Biodegradable Plastic of Jicama Starch ( Pachyrhizus Erosus ) With Precipitate Calcium Carbonate as A Filler

2016 ◽  
Author(s):  
Sri Elfina ◽  
◽  
Novesar Jamarun ◽  
Syukri Arief ◽  
Akmal Djamaan
Keyword(s):  
Calcium Carbonate ◽  
Biodegradable Plastic ◽  
Precipitate Calcium Carbonate ◽  
Pachyrhizus Erosus

Synthesis of Precipitate Calcium Carbonate with Variation Morphology from Limestone by Using Solution Mixing Method

2019 ◽  
Vol 966 ◽  
pp. 200-203
Author(s):  
Zaenal Arifin ◽  
Triwikantoro ◽  
Bintoro Anang Subagyo ◽  
Mochamad Zainuri ◽  
Darminto
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Carbonate ◽  
Molar Ratio ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
Precipitate Calcium Carbonate ◽  
X Ray ◽  
Mixing Method ◽  
Scanning Electron

Abstract. In this study, the CaCO3 powder has been successfully synthesized by mixing CaCl2 from natural limestone and Na2CO3 in the same molar ratio. The mixing process of solutions was carried out by employing the molar contents of 0.125, 0.25, 0.375 and 0.5M at varying temperatures of 30, 40, 60 and 80ᴼC. The produced CaCO3 microparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The highest content of aragonite phase with morphology rod-like of the samples is around 29 wt%, resulting from the process using solution of 0.125 M at 80 ᴼC. While at 30 ᴼC and 40 ᴼC produced 100 wt% calcite phase.

Effects of amine, amine salt and amide on the behaviour of carbon dioxide absorption into calcium hydroxide suspension to precipitate calcium carbonate

2013 ◽  
Vol 25 (12) ◽  
pp. 2507-2515 ◽  
Author(s):  
Wittaya Chuajiw ◽  
Mitsuru Nakano ◽  
Kazumasa Takatori ◽  
Toshiya Kojima ◽  
Yoshiki Wakimoto ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Calcium Carbonate ◽  
Calcium Hydroxide ◽  
Amine Salt ◽  
Carbon Dioxide Absorption ◽  
Precipitate Calcium Carbonate ◽  
Amine Amine

Optimization of HCO3- Production Reflect to CaСo3 Precipitation for Self-Healing by Bacillus sphaericus

2015 ◽  
Vol 802 ◽  
pp. 549-554 ◽  
Author(s):  
Norfaniza Mokhtar ◽  
Zhameir Shafiq Mohd Ilias ◽  
Husnul Azan Tajarudin ◽  
Megat Azmi Megat Johari
Keyword(s):  
Calcium Carbonate ◽  
Bacillus Sphaericus ◽  
Urea Concentration ◽  
Bacterial Degradation ◽  
Self Healing ◽  
Precipitate Calcium Carbonate ◽  
Urease Enzyme ◽  
Experimental Works ◽  
Metabolic Activities ◽  
Good Environment

Bacteria are able to perform metabolic activities which promote the precipitation of calcium carbonate in the form of calcite. Bacillus Sphaericus was used in this study, which is an ureolytic bacteria that can precipitate calcium carbonate in its environment by the decomposition of urea into ammonium and carbonate. The bacterial degradation of urea basically increases the pH and promotes the microbial deposition of carbonate as calcium carbonate. In this research, the capability of bacteria to influence the formation of HCO3- by the production of urease enzyme was investigated. Results of growth rate and characteristics of bacteria showed that 20g/L of urea concentration was able to provide a good environment for bacteria with sufficient amount of nutrient to survive. The formation of HCO3- was parallel with NH3 production where the formation of HCO3- increased slowly as the ammonia production decreased. Urea degradation with suitable concentration of urea by 20g/L may form high HCO3- compared to 25g/L urea concentration. The results from the experimental works indicated that the optimal urea concentration was 20g/L.

scholarly journals Development of Bacterium for Crack Healing and Improving Properties of Concrete under Wet–Dry and Full-Wet Curing

2020 ◽  
Vol 12 (24) ◽  
pp. 10346
Author(s):  
Arunachalam Sumathi ◽  
Gunasekaran Murali ◽  
Dharmalingam Gowdhaman ◽  
Mugahed Amran ◽  
Roman Fediuk ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Atmospheric Conditions ◽  
Crack Healing ◽  
Calcium Carbonate Precipitation ◽  
Precipitate Calcium Carbonate ◽  
Bacterial Concentration ◽  
Concrete Mixtures ◽  
Adverse Impacts ◽  
Novel Approach ◽  
Cracked Specimens

Concrete cracking is inevitable, coupled with increased permeability, exacerbating the adverse impacts of atmospheric conditions and chemical attacks. Calcium carbonate precipitation resulting from certain microorganisms’ metabolism is a novel approach that can self-heal the cracks and improve concrete properties. In this study, the development and effect of bacteria Bacillus cohnii on crack healing, regained compressive strength after pre-cracking, sorptivity, water absorption, and concrete microstructures were investigated. For this purpose, a Bacillus cohnii bacterial concentration of 105 cells/mL was used as a water replacement in the concrete mixtures. Two methods subsequently cured the prepared concrete specimens: wet–dry (W-D) cycle and full-wet (F-W). In the wet–dry cycle, the cast specimens were immersed in water for 24 h and then kept at room temperature for 24 h, which was considered as one cycle; this process was repeated for 28 days. In the full-wet curing, specimens were immersed in water for 28 days. However, the curing water was changed every 24 h to facilitate the essential oxygen supply for bacterial activity to precipitate calcium carbonate. The results revealed that 90% and 88% surface healing was noticed in full-wet and full-dry pre-cracked specimens at 28 days.

scholarly journals Intercomparison of four methods to estimate coral calcification under various environmental conditions

2019 ◽  
Author(s):  
Miguel Gómez Batista ◽  
Marc Metian ◽  
François Oberhänsli ◽  
Simon Pouil ◽  
Peter W. Swarzenski ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
The Other ◽  
Total Alkalinity ◽  
Precipitate Calcium Carbonate ◽  
High Quality ◽  
Stylophora Pistillata ◽  
Coral Calcification ◽  
Highly Correlated

Abstract. Coral reefs are constructed by calcifiers that precipitate calcium carbonate to build their shells or skeletons through the process of calcification. Accurately assessing coral calcification rates is crucial to determine the health of these ecosystems and their response to major environmental changes such as ocean warming and acidification. Several approaches have been used to assess rates of coral calcification but there is a real need to compare these approaches in order to ascertain that high quality and intercomparable results can be produced. Here, we assessed four methods (total alkalinity anomaly, calcium anomaly, 45Ca incorporation and 13C incorporation) to determine coral calcification of the reef-building coral Stylophora pistillata. Given the importance of environmental conditions on this process, the study was performed under two pH (ambient and low level) and two light (light and dark) conditions. Under all conditions, calcification rates estimated using the alkalinity and calcium anomaly techniques as well as 45Ca incorporation were highly correlated. Such a strong correlation between the alkalinity anomaly and 45Ca incorporation techniques has not been observed in previous studies and most probably results from improvements described in the present paper. The only method which provided calcification rates significantly different from the other three techniques was 13C incorporation. Calcification rates based on this method were consistently higher than those measured using the other techniques. Although reasons for these discrepancies remain unclear, the use of this technique for assessing calcification rates in corals is not recommended without further investigations.

scholarly journals Soil bacteria that precipitate calcium carbonate: mechanism and applications of the process

2018 ◽  
Vol 67 (2) ◽  
Author(s):  
Sandra Patricia Chaparro-Acuña ◽  
Mónica Liliana Becerra-Jiménez ◽  
José Jobanny Martínez-Zambrano ◽  
Hugo Alfonso Rojas-Sarmiento
Keyword(s):  
Calcium Carbonate ◽  
Soil Bacteria ◽  
Precipitate Calcium Carbonate

Las bacterias con actividad ureásica son microorganismos que se encuentran en el suelo, y que en presencia de urea y calcio, pueden producir carbonato de calcio, proceso conocido como precipitación de calcio inducida microbiológicamente (PCIM). Este artículo trata este proceso y su mecanismo, además de las ureasas de origen bacteriano, los cristales de carbonato de calcio formado, los factores que afectan la eficiencia la PCIM, como el tipo de bacteria, las concentraciones de células bacterianas, el pH, la temperatura y las concentraciones de calcio y urea. Además, se incluye las aplicaciones como la remoción de metales pesados en aguas, la bioconsolidación, biocemento y secuestro de CO2.

scholarly journals Intercomparison of four methods to estimate coral calcification under various environmental conditions

2020 ◽  
Vol 17 (4) ◽  
pp. 887-899 ◽  
Author(s):  
Miguel Gómez Batista ◽  
Marc Metian ◽  
François Oberhänsli ◽  
Simon Pouil ◽  
Peter W. Swarzenski ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
The Other ◽  
Total Alkalinity ◽  
Precipitate Calcium Carbonate ◽  
High Quality ◽  
Stylophora Pistillata ◽  
Coral Calcification ◽  
Highly Correlated

Abstract. Coral reefs are constructed by calcifiers that precipitate calcium carbonate to build their shells or skeletons through the process of calcification. Accurately assessing coral calcification rates is crucial to determine the health of these ecosystems and their response to major environmental changes such as ocean warming and acidification. Several approaches have been used to assess rates of coral calcification, but there is a real need to compare these approaches in order to ascertain that high-quality and intercomparable results can be produced. Here, we assessed four methods (total alkalinity anomaly, calcium anomaly, 45Ca incorporation, and 13C incorporation) to determine coral calcification of the reef-building coral Stylophora pistillata. Given the importance of environmental conditions for this process, the study was performed under two starting pH levels (ambient: 8.05 and low: 7.2) and two light (light and dark) conditions. Under all conditions, calcification rates estimated using the alkalinity and calcium anomaly techniques as well as 45Ca incorporation were highly correlated. Such a strong correlation between the alkalinity anomaly and 45Ca incorporation techniques has not been observed in previous studies and most probably results from improvements described in the present paper. The only method which provided calcification rates significantly different from the other three techniques was 13C incorporation. Calcification rates based on this method were consistently higher than those measured using the other techniques. Although reasons for these discrepancies remain unclear, the use of this technique for assessing calcification rates in corals is not recommended without further investigations.

scholarly journals Virtually Wall-Less Tubular Sponges as Compartmentalized Reaction Containers

Research ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Shaohua Jiang ◽  
Viktoria Gruen ◽  
Sabine Rosenfeldt ◽  
Anna S. Schenk ◽  
Seema Agarwal ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Evaporation Rate ◽  
Ammonium Carbonate ◽  
Glass Tube ◽  
Equilibration Time ◽  
High Porosity ◽  
Efficient Removal ◽  
Precipitate Calcium Carbonate ◽  
Carbonate Decomposition ◽  
New Applications

Sponges are open cellular materials with numerous interesting features. However, the potential of compartmentalized sponges has not been explored although many new properties and applications could be envisioned. We found that compartmentalized fibrous ultraporous polymer sponges with superhydrophobic surfaces could be designed as virtually wall-less reaction containers. With this, for example, the efficient removal of CO2 from water and the controlled mineralization of calcium carbonate are possible. The high porosity (>99%) and superhydrophobicity make these sponges ideal candidates to hold alkanolamine solution for absorbing CO2 and exchange gas through the walls of the sponges. The tubular sponge exhibits a much higher evaporation rate than a glass tube with the same diameter due to the much larger contact area between water and air. Therefore, the spongy reaction container also possesses a much faster adsorption rate, smaller equilibration time and higher efficiency for CO2 adsorption than the glass tube container. In addition, these tubular sponges are also utilized to precipitate calcium carbonate by ammonium carbonate decomposition, which can control the deposition rates and products by tailoring the porosity and surface chemistry in the future. These new sponges provide an ideal basis for numerous new applications, for example, as breathable pipe lines for gas-liquid exchange, slag slurry carbonization, humidifier, and blood enricher.

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