scholarly journals Ozonation of Amoxicillin and Ciprofloxacin in Model Hospital Wastewater to Increase Biotreatability

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1407
Author(s):  
Severina Aleksić ◽  
Andreja Žgajnar Gotvajn ◽  
Katarina Premzl ◽  
Mitja Kolar ◽  
Sonja Šostar Turk
Keyword(s):  
Solid Phase ◽  
Complete Removal ◽  
Hospital Wastewater ◽  
Environmental Toxicity ◽  
Quadrupole Mass ◽  
Ph Values ◽  
Toc Removal ◽  
Low Concentrations ◽  
Hospital Effluents ◽  
Analytical System

Amoxicillin (AMX) and Ciprofloxacin (CIP) are antibiotics commonly used in human medicine with high environmental toxicity and poor biodegradability. They have been found in various hospital effluents and groundwater, and their environmental impact is still not fully understood. In this work, we investigated the possibility of treating model wastewaters containing the antibiotics AMX and CIP using ozonation, with the addition of H2O2 under various conditions, including different pH values, H2O2, and ozone dosages. The quantification of and treatment efficacy for antibiotic removal were determined via solid phase extraction followed by chromatographic separation by liquid chromatography coupled with tandem triple quadrupole mass spectrometry (LC/MS/MS). This analytical system is quite efficient for the detection of all major antibiotic classes, even if they are present at very low concentrations. The efficiency of ozonation was determined by measuring the TOC (Total Organic Carbon) changes after ozonation of the model wastewater and by measuring the concentration of the two antibiotics. In a sequential activated sludge process of ozone-treated model wastewater, almost complete TOC removal and an overwhelming decrease in antibiotic concentrations (up to 99%) were observed. Ozonation resulted in complete removal of AMX and CIP in less than 30 and 120 min, respectively. The results of this work indicate that ozonation could be a suitable pretreatment method to reduce the toxicity of contaminants (AMX and CIP) and improve the biodegradability of hospital wastewater.

Development of Strategies for Glycopeptide Synthesis: An Overview on the Glycosidic Linkage

2020 ◽  
Vol 24 (21) ◽  
pp. 2475-2497
Author(s):  
Andrea Verónica Rodríguez-Mayor ◽  
German Jesid Peralta-Camacho ◽  
Karen Johanna Cárdenas-Martínez ◽  
Javier Eduardo García-Castañeda
Keyword(s):  
Chemical Synthesis ◽  
Solid Phase ◽  
Building Blocks ◽  
Heterogeneous Environments ◽  
Phase Synthesis ◽  
Low Concentrations ◽  
Biological Sources ◽  
Synthetic Routes ◽  
The Impact ◽  
Potential Use

Glycoproteins and glycopeptides are an interesting focus of research, because of their potential use as therapeutic agents, since they are related to carbohydrate-carbohydrate, carbohydrate-protein, and carbohydrate-lipid interactions, which are commonly involved in biological processes. It has been established that natural glycoconjugates could be an important source of templates for the design and development of molecules with therapeutic applications. However, isolating large quantities of glycoconjugates from biological sources with the required purity is extremely complex, because these molecules are found in heterogeneous environments and in very low concentrations. As an alternative to solving this problem, the chemical synthesis of glycoconjugates has been developed. In this context, several methods for the synthesis of glycopeptides in solution and/or solid-phase have been reported. In most of these methods, glycosylated amino acid derivatives are used as building blocks for both solution and solid-phase synthesis. The synthetic viability of glycoconjugates is a critical parameter for allowing their use as drugs to mitigate the impact of microbial resistance and/or cancer. However, the chemical synthesis of glycoconjugates is a challenge, because these molecules possess multiple reaction sites and have a very specific stereochemistry. Therefore, it is necessary to design and implement synthetic routes, which may involve various protection schemes but can be stereoselective, environmentally friendly, and high-yielding. This review focuses on glycopeptide synthesis by recapitulating the progress made over the last 15 years.

Comparison of the Effect of Boron and Phosphorus Impurities on Solid Phase Epitaxial Regrowth of Amorphous Silicon

1989 ◽  
Vol 157 ◽  
Author(s):  
Young-Jin Jeon ◽  
M.F. Becker ◽  
R.M. Walser
Keyword(s):  
Amorphous Silicon ◽  
Isothermal Annealing ◽  
Solid Phase ◽  
Laser Interferometry ◽  
Electron Pairs ◽  
Quadratic Equations ◽  
Low Concentrations ◽  
Fractional Ionization ◽  
Reported Data

ABSTRACTThis work was concerned with comparing the relative effects of boron and phosphorus impurities on the solid phase epitaxial (SPE) regrowth rate of self-ion amorphized layers in silicon wafers with (100) orientation. We used previously reported data measured by in situ, high precision, cw laser interferometry during isothermal annealing for temperatures from 450°C to 590°C, and concentrations in the range from 7.8×1018 cm-3 to 5×l020 cm-3 for boron (NB), and from 5×l017 cm-3 to 3×1020 cm-3 for phosphorus (Np) impurities. The basis for the comparison was a recently developed model that extends the Spaepen-Turnbull model for silicon recrystallization to include ionization enhanced processes.The experimental data for bom boron and phosphorus exhibited the linear variation in regrowth rate expected for low concentrations of implanted hydrogenic impurities having a concentration-independent fractional ionization in amorphous silicon. In the linear range the relative enhanced regrowth rate produced by these impurities can be expressed as a product of their, relative fractional ionizations, and the relative amount the rate constant for reconstruction is altered by localizing an electron, or a hole, at the reconstruction site. Assuming that a localized hole and electron equally softened the potential barrier for reconstruction, the experimental results indicated that boron had an ?40 meV lower barrier to ionization in amorphous silicon than phosphorus.The variations in the SPE regrowth rates with higher concentrations of both implanted boron and phosphorus were well fit by quadratic equations, but with different curvatures (+ and - for B and P respectively). This result was interpreted to indicate that SPE regrowth was further enhanced by localized hole pairs, but retarded by localized electron pairs.

Optical Waveguide Formation by Ion Implantation of Ti or Ag

1988 ◽  
Vol 100 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Ion Implantation ◽  
Concentration Profile ◽  
Optical Waveguides ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Effective Means ◽  
Complete Removal ◽  
Solid Phase Epitaxy ◽  
Annealing Temperatures ◽  
Residual Damage

ABSTRACTIon implantation of Ti into LINbO3 has been shown to be an effective means of producing optical waveguides, while maintaining better control over the resulting concentration profile of the dopant than can be achieved by in-diffusion. While undoped, amorphous LiNbO3 can be regrown by solid-phase epitaxy at 400°C with a regrowth velocity of 250 Å/min, the higher concentrations of Ti required to form a waveguide (∼10%) slow the regrowth considerably, so that temperatures approaching 800°C are used. Complete removal of residual damage requires annealing temperatures of 1000°C, not significantly lower than those used with in-diffusion. Solid phase epitaxy of Agimplanted LiNbO3, however, occurs at much lower temperatures. The regrowth is completed at 400°C, and annealing of all residual damage occurs at or below 800°C. Furthermore, the regrowth rate is independent of Ag concentration up to the highest dose implanted to date, 1 × 1017 Ag/cm2. The usefulness of Ag implantation for the formation of optical waveguides is limited, however, by the higher mobility of Ag at the annealing temperature, compared to Ti.

The Development of a Radioimmunoassay for the Measurement of Urinary Tammhorsfall Glycoprotein in the Presence of Sodium Dodecyl Sulphate

1973 ◽  
Vol 44 (2) ◽  
pp. 163-179 ◽  
Author(s):  
Anne M. S. Grant ◽  
A. Neuberger
Keyword(s):  
Guinea Pig ◽  
Sodium Dodecyl Sulphate ◽  
Solid Phase ◽  
Excretion Rate ◽  
Sodium Dodecyl ◽  
Antibody Concentration ◽  
Low Concentrations ◽  
Freeze Dried ◽  
Ionic Detergent ◽  
Normal Humans

1. A specific and quantitative radioimmunoassay was developed for the measurement of low concentrations of human and rabbit Tamm—Horsfall glycoprotein in the presence of other proteins. Antibody-coated tubes were used as a solid phase in the assay and the optimum antibody concentration and duration of antibody coating were established. 2. Pure Tamm—Horsfall glycoprotein was labelled with 125I and, because of its apparent susceptibility to radiation damage, was labelled at weekly intervals. 3. Sodium dodecyl sulphate, an ionic detergent, was included in the assay at a final concentration of 0.0005% to disaggregate the glycoprotein. An overnight preincubation step in the presence of the detergent was necessary before the disaggregated glycoprotein solutions were allowed to react with the antibody. Pretreatment of the tracer with detergent was not necessary. 4. Two glycoprotein standards were prepared fresh for each assay from freeze-dried material. The average linear range of the assay was between approx. 150 ng/ml and 2.5 μg/ml. Albumin was only shown to interfere with the assay at concentrations greater than 100 μg/ml. 5. Urines were dialysed against water for 3 days before assay to remove inhibitory material. Urines were never frozen as this was found to affect the assay. 6. A recovery experiment showed that the pure freeze-dried standard behaved in an immunologically identical way to the urinary glycoprotein. 7. Human Tamm-Horsfall glycoprotein cross-reacted with guinea-pig anti-(rabbit Tamm—Horsfall) antiserum and rabbit Tamm—Horsfall glycoprotein cross-reacted with guinea-pig anti-(human Tamm—Horsfall) antiserum, but not with rabbit anti-(human Tamm—Horsfall) antiserum. This showed a partial immunological identity between Tamm-Horsfall glycoprotein from humans and rabbits which was only evident when the antiserum was raised in a third species. 8. The excretion rate of Tamm—Horsfall glycoprotein in normal humans was found to be 48.1 ± 9.6 (SD) mg/24 h for males and 50.5 ± 14.8 (SD) mg/24 h for females. The mean excretion rate of the glycoprotein in New Zealand White rabbits was 34.8 ± 7.9 mg/24 h.

Impact of sulfate on the solubility of Tc(IV) in acidic to hyperalkaline aqueous reducing systems

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sarah B. Duckworth ◽  
Xavier Gaona ◽  
Alexander Baumann ◽  
Kathy Dardenne ◽  
Jörg Rothe ◽  
...  
Keyword(s):  
Solid Phase ◽  
Correction Factors ◽  
Mixed Salt ◽  
Ph Values ◽  
Reducing Conditions ◽  
Upper Limits ◽  
Salt Systems ◽  
Amorphous Character ◽  
Good Agreement

Abstract The solubility of 99Tc(IV) was investigated from undersaturation conditions in NaCl–Na2SO4 (0.3 M ≤ I ≤ 5.0 M), MgCl2–MgSO4 (I = 13.5 M) and CaCl2–CaSO4 (I = 13.5 M) systems with 0.001 M ≤ [SO4 2−]tot ≤ 1.0 M and 1 ≤ pH m  ≤ 12 (with pH m  = −log[H+], in molal units). Reducing conditions were set by either Sn(II) or Fe(0). Special efforts were dedicated to accurately characterize the correction factors A m required for the determination of pH m from the experimentally measured pH values in the mixed salt systems investigated, with pH m  = pHexp + A m . The combination of (pe + pH m ) measurements with Pourbaix diagrams of Tc suggests that technetium is present in its +IV redox state. This hypothesis is confirmed by XANES, which unambiguously shows the predominance of Tc(IV) both in the aqueous and solid phases of selected solubility samples. XRD and SEM–EDS support the amorphous character of the solid phase controlling the solubility of Tc(IV). EXAFS data confirm the predominance of TcO2(am, hyd) at pH m  > 1.5, whereas the formation of a Tc(IV)–O–Cl solid phase is hinted at lower pHm values in concentrated NaCl–Na2SO4 systems with ≈5 M NaCl. Solubility data collected in sulfate-containing systems are generally in good agreement with previous solubility studies conducted in sulfate-free NaCl, MgCl2 and CaCl2 solutions of analogous ionic strength. Although the complexation of Tc(IV) with sulfate cannot be completely ruled out, these results strongly support that, if occurring, complexation must be weak and has no significant impact on the solubility of Tc(IV) in dilute up to highly saline media. Solubility upper-limits determined in this work can be used for source term estimations including the effect of sulfate in a variety of geochemical conditions relevant in the context of nuclear waste disposal.

scholarly journals Adsorption Efficiency of Pentafl Uorobenzene on Ionic Liquids-Based Silicas

2018 ◽  
Vol 20 (3) ◽  
pp. 47-52 ◽  
Author(s):  
Xiaofei Wang ◽  
Liangwen Lin ◽  
Jinfeng Xie ◽  
Xuemin Yan ◽  
Wei Xiao ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Solid Phase ◽  
Solution System ◽  
Ph Values ◽  
Several Variables ◽  
Effi Ciency ◽  
Relative Standard ◽  
Effects Of Ph ◽  
Chloride Salts ◽  
Optimized Conditions

Abstract The adsorption of pentafl uorobenzene on nine ionic liquid-based silicas was investigated using solid phase extraction. The effects of several variables such as the type of ionic liquid groups, adsorption time, temperatures and water ratio in the solution system were experimentally evaluated. The imidazole-chloride ionic liquid group based silica exhibited the highest adsorption effi ciency under the optimized conditions of 5 min adsorption at 30oC in water/methanol (30:70, vol%) solution. In addition, the effects of pH, as well as type and concentrations of chloride salts were investigated. At pH values other than neutral and high salt concentration, the adsorption effi ciency was reduced. Finally, the relative standard deviation of less than 5.8% over a 5-day period showed a high precision for the nine tested sorbents.

Photon and thermal processing of CH3NH2-bearing ices. Synthesis of prebiotic species at low temperature (such as formamide, ethylamine, and methylcyanide), and N-heterocycles during warm up.

2021 ◽  
Author(s):  
Héctor Carrascosa ◽  
Cristóbal González Díaz ◽  
Guillermo M. Muñoz Caro ◽  
Pedro C. Gómez ◽  
María Luz Sanz
Keyword(s):  
Vacuum Chamber ◽  
Organic Molecules ◽  
Solid Phase ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Quadrupole Mass ◽  
Warm Up ◽  
Methyl Cyanide ◽  
Interstellar Ice ◽  
Complex Organic

<p>Hexamethylentetramine has drawn a lot of attention due to its potential to produce prebiotic species. This work aims to gain a better understanding in the chemical processes concerning methylamine under astrophysically relevant conditions. In particular, this work deeps into the formation of N-heterocycles in interstellar ice analogs exposed to UV radiation, which may lead to the formation of prebiotic species.</p> <p>Experimental simulations of interstellar ice analogs were carried out in ISAC. ISAC is an ultra-high vacuum chamber equipped with a cryostat, where gas and vapour species are frozen forming ice samples. Infrared and ultraviolet spectroscopy were used to monitor the solid phase, and quadrupole mass spectrometry served to measure the composition of the gas phase. The variety of species detected after UV irradiation of ices containing  methylamine revealed the presence of 12 species which have been already detected in the ISM, being 4 of them typically classified as complex organic molecules: formamide (HCONH<sub>2</sub>), methyl cyanide (CH<sub>3</sub>CN), CH<sub>3</sub>NH and CH<sub>3</sub>CHNH. Warming up of the irradiated CH<sub>3</sub>NH<sub>2</sub>-bearing ice samples lead to the formation of trimethylentriamine (TMT), a N-heterocycle precursor of HMT, and the subsequent synthesis of HMT at temperatures above 230 K.</p>

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