Enhanced effects of reducing agent on oxalate chelated Fe(II) catalyzed percarbonate system for benzene degradation

Abstract The addition of hydroxylamine hydrochloride (HAH), ascorbic acid (ASC), sodium ascorbate (SAS) to the OA-Fe(II)/SPC system could promote the generation of HO• by accelerating Fe(II)/Fe(III) recycles and H2O2 decomposition. The enhancement of HAH on HO• generation surpasses ASC and SAS in the OA-Fe(II)/SPC system. The generation of O2•− was also enhanced by HAH, ASC and SAS, and more significant promotion of O2•− generation was observed with ASC and SAS addition. More effective benzene removal was achieved in an OA-Fe(II)/SPC system with suitable HAH, ASC and SAS addition, compared to the parent system. Excessive HAH, ASC or SAS had a negative effect on benzene removal. Results of scavenger tests showed that HO• is indeed the dominant free radical for benzene removal in every system, but the addition of HAH, ASC and SAS increased the contribution of O2•− to benzene degradation. HAH, ASC and SAS enhanced OA-Fe(II)/SPC systems could be well utilized to acidic and neutral conditions, while HCO3−, high concentration of HA and alkaline conditions were not favorable to benzene removal. Moreover, the addition of HAH, ASC and SAS are conducive to benzene removal in actual groundwater, and HAH was the optimal reducing agent for the enhancement of the OA-Fe(II)/SPC system.

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Alkaline hydrogen peroxide pretreatment of energy crops for biogas production

Chemical Papers ◽

10.2478/s11696-013-0531-5 ◽

2014 ◽

Vol 68 (7) ◽

Cited By ~ 12

Author(s):

Karina Michalsk ◽

Stanisław Ledakowicz

Keyword(s):

Hydrogen Peroxide ◽

Biogas Production ◽

Energy Crops ◽

Alkaline Hydrogen Peroxide ◽

High Concentration ◽

H2o2 Decomposition ◽

Miscanthus Giganteus ◽

Alkaline Conditions ◽

Plant Sources ◽

H2o2 Pretreatment

AbstractIn this study, the influence of alkaline hydrogen peroxide (H2O2) pretreatment of the three different plant sources: Miscanthus giganteus, Sorghum Moench, and Sida hermaphrodita, for biogas production was investigated. The influence of temperature, reaction time, and H2O2 concentration on the efficiency of biomass degradation and on the further methanogenic fermentation were studied. The results obtained after chemical pretreatment indicate that using H2O2 at alkaline conditions leads to the decomposition of three major structures: lignin, hemicellulose, and cellulose. The best results were achieved for the process performed at 25°C for 24 h with the use of a 5 mass % H2O2 solution. Although the degradation level was very high for all three plant sources, the biogas production from the energy crops pretreated chemically was strongly inhibited by byproducts and the residual oxygen formed after H2O2 decomposition. This fact indicates that alkaline H2O2 pretreatment is a very promising method for plant material degradation for further biogas production, but pretreated biomass must be separated from supernatant before the fermentation process because of the high concentration of inhibitors in the hydrolysates. The best results were obtained for Sida with biogas and methane production of 2.29 Ndm3 and 1.06 Ndm3, respectively.

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Formation of Selenium Colloids Using Sodium Ascorbate as the Reducing Agent

Journal of Colloid and Interface Science ◽

10.1006/jcis.1995.1095 ◽

1995 ◽

Vol 170 (1) ◽

pp. 254-260 ◽

Cited By ~ 31

Author(s):

David R. Mees ◽

William Pysto ◽

Peter J. Tarcha

Keyword(s):

Reducing Agent ◽

Sodium Ascorbate

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Formulation of More Efficacious Curcumin Delivery Systems Using Colloid Science: Enhanced Solubility, Stability, and Bioavailability

Molecules ◽

10.3390/molecules25122791 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2791 ◽

Cited By ~ 1

Author(s):

Bingjing Zheng ◽

David Julian McClements

Keyword(s):

Water Solubility ◽

Biological Activities ◽

Anticancer Activities ◽

Potential Health ◽

Colloid Science ◽

Enhanced Solubility ◽

Alkaline Conditions ◽

Low Toxicity ◽

Neutral Conditions ◽

Bioactive Constituent

Curcumin is a bioactive constituent isolated from turmeric that has historically been used as a seasoning, pigment, and herbal medicine in food. Recently, it has become one of the most commonly studied nutraceuticals in the pharmaceutical, supplement, and food areas because of its myriad of potential health benefits. For instance, it is claimed to exhibit antioxidant, anti-inflammatory, antimicrobial, antiparasite, and anticancer activities when ingested as a drug, supplement, or food. Toxicity studies suggest that it is safe to consume, even at relatively high levels. Its broad-spectrum biological activities and low toxicity have meant that it has been widely explored as a nutraceutical ingredient for application in functional foods. However, there are several hurdles that formulators must overcome when incorporating curcumin into commercial products, such as its low water solubility (especially under acidic and neutral conditions), chemical instability (especially under neutral and alkaline conditions), rapid metabolism by enzymes in the human body, and limited bioavailability. As a result, only a small fraction of ingested curcumin is actually absorbed into the bloodstream. These hurdles can be at least partially overcome by using encapsulation technologies, which involve trapping the curcumin within small particles. Some of the most commonly used edible microparticles or nanoparticles utilized for this purpose are micelles, liposomes, emulsions, solid lipid particles, and biopolymer particles. Each of these encapsulation technologies has its own benefits and limitations for particular product applications and it is important to select the most appropriate one.

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Beneficial Effects of Biochar-Based Organic Fertilizer on Nitrogen Assimilation, Antioxidant Capacities, and Photosynthesis of Sugar Beet (Beta vulgaris L.) under Saline-Alkaline Stress

Agronomy ◽

10.3390/agronomy10101562 ◽

2020 ◽

Vol 10 (10) ◽

pp. 1562

Author(s):

Pengfei Zhang ◽

Fangfang Yang ◽

He Zhang ◽

Lei Liu ◽

Xinyu Liu ◽

...

Keyword(s):

Sugar Beet ◽

Nitrogen Assimilation ◽

Organic Fertilizer ◽

Root Activity ◽

Alkaline Stress ◽

Alkaline Soil ◽

Chemical Fertilizers ◽

Alkaline Conditions ◽

Negative Effect ◽

Antioxidant Enzymes Activities

The Songnen Plain, whose climatic conditions are perfectly suited to sugar beet growth, is located in northeastern China. Unfortunately, this region has a lot of saline-alkaline land, which is the most important factor limiting sugar beet production. This study was undertaken to determine whether biochar-based organic fertilizer could alleviate the negative effect of saline-alkaline soil on sugar beet yield and whether such an effect correlated with changes in nitrogen assimilation, antioxidant system, root activity, and photosynthesis. Three treatments were established: Chemical fertilizers were applied to neutral soil (CK), chemical fertilizers were applied to saline-alkaline soil (SA), and biochar-based organic fertilizer was applied to saline-alkaline soil (SA + B). Our results showed that saline-alkaline stress significantly inhibited the nitrogen assimilation and antioxidant enzymes activities in root, root activity, and photosynthesis, thus significantly reducing the yield and sugar content of sugar beet. Under saline-alkaline conditions, the application of biochar-based organic fertilizer improved the activities of nitrogen assimilation enzymes in the root; at the same time, the antioxidant enzymes activities of the root were significantly increased for improving root activity in this treatment. Moreover, the application of biochar-based organic fertilizer could improve the synthesis of photosynthetic pigments, PSII (Photosystem II) activity, stomatal opening, and photosynthesis of sugar beet under saline-alkaline conditions. Hence, the growth and yield of sugar beet were improved by applying biochar-based organic fertilizer to saline-alkaline soil. These results proved the significance of biochar-based organic fertilizer in alleviating the negative effect of saline-alkaline stress on sugar beet. The results obtained in the pot experiment may not be viable in field conditions. Therefore, in the future, we will verify whether biochar-based organic fertilizer could alleviate the adverse effects of saline-alkaline stress on sugar beets yield under field conditions.

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Hydrothermal Synthesis of Nanostructured TiO2 Particles and Characterization of Their Photocatalytic Antimicrobial Activity

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.c267 ◽

2008 ◽

Vol 8 (2) ◽

pp. 878-886 ◽

Cited By ~ 10

Author(s):

Beril K. Erdural ◽

Alp Yurum ◽

Ufuk Bakir ◽

Gurkan Karakas

Keyword(s):

Sol Gel ◽

Time Lag ◽

Alkaline Treatment ◽

Antimicrobial Activities ◽

Distilled Water ◽

Bacterial Inactivation ◽

Sem Images ◽

Alkaline Conditions ◽

Aqueous Conditions ◽

Neutral Conditions

Nanostructured titania particles were synthesized by using hydrothermal processing and the photocatalytic antimicrobial activities were characterized. Both sol–gel synthesized and commercial TiO2 (anatase) samples were processed with two step hydrothermal treatments, under alkaline and neutral conditions. Scanning Electron Microscope (SEM) images showed that alkaline treatment yields nanofibers and lamellar structured particles from the commercial anatase and sol–gel synthesized samples respectively. Further treatment of nanofibers and nanostructured lamellar particles with distilled water results with crystal growth and the formation of nano structured bipyramidal crystalline particles. The photocatalytic antimicrobial activities of the samples were determined against Escherichia coli under irradiation. It was observed that the samples treated under alkaline conditions have improved activity than the original anatase samples. Limited activity and resulting time lag in bacterial inactivation were observed for hydrothermally treated samples with distilled water. However, a post treatment comprising the UV irradiation in aqueous conditions enhanced the photocatalytic activity.

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Removal of VOCs by Ozone: n-Alkane Oxidation under Mild Conditions

Catalysts ◽

10.3390/catal11040506 ◽

2021 ◽

Vol 11 (4) ◽

pp. 506

Author(s):

Alina I. Mytareva ◽

Igor S. Mashkovsky ◽

Sergey A. Kanaev ◽

Dmitriy A. Bokarev ◽

Galina N. Baeva ◽

...

Keyword(s):

Catalytic Oxidation ◽

Oxygen Vacancies ◽

Oxide Catalyst ◽

Catalytic Performance ◽

High Concentration ◽

Volatile Organic ◽

Negative Effect ◽

Manganese Oxide Catalyst ◽

Conventional Solution ◽

Al2o3 Catalyst

Volatile organic compounds (VOCs) have a negative effect on both humans and the environment; therefore, it is crucial to minimize their emission. The conventional solution is the catalytic oxidation of VOCs by air; however, in some cases this method requires relatively high temperatures. Thus, the oxidation of short-chain alkanes, which demonstrate the lowest reactivity among VOCs, starts at 250–350 °C. This research deals with the ozone catalytic oxidation (OZCO) of alkanes at temperatures as low as 25–200 °C using an alumina-supported manganese oxide catalyst. Our data demonstrate that oxidation can be significantly accelerated in the presence of a small amount of O3. In particular, it was found that n-C4H10 can be readily oxidized by an air/O3 mixture over the Mn/Al2O3 catalyst at temperatures as low as 25 °C. According to the characterization data (SEM-EDX, XRD, H2-TPR, and XPS) the superior catalytic performance of the Mn/Al2O3 catalyst in OZCO stems from a high concentration of Mn2O3 species and oxygen vacancies.

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The Effects of Glycoprotein IIb/IIIa Antagonist RGDS on Platelet Aggregation and Release Reaction In Vitro.

Blood ◽

10.1182/blood.v108.11.3908.3908 ◽

2006 ◽

Vol 108 (11) ◽

pp. 3908-3908

Author(s):

Shuangfeng Xie ◽

Songmei Yin ◽

Danian Nie ◽

Yiqing Li ◽

Xiuju Wang ◽

...

Keyword(s):

Platelet Aggregation ◽

Platelet Adhesion ◽

Adenosine Diphosphate ◽

Platelet Glycoprotein ◽

High Concentration ◽

Release Reaction ◽

Dense Granules ◽

Negative Effect ◽

Platelet Release

Abstract Platelet activation, including platelet adhesion, platelet aggregation and platelet release reaction, played an important role in thrombogenesis. We all knew that Platelet glycoprotein IIb/IIIa antagonist was the most effective drug for anti-aggregation, while we don’t know clearly its effect on platelet release reaction and the relations between its effects on platelet aggregation and release reaction. Platelet release reactions included α-granules and dense granules releasing. When α-granules were released, its membrane glycoprotein CD62p was expressed in the platelet membrane. We used the CD62p expression as the index of platelet release reaction. In the current study, the 4-peptides RGDS (Arg-Gly-Asp-Ser) was used as glycoprotein IIb/IIIa antagonist. We detected the effects of RGDS on platelet aggregation and CD62p expression induced by adenosine diphosphate (ADP) (finial concentration, 5μmol/L) in vitro. 50, 100, 200, 400 and 800μmol/L RGDS were used separately in the test. RGDS of each concentration could significantly inhibited maximal platelet aggregation (PAG(M)) induced by ADP, the 50% inhibiting concentration was approximately 200μmol/L. 800μmol/L RGDS could inhibited PAG(M) by 80.48±8.18%. Only ≥200μmol/L RGDS could significantly inhibited platelet CD62p expression. 800μmol/L RGDS could inhibit platelet CD62p expression by 27.31±9.74%. The inhibiting effect of RGDS on PAG(M) and platelet CD62p expression had significantly correlation (r =0.976, P<0.05). These results indicated that RGDS in low concentration (<200μmol) had little negative effect on platelet release reaction induced by ATP, while in relatively high concentration (≥200μmol) RGDS could inhibit platelet release reaction. When RGDS concentrations were same its effect on platelet release reaction was much less than that on platelet aggregation, which indicated that platelet glycoprotein IIb/IIIa compound could only partly participated in the platelet release reaction but fully participated in platelet aggregation induced by ADP.

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Investigation of Phthalocyanine Catalysts for the Aerobic Synthesis of meso-Substituted Porphyrins

Journal of Porphyrins and Phthalocyanines ◽

10.1002/(sici)1099-1409(199710)1:4<385::aid-jpp42>3.0.co;2-i ◽

1997 ◽

Vol 01 (04) ◽

pp. 385-394 ◽

Cited By ~ 12

Author(s):

M. RAVIKANTH ◽

CATALINA ACHIM ◽

JOHN S. TYHONAS ◽

ECKARD MÜNCK ◽

JONATHAN S. LINDSEY

Keyword(s):

Trifluoroacetic Acid ◽

Room Temperature ◽

Heterogeneous Catalysts ◽

Mossbauer Spectroscopy ◽

Oxidation Process ◽

Aerobic Oxidation ◽

Heterogeneous Reactions ◽

High Concentration ◽

Neutral Conditions ◽

Homogeneous Reactions

The aerobic oxidation process for the synthesis of porphyrins, previously performed using 5 mol % p-chloranil (TCQ), 5 mol % iron(II) phthalocyanine ( FePc ) and stoichiometric amounts of O 2, has been refined using new phthalocyanine catalysts. Four phthalocyanine catalysts have been prepared, characterized by Mössbauer spectroscopy and examined for efficacy in the high concentration (0.1 M) synthesis of tetraphenylporphyrin at room temperature. Each phthalocyanine has been identified to be a μ-oxo dimer. Two catalysts are soluble (the μ-oxo dimers [(t-butyl)4 FePc ]2 O and [(n- C 6 H 13 O )4 FePc ]2 O ) and enable homogeneous reactions, while two are insoluble (the μ-oxo(1) and μ-oxo(2) dimers of FePc , ( FePc )2 O ) and give heterogeneous reactions. These four phthalocyanine compounds provide efficient catalysis at the 0.3–1 mol % level using only 1 mol % quinone or hydroquinone ( TCQ , DDQ , TCQH 2 or DDQH 2), affording ~25% yields of tetraphenylporphyrin in 60 min of oxidation. There are no discernible advantages of the homogeneous versus heterogeneous catalysts. The μ-oxo dimers are active, but FePc is inactive, at the 0.3 mol % level. The activity of the FePc sample at the 5 mol % level is attributed to residual μ-oxo dimer impurity. This aerobic oxidation process is superior to stoichiometric oxidation with TCQ or DDQ , and can be performed in the presence of BF 3· O ( Et )2, trifluoroacetic acid, or under neutral conditions.

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Removal of odorant dimethyl disulfide under alkaline and neutral conditions in biotrickling filters

Water Science & Technology ◽

10.2166/wst.2012.365 ◽

2012 ◽

Vol 66 (8) ◽

pp. 1641-1646 ◽

Cited By ~ 9

Author(s):

L. Arellano-García ◽

A. González-Sánchez ◽

H. Van Langenhove ◽

A. Kumar ◽

S. Revah

Keyword(s):

Main Product ◽

Dimethyl Disulfide ◽

Continuous Treatment ◽

Batch Experiments ◽

Reduced Sulfur Compounds ◽

Biotrickling Filters ◽

Bacterial Consortia ◽

Low Concentrations ◽

Alkaline Conditions ◽

Neutral Conditions

The aim of this paper was to evaluate the performance of biotrickling filters (BTFs) for treating low concentrations of dimethyl disulfide (DMDS), using different bacterial consortia adapted to consume reduced sulfur compounds under alkaline (pH ≈ 10) or neutral (pH ≈ 7) conditions. Solubility experiments indicated that the partition of DMDS in neutral and alkaline mineral media was similar to the value with distilled water. Respirometric assays showed that oxygen consumption was around ten times faster in the neutrophilic as compared with the alkaliphilic consortium. Batch experiments demonstrated that sulfate was the main product of the DMDS degradation. Two laboratory-scale BTFs were implemented for the continuous treatment of DMDS in both neutral and alkaline conditions. Elimination capacities of up to 17 and 24 gDMDS m−3 h−1 were achieved for the alkaliphilic and neutrophilic reactors with 100% removal efficiency after an initial adaptation and biomass build-up.

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Variability of factors that affect availability of iron, manganese and zinc in maize lines

Genetika ◽

10.2298/gensr1303907d ◽

2013 ◽

Vol 45 (3) ◽

pp. 907-920 ◽

Cited By ~ 4

Author(s):

Vesna Dragicevic ◽

Snezana Mladenovic-Drinic ◽

Milovan Stojiljkovic ◽

Milomir Filipovic ◽

Zoran Dumanovic ◽

...

Keyword(s):

Phytic Acid ◽

Inorganic Phosphorus ◽

Mineral Elements ◽

Point Of View ◽

High Concentration ◽

Carotene Content ◽

Inorganic P ◽

Negative Effect ◽

Set Up ◽

Iron Manganese

Deficiencies of some mineral elements are causing serious health problems, which could be prevented by increase of mineral nutrients in food with supplementation, food fortification or plant breeding. From this point, experiment with 78 maize inbred lines was set up to determine maize lines with improved contents of Fe, Zn and Mn, as well as their relations with phytic acid, inorganic phosphorus and ?-carotene, as factors which affect their absorption. Obtained results suggest that investigated maize lines show high variability in concentration of Fe, Mn and Zn, as well as phytic acid (which sustain availability of mineral elements) and ?-carotene (which enables better absorption of mineral element and minimize negative effect of phytic acid). From this point of view, group of genotypes with phytic P ? 3 g kg-1 was interesting. Among them, L2 and L23 are maize lines with relatively high inorganic P, Fe and Zn contents, and together with relatively low ratio between phytic and inorganic P, they could be used as a good source of P, Fe and Zn. On the other hand, L1 and L4 are also maize lines with high inorganic P, ?-carotene and Mn, and favourable ratio between phytic acid and Fe and Zn, what could give them advance as source of Mn in breeding programs. The same maize lines could also be candidates with improved ability for Fe and Zn absorption, what is based on high ?-carotene content. Maize line L14, with relatively high concentration of all three.

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