The impact of preozonation and biodegradation on disinfection by-product formation

1992 ◽  
Vol 26 (9) ◽  
pp. 1217-1227 ◽  
Author(s):  
H SHUKAIRY ◽  
R SCOTTSUMMERS
Keyword(s):  
Product Formation ◽  
The Impact

scholarly journals Side-by-Side Comparison of Clean and Biomass-Derived, Impurity-Containing Syngas as Substrate for Acetogenic Fermentation with Clostridium ljungdahlii

Fermentation ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 84
Author(s):  
Alba Infantes ◽  
Michaela Kugel ◽  
Klaus Raffelt ◽  
Anke Neumann
Keyword(s):  
Biomass Gasification ◽  
Product Formation ◽  
Inhibitory Effects ◽  
Fed Batch ◽  
Gaseous Mixtures ◽  
Clostridium Ljungdahlii ◽  
Acetogenic Bacteria ◽  
Fed Batch Fermentation ◽  
Total Productivity ◽  
The Impact

Syngas, the product of biomass gasification, can play an important role in moving towards the production of renewable chemical commodities, by using acetogenic bacteria to ferment those gaseous mixtures. Due to the complex and changing nature of biomass, the composition and the impurities present in the final biomass-derived syngas will vary. Because of this, it is important to assess the impact of these factors on the fermentation outcome, in terms of yields, productivity, and product formation and ratio. In this study, Clostridium ljungdahlii was used in a fed-batch fermentation system to analyze the effect of three different biomass-derived syngases, and to compare them to equivalent, clean syngas mixtures. Additionally, four other clean syngas mixtures were used, and the effects on product ratio, productivity, yield, and growth were documented. All biomass-derived syngases were suitable to be used as substrates, without experiencing any complete inhibitory effects. From the obtained results, it is clear that the type of syngas, biomass-derived or clean, had the greatest impact on product formation ratios, with all biomass-derived syngases producing more ethanol, albeit with lesser total productivity.

Investigation into the impact of tyrosine on the product formation and quality attributes of mAbs in rCHO cell cultures

2020 ◽  
Vol 104 (16) ◽  
pp. 6953-6966
Author(s):  
Weijian Zhang ◽  
Xuping Liu ◽  
Hongping Tang ◽  
Xinran Zhang ◽  
Yanan Zhou ◽  
...  
Keyword(s):  
Cell Cultures ◽  
Product Formation ◽  
Quality Attributes ◽  
Rcho Cell ◽  
The Impact

scholarly journals Alternative Routes for the Production of Natural 4-Vinylguaiacol from Sugar Beet Fiber Using Basidiomycetous Enzymes

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 631
Author(s):  
Thorben Günther ◽  
Lasse Schoppe ◽  
Franziska Ersoy ◽  
Ralf G. Berger
Keyword(s):  
Sugar Beet ◽  
Ferulic Acid ◽  
Solid Phase ◽  
Fixed Bed ◽  
Schizophyllum Commune ◽  
Product Formation ◽  
Feruloyl Esterase ◽  
Flavor Compound ◽  
Conversion Rates ◽  
The Impact

Traditional smoking generates not only the impact flavor compound 4-vinylguaiacol, but concurrently many unwanted and potent toxic compounds such as polycyclic aromatic hydrocarbons. Enzyme technology provides a solution without any side-product formation. A feruloyl esterase from Rhizoctonia solani (RspCAE) liberated ferulic acid from low-priced sugar beet fiber. Decarboxylation of ferulic acid to 4-vinylguaiacol was achieved by a second enzyme from Schizophyllum commune (ScoFAD). Both enzymes were covalently immobilized on agarose to enable reusability in a fixed-bed approach. The two enzyme cascades showed high conversion rates with yields of 0.8 and 0.95, respectively, and retained activity for nearly 80 h of continuous operation. The overall productivity of the model process with bed volumes of 300 µL and a substrate flow rate of 0.25 mL min−1 was 3.98 mg 4-vinylguaiacol per hour. A cold online solid phase extraction using XAD4 was integrated into the bioprocess and provided high recovery rates during multiple elution steps. Attempting to facilitate the bioprocess, a fused gene coding for the two enzymes and a set of different linker lengths and properties was constructed and introduced into Komagataella phaffii. Longer and rigid linkers resulted in higher activity of the fusion protein with a maximum of 67 U L−1.

scholarly journals NOx Reduction Pathways during LNT Operation over Ceria Containing Catalysts: Effect of Copper Presence and Barium Content

2021 ◽  
Vol 11 (12) ◽  
pp. 5700
Author(s):  
Juan Carlos Martínez-Munuera ◽  
Javier A. Giménez-Mañogil ◽  
Roberto Matarrese ◽  
Lidia Castoldi ◽  
Avelina García-García
Keyword(s):  
Noble Metals ◽  
Chemical Engineering ◽  
Materials Science ◽  
Control Strategies ◽  
Nox Reduction ◽  
Product Formation ◽  
Reduction Step ◽  
The Rich ◽  
Effect Of Copper ◽  
The Impact

Ceria-based catalysts, with Cu in substitution of noble metals, were studied in a vertical microreactor system under isothermal conditions, where NOx was previously stored, followed by the reduction step conducted under H2. The possible remaining ad-NOx species after the reduction stage, were investigated by Temperature Programmed Desorption in He. In situ DRIFTS was used as a complementary technique for the analysis of the surface species formation/transformation on the catalysts’ surface. Catalysts containing both Ba and Cu were found to be selective in the NOx reduction, producing N2 and minor amounts of NH3 during the reduction step, as well as NO. The different ceria-based formulations (containing copper and/or barium) were prepared and tested at two different temperatures in the NOx reduction (NSR) processes. Their catalytic activities were analyzed in terms of their compositions and have been useful in the elucidation of the possible origin and relevant pathways for NOx reduction product formation, which seems to involve the oxygen vacancies of the ceria-based materials (whose generation seems to be promoted by copper) during the rich step. The scope of this work involves an interdisciplinary study of the impact that catalysts’ formulations (noble metal-free) have on their LNT performance under simulated conditions, thus covering aspects of Materials Science and Chemical Engineering in a highly applied context, related to the development of control strategies for hybrid powertrains and/or the reduction of the impact of cold-start emissions.

scholarly journals Impact of the functionalization onto structure transformation and gas adsorption of MIL-68(In)

2018 ◽  
Vol 5 (12) ◽  
pp. 181378 ◽  
Author(s):  
Lei Wu ◽  
Weifeng Wang ◽  
Rong Liu ◽  
Gang Wu ◽  
Huaxin Chen
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Quadrupole Moment ◽  
Gas Adsorption ◽  
Product Formation ◽  
Negative Influence ◽  
Adsorption Enthalpy ◽  
Molar Ratios ◽  
Adsorption Desorption ◽  
The Impact

A series of functionalization –NH 2 , –Br and –NO 2 has been performed on MIL-68(In) material in order to improve the porosity features of the pristine material. The functional groups grafted onto the ligand and the molar ratios of the ingredient indicate a profound influence on product formation. With the incremental amount of metal source, product structures undergo the transformation from MIL-68 to MIL-53 or QMOF-2. The situation is different depending on the variation of the ligands. Gas (N 2 , Ar, H 2 and CO 2 ) adsorption–desorption isotherms were systematically investigated to explore the impact of the functionalization on the porous prototypical framework. Comparison of adsorption behaviour of N 2 and Ar indicates that the polar molecule exhibits striking interaction to N 2 molecule, which has a considerable quadrupole moment. Therefore, as a probe molecule, Ar with no quadrupole moment is more suitable to characterize the surface area with the polar groups. Meanwhile, Ar adsorption result confirms that the negative influence on the surface area stems from the size of the substituting groups. The uptake of H 2 and CO 2 indicates that the introduction of appropriate polar organic groups can effectively enhance the adsorption enthalpy of relative gases and improve the gas adsorption capacity apparently at low pressure. The introduction of –NO 2 is in favour of improving the H 2 adsorption capacity, while the grafted –NH 2 groups can most effectively enhance the CO 2 adsorption capacity.

Underlying Mechanisms in Groundwater Remediation via In Situ Chemical Oxidation

2021 ◽  
Author(s):  
Georgina C. Kalogerakis ◽  
Hardiljeet K. Boparai ◽  
Brent E. Sleep
Keyword(s):  
Groundwater Remediation ◽  
Fractured Rock ◽  
Product Formation ◽  
Chemical Oxidation ◽  
In Situ Chemical Oxidation ◽  
Remediation Efficiency ◽  
Flow Transport ◽  
Underlying Mechanisms ◽  
The Impact ◽  
By Products

<p>Remediation of groundwater contaminated by organic compounds in porous and fractured media is a persistent and not well understood challenge. <em>In</em> <em>situ</em> chemical oxidation (ISCO) is a remediation technology that delivers oxidants to the subsurface to transform contaminants into benign products. The reactions take place in the aqueous phase where the oxidant comes in contact with the dissolved phase of the contaminant. In this work, we report on the impact of by-product formation on the effectiveness of ISCO. We conducted a series of batch experiments to identify by-products and increase our understanding for time scales required for complete mineralization of petroleum hydrocarbons. This was coupled with micro-CT imaging of column experiments and imaging in a glass fractured rock replica to track the formation of gaseous and solid by-products and determine their effect on flow, transport, and mass transfer. The final aim of this study is to propose novel strategies for improved remediation efficiency.</p><p> </p>

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Geosciences Applied to Lunar Exploration

1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green
Keyword(s):  
Lunar Surface ◽  
Probable Mechanism ◽  
Point Of View ◽  
Lunar Exploration ◽  
Geological Model ◽  
Apply Geophysics ◽  
Surface Features ◽  
The Impact

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Sign in / Sign up

Export Citation Format

Share Document