prepare a precipitating solution to reduce the costs. In addition, xanthan gum was used as a benchmark to examine the efficiency of the calcium carbonate precipitation process. Modified direct shear tests were performed on the kaolin clay specimens with two different relative compactions, three concentrations of the precipitating solution, and three different geotextiles to assess the performance of the proposed method. The results revealed that the application of the proposed method improved the interfacial shear strength considerably with the interface efficiency increasing from 12 to 270% depending on the geotextile texture and roughness, the relative soil compaction, and the concentration of the precipitation solutions. The highest increase in the interfacial shear strength for all the concentrations of the precipitating solutions was obtained when the polypropylene nonwoven geotextile was used. In all the cases, increasing the relative soil compaction enhanced the interfacial shear strength and interface efficiency. The optimal concentration of the constituents in the precipitating solution was obtained when 0.64 molar (M) calcium chloride and 1 M urea were used. The results of this study can mark the beginning of a new type of geosynthetics with multiphase strength parameters after the addition of environmentally friendly materials. Moreover, they pave the way for using fine-grained soils as the bulk backfill material in reinforced soil structures where coarse-grained soil is not readily available.

Preliminary exploration of molybdenum isotope fractionation during coprecipitation of molybdate with abiotic and microbial calcite

Molybdenum isotopes in marine carbonates have been proposed to track the redox conditions of oceans through time. Large variations of Mo concentration and isotopic composition were observed in primary biogenic carbonates and shallow-water carbonate sediments from modern oceans. However, it remains unknown whether the abiotic calcium carbonate precipitation process fractionates Mo isotopes and affects Mo isotopic composition in marine carbonates. To better understand carbonate Mo isotope proxy, we conducted abiotic calcite coprecipitation experiment to determine Mo partition coefficient in calcite and Mo isotope fractionation during molybdate incorporation into calcite. We also investigated Mo isotopic compositions in microbial calcite induced by photosynthetic activity of cyanobacteria and diatoms in the surface water of Fayetteville Green Lake (FGL), New York, USA.Our calcite coprecipitation experiment, for the first time, determined the Mo partition coefficient Kd=MoCacalcite/MoO42−CO32−solution = 1.49 × 10−5 in calcite at pH ~8.3. We observed a relatively small Mo isotope fractionation of 0.15 ± 0.06‰ with light Mo isotopes preferentially incorporated into calcite. The Mo isotope fractionation observed in our experiment most likely results from equilibrium isotope fractionation among different Mo species and preferential incorporation of the isotopically light Mo(VI) species (MoO42−) into calcite. Microbial calcite formed in FGL fractionated Mo isotopes in the same direction as abiotic calcite coprecipitation experiment but with significantly larger isotope fractionations (0.82–2.45‰) and significantly higher Mo concentrations (0.04–0.28 ppm vs. the inferred 0.002 ppm Mo from our abiotic calcite coprecipitation experiment). Molybdenum isotopic composition decreased with Mn/Fe ratios from +1.56 to −0.07‰, suggesting that Fe and Mn oxides dominantly control Mo isotope fractionation in these microbial calcite samples. Additionally, isotopically light Mo associated with organic matter (e.g., live or dead microorganisms like cyanobacteria) might also contribute to the light Mo isotopic composition in microbial calcite.The relatively small Mo isotope fractionation (0.15 ± 0.06‰) and Mo partition coefficient (1.49 × 10−5) in our abiotic calcite coprecipitation experiment indicate that calcite precipitation process has negligible effects on Mo isotopic composition in primary biogenic calcite precipitates. In contrast, Mo associated with organic matter, detrital particles, and Fe and Mn oxides, and carbonate diagenesis strongly affect Mo isotopic compositions in calcium carbonate precipitates in nature. Caution should be taken when applying Mo isotopes in ancient carbonates rocks to track seawater redox conditions.

Mitigation of Dust Emissions of Silty Sand Induced by Wind Erosion Using Natural Soybean Biomaterial

Fugitive dust induced by wind erosion has been a serious environmental problem in many countries. In this research, a plant-derived urease enzyme named soybean, as a cheap and easily available enzyme-induced carbonate precipitation (EICP), is employed to stabilize loose soil-inducing fugitive dust. The tested silty sand soil was retrieved from one of the dust centers of Khuzestan-Iran with a low plasticity index. The treated experiments were prepared by two different methods of mixing and pouring the extract solution with and on the soil with both maximum and minimum densities. After a certain period of time, at which the calcium carbonate precipitation process was completed, unconfined compressive strength tests were conducted to monitor increase in the soil shear strength, treated with EICP. Then, water erosion test was conducted to evaluate resistance of the treated soil against water penetration and soil erosion due to water runoff. Later, trays containing bare and treated soils, obtained from different EICP applications, were sited in a wind tunnel to test their erosion performances. The results indicated that soybean enzyme which is much easier to prepare than the jack bean enzyme, previously suggested by other researchers, can control dust emissions induced by wind erosion.

Utilization of Gaseous Carbon Dioxide and Industrial Ca-Rich Waste for Calcium Carbonate Precipitation: A Review

Technologies for the management of various types of waste and the production of useful products from them are currently widely studied. Both carbon dioxide and calcium-rich waste from various production processes are problematic wastes that can be used to produce calcium carbonate. Therefore, the purpose of this paper is to provide an overview about the state of the development of processes that use these two wastes to obtain a valuable CaCO3 powder. The paper reviews the current research on the use of post-distillation liquid from the Solvay process, steelmaking slag, concrete, cement, and gypsum waste as well as some others industrial Ca-rich waste streams in the calcium carbonate precipitation process via carbonation route. This work is an attempt to collect the available information on the possibility of influencing the characteristics of the obtained calcium carbonate. It also indicates the possible limitations and implementation problems of the proposed technologies.

Newly-discovered interactions between bacteriophages and the process of calcium carbonate precipitation

Although it has been suggested that viruses may induce precipitation of carbonate, the exact mechanisms involved and the roles they might play in the nucleation of carbonates are still unknown. Experimental evidence is reported here demonstrating that bacteriophages are an important factor in calcium carbonate formation. Short-term experiments were designed to induce viral-mediated mineral precipitation at different fluid compositions. The precipitates obtained, analysed with fluorescence and electron microscopes and X-Ray diffraction, and evaluated by statistics, clearly show that bacteriophages strongly affect the process of carbonate precipitation. We demonstrate that as a result of the coalescence of the phages, the carbonate precipitates form large aggregates consisting of spheroids. The spheroids are constructed of angular nanoparticles resembling viral-like particles. In control experiments spheroids were also observed; however, they consist of irregular nanoparticles and additionally they do not form large aggregates. We also demonstrate that bacteriophages strongly influence the mineral composition of the precipitates, with vaterite being the dominant form, and they likely control vaterite stability.

Calcium carbonate precipitation catalyzed by soybean urease as an improvement method for fine-grained soil

Although great advances have recently been made in biological soil-improvement methods, the treatments of fine-grained soil using these methods are still challenging. In this study, we tested a new method for the improvement of silty soil. This method adopts the calcium carbonate precipitation process catalyzed by soybean urease. Crude urease is derived simply by collecting the liquid formed by soaking soybean powder in water. The activity of crude urease is linearly related to the amount of soybean powder added to the water, and is high enough to be used for soil treatment. Under batch conditions, the reactions catalyzed by crude urease can be completed, although the reaction rates are slower than those using live bacteria with the same initial activity. In triaxial consolidated undrained tests, the treated silty soil shows more dilative responses in the stress-strain curves and larger peak deviatoric stresses as compared with the untreated soil, indicating significant improvements in the mechanical behaviour. In the results of CaCO3 measurements, it is seen that there are continuous increases in the CaCO3 content of the samples during the treatment process, which implies that the silty soil samples are not clogged when treated by crude urease. Such results indicate that calcium carbonate precipitation catalyzed by soybean urease can be used for the improvement of fine-grained soil.

Precipitation, characterization, and kinetic modeling of calcium carbonate prepared using sodium myristate

Sodium myristate was used in the calcium carbonate precipitation process to investigate its potential as a crystal morphology modifier and its effect on the end-product characteristics. Calcium carbonate was precipitated with and without different concentrations of sodium myristate and the resulting crystals were evaluated using XRD, SEM, FTIR, BET, and particle size analysis. XRD and FTIR analysis revealed that the as-obtained crystals were in the form of calcite. A significant increase in the specific surface area was observed upon increasing the concentration of sodium myristate and the morphology of the calcium carbonate crystals changed from smooth to rough, smaller cubic-like particles. Contact angle measurements showed that the crystals prepared using 50 ppm sodium myristate have good hydrophobic properties. The calcium carbonate crystals were characterized using TGA and their thermal decomposition kinetics investigated. The thermal decomposition data were evaluated using different model-free kinetic models, such as FWO, KAS, and Starink. The average activation energy of calcium carbonate during the thermal decomposition process was found to be in the range of 147–188 kJ/mol, which decreased by ∼10% when sodium myristate was added to the precipitation process. Thus, sodium myristate can be used as the crystal size and shape modifier in the calcium carbonate precipitation process.

Selection of bacteria inducing calcium carbonate precipitation for self-healing concrete application

A modification of bacterial medium using calcium lactate pentahydrate was developed for calcium carbonate precipitation. A total of five strains of bacteria were cultivated on the solution medium containing nutrient broth and calcium lactate pentahydrate. In this study, the variation of 3.2 mM and 16.2 mM of calcium lactate pentahydrate was used to obtain the optimum condition for bacterial growth. The results showed that isolated strains CPB 1, CPB 3, and CPB 5 with medium containing nutrient broth and 3.2 mM calcium lactate pentahydrate gave the optimum growth, pH and Eh, thus being favourable for the process of calcium carbonate precipitation. Hence, this will be useful for self-healing concrete.

Seepage control in sand using bioslurry

Abstract This paper presents a new method for seepage control in sand using bioslurry, a suspension of CaCO3 crystals formed using a microbial calcium carbonate precipitation process (MICP). The bioslurry can be permeated through sand or deposit on top of a sand layer. The bioslurry contains high urease active bacteria cells and allows further MICP treatment when introducing cementation solution. In this way, the permeability of the bioslurry layer or bioslurry permeated sand layer could be further reduced to the order of 10−9 m/s through another 2–3 numbers of MICP treatment using a cementation solution with an optimum concentration of 1.6 M. Such a low permeability is hardly achievable using the conventional MICP method which would require many more numbers of treatment to reduce the permeability of sand to be below 10−7 m/s. Therefore, the proposed bioslurry method is not only more effective, but also more efficient. The water barrier layer formed using the proposed method is much less affected by wet and dry or temperature change cycles than compacted clay liners. It also allow cracks in the water barrier layer to be repaired if required.

Precipitation of Calcium Carbonate (CaCO3) in Water–Monoethylene Glycol Solutions

The influence of monoethylene glycol (MEG) on the precipitation process of calcium carbonate at constant supersaturation, 25 °C, and pH 8.5 was investigated. MEG aqueous solutions supersaturated with respect to all calcium carbonate polymorphs were used since they are often encountered in oil production processes where they are used as a hydrate inhibitor. Both seeded and unseeded experiments were done in aqueous supersaturated calcium carbonate solutions containing MEG over the concentration range 0–80% v/v. The presence of MEG affected the induction times and the subsequent rates of precipitation in unseeded, spontaneous precipitation of calcium carbonate. At low values of the supersaturation ratio (SRcalcite = 77.62–15 135.61 or σcalcite = 7.81–122) and for MEG concentrations in the range 30–80% v/v, the solutions were stable for 4 days. At lower than 30% v/v MEG concentrations, calcium carbonate precipitation took place past induction periods between 160 and 500 min. The morphological examination of the precipitates showed that in the presence of low MEG concentrations (10–20% v/v) the precursor vaterite was stabilized. The homogeneous nucleation and growth of calcium carbonate in the absence and in the presence of MEG was also investigated by the inoculation of stable supersaturated solutions with quartz and calcite seed crystals. In both cases nucleation and growth of calcium carbonate was significantly reduced with increasing MEG concentration in the solutions.

Evaluation of the effects of sodium laurate on calcium carbonate precipitation: Characterization and optimization studies

The effects of using sodium laurate as an additive on the calcium carbonate precipitation process and on the product characteristics were investigated experimentally through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), particle size, and Brunauer, Emmett, and Teller (BET) analysis. The characterization results showed that the addition of sodium laurate to the crystallization media contributed to the formation of the vaterite form of calcium carbonate. The average particle size changed from 32 µm to 14 µm with increasing sodium laurate concentration. The SEM results suggested that the presence of sodium laurate had a strong influence on the calcium carbonate morphology and the crystals transformed from cubic to ellipsoidal shape. This study also emphasized the application of a statistical tool, response surface methodology (RSM) based on Box–Behnken design (BBD), to determine the optimal conditions for the production of calcium carbonate crystals with high specific surface area. The precipitation process was performed using different combinations of additive concentration, pH, and temperature, which are the main parameters affecting this process. The effects of these parameters on the responses, i.e., average particle size, surface area, and the relative fraction of vaterite, were investigated. Second-order polynomial equations were developed for the particle size, specific surface area and vaterite composition to correlate the parameters. The maximum specific surface area (12.430 mg/g) was obtained under the optimal conditions of 50 ppm additive concentration, pH 8.5, and 40 °C.

Isolation and Urease Activity Test of Bacteria for Calcium Carbonate (Calcite) Precipitation (Biocementation) in Soil

The use of bacterial calcium carbonate (calcite) precipitation (biocementation) has recently become popular as a ground-improvement technique. Ureolytic bacteria having highly urease activities were known to have important roles in calcium carbonate precipitation process. One of our research objectives is to isolate and to select as many as possible such ureolytic bacteria from Indonesian soils to be further utilized for calcium carbonate (calcite) precipitation process in the soil for strengthening the soil structure. Isolation was performed anaerobically in selective media containing 40% urea. Four isolates with different morphologies were purified and coded as TK1, TK2, TK3, and TK4. Each of them was tested for its urease activity either as a pure culture or as a mixture of several cultures. The urease activity was measured based on the ammonia concentration produced in the growth media up to 7 x 24 hours. It was known that isolate TK4 had the highest urease activity on week 6, whilst a mixture of isolate cultures coded as TKC did not show a better urease activity than the isolate TK4. Hence, it could be concluded that the isolate TK4 was the best candidate to be used for further research on the calcium carbonate (calcite) precipitation process (biocementation) to strengthen the soil structure.

Effect of Soil Type on the Enzymatic Calcium Carbonate Precipitation Process Used for Soil Improvement

AbstractThis work analyzes the effect of soil type on the process of enzymatic calcium carbonate (CaCO3) precipitation. This methodology is tested for the stabilization of five soil types (poorly g...