Carbon Dioxide Equilibria and their Applications

Butler, James N.

doi:10.1201/9781315138770

Cited by 106 publications

(82 citation statements)

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“…The inhibition of bacterial growth due to high CO 2 concentration environment is thought to be occurred through the diffusion of H 2 CO 3 across the bacterial membrane that altering intracellular pH (Wolfe, ). These changes increased at low temperatures because of the higher solubility of CO 2 at decreased temperatures and may affect enzymes involved in metabolic pathways within the cell (Butler, ). Moreover, high CO 2 concentrations may inhibit decarboxylation reactions, in which CO 2 is released by feedback mechanisms.…”

Section: Resultsmentioning

confidence: 99%

Short‐term application of CO₂ gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Chandra

Lee

Hong

et al. 2018

Journal of Food Safety

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The effects of different concentrations (30, 50, and 70 kPa) and time (1 or 3 hr) of short‐term CO2 gas treatment on the quality, safety, and shelf life of “Charlotte” strawberry were evaluated during storage at 4°C. Color attributes were better maintained in CO2 treated strawberries while firmness increased significantly and maintained throughout the storage in 70 kPa CO2 treatments compared to untreated control. Total soluble solid, pH, and titratable acidity did not show remarkable changes among the treatments. Total anthocyanins accumulation was significantly (p ≤ .05) lower in fruits exposed to 70 kPa CO2 for 1 hr than that of control but insignificantly lower with other CO2 treatments at the end of storage while total phenolic content was almost unaffected by CO2 treatment. Lower number of microbial population and better maintenance of sensory qualities were found in strawberries treated with 70 kPa CO2; therefore, marketability extended by about 4 and 2 days compared to control and other CO2 treatments, respectively. Practical applications These results suggest that the physicochemical, microbial, and sensory quality of strawberries were better maintained in fruits exposed to 70 kPa CO2 either for 1 or 3 hr before storage than sample stored directly. The results of this study could be useful for maintaining the quality and extending the shelf life of “Charlotte” strawberry during storage or export at low temperature condition.

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Section: Resultsmentioning

confidence: 99%

Short‐term application of CO₂ gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Chandra

Lee

Hong

et al. 2018

Journal of Food Safety

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“…Dissolved CO 2 can also be hydrated to form carbonic acid; however, its concentration is ∼10 −3 of the concentration of dissolved CO 2 . Therefore, the hydrated and dissolved CO 2 may be considered as a single species . The associated rate and equilibrium constants for these reactions are taken from previous literature reports:

K_{1} = 3.35 x 1 0^{- 2} M a t m^{- 1}

K_{2} = 4.44 x 1 0^{7} M^{- 1}

k_{2 f} = 5.93 x 1 0^{3} M^{- 1} s^{- 1}

k_{2 r} = 1.34 x 1 0^{- 4} s^{- 1}

K_{3} = 4.66 x 1 0^{3} M^{- 1}

k_{3 f} = 1.00 x 1 0^{8} M^{- 1} s^{- 1}

k_{2 r} = 2.15 x 1 0^{4} s^{- 1}

.…”

Section: Methodsmentioning

confidence: 99%

Effects of Anion Identity and Concentration on Electrochemical Reduction of CO₂

et al. 2018

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The electrochemical reduction of CO2 is known to be influenced by the concentration and identity of the anionic species in the electrolyte; however, a full understanding of this phenomenon has not been developed. Here, we present the results of experimental and computational studies aimed at understanding the role of electrolyte anions on the reduction of CO2 over Cu surfaces. Experimental studies were performed to show the effects of bicarbonate buffer concentration and the composition of other buffering anions on the partial currents of the major products formed by reduction of CO2 over Cu. It was demonstrated that the composition and concentration of electrolyte anions has relatively little effect on the formation of CO, HCOO−, C2H4, and CH3CH2OH, but has a significant effect on the formation of H2 and CH4. Continuum modeling was used to assess the effects of buffering anions on the pH at the electrode surface. The influence of pH on the activity of Cu for producing H2 and CH4 was also considered. Changes in the pH near the electrode surface were insufficient to explain the differences in activity and selectivity observed with changes in anion buffering capacity observed for the formation of H2 and CH4. Therefore, it is proposed that these differences are the result of the ability of buffering anions to donate hydrogen directly to the electrode surface and in competition with water. The effectiveness of buffering anions to serve as hydrogen donors is found to increase with decreasing pKa of the buffering anion.

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“…CO 2A was calculated from an assumed mole fraction of CO 2 in the atmosphere (CO 2X ) and relating it to a CO 2 concentration in the water by using Henry's law:

{normalC normalO}_{2 normalA} = K_{H} \times {normalC normalO}_{2 normalX} \times P_{normalA normalT normalM} = K_{H} \times p {normalC normalO}_{2}

where CO 2A is the equilibrium CO 2 concentration (µmol L −1 ); K H is the temperature‐dependent Henry's constant (L atm mol −1 ) [ Butler , ]; CO 2X is the partial pressure of CO 2 in the atmosphere, assumed to be 390 ppmv; and P ATM is the atmospheric pressure, in atmospheres, calculated from either observed barometric pressure or from the reported elevation of the monitoring location. ΔCO 2 was then calculated as

{normalΔ normalC normalO}_{2} = {normalC normalO}_{2 normalW} - {normalC normalO}_{2 normalA} .

…”

Section: Methodsmentioning

confidence: 99%

“…Aerobic metabolism couples the production and consumption of O 2 and CO 2 such that the molar departures of the gases from atmospheric equilibrium, ΔO 2 and ΔCO 2 , respectively, are expected to have predictable behavior. However, in water with relatively high pH (~8.0 or higher), the hydrated form of CO 2 , H 2 CO 3 , can ionize to H + + HCO 3 − [ Butler , ], and so ΔCO 2 and −ΔO 2 will be neither equivalent nor related by a fixed stoichiometry. In high‐pH/high‐alkalinity waters, some of the CO 2 added or removed through reactions such as primary production and aerobic respiration will exist in the ionized form.…”

Section: Introductionmentioning

confidence: 99%

Carbonate buffering and metabolic controls on carbon dioxide in rivers

Stets

Butman

McDonald³

et al. 2017

Global Biogeochemical Cycles

115

117

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Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2 consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2 and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = −0.67 and ρ = −0.63, respectively), although the correlations were weaker in high‐alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air‐water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape‐scale differences in the behavior of CO2 between high‐ and low‐alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

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Carbon Dioxide Equilibria and their Applications

Cited by 106 publications

References 0 publications

Short‐term application of CO₂ gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Short‐term application of CO₂ gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Effects of Anion Identity and Concentration on Electrochemical Reduction of CO₂

Carbonate buffering and metabolic controls on carbon dioxide in rivers

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Carbon Dioxide Equilibria and their Applications

Cited by 106 publications

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Short‐term application of CO2 gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Short‐term application of CO2 gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Effects of Anion Identity and Concentration on Electrochemical Reduction of CO2

Carbonate buffering and metabolic controls on carbon dioxide in rivers

Contact Info

Product

Resources

About

Short‐term application of CO₂ gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Short‐term application of CO₂ gas: Effects on physicochemical, microbial, and sensory qualities of “Charlotte” strawberry during storage

Effects of Anion Identity and Concentration on Electrochemical Reduction of CO₂