高效石油烃降解菌的分离鉴定及降解特性

为获得更为丰富的石油降解微生物资源,从沈抚污灌区石油污染土壤和实验室高浓度柴油胁迫土壤中筛选出了4株高效石油烃降解菌SF-422、SF-428、SF-433和SYS-1.这4株菌总石油烃(Total petroleum hydrocarbon/TPH)生物降解率为67.4%~73.6%.经过16项生理生化特性实验和16S rDNA序列分析鉴定,SF-433,SF-428,SF-422和SYS-1分别为蜡状芽孢杆菌(Bacillus cereus),木糖氧化无色杆菌(Achromobacter xylosoxidans),施氏假单胞菌(Pseudomonas stutzeri)和洋葱伯克霍尔德氏菌(Burkholderia cepacia).纯烃降解定性实验表明所筛选出的4株高效降解菌均能够利用正十六烷、苯、菲和环己烷为唯一碳源生长,其中菌株SF-428和SYS-1显示了对芳烃及环烷烃较强的利用能力.

Decomposition of transformer oil under ultrasonic irradiation during degassing process

In the degassing process of transformer oil with ultrasonic waves, decomposition of the oil was observed. Light hydrocarbons, including methane, ethane, ethylene, acetylene, propane etc, were found to be released continuously from the oil into headspace within a closed vial placed in an ultrasonic field. The gases came from decomposition of hydrocarbon Molecules under cavitation effect.

Remediation of Persistent Organic Pollutants (POPs) in Two Different Soils

Persistent organic pollutants (POPs) are a set of chemicals that are toxic, persist in the environment for long periods of time, and biomagnify as they move up through the food chain. The most widely used method of POP destruction is incineration, which is expensive and could result in undesirable by-products. An alternative bioremediation technology, which is cheaper and environ-mentally friendly, was tested during this experiment. Two different soil types containing high and low organic matter (OM) were spiked with 100 mg/kg each of pyrene and Aroclor 1248 and planted with three different species of grasses. The objective of the study was to determine residue recovery levels (availability) and potential effectiveness of these plant species for the remediation of POPs. The results showed that recovery levels were highly dependent on the soil organic matter content—very low in all treatments with the high OM content soil compared to recoveries in the low OM soil. This indicates that availability, and, hence, biodegradability of the contaminants is dependent on the organic matter content of the soil. Moreover, the degree of availability was also significantly different for the two classes of chemicals. The polyaromatic hydrocarbon (PAH) recovery (availability) was extremely low in the high organic matter content soil compared to that of the polychlorinated biphenyls (PCBs). In both soil types, all of the plant species treatments showed significantly greater PCB biodegradation compared to the unplanted controls. Planting did not have any significant effect on the transformation of the PAHs in both soil types; however, planting with switchgrass was the best remedial option for both soil types contaminated with PCB.

Infrared spectroscopic study on thermal behavior of Langmuir-Blodgett films of octadecyl ammonium octadecanoate and octadecylammonium octadecanoate-d(35)

Langmuir-Blodgett (LB) films of octadecylammonium octadecanoate (C(18)H(37)j7NH(3)(+)C(17)H(35)COO(-),ODASA) and octadecylammonium octadecanoate-d(35) (C18H37+NH3+C17D35COO-, ODASA-d(53)) were prepared and their thermal behaviors were investigated by variable-temperature Fourier transform infrared transmission spectroscopy. It was found that the two hydrocarbon chains of ODASA molecule in LB films are highly ordered while that protonated (H) chain in ODASA-d(35) is partially disordered with some gauche conformers introduced at room temperature.

Bump-Surface Multicompartment Micelles from a Linear ABC Triblock Copolymer: A Combination Study by Experiment and Computer Simulation

Novel bump-surface multicompartment micelles formed by a linear amphiphilic ABC triblock copolymer via self-assembly in selective solvent were successfully observed both in simulation and experiment. The results revealed that the block A forms the most inner core, and the blocks B and C form the inner and outer layers, respectively, and the bumps were formed by block A and more likely to be born on curving surfaces. Moreover, the micelle shape could be controlled by changing the solvent selectivity of the blocks A and B. Spherical, cylindrical, and discoidal micelles with bumpy surfaces were obtained both in experiment and simulation.

An infrared study on Langmuir-Blodgett films of octadecylammonium octadecanoate: FWHM and the vibrational coupling

The monolayer of the mixture of octadecanoic acid and octadecylamine with molar ratio 1: 1 has been investigated at the air-water interface. It was found that the monolayer shows a rather stable state at the surface pressure of 30 mN/m and this monolayer can be transferred onto a CaF2 plate by Langmuir-Blodgett (LB) technique. The infrared spectra of LB films indicated that octadecyl ammonium octadecanoate is formed by an intermolecular proton exchange between adjacent carboxylic and aminic groups (COO- and NH3+). In three-layer LB film, the CH2 scissoring mode of the long hydrocarbon chains of octadecyl ammonium octadecanoate shows a broad band feature at about 1468 cm(-1) while this vibrational mode of three-layer LB film of the mixture (1: 1) of deuterated stearic acid and octadecylamine (octadecylammonium octadecanoate-d35, C18H37NH3+C17D35COO-) only shows a narrow band. The broad feature of the CH2 scissoring mode in octadecylammonium octadecanoate probably originates from the coupling between the chain of stearic acid and that of octadecylamine while this kind of coupling could be completely removed in octadecylammonium octadecanoate-d35.

Infrared spectrum of 2-octadecyl-7,7,8,8-tetracyanoquinodimethane

Infrared spectrum of 2-octadecyl-7,7,8,8-tetracyanoquinodimethane was dealt with 2nd-derivative and deconvolution methods. It was first discovered that the band near 2849 cm(-1) assigned to the CH2 Symmetric stretching mode splited into two bands and this splitting might result from the coexistence of two kinds of conformations of CH2 in the hydrocarbon chain.

A study on the catalytic behaviors of concentrated heteropolyacid solution - I. A novel catalyst for isobutane alkylation with butene

The catalytic behaviors of a novel liquid acid catalyst (composed of heteropolyacid and acetic acid) for alkylation of isobutane with butene was investigated. As a solvent acetic acid had a synergistic effect. It enhanced the acid strength of HPA and its stability. The conditions for the formation of the catalytically active phase were studied systematically. The content of crystal water of HPA and the quantity of solvent affect the formation of active phase and the catalytic activity. Catalytically active phase consists of HPA, acetic acid and hydrocarbon produced from the reaction, as well as traces of water from the crystal water of HPA. This catalyst system is comparable to the sulfuric acid in catalytic activity.

Self-assembled monolayer growth of phospholipids on hydrophobic surface toward mimetic biomembranes: Scanning probe microscopy study

Atomic force microscopy (AFM) and lateral force microscopy (LFM) were used simultaneously to analyze a model membrane bilayer structure consisting of a phospholipid outer monolayer deposited onto organosilane-derivatized mica surfaces, which were constructed by using painting and self-assembly methods. The phospholipid used as outer monolayer was dimyristoylphosphatidylcholine (DMPC). The hydrocarbon-covered substrate that formed the inner half bilayer was composed of a self-assembly monolayer (SAM) of octadecyltrichloroorganosilane (OTS) on mica. SAMs of DMPC were formed by exposing hydrophobic mica to a solution of DMPC in decane/isobutanol and subsequently immersing into pure water. AFM images of samples immersed in solution for varying exposure times showed that before forming a complete monolayer the molecules aggregated into dense islands (2.2-2.6 nm high) on the surface. The islands had a compact and rounded morphology. LFM, coupled with topographic data obtained with the atomic force mode, had made possible the distinction between DMPC and OTS. The rate constant of DMPC growth was calculated. This is the first systematic study of the SAM formation of DMPC by AFM and LFM imaging. It reveals more direct information about the film morphology than previous studies with conventional surface analytical techniques such as infrared spectroscopy, X-ray, or fluorescence microscopy.

X-ray photoelectron spectroscopy and mass spectra study of alpha-amino acid

X-ray photoelectron spectroscopy and mass spectrometry have been used to study the ten alpha-Amino Acids. The chemical shiftss of N-1s electron binding energy have been explained by means of the difference in the hydrocarbon group of amino acids. The influence of the hydrocarbon group on NH2 has been disscussed using the XPS and MS results.

The polymerization of methyl methacrylate with a new Nd(O-i-Pr)(3)-Al(i-Bu)(3) catalyst system

Methyl methacrylate (MMA) was polymerized with the rare earth coordination catalyst-system of Nd(O - i-Pr)(3) in toluene. The influences of various ligands in neodymium complexes, molar ratio of Al/Nd, catalyst concentration, catalyst aging time, solvents, the third component CCl4, temperature and time on the polymerization of MMA were studied. The results showed that the polymerization conversion reached more than 80% at a catalyst concentration of 9.2 x 10(-3) mol/L. The appropriate molar ratio of CCl4/Nd was 4. Hydrocarbon was preferred for the polymerzation to obtain a high conversion and a high <(M)over bar w> of PMMA. The H-1 NMR spectra of PMMA indicated that the lower the temperature, the higher the syndiotactic content of PMMA was obtained.

Studies on preparation of iron phenanthroline and 8-hydroxyquinoline complexes/Y zeolite, characterization and catalytic hydroxylation of phenol

Iron phenanthroline - and 8 - hydroxyquinoline complexes /Y zeolite, denoted a FePhen/Y and FeOx/Y respectively, were prepared; The formation of the metal complexes mentioned above within the cages of Y zeolite and their crystal structures were determined by elemental analyses, diffuse reflectance UV-Vis,SEM,BET,and XRD methods; The influence of experimental parameters upon phenol conversion and product selectivities were investigated as well.

Supported phospholipid membranes: Comparison among different deposition methods for a phospholipid monolayer

Supported lipid membranes consisting of self-assembled alkanethiol and lipid monolayers on gold substrates could be produced by three different deposition methods: the Langmuir-Blodgett (L-B) technique, the painted method, and the paint-freeze method, By using cyclic voltammetry, chronoamperometry/chronocoulometry and a.c. impedance measurements, we demonstrated that lipid membranes prepared by these three deposition methods had obvious differences in specific capacitance, resistance and thickness. The specific capacitance of lipid membranes prepared by depositing an L-B monolayer on the alkanethiol alkylated surfaces was 0.53 mu Fcm(-2), 0.44 mu Fcm(-2) by the painted method and 0.68 mu Fcm(-2) by the paint-freeze method. The specific conductivity of lipid membranes prepared by the L-B method was over three times lower than that of the painted lipid membranes, while that of the paint-freeze method was the lowest. The difference among the three types of lipid membranes was ascribed to the influence of the organic solvent in lipid films and the changes in density of the films. The lipid membranes prepared by the usual painted method contained a trace amount of the organic solvent. The organic solvent existing in the hydrocarbon core of the membrane reduced the density of the membrane and increased the thickness of the membrane. The membrane prepared by depositing an L-B monolayer containing no solvent had higher density and the lowest fluidity, and the thickness of the membrane was smaller. The lipid membrane prepared by the paint-freeze method changed its structure sharply at the lower temperature. The organic solvent was frozen out of the membrane while the density of the membrane increased greatly. All these caused the membrane to exist in a ''tilted'' state and the thickness of this membrane was the smallest. The lipid membrane produced by the paint-freeze method was a membrane not containing organic solvent. This method was easier in manipulation and had better reproducibility than that of the usual painting method and the method of forming free-standing lipid film. The solvent-free membrane had a long lifetime and a higher mechanical stability. This model membrane would be useful in many areas of scientific research.

BIS(ETA-HEPTYLAMMONIUM) TETRACHLOROZINCATE

The crystal structure of (C7H18N)(2)[ZnCl4] is composed of alternating layers of inorganic ions and paraffinic chains. It differs from the structures of analogous compounds that have a hydrocarbon chain containing an even number of C atoms. This may explain the odd-even effects observed in differential scanning calorimetry (DSC) measurements on these compounds.