Effect Of Anthracene Research Articles

Pyrolysis of heavy tar for improving the yield of light components through a microwave pyrolysis reactor

ABSTRACTThe composition of a heavy tar can still be divided into two fractions, the light organic components (LC) and heavy organic components (HC). The HC is hard to be processed into liquid fuel due to its high viscosity and coke formation tendency. In this work, the pyrolysis of HC is tested for improving the yield of LC product from HC pyrolysis with a microwave reactor. It is found that the existence of LC in heavy tar can promote the conversion of HC to LC product. As potential H donors, the effect of Anthracene (ANT) and 9,10-hydrogenated anthracene (HAN) in LC on HC pyrolysis are particularly evaluated. The improved yield of LC product from HC pyrolysis with LC is attributed to the hydrogenated aromatics in LC.

Enhancing Liquid-Phase Exfoliation of Graphene with Addition of Anthracene in Organic Solvents

In this work, graphene is synthesized via liquid-phase exfoliation of graphite in organic solvents with addition of anthracene. Graphene concentration is enhanced by adding anthracene in organic solvents. Anthracene intercalates into the edges of graphite and results in graphene concentration enhancement. By adding anthracene in benzonitrile (BZN) solvent, the graphene concentration is increased from 0.01 to 0.03 mg/ml. The effect of anthracene in concentration enhancement is most prominent in 1-methyl-2-pyrrolidone (NMP), orthodichlorobenzene (ODCB) and BZN solvents as compared to others. With addition of anthracene, the graphene concentration in NMP and ODCB solvents is increased to 0.04 mg/ml. This facile method of concentration enhancement is highly suitable for preparing conducting graphene films and composites for various electronics device applications such as field-effect transistors, flexible paper supercapacitors.

Effect of Anthracene (ANT) on Growth, Microcystin (MC) Production and Expression of MC Synthetase (mcy) Genes in Microcystis aeruginosa

ANT is a commonly occurring polycyclic aromatic hydrocarbon (PAH) in natural eutrophic waters where Microcystis blooms break out usually. In this study, effects of ANT at different concentrations (0.02, 0.06, 0.18, 0.54, and 1.62 μg/mL) on the growth, microcystin-LR (MC-LR) production, and expression of three key mcy genes in Microcystis aeruginosa were investigated. The results showed that all the tested concentrations of ANT inhibited M. aeruginosa growth significantly except 0.02 μg/mL ANT in the early stage of the experiment. In the culture media, initially applied ANT concentrations decreased significantly after 3 days of incubation. ANT stimulated MC-LR production in a concentration-dependent manner. After exposure to ANT for 1 day, the expression of mcyB gene was inhibited and the inhibitory effects increased with ANT concentrations. ANT at higher concentrations (above 0.02 μg/mL) stimulated gene expression of mcyD (P < 0.05) and mcyH (P < 0.01) significantly, and 0.02 μg/mL of ANT inhibited their expression significantly (P < 0.01). With increasing culture time, 0.18 μg/mL of ANT inhibited mcyB gene expression first and then stimulated it while gene expressions of mcyD and mcyH were stimulated throughout the experiment. Our results suggested that ANT in natural waters could affect not only Microcystis growth but also MC production via modifying mcy gene expressions.

The effect of anthracene on total dry matter and extracellular enzyme analysis of a starch-amended composting process

ABSTRACTComposting technology has been widely used as a cost-effective, eco-friendly, and efficient solid waste management option for the bioremediation of organic pollutants. Most studies have focused on the use of compost in the bioremediation of organic pollutants, without any attention being paid to the effect of the organic pollutants on the composting process. Therefore, in this study, the effect of an organic pollutant (anthracene) on a starch-amended composting process is reported. In order to determine the effect, the total dry matter and the extracellular enzyme analysis (EEA) of starch-specific (α-glucosidase) and -nonspecific (β-glucosidase) substrates were monitored. Over the course of the experiments, there appeared to be some form of anthracene effect on the progression in the total dry matter and the extracellular enzyme analysis (EEA) of the α-glucosidase, particularly in the starch and anthracene–amended composts. The interactions between the starch and the anthracene consistently increased the total dry matter and the α-glucosidase activity of the starch and anthracene–amended composts. This observation is novel, and the kind of interaction is yet unknown. Therefore, detailed investigation to understand the magnitude of such interaction is necessary to potentially resolve these issues.

Effect of soil contamination with anthracene and pyrene on yield and accumulation of macronutrients in butter lettuce (Lactuca sativa L.)

Toxic compounds which belong to PAHs are generated during all types of combustion of fuels and other substances as well as a result of natural processes (mineralisation). Products which appear during the above processes eventually reach soil, where they accumulate. The objective of this study has been to evaluate the effect of anthracene and pyrene accumulated in soil on yield, concentration of macronutrients (N, P, K, Mg, Ca, Na) and their uptake by cv. Vilmorin butter lettuce (Lactuca sativa L.) grown under the minimum and 3-fold enriched abundance of substrate. A pot experiment in four replicates was carried out twice in a greenhouse at the University of Warmia and Mazury in Olsztyn, in the spring of 2007 and 2008. Supplementary fertilisation was applied before planting butter lettuce. At the first rate of fertilisation, nitorgen was introduced in a full dose before planting lettuce, but at the triple rate of nutrients in substrate, it was divided into 2/3 of the dose before planting and the remaining 1/3 applied to soil 10 days after planting. Soil contamination with anthracene (ANT) and pyrene (PYR) or their mixture started 10 days after planting lettuce. Soil application of the two PAHs was performed 5 times at five-day intervals until the end of the growing season of lettuce. Determination of macronutrients (N, P, K, Mg, Ca, Na) was accomplished with standard methods after mineralisation (H 2 SO 4 + H 2 O 2 ) of the plant material dried at 60 o C. The determinations were peformed in comparison to certified material (CTA-VTL-2). Increasing the abundance of substrate in nutrients (N, P, K, Mg, Na, Cl) by three-fold led to a 13.7% increase in yield of lettuce heads. The PAH compounds present in the substrate depressed lettuce yield. This tendency was more evident when anthracene rather than pyrene contaminated soil. ANT and PYR depressed the concentration of nitrogen but raised the concentration of calcium in substrate less abundant in nutrients.

The effect of anthracene and phenanthrene on the growth, photosynthesis, and SOD activity of the green alga Scenedesmus armatus depends on the PAR irradiance and CO2 level.

Short-term (24-h) experiments were performed to examine the effect of phenanthrene (PHE) and anthracene (ANT) on algae grown in a batch culture system at irradiances of 12, 33, 48, and 64 W m(-2) of the PAR range. Cultures were aerated (0.1 or 2% CO(2)) or nonaerated. As a result of aeration the concentration of ANT dropped from 0.45 mg L(-1) at the beginning of the experiment (t(0)) to an undetectable value after 10 h. The PHE concentration dropped from 9.36 mg L(-1) at t0 to 0.17 mg L(-1) after 24 h. ANT at nominal concentrations exceeding 0.05 mg L(-1) inhibited the growth of the algae in a concentration- and irradiance-dependent manner. The algistatic effect of ANT observed at 64 and 48 W m(-2) was independent of the CO(2) level, whereas the growth inhibition at 33 and 12 W m(-2) was much greater in cultures aerated with 2% than with 0.1% CO(2). PHE inhibited the growth only at a concentration of 10 mg L(-1) (about 50% of the control) regardless of the irradiance or the CO(2) concentration. The toxicity of both PHE and ANT was similar in aerated (0.1% CO(2)) and nonaerated cultures. ANT and PHE had a distinct effect on the photosynthesis. At 0.1% CO(2), the irradiance-dependent inhibition (ANT) and stimulation (PHE) of the photosynthesis was observed. The inhibitory effect of ANT was enhanced when algae were grown at 2% CO(2), but at the same CO(2) concentration PHE did not affect the photosynthesis. ANT stimulated the total superoxide dismutase (SOD) activity in the cells, this effect being generally more pronounced at elevated CO(2) levels and increasing with the irradiance. The total SOD activity was 250-300% higher in cells treated with PHE aerated with 0.1% CO(2). At 2% CO(2) no effect of PHE on the enzyme's activity was noted. The results obtained indicate that ANT acts as a photosensitizer causing an oxidative damage of cells, while PHE seems to affect the macromolecular synthesis.

EFFECT OF ANTHRACENE AND PYRENE ON DEHYDROGENASES ACTIVITY IN SOILS EXPOSED AND UNEXPOSED TO PAHS

The effect of anthracene and pyrene on dehydrogenases activitywas compared between freshly spiked soils and soils previouslyexposed to PAHs. Four different soils (two soils from anunpolluted rural area and two soils from highly pollutedindustrial areas) were spiked with anthracene and pyrene atthe levels of 1, 10, 100 and 400 mg Σ2PAH per kg of soil (laboratory experiments). The soil samples were moisted to60% of water holding capacity and incubated in the dark at 18-20 °C. Dehydrogenase activity was determined after 7 and30 days. The results indicate that long-term exposure of soilfrom an industrial area to high level of PAHs (Σ13PAH = 40 mg kg-1) caused the acclimatisation of soilmicroorganisms and lowered their sensitivity to these compounds.After the longer incubation period (30 days vs. 7 days)the soil microorganisms in the uncontaminated rural samples showed an increase in their tolerance to the freshly introduced PAH compounds; in the industrial soils the effect was less pronounced. However, this apparent adaptation of soil microorganisms may be also partly explained by the dissipation and/or ageing processes of anthracene and pyrene during incubation.

Anthracene influence on (15NH4)2SO4 fertilization of wheat seedlings

The influence of the addition of anthracene (1 μg anthracene g−1 soil) in N transformations following (15NH4)2SO4 fertilization (200 mg N g−1 soil) was investigated in wheat pots by quadrapole mass-spectrometry. The dry matter yield at harvesting (after 16 days) was not statistically affected (P=0.05) by anthracene addition. The total amount of N from the fertilizer taken up by wheat seedings in 16 days was 29 and 26.8% of the added N in the absence and in the presence of anthracene, respectively, but the difference was not significantly different at level P=0.05. In order to investigate more deeply the effect of anthracene on the N cycle in the soil-plant system, the first-order rate constants of N mineralization, N immobilization, nitrification and N plant uptake have been determined according to a 15N + 14N soil-plant model. The comparison of the constants showed that organic N mineralization, nitrification and plant uptake proceeded at the same rate, while a small different rate (P=0.05) was shown by N immobilization. In fact, the N immobilization constant increased from 0.14±0.012 to 0.21±0.014 day−1 as a consequence of anthracene addition.

Effect of anthracene and solar ultraviolet radiation exposure on gill ATPase and selected hematologic measurements m the bluegill sunfish ( Lepomis macrochirus)

Anthracene, a polycyclic aromatic hydrocarbon, is acutely toxic to fish when they are exposed simultaneously to solar ultraviolet radiation (SUVR). However, the physiological mechanism of acute anthracene photo-induced toxicity is not known. The purpose of this study was to investigate possible modes of action associated with simultaneous anthracene and SUVR exposure using blood and gill biochemistry in bluegill sunfish ( Lepomis macrochirus). Fish were exposed to anthracene (< 0.01 and 7.04 μg/ l) and SUVR in a flow-through system. Following 96 h of anthracene and SUVR exposure, fish exhibited significant increases in hematocrit and significant decreases in whole blood hemoglobin content when compared to no-anthracene controls. Evidence of hemolysis was also observed in anthracene and SUVR exposed fish. Using in vitro enzyme analysis, both Na,K-ATPase and Mg-ATPase were signficantly inhibited in gill tissue homogenates exposed to anthracene and SUVR when compared to homogenates exposed to SUVR alone. These blood and gill measurements provide evidence of osmotic stress in exposed fish. Given the results presented in this and in previous studies, we conclude that there are numerous sites of acute toxic action with anthracene and SUVR exposure in fish and that this toxicity appears to be associated with a general disruption of cell membrane function.

Eosin-sensitized photoreduction of benzil with 1-benzyl-1,4-dihydronicotinamide

The mechanism of eosin-sensitized photoreduction of benzil with 1-benzyl-1, 4-dihydronicotinamide, a model compound of NAD(P)H and the behavior of the excited states of eosin have been investigated. From the effect of anthracene as a diffusion-controlled quencher of the photoreaction, it is indicated that both excited triplet state and an unquenchable excited singlet state of eosin participated in the sensitized photoreaction. From the Stern-Volmer plot of quantum yield vs. anthracene concentration, the triplet reaction rate constant has been calculated to be 0.78×10~8L·mol~(-1)·s~(-1), while the singlet reaction rate constant determined from quenching of eosin fluorescence by benzil is equal to 7.2×10~9L·mol~(-1)·s~(-1). The singlet and triplet quantum yields φ_S~0 and φ_T~0 are also determined to be 0.09 and 0.18 respectively. Since both the singlet and triplet energies of eosin are lower than that of benzil, energy transfer sensitization is not feasible. It is proposed that electron transfer from the excited cesin to benzil is responsible for the initiation process.

The effect of anthracene on isoprene and styrene polymerizations initiated with lithium

The effect of anthracene on isoprene and styrene polymerizations initiated with lithium