Total Oil Concentration Research Articles

Biodegradabilities of some chain oils in groundwater as determined by the respirometric BOD OxiTop method

The respirometric BOD OxiTop method was used to monitor the biodegradation of different chain oils (mineral, rapeseed and tall oils) over 28 days in groundwater, as well as in standard conditions described by OECD 301 F. The aim of the study was to gather more information about the biodegradability of forestry oils in groundwater, as well as about the suitability of the automatic OxiTop method for biodegradation measurements. The BOD OxiTop method proved to be a precise and reliable technique for determining the biodegradations of different oils. Some comparative studies were also made using a traditional IR method in order to clarify the total oil concentrations. The results show that if biodegradation only is to be monitored, the OxiTop method is preferable. This is due to the influence of other reactions aside from biodegradation on total hydrocarbon concentrations when using the IR method.

Estimating soybean seed protein and oil concentration before harvest

AbstractTemperature and precipitation during the growing season have been shown to influence the protein and oil composition of the soybean [Glycine max L. Merr.] seed. A method based on these parameters was developed to estimate protein and oil concentrations of the seed before harvest. This method was developed with protein and oil data and temperature and precipitation data from the Uniform Soybean Tests, Southern Region, for the years 1975 to 1983. Classification and regression “tree‐based” analyses were used to determine the month and numeric value (“splitting point”) of the environmental variable that correctly classified the variation from median protein and oil composition for the 126 location‐years. Temperature in September was most influential in determining the splitting point for three of the four variables. Oil concentrations from the location‐years were separated into low vs. high median‐based boundary categories most readily by the September sum of minimum temperatures. Total protein and oil concentrations from the location‐years were classified best by September growing degree days. Protein‐to‐oil ratios were best separated by the September mean minimum temperature. The August mean maximum temperature best separated protein concentration. These data demonstrate that temperature during specific months of the crop year were useful in estimating the final concentration of protein and oil in the seed and could be used by seed processors to estimate seed composition before harvest.

Elevated Temperature and Carbon Dioxide Effects on Soybean Seed Composition and Transcript Abundance

Climate change due to increased [CO2] and elevated temperature may impact the composition of crop seed. This study was conducted to determine the potential effects of climate change on composition and gene expression of soybean [Glycine max (L.) Merr. cv. ‘Bragg’] seed. Soybean plants were grown in sunlit, controlled environment chambers under diel, sinusoidal temperatures of 28/18, 32/22, 36/26, 40/30, and 44/34°C (day/night, maximum/minimum), and two levels of [CO2], 350 and 700 μmol mol−1, imposed during the entire life cycle. The effect of temperature on mature seed composition and transcripts in developing seed was pronounced, but there was no effect of [CO2]. Total oil concentration was highest at 32/22°C and decreased with further increase in temperature. Oleic acid concentration increased with increasing temperature whereas linolenic acid decreased. Concentrations of N and P increased with temperature to 40/30°C, then decreased. Total nonstructural carbohydrates (TNC) decreased as temperatures increased, and the proportion of soluble sugars to starch decreased. Transcripts of a gene that is downregulated by auxin (ADR12) were dramatically downregulated by elevated temperature, possibly reflecting the altered course of seed development under environmental stress. Transcripts of β‐glucosidase, a gene expressed during normal soybean seed development, were detected in seed grown at 28/18°C but not in seed grown at 40/30°C, which also suggests that normal programs affecting seed composition were perturbed by elevated temperature. These results confirm previous studies indicating that high temperature alters soybean seed composition, and suggest possible mechanisms by which climate change may affect soybean seed development and composition.

Rapid in situ determination of total oil concentration in water using ultraviolet fluorescence and light scattering coupled with artificial neural networks

Real-time measurement of total oil concentration in complex samples is required in wastewater discharge streams from ships and processing industries. A novel technology has been developed for the accurate quantification of a variety of single oils and their mixtures. Four major types of oils (lube oils 2190 and 9250, diesel fuel marine (DFM), and jet fuel (JP5)), each of which consisted of a dozen subtypes of oil samples, were examined to obtain both fluorescence and light scattering spectra as a function of concentration of single oils and mixtures. Tremendous variations in both fluorescence and scattering were observed among oil types, subtypes, and mixtures. The spectral response of an oil mixture was not the simple summation of respective single oils. To account for all these variations, a multivariate, nonlinear calibration method is applied to associate instrumental responses with oil concentrations using artificial neural networks (ANNs). The neural network architecture has been established by optimizing network parameters such as epochs, the number of neurons in the hidden layer, and learning rates in order to achieve the maximum accuracy of oil concentration measurements. It is demonstrated that the simultaneous, combined use of fluorescence and light scattering significantly improves the accuracy of measurement for oil samples. The newly developed technique permits the reliable, real-time determination of the total concentration of various oils and mixtures in water.

Evaluation of PCBs biodegradability in sludges by various microbial cultures

AbstractThe application of aerobic and anaerobic treatment for removal of PCBs in sludges generated from a groundwater treatment system was investigated. The sludge was characterized by PCB concentrations of > 520 ppm, with Aroclors 1254 and 1260 accounting for 26 and 74%, respectively, as well as total organic carbon (TOC), and oil and grease (O&G) concentrations of 108,500 and 18,600 mg/L, respectively. Four treatments were explored: three aerobic and one anaerobic. Two types of bacterial innocula were aerobically tested: sludge from a poultry processing wastewater treatment plant, and a commercial seed (Petrobio®). Petrobio was tested aerobically with and without a biosurfactant/enzymes product (BOD‐Balance™), and was also tested anaerobically. Over a period of 60 days, PCB concentrations on a volumetric and solids basis were reduced by 73.4 to 88.0% and 64.7 to 80%, respectively. Aroclors 1254 and 1260 concentrations decreased by about 76 to 89%, and 73 to 89%, respectively. TOC and O&G removal efficiencies ranged from 77 to 93%, and from 52 to 86%, respectively.Generally, sludge from the poultry processing facility achieved the best results and exhibited the most rapid biodegradation kinetics. Aerobic PCB biodegradation rates for Aroclors 1254 and 1260 were 13.5% and 23%, respectively, faster than the anaerobic biodegradation rates. Overall PCB biodegradation kinetics conformed to first‐order, with rate constants ranging from 0.017 d−1 under anaerobic conditions to 0.022 d−1 under aerobic conditions, while both TOC and O&G biodegradation kinetics followed first‐order kinetics, with rate coefficients in the ranges of 0.025–0.047 and 0.014 and 0.04 d−1, respectively.

Performance of an Internal Circulating Three-Phase Fluidized Bed Bioreactor in Treating Petrochemical Wastewater

A 4.75 m3 volume pilot internal circulating three-phase fluidized bed bioreactor (ICTFBB) was developed to treat petrochemical wastewater with ceramic particles as biocarriers. In situ experimental results showed that: due to its higher content of extracellular polymer and filamentous microbes, collapsed biofilm was better than activated sludge as inoculum for new biofilm to build up and for the ICTFBB to start up. When influent total COD, oil, phenol, NH4-N and PO4-P concentrations were in the range of 353–1911 mg l−1, 11.6–55.7 mg l−1, 1.57–48.7 mg l−1, 10.1–53.5 mg l−1 and 2.3–5.4 mg l−1 respectively, average removal efficiencies of them were 75.9%, 75.3%, 92.8%, 40% and 87.2%, respectively. Average total COD removal rates were in the range of 6.6–10.4 kgCOD m−3.d−1, much higher than that of the control, the conventional activated sludge reactor, 1.28–2.5 kgCOD m−3d−1. Oxygen utilization efficiency was high as 14–22% in ICTFBB, higher than that of the control, 6–10%. Air supply was much lower in the ICTFBB. In addition, the ICTFBB had higher resistance to COD and phenol shock and ran more stable than the control.

Recovery of coal fines from washery and power plant effluents by integrated technique of oil agglomeration and biofilm formation.

The possibility of applying an integrated technique of oil agglomeration and biofilm formation for recovery of coal fines from coal washeries and power plants effluents has been explored. Laboratory experiments with simulated slurries of different Indian coal fines demonstrate that vegetable oils are satisfactory agglomerating agents for recovery of most of the coal fines depending on the nature of coal and type of oil. The agglomeration behaviour of coal fines was assessed in terms of % yield, % organic matter recovery and % ash rejections. Maximum 85% agglomerate recovery was obtained in the agglomeration stage. Residual oil concentrations in some cases were found to exceed the permissible limit. Recovery of residual coal fines and reduction in residual oil concentration in the resultant slurry after oil agglomeration have been attempted using biofilm formation. A laboratory scale treatment reactor was put under complete recirculation to facilitate attached microbial growth on coal particles as carrier under aerobic conditions. The influence of various parameters on attached growth and stable biofilm formation were studied. The growth patterns of attached cell in suspension and consumption pattern of carbon substrate (oil) have been investigated. Steady decline in residual substrate concentration in the slurry with corresponding increase in the growth of attached and free cell mass is observed. The growth process was favoured in pH range of 6.5-7.0. The attached growth was found to be expanded in size in due course of time ultimately leading to the formation of stable biofilm in the treatment reactor which was subjected to the influent total suspended solids loading resulting from oil agglomeration step. Performance of the biofilm reactor in terms of % reduction in total suspended solids and residual oil concentration in the influent slurry was assessed in continuous mode. Complete recovery of coal fines and 60% degradation of oil was observed in the final effluent discharged from the treatment reactor.

Optimum planting densities for the production of eucalyptus oil from blue mallee ( Eucalyptus polybractea) and oil mallee ( E. kochii)

Mallees have the potential to become a new industrial crop for much of the cereal growing areas of Australia, providing alternative income and environmental salvation for farmers with land at risk to salinisation. Two species of mallee, blue mallee ( Eucalyptus polybractea) and oil mallee ( E. kochii]), were tested at Condobolin, New South Wales over a five year period to assess biomass and oil production. Plots were established at five planting densities (between 2000 and 9000 plants/ha) and harvested annually, each August. Leaf oil concentration was measured by steam distillation at each harvest and used with biomass to calculate total oil production. Biomass and oil production were not significantly different for either species between 3300 and 9000 plants/ha in any year, but significantly greater than plantings at the lowest density. Leaf oil concentration did not differ significantly with each harvest nor was it affected by planting density. Oil mallee had significantly higher leaf oil concentration than blue mallee. Oil quality and quantity determinations were made on leaf samples which were solvent extracted and analysed by GC. Small samples of leaf were taken every three months for the first three years then at the fourth harvest. For both species, total oil concentration was significantly higher in six and nine month-old regrowth than the other sampling periods. Cineole was by far the most abundant component for both species and its concentration in leaf from 12 month-old regrowth was significantly higher than that from three, six or nine month-old regrowth. For maximum oil production per unit area of plantation, blue mallee is better suited to the Condobolin environment than oil mallee. The normal planting density of 5000 plants/ha currently used by growers appears optimum, but this may be modified after considering seedling costs, projected longevity of the crop and management strategies.

Effects of dispersed and adsorbed crude oil on microalgal and bacterial communities of cold seawater

: Mesocosm facilities consisting of five 3.5 m(3) stainless steel tanks filled with seawater from the St Lawrence Estuary (Québec, Canada) were used to conduct a 2 month experiment under the natural conditions prevailing at the end of the winter in subarctic environments, with seawater temperatures ranging from-1.5°C (surface ice cover) to 3°C. Various oil treatments were simulated in mesocosms: Forties crude oil was chemically dispersed, adsorbed onto an immersed substrate and spilled without any treatment. Total oil concentrations ranged from <1 mgl(-1) (untreated oil) to 44.6 mgl(-1) (dispersed oil). Contrasting with the parent crude oil and dispersed oil, the dissolved phase was enriched with low molecular weight polycyclic aromatic hydrocarbons (PAH). As revealed by pH variations, chlorophyll a contents and degraded pigments, the phytoplankton growth was inhibited early in tanks contaminated with dispersed and adsorbed oil. Although global measurements showed a recovery of the microalgal activity while the dispersed oil was diluted in a flow-through cascade system, the specific composition was quite different from the control, with an increase in small microflagellate species and a marked decline in the diversity of centric diatoms. Small microflagellates also dominated in the heavily oil-contaminated surface microlayer. The growth of viable heterotrophic bacteria (VHB) was immediately stimulated by both dispersed and adsorbed oil (10(4)-10(5) colony forming units per ml) and oil-degrading bacteria (ODB) reached maximum densities (10(2) CFU ml(-1)) later in the experiment. The adaptation of the indigenous community was assessed using the ODB/VHB ratio, which increased by ten times in the seawater contaminated with dispersed oil. No significant bacterial enhancement was observed in the tank that received untreated oil. No bacterial enrichment was found in the surface microlayer. In sediment traps, the bacterial density increased with the amount of total settling matter and oil residues.

Droplet composition affects the rate of oxidation of emulsified ethyl linoleate

AbstractOur objective was to study the influence of droplet composition on the rate of lipid oxidation in emulsions. A series of oil‐in‐water emulsions stabilized by a nonionic surfactant (Tween 20) was studied. These emulsions had the same total oil concentration (5 wt%) and initial droplet diameter (0.3 μm), but contained droplets with different ratios of ethyl linoleate (substrate) andn‐tetradecane (inert diluent). Lipid oxidation was measured as a function of time by three different methods: gas‐chromatographic determination of residual substrate; ultraviolet‐visible spectrophotometric determination of conjugated dienes; and measurement of aqueous thiobarbituric acid‐reactive substances. All three methods showed similar trends for emulsions of similar composition. The progress of lipid oxidation in the emulsions was dependent on the concentration of ethyl linoleate in the emulsion droplets. At low concentrations (1% oil as substrate), oxidation proceeded at a relatively slow and constant rate. At intermediate concentrations (20%), the oxidation rate was rapid initially and then slowed down with time. At high concentrations (100%), the oxidation rate was slow at first, and then increased with time. An explanation of our results is proposed in terms of the distribution of substrate molecules between the droplet interior and interface, and the ingress of aqueous radicals into the emulsion droplets.

Fate and effects of dispersed crude oil under icy conditions simulated in mesocosms

The fate of the chemically dispersed crude oil Forties, the effects on natural phytoplankton and bacteria and the hydrocarbon biodegradation were studied in mesocosms during a two-week period in winter. Five double-walled stainless steel tanks (3 m height; 3·5 m 3) were used. Each tank was equipped with a cooling system maintaining entrapped seawater below zero (−1·6 ± 0·2°C) and under an ice coverage, simulating winter conditions prevailing in boreal/sub-boreal environments. A flow-through cascade set-up between three tanks simulated the progressive dilution of the oil in the water mass. A total oil concentration of 7·5 mg liter −1 was measured in the water column of the oiled cascading tanks, four days after the addition of 435 g (nominal concentration of 124 mg liter −1) of dispersed crude oil. At this time, most of the oil (> 90%) initially introduced into mesocosms had escaped the water column, mainly toward the surface. A non-negligible portion of the oil (5·7%) was settling during the course of the experiment. The low efficiency of the dispersant mixture used and the oil settling seemed to be due to the very low seawater temperature tested here. In the first days following the oil addition, a slight decline of viable heterotrophic bacteria was noted in the tanks, and then the oil improved the heterotrophic activity by the end of the experiment. The marked increase of both density and proportion of oil-degrading bacteria observed two days after the oil addition gave evidence of the potential capability of the indigenous bacterial community to adapt to an oil spill event. However, under such extreme icy conditions, the biodegradation of the dispersed oil was reduced and only the aliphatic hydrocarbon fraction, mainly recovered as dispersed oil droplets, was slightly degraded. The aromata hydrocarbon fraction, on the other hand, essentially recovered as dissolved/colloidal compounds (< 0·7 μm), was not altered after two weeks. Oil biodegradation in the material collected in sediment traps progressed more rapidly than in the water column. At the end of the experiment, about 1–2 mg liter −1 of oil remained in the water column and still induced a chl-a inhibition, but no significant change of the specific composition of the phytoplankton was noted, microflagellates remaining dominant throughout the experiment (40·5–76% in number).

Twenty‐Four Cycles of Phenotypic Recurrent Selection for Percent Oil in Maize. I. Per Se and Test‐Cross Performance

Responses and limits to selection are found to differ in various maize (Zea mays L.) populations and traits. Twenty‐four cycles of recurrent selection for high oil concentration have been completed in maize population Alexho Synthetic. The objectives of this study were to determine the response of oil concentration direct selection and correlated responses of fatty acid concentration, grain yield, and other agronomic traits. Cycles 0, 3, 5, 9, 11, 15, 18, 21, and 24 per se, the same cycles crossed to inbreds B73 and R802A, and hybrid check B73 ✕ Mo17, were evaluated in six environments at Yugoslavia and at Urbana, IL in 1985 and 1986. Selection was effective in increasing oil concentration. Total oil concentration increased by 118, 51, and 57 g kg−1 of dry matter in cycles per se B73 and R802A testcrosses, respectively. The rate of response in oil concentration was 4.9, 2.1, and 2.4 g kg−1 cycle−1 for the cycles per se for B73 and R802A testcrosses, respectively. The quadratic response was significant in testcrosses, but not in cycles per se. Thus, oil concentration has not yet shown evidence of plateauing. Oleic and linoleic acid concentration changed with selection for oil concentration in cycles per se −1.39 and 1.39 g kg−1 cycle−1, respectively. Total grain yield of the cycles per se decreased by 1718 kg ha−1, which corresponds to a response of −71.6 kg ha−1 cycle−1. Yield of the testcrosses to inbreds B73 and R802 decreased 19.7 and 15.2 kg ha−1 cycle−1, respectively. Plant height, ear height, 500 kernel weight, ear length, and lodging decreased, while grain moisture and ear row number increased with selection for oil concentration. No change was found in days to silk.

Experimental studies of the effects of drilling discharges

The long-term effects of diesel and four different low-toxicity oil-based drilling-mud cuttings on the chemistry and benthic fauna of a marine sediment were compared. Eighteen tanks (mesocosms) containing beach sediment were deployed in a control and five treatment, three replicate experimental set-up. The drill cuttings used had total oil concentrations ranging from 6 to 15% and were added to the tanks in quantities calculated to be representative of hydrocarbon levels measured in sediments 400-500 m from platforms in the North Sea. Selected parameters monitored at varied intervals throughout the experiment were: redox profiles, sulphide concentrations, hydrocarbon concentration and meiofaunal abundance. Numbers of macrofaunal organisms evacuating the sediments in the seven days after treatment application were also recorded. Redox measurements showed all sediments other than controls to be significantly reduced, but no differences were observed between treatments. Sediments became most reduced after 3 months and showed recovery thereafter, approaching control values after 15 months. Sulphide levels peaked at about 3 months and declined thereafter, but were still elevated above control levels after 15 months. Highest concentrations were recorded in treatments with the highest oil content. Mesobenthic meiofaunal abundance was significantly reduced in all cuttings treatments, but effects from individual treatments were indistinguishable. Epi/ endobenthic copepod abundance increased markedly in all low-toxicity treatments, and particularly in those with lower oil content, but remained similar to control levels in diesel treatments throughout the experiment. In the seven days after treatments, sediment evacuation rates by Tellina were highest in diesel and tended to reflect oil concentrations in low-toxicity treatments. The results show that in equal oil concentrations diesel and low-toxicity oil-based drilling-mud cuttings have indistinguishable effects on sediment chemistry, but that, even after 15 months of weathering, diesel-based cuttings are demonstrably more toxic to benthic fauna.

Estimates of oil in aquatic sediments by fluorescence spectroscopy

Aromatic substances extracted with n-hexane from various sediments were analysed by fluorescence spectroscopy. Contour diagrams of fluorescence intensity at various excitation and emission wavelengths were used to compare fluorescence spectral patterns of sample extracts and standard oils. Similarities in spectral contour diagrams confirmed the presence of petroleum residues in Bermuda beach sand, intertidal sand and sedimenting material from an inlet near an oil refinery in Nova Scotia, and in sand from Chedabucto Bay contaminated by the Arrow stranding in 1970. Total oil concentrations ranged from 10–3000 μg/g wet sediment with highest concentrations occurring in sedimenting particles. Fluorescence patterns in many sample extracts did not resemble any standard oil, indicating the presence of fluorescing material not originating from fresh petroleum.