Abiotic reduction of 2,4-dinitrotoluene in the presence of sulfide minerals under anoxic conditions

1996 ◽  
Vol 34 (10) ◽  
pp. 25-33 ◽  
Author(s):  
Cheng Jiayang ◽  
Makram T. Suidan ◽  
Albert D. Venosa
Keyword(s):  
Electron Donor ◽  
Chemical Reduction ◽  
Sulfide Minerals ◽  
Sulfide Concentration ◽  
Magnesium Ions ◽  
High Concentration ◽  
Anoxic Conditions ◽  
High Affinity ◽  
Iron Nickel ◽  
Abiotic Reduction

Abiotic reduction of 2,4-dinitrotoluene (DNT) in the presence of sulfide minerals has been investigated under anoxic conditions at 35°C. 2,4-DNT was abiotically reduced to 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) in the presence of high concentration of sulfide (0.84 mM). No abiotic reduction of 2,4-DNT was observed in the presence of low sulfide concentration (0.42 mM). The rate and the extent of the abiotic reduction of 2,4-DNT were increased with an increase in sulfide concentration. Sulfide served as an electron donor for the reduction of 2,4-DNT. The 2-nitro group was preferentially reduced, making the 2-A-4-NT:4-A-2-NT ratio in the final products 2:1. The addition of iron, nickel, and cobalt minerals significantly enhanced the abiotic reduction. The FeS, NiS, and CoS solids formed in the serum bottles catalyzed the reduction of 2,4-DNT preferentially to 4-A-2-NT. MnS and CuS solids also catalyzed the reduction of 2,4-DNT to 4-A-2-NT, but did not change the overall reduction of 2,4-DNT. However, the presence of calcium, zinc, and magnesium minerals impeded 2,4-DNT reduction. The calcium, zinc, and magnesium ions have a high affinity to sulfide, inactivating sulfide as an electron donor for the chemical reduction of 2,4-DNT.

Synthesis and Fabrication of PVA-Ag-Cu and PANI-Ag-Cu Nanocomposite Thin Film Sensor for Detection of E. coli in Water

2014 ◽  
Vol 911 ◽  
pp. 131-135 ◽  
Author(s):  
H. Abdullah ◽  
Noor Azwen Noor Azmy ◽  
Norshafadzila Mohammad Naim ◽  
Aisyah Bolhan ◽  
Aidil Abdul Hamid ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Reduction ◽  
Oxidative Polymerization ◽  
Face Centered Cubic ◽  
High Concentration ◽  
Film Sensor ◽  
E Coli ◽  
Host Materials ◽  
Face Centered ◽  
Xrd Patterns

Polymers are excellent host materials for nanoparticles of metals and semiconductors. PVAAgCu nanocomposite was synthesized from chemical reduction, whereas PANIAgCu nanocomposite was synthesized by chemical oxidative polymerization. PVAAgCu and PANIAgCu thin films were deposited on the glass substrate by spin coating technique. The films were characterized by using XRD and AFM. The sensitivity of the samples was analyzed by IV measurement. The peaks in XRD patterns confirm the presence of Ag-Cu nanoparticles in face centered cubic structure. AFM images show the roughness of PVAAgCu and PANIAgCu increased as Ag concentration decreased and Cu concentration increased. I-V measurements indicate that the change in the current of the films increases with the presence of E. coli. The sensitivity on E. coli increases for PVAAgCu and PANIAgCu thin films with high concentration of Cu.

scholarly journals Semenogelins I and II bind zinc and regulate the activity of prostate-specific antigen

2005 ◽  
Vol 387 (2) ◽  
pp. 447-453 ◽  
Author(s):  
Magnus JONSSON ◽  
Sara LINSE ◽  
Birgitta FROHM ◽  
Åke LUNDWALL ◽  
Johan MALM
Keyword(s):  
Enzymatic Activity ◽  
Dissociation Constant ◽  
Prostate Specific Antigen ◽  
Protease Activity ◽  
Specific Antigen ◽  
Active State ◽  
Chromogenic Substrate ◽  
Nmr Analysis ◽  
High Concentration ◽  
High Affinity

In semen, the gel proteins SgI and SgII (semenogelins I and II) are digested by PSA (prostate-specific antigen), resulting in liquefaction and release of motile spermatozoa. Semen contains a high concentration of Zn2+, which is known to inhibit the protease activity of PSA. We characterized the binding of Zn2+ to SgI and SgII and found evidence that these proteins are involved in regulating the activity of PSA. Intact SgI and SgII and synthetic semenogelin peptides were used in the experiments. Binding of Zn2+ was studied by radioligand blotting, titration with a zinc (II) fluorophore chelator and NMR analysis. A chromogenic substrate was used to measure the enzymatic activity of PSA. SgI and SgII bound Zn2+ with a stoichiometry of at least 10 mol (mol of protein)−1 and with an average dissociation constant of approx. 5 μM per site. Moreover, Zn2+-inhibited PSA was activated by exposure to SgI or SgII. Since both proteins have high affinity for Zn2+ and are the dominating proteins in semen, they probably represent the major Zn2+ binders in semen, one function of which may be to regulate the activity of PSA. The system is self-regulating, and PSA is maintained in an active state by its substrate.

scholarly journals Heterogeneous Catalytic Ozonation of Phenol by a Novel Binary Catalyst of Fe-Ni/MAC

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1123
Author(s):  
Yunlong Yang ◽  
Xianwei Shi ◽  
Min Zhao ◽  
Shuyi Chu ◽  
Jibo Xiao
Keyword(s):  
Active Species ◽  
Catalytic Ozonation ◽  
High Concentration ◽  
Fluorescence Excitation ◽  
Heterogeneous Catalytic ◽  
Ni Alloy ◽  
Iron Nickel ◽  
Real Wastewater ◽  
Binary Catalyst ◽  
Fluorescence Excitation Emission Matrices

Iron-nickel supported on modified active carbon (Fe-Ni/MAC) was prepared and characterized by XRD, SEM, XPS and EDS, followed by evaluating the practicability of Fe-Ni/MAC in treating real wastewater with a high concentration of phenol. Results showed that the optimal conditions for catalytic ozonation obtained by response surface methodology (RSM) were catalyst 10 g/L, ozone 68 mg/L, pH 9 and reaction time 90 min. Fe-Ni alloy and NiFe2O4 were demonstrated to be the dominant active species involved in catalytic reaction. The Fe-Ni/MAC catalyst can be reused six times with a satisfactory performance and little leaching of metal ions. Although some radicals like ·OH and ·O2− functioned well, singlet oxygen (1O2) was regarded as the most important radical in the Fe-Ni/MAC process. Most noticeably, the fluorescence excitation emission matrices (EEMs) certified that as much as 1243 mg/L phenol in the real wastewater was completely degraded, which made Fe-Ni/MAC a fairly practical catalyst.

Respiratory functions of blood of the yak, llama, camel, Dybowski deer, and African elephant

1963 ◽  
Vol 205 (2) ◽  
pp. 331-336 ◽  
Author(s):  
Heinz Bartels ◽  
Peter Hilpert ◽  
Klaus Barbey ◽  
Klaus Betke ◽  
Klaus Riegel ◽  
...  
Keyword(s):  
Respiratory Function ◽  
African Elephant ◽  
Red Cells ◽  
Oxygen Dissociation Curve ◽  
Dissociation Curve ◽  
High Concentration ◽  
Blood Samples ◽  
High Affinity ◽  
Oxygen Dissociation ◽  
Oxygen Capacity

Blood samples from a yak, llama, camel, deer, and African elephant were analyzed for oxygen capacity, "standard bicarbonate" content, oxygen dissociation curve, and the magnitude of the Bohr and Haldane effects. These parameters of the respiratory function of the blood have been related to the morphology of the red cells, to the weights of the animals, and to the most important electrolytes in the erythrocytes and in the plasma. The high affinity for oxygen described previously for llama blood is shared by its relative, the camel. Both these animals have a high concentration of hemoglobin within their erythrocytes. Blood from the African elephant showed the greatest affinity for oxygen among the subjects studied.

scholarly journals Nanostructural Features of Silver Nanoparticles Powder Synthesized through Concurrent Formation of the Nanosized Particles of Both Starch and Silver

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
A. Hebeish ◽  
M. H. El-Rafie ◽  
M. A. El-Sheikh ◽  
Mehrez E. El-Naggar
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
High Speed ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Nanosized Particles ◽  
High Concentration ◽  
Particle Size Analyzer ◽  
Vis Spectroscopy

Green innovative strategy was developed to accomplish silver nanoparticles formation of starch-silver nanoparticles (St-AgNPs) in the powder form. Thus, St-AgNPs were synthesized through concurrent formation of the nanosized particles of both starch and silver. The alkali dissolved starch acts as reducing agent for silver ions and as stabilizing agent for the formed AgNPs. The chemical reduction process occurred in water bath under high-speed homogenizer. After completion of the reaction, the colloidal solution of AgNPs coated with alkali dissolved starch was cooled and precipitated using ethanol. The powder precipitate was collected by centrifugation, then washed, and dried; St-AgNPs powder was characterized using state-of-the-art facilities including UV-vis spectroscopy, Transmission Electron Microscopy (TEM), particle size analyzer (PS), Polydispersity index (PdI), Zeta potential (ZP), XRD, FT-IR, EDX, and TGA. TEM and XRD indicate that the average size of pure AgNPs does not exceed 20 nm with spherical shape and high concentration of AgNPs (30000 ppm). The results obtained from TGA indicates that the higher thermal stability of starch coated AgNPS than that of starch nanoparticles alone. In addition to the data obtained from EDX which reveals the presence of AgNPs and the data obtained from particle size analyzer and zeta potential determination indicate that the good uniformity and the highly stability of St-AgNPs).

Iron-Mediated Microbial Oxidation and Abiotic Reduction of Organic Contaminants under Anoxic Conditions

2007 ◽  
Vol 41 (22) ◽  
pp. 7765-7772 ◽  
Author(s):  
Nicole B. Tobler ◽  
Thomas B. Hofstetter ◽  
Kristina L. Straub ◽  
Daniela Fontana ◽  
René P. Schwarzenbach
Keyword(s):  
Organic Contaminants ◽  
Microbial Oxidation ◽  
Anoxic Conditions ◽  
Abiotic Reduction

scholarly journals Enzymatic Pretreatment of Byproducts from Soapstock Splitting and Glycerol Processing for Improvement of Biogas Production

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6782
Author(s):  
Sebastian Borowski ◽  
Weronika Cieciura-Włoch
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Sulfide Concentration ◽  
Organic Loading ◽  
High Concentration ◽  
Enzymatic Pretreatment ◽  
Thermophilic Anaerobic Digestion ◽  
Commercial Enzymes ◽  
Wet Weight

This study investigated acid splitting wastewater (ASW) and interphase (IF) from soapstock splitting, as well as matter organic non glycerol (MONG) from glycerol processing, as potential substrates for biogas production. Batch and semicontinuous thermophilic anaerobic digestion experiments were conducted, and the substrates were preliminary treated using commercial enzymes kindly delivered by Novozymes A/C. The greatest enhancement in the batch digestion efficiency was achieved when three preparations; EversaTransform, NovoShape, and Lecitase were applied in the hydrolysis stage, which resulted in the maximum methane yields of 937 NL/kg VS and 915 NL/kg VS obtained from IF and MONG, respectively. The co-digestion of 68% ASW, 16% IF, and 16% MONG (wet weight basis) performed at an organic loading rate (OLR) of 1.5 kg VS/m3/day provided an average methane yield of 515 NLCH4/kg VSadded and a volatile solid reduction of nearly 95%. A relatively high concentration of sulfates in the feed did not significantly affect the digestion performance but resulted in an increased hydrogen sulfide concentration in the biogas with the peak of 4000 ppm.

scholarly journals ASSESMENT OF HEAVY METALS IN MANIHOT ESCULENTA (CASSAVA) IN SELECTED FARMS IN LAGOS STATE, NIGERIA

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Abosede A. Adu ◽  
Bamidele I. John ◽  
Anthony B. Ojekale ◽  
O.J. Aderinola
Keyword(s):  
Heavy Metals ◽  
Manihot Esculenta ◽  
Anthropogenic Activities ◽  
High Concentration ◽  
Lagos State ◽  
Iron Nickel ◽  
Lead Zinc ◽  
Aas Method ◽  
Sodium And Potassium ◽  
Recommended Level

Introduction: Anthropogenic activities by man in Nigeria especially Lagos State have induced accumulation of heavy metals in soils which invariably have resulted in the disturbance of living organism’s biochemical and physiological functions. Aim: This study assessed the level of heavy metals concentration in cassava (Manihot esculenta) harvested in selected farms in Lagos state. Materials and Methods: Leaves, stems, tubers of cassava were obtained from Morogbo, Badagry area and Odogunyan, Ikorodu area; and the concentrations of heavy metals content were determined using Atomic Absorption Spectrophotometric (AAS) method. Results: The results in mg/kg showed that heavy metals concentration [Nickel (3559.67 ± 5794.16), Manganese (120.33 ± 5.51), Copper (52.10 ± 2.85 and so on] were highly bioaccumulated in leafy part of the cassava. Conversely, Sodium (11620.00 ± 820.18) and Potassium (15133.33 ± 508.46) were highly bio-accumulated in the cassava’s stem while Calcium (3996.67 + 35.12) was found in high concentration in the cassava’s tuber. Lead (0.03 ± 0.05) and Cadmium (0.08 ± 0.08) were of significant values in the soil of Ikorodu and lower in the soil of Badagry. Heavy metal (Ni, Mn, Cd, Mg and Na) bio-accumulation in the two different location were higher in Badagry than Ikorodu, while Zn, Fe and K were higher in Ikorodu than in Badagry but Cobalt was not detected in both sites. Conclusion: Copper, Lead, Zinc, Manganese, Iron, Nickel, Calcium, Sodium and Potassium were above the recommended level of W.H.O. Therefore, consumption of leafy and tuber part of the cassava in both Ikorodu and Badagry areas could pose threat to animals.

scholarly journals Responses of Pigs to Stunning with Nitrogen Filled High-Expansion Foam

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2210
Author(s):  
Cecilia Lindahl ◽  
Erik Sindhøj ◽  
Rebecka Brattlund Hellgren ◽  
Charlotte Berg ◽  
Anna Wallenbeck
Keyword(s):  
Animal Welfare ◽  
Viable Alternative ◽  
High Concentration ◽  
Nitrogen Gas ◽  
Closed Container ◽  
Feasible Method ◽  
Anoxic Conditions ◽  
The Mean ◽  
Expansion Foam ◽  
Mean Time

Nitrogen gas (N2) delivered in high expansion foam in a closed container could be a feasible method for humanely stunning pigs. This study aimed to evaluate potential aversion in pigs to the N2 foam method and its effect on stun quality. Furthermore, the study aimed to assess potential aversion to the foam itself. Sixty pigs (27.8 ± 4.4 kg) were divided into three treatments and were exposed to either N2-filled foam, air-filled foam, or no foam air. The N2 foam was effective at purging the air from the container and quickly created stable anoxic conditions. The pigs did not show any strong aversive behaviours when exposed to foam. However, they seemed to avoid putting their heads and snouts into the foam when foam levels became high. Escape attempts through the lid also increased when the foam started covering their heads. The mean time to loss of posture was 57.9 s. Based on the results, stunning with the N2 foam technique could be a viable alternative to high concentration CO2 stunning and potentially lead to improved animal welfare at slaughter.

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