mL Of H2O2 Research Articles

Synthesis of Green Magnetite/Carbonized Coffee Composite from Natural Pyrite for Effective Decontamination of Congo Red Dye: Steric, Synergetic, Oxidation, and Ecotoxicity Studies

Green magnetite/carbonized spent coffee (MG/CFC) composite was synthesized from natural pyrite and characterized as an adsorbent and catalyst in photo-Fenton’s oxidation system of Congo red dye (C.R). The absorption behavior was illustrated based on the steric and energetic parameters of the advanced Monolayer equilibrium model of one energetic site (R2 > 0.99). The structure exhibits 855 mg/g as effective site density which induces its C.R saturation adsorption capacity to 436.1 mg/g. The change in the number of absorbed C.R per site with temperature (n = 1.53 (293) to 0.51 (313 K)) suggests changes in the mechanism from multimolecular (up to 2 molecules per site) to multianchorage (one molecule per more than one site) processes. The energetic studies (ΔE = 6.2–8.2 kJ/mol) validate the physical uptake of C.R by MG/CFC which might be included van der Waals forces, electrostatic attractions, and hydrogen bonding. As a catalyst, MG/CFC exhibits significant activity during the photo-Fenton’s oxidation of C.R under visible light. The complete oxidation of C.R was detected after 105 min (5 mg/L), 120 min (10 mg/L), 135 min (15 mg/L), 180 min (20 mg/L), and 240 min (25 mg/L) using MG/CFC at 0.2 g/L dosage and 0.1 mL of H2O2. Increasing the dosage up to 0.5 g/L reduce the complete oxidation interval of C.R (5 mg/L) down to 30 min while the complete mineralization was detected after 120 min. The acute and chronic toxicities of the treated samples demonstrate significant safe products of no toxic effects on aquatic organisms as compared to the parent C.R solution.

Development of a Novel Steam Distillation TBA Test for the Determination of Lipid Oxidation in Meat Products.

The 2-thiobarbituric acid (TBA) method has been used for the spectrophotometric determination of secondary lipid oxidation products, such as malonaldehyde (MA), due to its good correlation with sensorial perception of lipid oxidation. Other approaches have been proposed over time. Direct distillation can result in artificially increased MA concentrations due to intense heating. Extraction is a milder and faster method, but it suffers from false color development in the presence of sugars or other compounds. A novel approach using steam distillation for the recovery of MA was developed. Validation and optimization studies were conducted, aiming to maximize MA recovery from various meat product samples by adjusting the steam distillation parameters. For the optimal MA recovery, 10 g of the sample, 25 mL of H2O, and 5 mL of 2 N HCl were used. The sample was distilled using a stream of water vapor until 50 mL of the distillate was collected in less than 3 min. Subsequently, 5 mL of the distillate was reacted with 5 mL of 0.02 M TBA, and the absorbance was measured at 532 nm. MA recovery was 61.8%. Experimentation with varying nitrite levels suggested that the addition of sulfanilamide is necessary when NaNO2 is more than 50 mg MA/kg. The proposed method is fast, milder than direct distillation, and eliminates the issue of TBA interacting with sugars and other compounds.

A spherical fountain prototype photoreactor operated under natural sunlight: Mechanism, toxicology assessment, and economics

Many investigations have reported the study of dispersed nanoparticle photocatalysts on a laboratory scale. Herein, we present a working spherical fountain prototype photoreactor spray-coated with galvanic sludge to prevent agglomeration and increase surface activity. The degradation process was performed under natural sunlight to make the process sustainable. This photocatalytic reactor exhibited an efficiency of 90.4 % during the photodegradation of 4-Nitrophenol at the optimal conditions of a pollutant concentration of 25 ppm with a photocatalyst loading of 5 g at a natural pH for an operating volume of 7 L with an addition of 0.7 mL of H2O2. Detailed specific surface area, pore volume, pore diameter, shape, and agglomeration were studied by BET and HRTEM. There was a significant change observed in the morphology and crystallinity of the recycled photocatalyst, which could be due to photo-corrosion, as shown in the FESEM and XRD analyses. Moreover, a detailed mechanism was elucidated to understand the fate of 4-Nitrophenol during photodegradation. Furthermore, a toxicology assessment was conducted for the pollutant before and after degradation using Escherichia coli, which showed a decrease in the toxicity. Lastly, an economic evaluation was carried out to deduce the cost of treating 1 m3 of wastewater, which was determined to be USD 10.8/m3 for this photoreactor model.

H3PMo12O40@MOF as a New Catalytic System for Cycloxexanone Oxidation to Adipic Acid

Keggin-type phosphomolibdic acid (H3PMo12O40, PMo12) encapsulated in the mesocages of chromium-based terephthalate metal–organic framework (MIL-101), was established to be an active and new green catalyst for the adipic acid (AA) synthesis via cyclohexanone (-One) oxidation in free solvent conditions and hydrogen peroxide as green oxidant. In this paper, we wish to report the synthesis of MIL-101 with different high loadings of the PMo12 nanocrystals incorporated within the large pores of MIL-101. Two and five POMs per large cavity can be incorporated into the matrix of MIL-101 respectively, xH3PMo12@ MIL101 with x=0, 2 and 5, they were characterized by several physic-chemical technics, then investigated in the reaction oxidation with 30 mmol –One at 90 ° C for 20h. A sequenced addition of 0.5ml of H2O2 (30%) was made every 30 min. The catalysts have shown good activity and the purity of AA was invistigeted by 1H and 13C NMR.

Assessment of selected heavy metals in honey samples using flame atomic absorption spectroscopy (FAAS), Ethiopia

Honey is a natural, sugary and sticky liquid that is produced from the nectars of flowers by the bees. This study aimed to analyze the concentration of some selected heavy Metals in honey samples. 1 g of honey sample was digested by a hot plate using 9ml of HNO3 and 3ml of H2O2. The concentrations of the heavy metals in the digested were detected using a flame atomic absorption spectrometer. The results of this study found that the concentrations of the heavy metals in the honey samples were ranged from 1.97 to 2.04 µg/g for Zn, 1.93 µg/g to 2 µg/g for Cu, 0.83 to 1.01 µg/g for Mn, 0.25 to 0.45 µg/g for Cr, 0.025–0.031 µg/g for Cd. However, Pb was not detected in all honey samples. Hence, the levels of heavy metals found were below the permitted levels set by the World Health Organization. From the results, the levels of heavy metals found were below the permitted levels set by the World Health Organization. Thus, the heavy metals in the sampled honey are safe for human consumption in these selected areas.

A new methodology based on TRU resin to measure U-, Th-isotopes and 210Po by alpha-particle spectrometry

This report presents a new methodology to isolate and measure 210Po, as well as uranium and thorium isotopes. This new methodology reduces the standard time of operation, the minimum amount of chemical reagents and the quantity of resin used in comparison with other standard and well-established procedures for alpha spectrometry. Thus, the amount of chemicals reagent was lower than the amount used in other standard radiochemical processes: only 6 mL of 1 M HCl was used for the thorium elution, and 2 mL of H2O and 1 mL of Ammonium Oxalate (0.05 M) (3 mL in total) for the uranium elution. Likewise, many samples of various activities and materials (liquids and solids) were used to validate the method.

332 Evaluating the Effects of Lactic Acid Adaptation in Beef Cattle Prior to an Acidosis Challenge

Abstract The objective was to determine if a 7-day lactic acid adaptation in cannulated steers affected ruminal fermentation during an acidosis challenge. Steers (n=18; 790 ± 68 kg) were assigned to one of two treatments: control (CON) 500 mL of H2O or 1 mM DL-Lactic acid solution per kg steer BW (LAC). Steers were dosed with treatments via the cannula prior to feeding for seven days during the adaptation period. The adaptation diet consisted of 25% corn silage, 30% grass hay, 15% dry distillers grains, 25% dry rolled corn, 5% molasses and 10% supplement. To induce acidosis, steers were fasted for 24 hours and subsequently fed a high concentrate diet consisting of 15% corn silage, 15% dry distillers grains, 55% high moisture corn, 5% molasses, 10% supplement. Rumen fluid was collected throughout the acidosis challenge to measure fermentation characteristics including rumen pH, redox, ammonia, volatile fatty acids, and lactic acid. Data were analyzed using the MIXED procedure of SAS 9.4 with a repeated measures analysis. Dry matter intake was not affected (P ≥ 0.65) by treatment before or after the acidosis challenge. A treatment × time interaction was not observed (P = 0.83) for ruminal pH, but pH was affected (P < 0.01) by time and remained between 5.6 and 5.0 for about 14 hours during the challenge. A treatment × hour interaction tended (P = 0.08) to be observed for lactate; LAC had a greater concentration than CON at hour 14 during the challenge. However, a treatment × hour interaction was not detected (P ≥ 0.38) for ammonia, volatile fatty acids, fecal pH and redox potential. In conclusion, these results indicate that a 7-day lactic acid adaption at 1 mM per kg BW did not affect ruminal fermentation characteristics during an acidosis challenge.

Process optimization, characterization and economic evaluation of nanoparticles derived from galvanic sludge for photodegradation of 4-nitrophenol under natural sunlight

The United Arab Emirates has an average of 10 h of sunlight and is available almost throughout the year. This energy has a huge potential to be utilized in photodegrading wastewater. To engineer a sustainable photocatalyst, the waste (galvanic sludge) obtained from the galvanization industry was utilized to degrade 4-nitrophenol under natural sunlight. Detailed morphological, chemical, and optical characterization of galvanic sludge (GS) was performed by UV-DRS, FESEM-EDX, XRD, XPS, PL, FTIR, and GC-MS. RSM-CCD was utilized for optimizing the three key parameters, such as pH, photocatalyst loading, and 4-nitrophenol concentration. The highest photodegradation efficiency of about 94.5% was obtained for a 4-nitrophenol concentration of 30 ppm with a photocatalyst loading of 0.02 g at a pH of 6 with 0.01 mL of H2O2. Based on the analysis of variance results, the R2 value of the overall model was 98.1%, which indicated that the obtained model was well suited for degrading 4-nitrophenol. An economic evaluation was performed for applicability in the real world. For this photodegradation model, the cost of treatment was determined to be USD 17.5/m3. To the best of our knowledge, for the first time we have innovatively used GS as an efficient photocatalyst for treating 4-nitrophenol.

Eco-Friendly Organic Acid-Assisted Mechanochemical Process for Metal Extraction from Spent Lithium-Ion Batteries

This work represents a combination of mechanochemistry with eco-friendly low-cost natural organic acids to recover metal ions from spent lithium-ion battery (LIB) cathode materials. The effects of various reaction parameters on the metal extraction efficiency during the mechanochemical process were investigated. The results showed that under the optimal recovery conditions, that is, 2 mL of H2O2, mass ratio of LiCoO2 (LCO) to alginic acid of 1:10, rotation speed of 500 rpm, and grinding time of 4 h, the recovery efficiencies of Li and Co were 97.58 and 98.59%, respectively. The reaction mechanism of the mechanochemical process was discussed and verified. LCO combines with alginic acid and converts into water-soluble alginate under the action of a mechanical force and a reducing agent, and the metal ions are extracted and recovered in the subsequent water leaching process. In addition, the preliminary environmental and economic evaluation of the recycling process was assessed. The mechanochemical route proposed in this work can achieve green, efficient, and low-cost recovery of cathode scrap, which is a prospective guideline for the future industrial recycling of spent LIBs.

Rapid Vanadium Extraction from Roasted Vanadium Steel Slag via a H2SO4-H2O2 System: Process and Mechanism.

A H2SO4–H2O2 system was developed to enhance the efficacy of vanadium extraction from roasted vanadium steel slag. The optimum parameters and the behavior of vanadium extraction were investigated systematically. When 1 mL of H2O2 per gram of vanadium slag was added to a leaching mixture at 50 °C, along with 30% H2SO4, 80.5% of vanadium extraction was achieved within 15 min. However, without H2O2, only 58.5% of vanadium extraction was achieved at the same leaching time. The H2SO4–H2O2 system facilitated the dissolution of metallic ions in a short time and then triggered the production of strong oxidizing substances, such as HO• and O2–•, via the Fenton reaction and Fenton-like reaction. Subsequently, the low-valence vanadium, existing in the leaching solution or located on the surface of the particle, was converted to pentavalent vanadium by strongly oxidizing substances, such as H2O2 and its derivatives HO• and O2. The complex oxides on the surface of the particle were destroyed, after which the vanadium inside the particle was gradually exposed to the acid leaching solution. The vanadium was oxidized to pentavalent vanadium, which then entered the leaching solution. Finally, a pathway of vanadium extraction via the H2SO4–H2O2 system was proposed to gain insight into rapid vanadium leaching.

(Digital Presentation) Development of Linear Paired Electrolysis for the Oxidation of Benzyl Alcohol

Electrochemical processes are always coupled reactions, with anodic oxidation and cathodic reduction. Paired electrolysis system can produce valuable products at both anode and cathode, and maximizes the efficient use of applied energy. Especially, the conversion of a single raw material to a single valuable product by paired electrolysis referred to as linear paired electrolysis. Since the electron transfers at both electrodes can produce a single valuable product in the linear paired electrolysis system, a single compound is generated with a current efficiency of 200%, theoretically. The linear paired electrolysis is appearing electrochemical process, however, it remains a challenging topic in organic electrochemical synthesis because it is complicated system. Herein, we develop the synthesis process of benzaldehyde by oxidation of benzyl alcohol using linear paired electrolysis. Electrochemical synthesis of carbonyl compounds by oxidation of alcohol is a challenging topic due to the selectivity and efficiency. We use aqueous media as the electrolyte and oxygen as the terminal oxidant to increase the selectivity and efficiency in the electrochemical transformation.Electrochemical oxidation of benzyl alcohol was performed by following method. A 4.0 mmol of tetraethylammonium perchlorate (Et4NClO4) was dissolved in 20 mL of acetonitrile (CH3CN) and 20 mL of H2O (Milli-Q water). The resultant mixture was used as an electrolyte in this study. The electrolyte was purged with O2 or Ar for 30 min, and then a 0.5 mmol of benzyl alcohol was dissolved in the electrolyte. A 20 mL of cyclohexane was added to the electrolyte to prevent overoxidation of the product. Electrolysis was conducted at room temperature with three electrodes method: a 2 cm2 of carbon felt (CF) anode, a 2 cm2 of various cathode materials, and a Ag/AgCl reference electrode.In the present study, transformation of 4-tert-butyl-benzyl alcohol (peak potential of oxidation: +1.76 V vs. Ag/AgCl) to 4-tert-butyl-benzaldehyde was used as a model reaction for optimization of reaction condition. First, we carried out constant potential electrolysis at +1.8 V vs. Ag/AgCl. Electrolysis using O2-saturated electrolyte resulted in a higher yield of the benzaldehyde (71%) than that using an Ar-saturated electrolyte (45%) when the coulomb amount was 2 F. This result suggested that O2 promoted the desired conversion. Cyclic voltammograms of the electrolyte suggested that reduction of O2 could proceed at cathode. Cathodic reduction of O2 could produce reactive oxygen species (ROS) which have strong oxidizing power. As a result, cathode in our electrochemical cell could have high oxidation potential. Therefore, it was indicated that desired oxidation progressed using ROS in our electrochemical system. In next step, we conducted electrochemical reactions under constant potential electrolysis at −0.7 V vs. Ag/AgCl which was suitable for the reduction of O2. In this condition, benzaldehyde was obtained in 86% yield when the coulomb amount was 2 F, and no byproduct was observed. From this result, we proposed the indirect oxidation pass using ROS generated at cathode. Interestingly, when the cathode (working electrode) was set to −0.7 V vs. Ag/AgCl, the measured potential of the anode (counter electrode) was +1.5 to +1.8 V vs. Ag/AgCl. Therefore, when the reduction of O2 proceeded at cathode, potential of anode reached sufficient value to oxidize the benzyl alcohol. It meant both direct oxidation and indirect oxidation progressed in a single electrochemical cell. It was linear paired electrolysis system of oxidation of benzyl alcohol.We considered the reaction on cathode was important to progress desired oxidation, and the effect of different cathode materials was also investigated. In this investigation, carbon felt, glassy carbon, Pt, and Ni could be used as cathodes in the linear paired electrolysis system. In contrast, a sharp decrease in current was observed immediately after the start of electrolysis using Al as the cathode. Observation and analysis of the used Al electrodes suggested that surface of Al cathodes was passivated. It was indicated that electrochemically generated ROS with high oxidizing power might promote the passivation of the cathode materials. The observed passivation also supported the generation of ROS at cathode in our electrochemical cells.Finally, we demonstrated the versatility of developed linear paired electrolysis with various benzyl alcohols. Especially, 4-Methoxybenzaldehyde was not only obtained in high yields (94%) but also with maximum current efficiencies of 146%. The exceeding 100% current efficiency also supported the linear paired electrolysis system.In summary, we successfully developed a process for oxidation of benzyl alcohols via linear paired electrolysis with high selectivity and efficiency. Since desired reaction progressed both electrodes and aqueous media and O2 were used, this system offered green and sustainable chemical synthesis process. Figure 1

Palladium-Catalyzed Preparation of N-Substituted Benz[c,d]indol-2-imines and N-Substituted Amino-1-naphthylamides.

Here, we report a novel and facile protocol for the synthesis of benz[c,d]indol-2-imines via palladium-catalyzed C-C and C-N coupling of 8-halo-1-naphthylamines with isocyanides in a single step. The reaction features broad substrate scopes and mild conditions, providing an efficient alternative for the construction of antiproliferative agents and BET bromodomain inhibitors. If 0.1 mL of H2O was added to this reaction, the N-substituted amino-1-naphthylamides could be obtained easily.

Photocatalytic Methane Conversion: Insight into the Mechanism of C(sp 3 )–H Bond Activation

Photocatalytic Methane Conversion: Insight into the Mechanism of C(sp ³ )–H Bond Activation

Preparation of Ca0.1Cu0.90Bi2O4 heterojunction with improved visible light photocatalytic performance of congo red: Kinetics and degradation mechanisms

Progression in nano technology enormously influence on the synthesis of highly proficient photo materials and investigate their applications in diverse fields. The CuBi2O4 and Ca0.05Cu0.95Bi2O4, Ca0.1Cu0.90Bi2O4, and Ca0.15Cu0.95Bi2O4 microspheres were prepared by one-step simple hydrothermal method. All the synthesized nanostructures were comprehensively characterized by different spectroscopic techniques. The composite was used in treating water contaminated by azo dye Congo red under visible light irradiation. The pure CuBi2O4 showed 46% of congo red degradation within 70 min of irradiation, while Ca0.1Cu0.95Bi2O4 showed 82% of photo degradation within 70 min of irradiation. Among all the synthesized materials the Ca0.1Cu0.95Bi2O4 showed best efficiency with high degradation constant using lest time. Meanwhile, the photocatalytic study of dye was studied under six operational parameters such as effect of dosage, initial concentration, pH, H2O2 and inorganic salts. The maximum photocatalytic activity was obtained 94% within 60 min of irradiation in the presence of 0.6 mL of H2O2. The obvious enhanced photocatalytic efficiency of Ca0.1Cu0.95Bi2O4 should be attributed to uniform dispersion and floating behaviour of the well-designed photocatalyst. As a result, the Ca0.1Cu0.95Bi2O4 photocatalyst with hierarchical porous structure would open an avenue for the treatment of wastewater.

Psittaciformes mineral feed analysis method choice and optimization employing chemometric tools

BackgroundIn this work, a multivariated approach based on factorial design and principal component analysis was used to perform the optimization of sample decomposition. The method was applied for the first time to quantify several chemical elements (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se and Zn) in Psittaciformes feed. The choice of the best sample decomposition method is a challenging task considering all variables involved in the process. Generally, this choice is made by using individual monovariated experiments and sometimes interaction effects between these variables as mass of the sample, acid composition, temperature, etc, are not considered. MethodsSample decomposition: 200 mg of sample was mixed with 3.5 mL of HNO3 65% and left at room temperature for 24 h, in a pre-decomposition step, heated at 150 °C for 50 minutes employing a digestion block and mixed with 1.5 mL of H2O2 in the last ten minutes of decomposition. Chemical analysis: A total of 44 samples of Psittaciformes feed digests, among extruded feed, flour and snacks), purchased at pet stores or similar stores in six states in Brazil, were analyzed by inductively coupled plasma optical emission spectrometry (ICP OES). Method accuracy was assessed using certified reference materials SRM 1567a, SRM 1573a, SRM 1577b and IMEP 19. ResultsThe limits of detection (LoD) and quantification (LoQ) ranged from 0.02 mg kg−1 to 0.07 mg kg−1 (Se) and from 1.79 mg kg−1 to 5.41 mg.kg−1 (Ca), respectively. The concentration of chemical elements in animal food ranged from <0.27 mgkg −1 (Fe) to 41.4 ± 2.9 g kg−1 (P), in flour concentrations ranged from <0.05 mg kg−1 (Mg) to 23.8 ± 4.1 g kg−1 (P) and concentrations ranged from <0.05 mg kg−1 (Mn) to 6.8 ± 0.9 g kg−1 (Ca) in snacks. ConclusionThe approach based on multivariate analysis to perform a sample decomposition was successfully applied for Psittaciformes feed. In general, the chemical elements listed on the product labels (Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, P, Pb, Se and Zn) were detected at variable contents when compared to the recommender nutritional values. Toxic elements, Cd and Pb were not detected in any of the analyzed samples. The detection and quantification of chemical elements not listed in nutritional tables and in each product label indicates that mineral addition by manufacturers is performed without considering the chemical composition of the raw materials used in the production process, which can lead to nutritional issues. Thus, a broad revision of Brazilian Legislation concerning product classification considering quality and mineral addition criteria in daily animal feed, especially pets, is urgently required.

SnO2/UV/H2O2 and TiO2/UV/H2O2 Efficiency for the Degradation of Reactive Yellow 160A: By-Product Distribution, Cytotoxicity and Mutagenicity Evaluation

Advanced oxidation processes (AOPs) have emerged as a promising approach for the removal of organic dyes from effluents. Different AOPs were employed for the degradation of Reactive Yellow 160A (RY-160A) dye, i.e., SnO2/UV/H2O2 and TiO2/UV/H2O2. In the case of UV treatment, maximum degradation of 28% was observed, while UV/H2O2 furnished 77.78% degradation, and UV/H2O2/TiO2 degraded the RY-160A dye up to 90.40% (RY-160A 30 mg/L, 0.8 mL of H2O2). The dye degradation was 82.66% in the case of UV/H2O2/SnO2 at pH 3. FTIR and LC-MS analyses were performed in order to monitor the degradation by-products. The cytotoxicity and mutagenicity of RY-160A dye were evaluated by hemolytic and Ames (TA98 and TA100 strains) assays. It was observed that the RY-160A dye solution was toxic before treatment, and toxicity was reduced significantly after treatment. Results indicated that UV/H2O2/TiO2 is more efficient at degrading RY-160A versus other AOPs, which have potential application for the remediation of dyes in textile effluents.

Imaging of gastric acidity scale by integration of pH-conversion model (pH-CM) into 3D-gastro electrical impedance tomography (3D-g-EIT)

The gastric acidity scale has been imaged by integration of the pH-conversion model (pH-CM) into 3D-gastro electrical impedance tomography (3D-g-EIT) under the influence of spatial mean hydrogen-specific conductivity σH+. The pH-CM uses Debye-Hückel-Onsager (DHO) interionic equation, molar conductivity ratio, ωH+, viscosity ηstate(k) and relative permittivity εstate(k) in order to convert the imaged conductivity distribution σ to the pH distribution pH*. With the proposed integration, phantoms of empty (S1), liquid storage (S2-S4), and solid meal storage (S5) states are measured to reflect the dilution state. In the case of empty (S1), the artificial gastric juice is made based on 99.50% of H2O and 0.50% solution consisting of HCl (1.4263 g/L), KCl (0.8647 g/L), and NaCl (2.8559 g/L). In the case of the liquid storage (S2-S4) state, 200 mL of H2O is added three times as a dilution of artificial gastric juice in each S2, S3, and S4. In the solid meal storage (S5) state, an acid solid meal is blended into the artificial gastric content. The modified constants, α, and β are calculated based on the variation of viscosity ηstate(k) and permittivity εstate(k) of each state. The conductivity of gastric-shape models in five states is studied in the simulation. In the experiments, the simulated models were measured as gastric phantoms. Integrating pH-CM into 3D-g-EIT successfully images the pH* in the simulations and experiments. As a result, the estimated acidity scale 〈pH〉 is inversely proportional to σH+ with mean pH error evaluation of simulations eˆpH(sim) and experiments eˆpH(sim) are 15.8% and 8.5%, respectively.

Comparison of in-situ and ex-situ methods for synthesis of iron magnetic nanoparticles-doped graphene oxide: Characterization, adsorption capacity, and Fenton catalytic efficiency

In this research, iron magnetic nanoparticles-doped graphene oxide (Fe3O4/GO or FG) materials were synthesized via the in-situ (FGI) and ex-situ (FGE) methods, with several mass ratios of precursors. The FG2I and FG2E samples with the mass ratio of Fe3O4:GO = 3:7 exhibit effective removal of methylene blue (MB) in water by utilizing the adsorption and Fenton catalyst methods. Characterizations of the materials were investigated by modern analysis methods. The results showed that FGI material possesses a larger specific surface area and Fe3O4 nanoparticles are more evenly dispersed on the GO surface than that of FG2E. The examination of MB removal also demonstrated the predominance of FGI over FGE material in both adsorption and Fenton catalyst evaluations. The MB adsorption process of FGI is consistent with the apparent second-order kinetics equation and the Langmuir isotherm model. The highest removal by Fenton reaction of MB (over 99 %) using FG2I was achieved with 1 mL of H2O2 and 50 mg/L of MB at a temperature of 50 °C for 180 min. Thus, the efficiency of the material via adsorption and Fenton catalytic experiments reached 69.21 and 91.23 %, respectively, after five consecutive runs. Therefore, the use of FGI is cost-saving and relatively effective for eliminating organic contaminants in water, which shows its high potential in future applications.

241 Evaluating the Effects of Lactate Adaptation in Cannulated Steers on Fermentation Characteristics in an Ex Vivo Model of Ruminal Acidosis

Abstract The objective was to determine if lactate adaption in cannulated steers affected fermentation characteristics in an ex vivo model of ruminal acidosis. Eighteen cannulated steers (790 ± 68 kg) were assigned to 1 of 2 treatments: 500 mL of H2O (CON) or 1 mM DL-Lactic acid solution per kg steer BW (LAC). After treatments were dosed prior to feeding for 6 d, rumen fluid was collected for an ex vivo study. Three flasks for each steer contained 7.5 g DM of substrate (70% corn, 15% DDG, and 15% silage) and 160 mL of inoculum with rumen fluid and McDougall’s buffer (4:1 ratio). Sample aliquots (1.7 mL) were collected every 4 h from the flask for 36 h fermentation for later analysis. At 12 h, 90 mM of neutralized DL-Lactic acid was added to each flask to further evaluate lactate utilization over time. Data were analyzed using the MIXED procedure of SAS 9.4 with a repeated measures analysis. A treatment by hour interaction was not detected (P = 0.19) for pH. However, steers on LAC tended (P = 0.06) to have a greater pH than CON. No treatment by hour interaction or treatment effect was observed (P ≥ 0.44) for molar proportion of acetate, propionate, butyrate, and ammonia. A treatment by hour interaction tended (P = 0.07) to be observed for total VFA; CON was greater than LAC at hour 8, 13, 16, and 20. Control steers had a greater (P = 0.03) in vitro dry matter disappearance compared with LAC (63.6 vs. 54.0%, respectively). Although results indicated that rumen fluid from lactate-adapted steers had a greater pH in an acidosis model, rumen fluid from CON steers had improved IVDMD and total VFA concentrations.

Simultaneous Determination of Fifteen Polyphenols in Fruit Juice Using Ultrahigh-Performance Liquid Chromatography-Tandem Mass Spectrometry Combining Dispersive Liquid-Liquid Microextraction.

Polyphenols are secondary metabolites of plants and used as effective antioxidants in dietary supplements, whose main sources are fruits, vegetables, and grains. To clarify the content and distribution of polyphenols in different fruit species samples accurately, a rapid and sensitive ultrahigh-pressure liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method combining dispersive liquid-liquid microextraction (DLLME) was developed for quantitative determination of fifteen polyphenol compounds in fruit juice. In this method, the targets were first extracted from 1 g of fruit juice sample using 10 mL of 80% ethanol solution by ultrasonic-assisted extraction (UAE). Then, 1.0 mL of UAE extracted solution, 60 μL of n-octanol and 2.0 mL of H2O were performed in the following DLLME procedure. A C18 reversed-phase column, ZORBAX SB (100 × 4.6 mm, 3.5 μm), was proposed under gradient elution with 0.1% formic acid aqueous solution and methanol mobile phases for the determination of 15 polyphenols, allowing us to obtain polyphenolic profiles in less than 23.0 min. Under the optimum conditions, the enrichment factors ranged from 162 to 194. The results showed that the 15 polyphenols had linear correlation coefficients (R2) more than 0.99. The limits of detection (LODs) were between 18.3 and 103.5 ng/g, and the average recoveries were between 96.9 and 116.3% with interday relative standard deviations (RSDs) ranging from 4.4 to 8.2% in all cases. The method was successfully applied to the analysis of real fruit juice samples and presented itself as a simple, rapid, practical, and environment-friendly technique.