Identification of endogenous and anthropogenic hydrocarbons in bottom deposits of peat lakes and evaluation of their contribution to the “hydrocarbon index”

Gas chromatography with mass spectrometric detection was used to analyze bitumens isolated from bottom sediments of peat lakes contaminated with petroleum products. Endogenous hydrocarbons are characterized by the presence of n-alkanes with an odd number of carbon atoms in the molecule in the characteristic region of C₂₃–C₃₃, the absence of a “hump” characteristic of oil products in the chromatogram, and the presence of light hydrocarbons, eluting in the initial part of the chromatogram (light hydrocarbons are usually lost when the sample is dried). The distribution profile of odd n-alkanes is used to assess the contribution of endogenous hydrocarbons to the “hydrocarbon index” with the help of the pattern recognition method. The concentration of light hydrocarbons is from 50 and 300–400 to 3500–5000 mg/kg for a number of samples and even up to 26000 mg/kg in some samples. The concentration of petroleum hydrocarbons and heteroatomic compounds varies from the lowest values of 30–80 mg/kg up to 20000 mg/kg and higher.     

Mathematical algorithm for qualitative and semiquantitative analysis of petroleum hydrocarbons in solid wastes using on-line gas chromatography

Non-degradated mineral-oils like gasoline, solvent naphtha, diesel fuel, fuel and lubricating oils provide a characteristic fingerprint gas chromatogram. This visual classification, e.g. in solid wastes, is complicated due to the simultaneous presence of several mineral-oils. Therefore, a mathematical algorithm for the separation of gas chromatographic fingerprint of “single mixtures” of aliphatic hydrocarbons is developed. The technique ¶is essential for analysis of time-overlapping “single mixtures” of petroleum hydrocarbons (so-called “complex mixtures”) and it relies on the concentration-varying hydrocarbons during evaporation. It is possible to separate the data from the gas chromatogram of a “complex mixture” of hydrocarbons into the chromatograms of the pure “single mixtures” and to give their respective concentrations. A synthetic ?complex mixture” of kerosene, diesel fuel and lubricating oil is used to illustrate the method.     

Utilization of the Sadtler standard RI system in micropollution analyses

During the development of a GC retention index library very rigorous standard parameters were used in the SADTLER laboratories. Because most chromatographers presumably have their “favourite” and well-proven columns a study has been carried out on how to make use of them for standard index generation. Variables such as column geometry, split ratio, and film thickness were examined and the calculated indices were compared to some “basic” values. Splitless and cool on-column injection techniques were also investigated and comparable temperature programming indices have been obtained. Finally, standard index values of 53 volatile halogenated hydrocarbons measured on very thick-film bonded fused silica capillary columns are tabulated.     

On the limitation of the term <Emphasis Type="Italic">petroleum products</Emphasis> in the determination of the oil pollution of bottom sediments

Problems related to the determination of the oil pollution of bottom sediments are discussed. Tarry substances resistant to degradation, whose content can be as high as 50% on a total oil basis, are accumulated in the bottom sediments. The conventional term petroleum products, which implies only a hydrocarbon fraction, does not adequately describe these substances; because of this, the really evaluated level of the oil pollution of bottom sediments becomes underestimated to a considerable degree. We proposed to determine tarry substances in bottom sediments by fluorescence spectrometry at 490–510 nm in combination with a stage of the chromatographic preconcentration and separation of oils and petroleum products into the following main group components: hydrocarbons, tars, and asphaltenes. The substances coextracted with the petroleum products (pesticides, phenols, pigments, etc.) occurred in a chromatographic zone of tars and asphaltenes, but they fluoresce at other wavelengths and do not interfere with the determination. The typical chromatograms of hydrocarbons from the bottom sediments of different water bodies obtained by gas chromatography are given.     

Characteristics of petroleum contaminants and their distribution in Lake Taihu, China

ABSTRACT: BACKGROUND: Taihu Lake is a typical plain eutrophic shallow lake. With rapidly economic development of the lake area, the petroleum products and oil wastewater produced in various processes have been inevitably discharged into Taihu Lake. As the major fresh water resource in the economically developed region of Yangtze River Delta, the water quality and environmental condition of Taihu Lake have the direct bearing on the natural environment and sustainable development of economy in this region. For this reason we carried out the study to explore the composition, distribution characteristics and sources of petroleum contaminants in Taihu Lake. The aim of this study was to provide the basis for standard management and pollution control of the Taihu Lake environment. RESULTS: The result showed that water samples from near industrial locations were of relatively higher petroleum contaminants concentrations. The oil pollutants concentrations in different areas of Lake Taihu ranged from 0.106 mg/L to 1.168 mg/L, and the sequence of total contents distribution characteristics of petroleum pollutants from high to low in different regions of Taihu Lake was: "Dapu", "Xiaomeikou", "Zhushan Bay", "Lake center", "Qidu". The results showed that total concentrations of n-alkanes and PAHs ranged from 0.045 to 0.281 mg/L and from 0.011 to 0.034 mg/L respectively. In the same region, the concentrations of hydrocarbon pollutants in the surface and bottom of the lake were higher than that in the middle. CONCLUSION: This paper reached a conclusion that the petroleum contaminants in Taihu Lake mainly derived from petroleum pollution caused by human activities as indicated by OEP, bimodal distribution, CPI, Pr/Ph ratio, the LMW/HMW ratio and other evaluation indices for sources of n-alkanes and polycyclic aromatic hydrocarbons (PAHs).     

Electrochemical treatment of olive oil mill wastewater

The possibility of oxidizing at a PbO2 anode the phenols and polyphenols, present in the olive oil mill wastewater, has been studied as a pretreatment for the submission of such wastewater to the traditional biological treatments. The results obtained operating at current densities ranging 500 to 2000 A/m2 show that it is possible to reduce the concentration of the phenolic components, which interfere with the biological treatments, down to low values without decreasing too much the total organic content of the wastewater.     

Glass capillary SCOT columns by a single-step coating method

A single-step coating method for the preparation of glass capillary SCOT columns is described. It is reproducible and less time-consuming than the well-known two-step coating procedures. Other methods attempted are discussed briefly. Both the flame ionization and electron capture detectors could be used in conjunction with temperature programming. The separations achieved with an “activity mixture”, phenols and phenolic acids, illustrate the resolution obtained. The columns are suitable for quantitative determinations and a comparison is made with a conventional packed column.     

Bioactive compounds, RP-HPLC analysis of phenolics, and antioxidant activity of some Portuguese shrub species extracts

In the ecosystem of Serra Da Estrela, some plant species have the potential to be used as raw material for extraction of bioactive products. The goal of this work was to determine the phenolic, flavonoid, tannin and alkaloid contents of the methanolic extracts of some shrubs (Echinospartum ibericum, Pterospartum tridentatum, Juniperus communis, Ruscus aculeatus, Rubus ulmifolius, Hakea sericea, Cytisus multiflorus, Crataegus monogyna, Erica arborea and Ipomoea acuminata), and then to correlate the phenolic compounds and flavonoids with the antioxidant activity of each extract. The Folin-Ciocalteu's method was used for the determination of total phenols, and tannins were then precipitated with polyvinylpolypyrrolidone (PVPP); a colorimetric method with aluminum chloride was used for the determination of flavonoids, and a Dragendorff's reagent method was used for total alkaloid estimation. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene bleaching tests were used to assess the antioxidant activity of extracts. The identification of phenolic compounds present in extracts was performed using RP-HPLC. A positive linear correlation between antioxidant activity index and total phenolic content of methanolic extracts was observed. The RP-HPLC procedure showed that the most common compounds were ferulic and ellagic acids and quercetin. Most of the studied shrubs have significant antioxidant properties that are probably due to the existence of phenolic compounds in the extracts. It is noteworthy to emphasize that for Echinospartum ibericum, Hakea sericea and Ipomoea acuminata, to the best of our knowledge, no phytochemical studies have been undertaken nor their use in traditional medicine been described.     

Effect of concomitant organic compounds on the value of phenolic index

The contribution of organic compounds to the value of phenolic index has been determined. It has been found that, in the determination of the given index, other oxygen-containing aromatic compounds can be determined along with phenols and a series of toxic chlorinated phenols.     

Contamination Pétrolière de la Microcouche de Surface du Golfe de Fos-sur-mer (Mer Méditerranéee)

Abstract

In a general study on the petroleum contamination of the Fos-sur-mer Gulf (Mediterranean Sea), the surface microlayer was sampled. We present here the first results reported up to date in this area, based on a sampling carried out with a rotating PVC drum at 3 stations in May 1985.

Very high hydrocarbons concentrations were sometimes observed in the surface film, which appears more heterogeneous than the underlaying water column (0.5-2m). Water samples were filtered through fiberglass filters (0.5-1 μm). Both dissolved and particulate phases were separately extracted and analysed, providing evidence that suspended particles are the major vector for the accumulation and the transport of petroleum pollutants in these neritic waters.

The petroleum origin of “total hydrocarbons” fractions is confirmed by GC and HPLC which reveal characteristic features for n-alkanes and polynuclear aromatic hydrocarbons. HPLC analysis of polar (non-hydrocarbons) fractions could indicate their formation from petroleum components. Furthermore, the comparison with the underlying waters shows that volatilization and biodegradation are the major processes affecting hydrocarbons distribution in these superficial waters.

Biological data (bacteria, chlorophylls, ATP and energetic charge) were simultaneously measured and indicated an important inhibition of phyto- and bacterio- neuston regarding to the planktonic organisms.     

The Fischer-Tropsch Synthesis: Molecular Weight Distribution of Primary Products and Reaction Mechanism

An evaluation of literature data concerning the production of hydrocarbons and alcohols by the Fischer-Tropsch procedure indicates that the molecular weight distribution of the primary products can be described by the Schulz-Flory equation (“normal” or “most probable” distribution). It follows that the highest attainable selectivity for a given molecular weight range can be calculated. A reaction mechanism is suggested.     

水稻秸秆石油醚和乙醇萃取物的组成分析

用石油醚和乙醇在索式萃取器中对水稻秸秆进行了萃取,萃取物用傅里叶转换红外光谱仪（FTIR）和气相色谱 质谱联用仪（GC/MS）分析。 结果表明,乙醇和石油醚的萃取率分别为8%和6%。 萃取物中共检测到40种物质,主要分为醇酚（APs）、醛、酮、酸、酯、烃（HCs）及含氮化合物（ONs）7种类别。 其中,石油醚萃取物中酯、HCs和APs 3类物质含量较高,总的相对含量为91.7%;乙醇萃取物中HCs、酸、酯及APs含量较高,总的相对含量为83.9%。 该研究在开发稻秆的高附加值利用方面具有重要的基础理论意义。     

A novel infrared spectrophotometric method for the rapid determination of petroleum hydrocarbons, and animal and vegetable oils in water

To determine the concentrations of total oils,petroleum hydrocarbons,and animal and vegetable oils in water,the conventional analytical methods involve two scans as well as a step of magnesium silicate adsorption to remove the animal and vegetable oils in water samples.In this study,a novel analytical method was developed to determine the above oils in wastewater samples through just one scan—the concentration of animal and vegetable oils,and that of total oils were determined by measuring the absorbance of the >C=O bond in the peak area between 1750 cm and 1735 cm^-1,and of the C-H bond at 2930 cm^-1,2960 cm,and 3030 cm^-1,respectively.The concentration of petroleum hydrocarbons was then calculated by subtracting the concentration of animal and vegetable oils from that of total oils.Compared with the well-known analytical method GB/T 16488-1996,the novel approach displayed similar accuracy in the quantitative determination of oils in wastewater samples,but significantly reduced material cost and operation time.     

Interactions of stabilizers during oxidation processes

The antioxidative action of mixtures of phenols, phosphites, HALS, ^a) and some of their transformation products in various compositions has been studied in the thermo- and photo-oxidation of hydrocarbons and polypropylene under different conditions. In the AIBN-initiated oxidation of hydrocarbons at low temperatures (< 80°C), hindered phenols, hindered aryl phosphites and the nitroxyl derivatives of HALS act antioxidatively when used individually in appropriate concentrations. Secondary HALS do not show any induction period, but a certain retardation of the oxidation process after some reaction time. The inhibiting efficiency of nitroxyls observed cannot be explained completely by the currently accepted action mechanisms of HALS, but is also related to the reaction of the nitroxyls with alkylperoxyl radicals. In mixtures with hindered phenols, HALS have almost no influence on the rate of thermooxidation at low temperatures. Their nitroxyl derivatives, however, always exhibit synergism, most pronounced when both stabilizers are used in equimolar ratios. During the photooxidation phenols lower the efficiency of HALS. The influence of mixtures of stabilizers on the oxidative stability of polypropylene is rather different and depends on the oxidation conditions, the structure, the concentration and the ratio of the stabilizers. Synergistic as well as antagonistic effects are observed. Both aliphatic and aromatic phosphites studied act synergistically when used together and with phenols. This demonstrates that for acting as synergist for phenols, the hydrogen peroxide decomposing capability of the phosphites, but not their chain breaking activity is important. HALS-phosphites and phosphonites, containing amine and phosphorus units in one molecule, are highly effective inhibitors of photo- and thermooxidation and exhibit lower critical antioxidant concentrations and longer induction periods than phosphites alone. They even exceed the efficiency of phenols in many cases. Transformation products of phenolic antioxidants investigated act differently and in many cases contrarily under photo- and thermooxidative conditions. Therefore, they influence the efficiency of stabilizer mixtures also in a different way.     

Monoacetamidation de quelques hydrocarbures polycycliques par voie electrochimique

Anodic oxidation in acetonitrile of five polycyclic hydrocarbons gives products in ratios related to the relative stabilities of intermediate carbocations. If “non-classical” ions form they arise apparently from “classical” transition states.     

Distribution characteristics and source tracing of petroleum hydrocarbons in the northeastern South China Sea

In recent years, oil spills caused by human activities have occurred frequently, and the resultant oil pollution has received extensive attention worldwide. In this paper, a total of 50 water samples were collected from the northeastern part of the South China Sea, and total petroleum hydrocarbons (TPHs) and n-alkane content in the samples were analyzed by gas chromatography-flame ionization detector (GC-FID) technology. The petroleum hydrocarbon characteristic indices, such as carbon predominance index (CPI) and terrigenous/aquatic ratio (TAR), were calculated to trace the source of petroleum hydrocarbons. The measured value of TPHs ranged from 121.31–603.02 μg/L. For surface waters, the TPHs in the northern coastal waters and the central waters were higher than that in the far shore. For vertical waters, the TPHs sharply decreased at first, and then increased slowly and finally reached a steady state. The n-alkanes in the water samples were concentrated in C10-C38, and they were mainly from terrestrial higher plant. The waters in the near shore, mid-layer and deep sea showed a strong reducing terrestrial characteristic, while the surface waters in the open sea showed an obvious oxidizing endogenous characteristic.     

Tannin-Based Adhesives

The word “tannin” has loosely been used to define two different classes of chemical compounds of mainly phenolic nature: hydrolyz-able tannins and condensed tannins. The former, including chestnut, myrobolans (Terminalia and Phyllantus tree species), and dividivi (Caesalpina coraria) extracts, are mixtures of simple phenols, such as pyrogallol and ellagic acid, and of esters of a sugar, mainly glucose, with gallic and digallic acids.     

Analysis of resoles by gel-permeation chromatography

Resoles, the complex, heat-sensitive product mixture from the alkali-catalyzed reactions of phenol with formaldehyde were investigated by gel-permeation chromatography (GPC). The low molecular weight species of these resins which consisted of mono-and dinuclear methylol phenols were resolved into multiple peaks. Model compounds were used to identify the peaks of the specific methylol phenols or methylene etherbridged diphenols. Differences in the refractive index of individual species restricted the quantitative analysis of low molecular weight components in the resole. The effects of sodium and barium hydroxides and hexamethylene-tetramine as catalysts, reaction temperature, and time on the total composition of a resole are demonstrated with the gel-permeation chromatographic spectrum and with the aid of NMR. Formation of a “secondary” resole by methylolation of the bisphenol of formaldehyde was also monitored by GPC.     

Environmental State of Water in the Blagopoluchiya Bay of Solovetskii Island According to Hydrochemical and Hydrobiological Parameters

The results of hydrochemical and hydrobiological studies performed in October 2009, July 2010, and July 2016 in the Blagopoluchiya Bay of Solovetsky Island are given. The concentrations of petroleum hydrocarbons, phenols, oxygen, nutrients, and chlorophyll a, BOD₅, and qualitative and quantitative compositions of phytoplankton have been determined. The integrated pollution and eutrophication indices have been calculated, and the up-to-date water quality in the Blagopoluchiya Bay has been assessed; increased level of seawater pollution has been revealed. The obtained results are important from both scientific and practical viewpoints with respect to environmental safety of the community facilities in the study region.

     

Characterization of Major and Minor Organic Pollutants in Wastewaters from Coal Gasification Processes

Abstract

In order to investigate the feasibility of anaerobic biological treatment for wastewaters generated from thermal gasification processes of coal, a characterization program was implemented whose major effort consisted in the elucidation of specific organic constituents contained in the wastewater. Solvent extraction in acid and base conditions followed by glass capillary gas chromatography in combination with several detectors (i.e., FID, NPD, and MS-DS) were employed for the investigation of major and minor “extractable” organic constituents. Direct aqueous injection on a polar glass capillary column (i.e., OV-351) was used for the major “nonsolvent extractable” organic constituents amenable to GC. The identity of 28 organic compounds was confirmed by comparison with pure standards. Phenol, the three cresol isomers, 5,5-dimethyl-hydantoin and 5-methyl,5-ethylhydantoin were identified as major wastewater constituents. Several substituted phenols (e.g., methyl, dimethyl, trimethyl, methylethyl, hydroxy and methoxy), pyridines, anilines, quinolines, PAHs, dibenzofuran and aldehydes were either confirmed or tentatively identified as minor wastewater constituents. Although the organics identified did not account for the total organic content, which implies the presence of still unidentified highly polar compounds, the information was utilized to set a data base for monitoring the biological treatment operations. Process monitoring data indicated that several organics (i.e., 5,5-dimethyl-hydantoin, 5-methyl,5-ethylhydantoin, o-cresol, m-cresol and p-cresol) were only partially removed by the treatment process employed.