Glyphosate: environmental fate and impact

Weed Science ◽  
2020 ◽  
Vol 68 (3) ◽  
pp. 201-207 ◽  
Author(s):  
Stephen O. Duke
Keyword(s):  
Environmental Impact ◽  
Weed Management ◽  
Carbon Dioxide Emissions ◽  
Plant Pathogens ◽  
Water Solubility ◽  
Environmental Fate ◽  
High Water ◽  
Microbial Product ◽  
Herbicide Alternatives ◽  
Environmental Impact Quotient

AbstractGlyphosate is the most used herbicide worldwide, which has contributed to concerns about its environmental impact. Compared with most other herbicides, glyphosate has a half-life in soil and water that is relatively short (averaging about 30 d in temperate climates), mostly due to microbial degradation. Its primary microbial product, aminomethylphosphonic acid, is slightly more persistent than glyphosate. In soil, glyphosate is virtually biologically inactive due to its strong binding to soil components. Glyphosate does not bioaccumulate in organisms, largely due to its high water solubility. Glyphosate-resistant crops have greatly facilitated reduced-tillage agriculture, thereby reducing soil loss, soil compaction, carbon dioxide emissions, and fossil fuel use. Agricultural economists have projected that loss of glyphosate would result in increased cropping area, some gained by deforestation, and an increase in environmental impact quotient of weed management. Some drift doses of glyphosate to non-target plants can cause increased plant growth (hormesis) and/or increased susceptibility to plant pathogens, although these non-target effects are not well documented. The preponderance of evidence confirms that glyphosate does not harm plants by interfering with mineral nutrition and that it has no agriculturally significant effects on soil microbiota. Glyphosate has a lower environmental impact quotient than most synthetic herbicide alternatives.

scholarly journals Biohydrogen from Microalgae: Production and Applications

2021 ◽  
Vol 11 (4) ◽  
pp. 1616
Author(s):  
Antonina Rita Limongi ◽  
Emanuele Viviano ◽  
Maria De Luca ◽  
Rosa Paola Radice ◽  
Giuliana Bianco ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Environmental Impact ◽  
Carbon Dioxide Emissions ◽  
Alternative Energy ◽  
Electricity Production ◽  
Energy Sources ◽  
Molecular Processes ◽  
Significant Development ◽  
Alternative Energy Sources ◽  
Natural Way

The need to safeguard our planet by reducing carbon dioxide emissions has led to a significant development of research in the field of alternative energy sources. Hydrogen has proved to be the most promising molecule, as a fuel, due to its low environmental impact. Even if various methods already exist for producing hydrogen, most of them are not sustainable. Thus, research focuses on the biological sector, studying microalgae, and other microorganisms’ ability to produce this precious molecule in a natural way. In this review, we provide a description of the biochemical and molecular processes for the production of biohydrogen and give a general overview of one of the most interesting technologies in which hydrogen finds application for electricity production: fuel cells.

A Fluorescence Quenching Analysis of the Binding of Fluoroquinolones to Humic Acid

2017 ◽  
Vol 71 (11) ◽  
pp. 2512-2518 ◽  
Author(s):  
Ryan P. Ferrie ◽  
Gregory E. Hewitt ◽  
Bruce D. Anderson
Keyword(s):  
Humic Acid ◽  
Fluorescence Quenching ◽  
Water Solubility ◽  
Binding Constants ◽  
High Water ◽  
Static Quenching ◽  
Temperature Range ◽  
Equilibrium Binding ◽  
Quenching Analysis ◽  
High Water Solubility

Fluorescence quenching was used to investigate the interaction of six fluoroquinolones with humic acid. Static quenching was observed for the binding of ciprofloxacin, enoxacin, fleroxacin, levofloxacin, norfloxacin, and ofloxacin to humic acid. The equilibrium binding constants were found from Stern–Volmer plots of the data. The quenching experiments were repeated over a temperature range of 25–45 ℃ and van’t Hoff plots were generated. From these linear plots, thermodynamic values were calculated for Δ H, Δ G, and Δ S for each of the fluoroquinolones. The equilibrium binding constants were found to be <1 for all the antibiotics studied. The calculated ΔH values were all negative and ranged from −9.5 to −27.6 kJ/mol. The high water solubility of the antibiotics and low ΔH of binding suggests that the antibiotics will be transported easily through the environment. Finally, whether the fluoroquinolones are in a protonated, deprotonated, or partially protonated state is found to correlate to the strength of binding to humic acid.

Novel tetrazole PtII and PdII complexes with enhanced water solubility: synthesis, structural characterization and evaluation of antiproliferative activity

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tatiyana V. Serebryanskaya ◽  
Alexander S. Lyakhov ◽  
Ludmila S. Ivashkevich ◽  
Yuri V. Grigoriev ◽  
Andreii S. Kritchenkov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Water Solubility ◽  
Thermal Analyses ◽  
High Water ◽  
Acetonitrile Solution ◽  
X Ray ◽  
Molecular And Crystal Structures ◽  
Tetrazole Derivatives ◽  
High Water Solubility

AbstractNovel platinum(II) and palladium(II) chlorido complexes with tetrazole derivatives 1-(2-hydroxyethyl)tetrazole (het) and 1-[tris(hydroxymethyl)methyl]tetrazole (thm), viz. cis-[Pt(het)2Cl2], trans-[Pt(het)2Cl2], trans-[Pt(thm)2Cl2], trans-[Pd(het)2Cl2], and trans-[Pd(thm)2Cl2], were synthesized. The compounds were characterized by elemental and high-resolution electrospray ionization (HRESI) mass spectrometry, high-performance liquid chromatography (HPLC), 1H, 13C and 195Pt nuclear magnetic resonance (NMR) spectroscopy, thermal analyses, and Infrared (IR) spectroscopy. Molecular and crystal structures of trans-[PdL2Cl2] and trans-[PtL2Cl2] (L = het, thm) were established by single-crystal X-ray analysis. The complex cis-[Pt(het)2Cl2] was found to undergo cis–to–trans isomerization upon heating in acetonitrile solution and in the solid state. The synthesized complexes show rather high water solubility lying in the range of 2–10 mg/L.

scholarly journals Optimization and Modeling of an Emulsion Polymerization Reactor

2021 ◽  
Author(s):  
Narges Ghadi
Keyword(s):  
Emulsion Polymerization ◽  
Water Solubility ◽  
Monomer Conversion ◽  
High Water ◽  
Oscillatory Behavior ◽  
Operating Conditions ◽  
Polymer Properties ◽  
Continuous Polymerization ◽  
Simulation Results ◽  
The Impact

A mathematical model was developed to simulate emulsion polymerization in batch, semi-batch and continuous reactors for monomers with high water solubility and significant desorption such as vinyl acetate. The effects of operating conditions such as initiator and emulsifier concentration as well as reactor temperature have been studied. The simulation results revealed the sensitivity of polymer properties and monomer conversion to variation of these operating conditions. Furthermore, the impact of monomer soluble impurities on reduction of monomer conversion has been investigated. In order to control polymer molecular weight, application of chain transfer agents such as t-nonyl mercaptan was suggested. Generally, the simulation results fitted well [with] experimental data from the literature. Several optimizing policies were considered to enhance the reaction operation for better product quality. During continuous polymerization, the reactor demonstrates oscillatory behavior throughout the operation. A new reactor train configuration was consistent with the aim of damping the oscillations and producing high-quality latex.

scholarly journals Energy Consumption of Rail Baltica Project: Regional Aspects of Environmental Impact

2019 ◽  
Vol 16 (1) ◽  
pp. 148-160
Author(s):  
Olga Piterina ◽  
Alexander Masharsky
Keyword(s):  
Carbon Dioxide ◽  
Energy Consumption ◽  
Environmental Impact ◽  
Carbon Dioxide Emissions ◽  
High Speed ◽  
International Energy Agency ◽  
Future Research ◽  
Energy Agency ◽  
Load Rate ◽  
Emissions Intensity

Abstract Research purpose. The high-speed railway (HSR) construction project in the Baltic States is the largest joint infrastructure project since the restoration of independence of Latvia, Lithuania and Estonia. Rail Baltica (RB) is considered as the most energy-efficient project having the lowest environmental impact. However, the issue of energy consumption of the project was not sufficiently addressed either in the investment justification of the RB construction or in the relevant research works regarding the project. The aim of the current research is to determine the indicators of energy consumption and carbon dioxide (CO2) emissions intensity of the Latvian section of RB, since they are the key factors of the quantitative assessment of sustainability. Design/Methodology/Approach. Critical analysis of the academic research works and reports of the official international organizations dedicated to the topic of energy consumption and CO2 emissions of HSR was conducted prior to the calculation of the above-mentioned indicators. The method of calculation based on International Union of Railways (UIC) was used in order to conduct the cluster analysis within the framework of current work. The main points considered are electricity consumption, carbon dioxide emissions, and level of passenger and freight demand. Statistical databases of UIC and International Energy Agency were used. Findings. The calculations carried out by the authors of the given article demonstrate substantial figures of CO2 emissions intensity for Latvian section of the project related to the train load rate and traffic intensity which is evened out only by the CO2 emissions factor in Latvia. Originality/Value/Practical implications. On this basis the authors present the directions for future research required for the development of the effective strategy for the Latvian Republic with the aim of achieving the increase in the RB project’s ecological efficiency.

scholarly journals CCN activity of organic aerosols observed downwind of urban emissions during CARES

2013 ◽  
Vol 13 (4) ◽  
pp. 9355-9399 ◽  
Author(s):  
F. Mei ◽  
A. Setyan ◽  
Q. Zhang ◽  
J. Wang
Keyword(s):  
Chemical Composition ◽  
Water Solubility ◽  
Volume Fraction ◽  
Field Studies ◽  
High Water ◽  
Carbonaceous Aerosols ◽  
Mass Spectral ◽  
Least Squares Fit ◽  
The Relationship ◽  
Aerosol Chemical Composition

Abstract. During the Carbonaceous Aerosols and Radiative Effects Study (CARES), activation fraction of size-resolved aerosol particles and aerosol chemical composition were characterized at the T1 site (~60 km downwind of Sacramento, California) from 10 June to 28 June 2010. The hygroscopicity of CCN-active particles (κCCN) with diameter from 100 to 171 nm, derived from the size-resolved activated fraction, varied from 0.10 to 0.21, with an average of 0.15, which was substantially lower than that proposed for continental sites in earlier studies. The low κCCN value was due to the high organic volume fraction, averaged over 80% at the T1 site. The derived κCCN exhibited little diurnal variation, consistent with the relatively constant organic volume fraction observed. At any time, over 90% of the size selected particles with diameter between 100 and 171 nm were CCN active, suggesting most particles within this size range were aged background particles. Due to the large organic volume fraction, organic hygroscopicity (κorg) strongly impacted particle hygroscopicity and therefore calculated CCN concentration. For vast majority of the cases, an increase of κorg from 0.03 to 0.18, which are within the typical range, doubled the calculated CCN concentration. Organic hygroscopicity was derived from κCCN and aerosol chemical composition, and its variations with the fraction of total organic mass spectral signal at m/z 44 (f44) and O : C were compared to results from previous studies. Overall, the relationships between κorg and f44 are quite consistent for organic aerosol (OA) observed during field studies and those formed in smog chamber. Compared to the relationship between κorg and f44, the relationship between κorg and O : C exhibits more significant differences among different studies, suggesting κorg may be better parameterized using f44. A least squares fit yielded κorg = 2.04 (± 0.07) × f44 − 0.11 (± 0.01) with the Pearson R2 value of 0.71. One possible explanation for the stronger correlation between κorg and f44 is that the m/z 44 signal (mostly contributed by the CO2+ ion) is more closely related to organic acids, which may dominate the overall κorg due to their relatively high water solubility and hygroscopicity.

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