The effect of diameter on the burning of crude oil pool fires

In order to understand the combustion characteristics of crude oil pool fires, an experimental study was carried out at the Fire Research Institute (FRI) large scale test facility. The radiative output, burning rate, and the concentrations of CO, CO₂, and smoke (above the flame tip) were measured during the burning of Arabian light crude oil, heptane, toluene, and kerosene floating on water. The effect of scale was studied by using steel pans ranging from 0.6 to 3 meters in diameter.Crude oil burned less rapidly and gave off less thermal radiation compared with heptane, but when water boiling, i.e., boilover, occurred, the burning rate increased by a factor of two or more. The intensity of boilover is related to pan diameter and initial fuel layer thickness.     

The effect of weathering on a crude oil residue exposed at sea

Kuwait crude oil residues have been exposed to weathering at sea (Langstone Harbour, Portsmouth) for 2 yr. in the form of a water-in-oil emulsion (“chocolate mousse”) in a floating layer about 1·4 cm thick. One batch of oil was exposed in a tank open to tidal flushing below the water line, and a second batch was exposed in a closed tank. A number of chemical and physical properties of the oil were measured at intervals, as were the concentrations of mineral nutrients and bacterial numbers in the sea water. Asphaltenes, specific gravity and viscosity all increased, as did the “polar” fraction from liquid chromatography. The n-alkanes decreased to about half the original levels in the open tank but were little altered in the closed tank. The constancy of vanadium and nickel concentrations suggest that no net loss of oil occurred, the substantial changes in properties deriving from chemical modification (probably oxidation and polymerization) of oil components, rather than mineralization (conversion to carbon dioxide and water) of some components leaving a residue of altered composition. It was not determined which of several processes predominated in causing these changes, but it is thought likely that in this thick layer of mousse auto-oxidation predominated over biodegradation.     

Competitive adsorption of phosphate and phosphonates onto goethite

Phosphate and phosphonates are both strongly adsorbed onto mineral surfaces and their removal during wastewater treatment is mainly due to adsorptive processes. We have conducted experiments to study the mutual influence of phosphate and six different phosphonates on each other in buffered medium at pH 7.2. We have used phosphonates having one to five phosphonic acid groups (HMP, IDMP, HEDP, NTMP, EDTMP and DTPMP). The presence of phosphonates suppressed the adsorption of phosphate. The monophosphonate HMP had the smallest and the polyphosphonates the largest effect on phosphate adsorption. The presence of phosphate lowered phosphonate adsorption. The competition in the multicomponent system can reasonably well be predicted using a surface complexation model developed for single component systems. The competitive model only failed in systems containing the polyphosphonate DTPMP. With this approach we can predict the behavior of both compounds during wastewater treatment. The calculations show that phosphonates have a small effect on phosphate adsorption at the actual concentrations in observed wastewater. Adsorption of low concentrations of phosphonates was calculated to be significantly reduced by phosphate concentrations as observed in wastewater.     

Combustion of crude oil on water

Large-scale test burns on the combustion of crude oil on water completed in a 2 m i.d. test pan to simulate large-scale crude oil fires. Data on burning rate, composition changes, thermal radiation, and the effect of heat addition, indicate combustion may be a viable method for mitigating oil spills on open waters. With the exception of thermal radiation data, the data are presented in this paper. The combustion mechanism appears to be described by equilibrium flash vaporization (EFV) followed by a limited amount of entrainment. In addition, burning rate for the crude oils tested was found to be a weak function of heat addition and to be relatively independent of specific gravity.     

Effects of a fulvic acid on the adsorption of mercury and cadmium on goethite

The effects of an aquatic fulvic acid on the pH-dependent adsorption of Hg(II) and Cd(II) to particulate goethite (alpha-FeOOH) were studied in batch systems. The ionic medium consisted of 0.01 M HClO(4) and the total concentrations of mercury and cadmium were maintained at 10(-8) M with 203Hg and 109Cd as tracers. pH In the systems was varied in the range 3-10 by addition of HClO(4) and NaOH. All commercial chemicals were of analytical grade or better. An aquatic fulvic acid (20 ppm), previously isolated and characterised in detail, was used as a model for humic substances and its adsorption to goethite is included in this study. The adsorption of the fulvic acid (20 ppm) onto goethite decreased slowly from 90% at pH 3-7.5 to 10% at pH 10. In systems without fulvic acid the adsorption of mercury increased in a linear fashion from 10% at pH 3 to 70% at pH 10. In the presence of fulvic acid (20 ppm), the adsorption was almost quantitative in the intermediate pH range (pH 5-7), and exceeded 92% over the entire pH range. Thus, association between mercury and the fulvic acid enhanced adsorption in general although the largest impact was found at low pH. Adsorption of cadmium increased from nearly 0 to almost 100% at approximately pH 6. In the presence of fulvic acid, the adsorption increased below pH 7 and decreased above pH 7. The adsorption isotherm for mercury when the concentration was increased from 10(-8) to 1.8 x 10(-4) M showed a corresponding increase of K(d) (l/g) up to a total concentration at 10(-6) M. At higher mercury concentrations K(d) was lowered. In the presence of fulvic acid the corresponding relationship of K(d) was bi-modal, i.e. high values at low and intermediate concentrations of mercury. This behaviour suggests that in the absence of fulvic acid the adsorption follow the expected behaviour, i.e. adsorption sites with similar affinity for mercury. In the presence of fulvic acid, additional adsorption sites are available by the organic molecule (possibly sulfur groups) when it is associated to the goethite. The adsorption isotherm for cadmium indicates a lowering of K(d) at 10(-4) M. Cadmium had no competitive effect on mercury and vice versa. Zinc, however, affected the adsorption of cadmium but not the adsorption of mercury.     

The effect of crude oil pollution and subsequent fire on the engineering properties of soils in the Niger Delta

The Niger Delta is a major area of crude oil exploration, exploitation and processing. This brief paper reports laboratory tests on polluted and unpolluted soils following an oil blow-out and fire outbreak and concludes that the effects were minimal.      

立体定向置管引流术治疗深部高血压脑出血效果观察

目的:观察深部高血压脑出血采取立体定向置管引流术治疗的临床效果。方法:选取2008年3月-2014年7月在本院接收的62例深部高血压脑出血患者,采取立体定向置管引流术进行治疗,根据GOS评分分析其治疗效果。结果:术后24~72 h拔管,术后30 d良好率为27.42%;术后2~30个月良好率为56.45%。结论:深部高血压脑出血采取立体定向置管引流术治疗,可使临床疗效进一步提高,特别对血肿量较少的患者效果更加明显,具有临床推广价值。     

Effect of Ni ion doping on the physical characteristics and chromate adsorption behavior of goethite

Pure and 0.25% Ni²⁺ ion doped goethite samples, prepared by the coprecipitation method, were characterized for pH of Point of Zero Charge (pH_pzc), Surface area, XRD, TG-DTA, FTIR and TEM. Effect of Ni²⁺ ions doping on the adsorption of chromate on goethite was investigated at pH-3, -5 and -7 in the temperature range 303-323 K. It was found that adsorption of chromate increases with decreasing pH and increasing temperature on both pure and Ni²⁺-doped goethite. Adsorption of chromate was found to increase from 61.4% to 82.92% with Ni²⁺ ion doping in goethite matrix at the lowest pH (pH-3) and highest temperature (323 K), using 1.02 mmol L⁻¹ chromate solution. Langmuir isotherm was found applicable to the experimental data. The values of (isosteric heat of adsorption) calculated for both the samples of goethite were positive, showing endothermic nature of the adsorption process.     

Evaporation of crude oil at sea

A simple model for describing the simultaneous evaporation and spreading of oil spills at sea has been developed and tested. A previously reported theory was used for calculating the aerodynamic part of the evaporation process. Here, the thermodynamic part, i.e. the oil characterization and the weathering processes, is described in detail. By comparison with the results of laboratory evaporation experiments and sea trials the model is shown to work quite adequately. Also, the influence of the mixing of oil into the water column, e.g. due to wave action, is shown to be small enough to be neglected. The spreading model was purposely kept as simple as possible, in view of the uncertain influences of wave action and emulsion formation. The velocity of the edge of the oil slick is prescribed and a critical thickness beyond which the slick stops spreading is introduced. The latter turns out to have a significant influence on the rate of evaporation. Examples of crude evaporation are given and the influence of temperature and wind velocity is investigated.     

Humic acid adsorption and surface charge effects on schwertmannite and goethite in acid sulphate waters

In acid conditions, as in acid mine drainage waters, iron oxide particles are positively charged, attracting negatively charged organic particles present in surrounding natural waters. Schwertmannite (Fe8O8(OH)6SO4) and goethite (alpha-FeOOH) are the most typical iron oxide minerals found in mine effluents. We studied schwertmannite formation in the presence of humic acid. Further, surface charge and adsorption of humic acid on synthetic schwertmannite and goethite surfaces in pH 2-9 and in humic acid concentrations of 0.1-100 mg/L C were examined. Schwertmannite did precipitate despite the presence of humic acid, although it contained more sulphate and had higher specific surface area than ordinary schwertmannite. Specific surface area weighted results showed that schwertmannite and goethite had similar humic acid adsorption capacities. Sulphate was released from schwertmannite surfaces with increasing pH, resulting in an increase in specific surface area. Presence of sulphate in solution decreased the surface charge of schwertmannite and goethite similarly, causing coagulation. In acid conditions (pH 2-3.5), according to the zeta potential, schwertmannite is expected to coagulate even in the presence of high concentrations of humic acid (< or = 100 mg/L C). However, at high humic acid concentrations (10-100 mg/L C) with moderate acid conditions (pH>3.5), both schwertmannite and goethite surfaces are strongly negatively charged (zeta potential < -30 mV) thus posing a risk for colloid stabilization and colloidal transport.     

Large-scale boilover experiments using crude oil

In order to know the mechanisms of boilover in a large tank, large-scale experiments using a 5 m diameter pan filled with crude oil were conducted. The initial fuel layer thickness was 0.45 m. At about 70 min after ignition, boilover occurred. The maximum irradiance was observed at the boilover and was about 22 times greater than that at steady burning. The increasing rate of the isothermal layer (hot zone) thickness was evaluated on the basis of measured temperature profile changes in the fuel. The measured periods from ignition to boilover coincide fairly well with those measured in the previous studies.     

The role of Al-Goethites on arsenate mobility

The geochemical fates of Fe and As are so closely correlated that methods of As removal from contaminated water are in general based on the high affinity of this metalloid for Fe (hydr)oxides. Dissimilatory Fe reducing bacteria, however, play a fundamental role in catalysing the redox transformations that ultimately control the mobility of As in anoxic environments. The potential of Al-goethites in adsorbing As(V) compared with hematite, goethite, ferrihydrite, and gibbsite, and the stability of As retained by the Fe compounds under anoxic conditions were investigated in this study. The (hydr)oxides were synthesised, and adsorption isotherms and As(V) adsorption maxima at different pH were measured. Arsenic loaded samples were anaerobically incubated in the presence of Shewanella putrefaciens, and periodically sampled to evaluate the contents of soluble As and Fe. The As(V) adsorption maxima decreased in the following order: Fh > AlGt₁₃ > AlGt₂₀ > AlGt₂₃ > Gb > Hm > Gt. In terms of surface area, Gb, Gt, and Hm showed higher As(V) loading capacity than Fh, suggesting available reactive sites not fully occupied by arsenate on Fh. The same hypothesis can be considered for Al-goethites, as they showed even lower arsenate loading capacity per surface area. The presence of structural Al in the goethites enhanced considerably the As uptake capacity and stability under reducing conditions. Therefore, the Al-goethites showed good potential as adsorbents to remove As from water. S. putrefaciens cells were able to utilise both noncrystalline and crystalline Fe (hydr)oxides as electron acceptors, releasing As into solution. Al-goethites showed a decrease in Fe and As mobilisation as structural Al increased.     

The present state of underground crude oil storage technology in japan

Although Japan is a major consumer of petroleum, it depends almost completely on imports from abroad and thus is easily affected by external conditions concerning petroleum. To reduce this import dependency, Japan is engaged in a long-term program to improve and strengthen its vulnerable position. The program includes the use of underground crude oil storage facilities, construction of which is now in progress. Referring to examples of the underground storage in Europe and America, the technology for these facilities is being developed into a system suited to the natural and social conditions of Japan on the basis of the results of construction and operation of a test plant. This paper reports on the present state of underground oil storage technology in Japan.     

活性氧化铝吸附水中砷的动态试验研究

近年来,饮用水砷污染事件层出不穷,选择高效合适的除砷方法,已成为全球关注的问题.试验采用逆流式单床吸附柱的吸附方式,对活性氧化铝吸附砷做了动态试验研究.研究结果显示,当初始砷浓度为10mg/L时,砷的去除率均在90%以上;当初始砷浓度为50mg/L时,以5mg/L为穿透点,穿透体积为110L,动态吸附量为3.43mg/g.结果表明,在水中砷的去除方面,活性氧化铝可作为一种有效吸附剂.该研究对实际应用中的活性氧化铝改性及饮用水处理具有重要意义.     

Intraparticle diffusion and adsorption of arsenate onto granular ferric hydroxide (GFH)

Porous iron oxides are being evaluated and selected for arsenic removal in potable water systems. Granular ferric hydroxide, a typical porous iron adsorbent, is commercially available and frequently considered in evaluation of arsenic removal methods. GFH is a highly porous (micropore volume approximately 0.0394+/-0.0056 cm(3)g(-1), mesopore volume approximately 0.0995+/-0.0096 cm(3)g(-1)) adsorbent with a BET surface area of 235+/-8 m(2)g(-1). The purpose of this paper is to quantify arsenate adsorption kinetics on GFH and to determine if intraparticle diffusion is a rate-limiting step for arsenic removal in packed-bed treatment systems. Data from bottle-point isotherm and differential column batch reactor (DCBR) experiments were used to estimate Freundlich isotherm parameters (K and 1/n) as well as kinetic parameters describing mass transfer resistances due to film diffusion (k(f)) and intraparticle surface diffusion (D(s)). The pseudo-equilibrium (18 days of contact time) arsenate adsorption density at pH 7 was 8 microg As/mg dry GFH at a liquid phase arsenate concentration of 10 microg As/L. The homogeneous surface diffusion model (HSDM) was used to describe the DCBR data. A non-linear relationship (D(S)=3.0(-9) x R(p)(1.4)) was observed between D(s) and GFH particle radius (R(P)) with D(s) values ranging from 2.98 x 10(-12) cm(2)s(-1) for the smallest GFH mesh size (100 x 140) to 64 x 10(-11) cm(2)s(-1) for the largest GFH mesh size (10 x 30). The rate-limiting process of intraparticle surface diffusion for arsenate adsorption by porous iron oxides appears analogous to organic compound adsorption by activated carbon despite differences in adsorption mechanisms (inner-sphere complexes for As versus hydrophobic interactions for organic contaminants). The findings are discussed in the context of intraparticle surface diffusion affecting packed-bed treatment system design and application of rapid small-scale column tests (RSSCTs) to simulate the performance of pilot- or full-scale systems at the bench-scale.     

雾化湿法与过滤吸附相结合的净化试验研究

为解决餐饮业和家庭厨房产生的油烟问题，在分析已有净化方式的基础上，提出雾化湿法与过滤吸附相结合的方法，并分别对雾化法、吸附法及二者相结合的方法作了试验，结果表明二者相结合的方法油烟去除效率最高，达92％以上，且净化后油烟排放的浓度符合国家标准。     

塔河原油特性与塔河稠油生产工艺

从油藏特征、成藏条件、原油性质角度简要综述了塔河原油及渣油的主要性质，并通过对原油及渣油性质的了解，分析针对塔河原油及渣油的炼化技术，探讨了塔河原油的生产工艺。     

The environmental impact of crude oil formation water: A multivariate approach

Water bodies receiving effluents from gas flow stations were sampled for ten months (March to December). Fifteen physicochemical parameters were monitored at six locations. Results obtained were analyzed unsing principal component analysis and cluster analysis. Five principal componets accounting for 72.43% of total variance were isolated. The first principal component was a measure of sea water intrusion, the second componet was a measure of total solids, the third component was a measure of organic pollution while the fourth and fifth principal component depicted the impact of effluent discharges. Effluents from gas flow stations were not the major causes of pollution of water resources in the locations of study. Cluster analysis showed no significant variation in the physicochemical characteristics of water samples based on location. Physicochemical parameters exhibited a seasonal pattern as a result of dilution by rainfall, reduced rate of evaporation in rainy season and dissolution of gaseous products of gas flaring in rain. Metals had no significant effect on the quality of water sampled from the six locations during the period of monitoring.     

Responses of model freshwater ecosystems to crude oil

Major responses of model ecosystems (microcosms) simulating two freshwater lakes of the Rocky Mountains to crude oil were: (1) increased rates of oxygen consumption, (2) increased nutrient uptake rates by the decomposer community and (3) a shift from autotrophic to heterotrophic domination. Oxygen utilization in the microcosms maintained in darkness was increased up to 400% by oil at an areal loading of 0.212 lm⁻². There were no apparent toxic effects of oil on the overall bacterial community. Bacterial counts indicate bacterial populations responded positively to oil addition within seven days. Unweathered crude oil was toxic to the alga, Selenastrum capricornutum in bioassay tests, but oil weathered 48 days in solution was not. The mixed community of phytoplankton in the diurnal model ecosystems had a greater standing crop in oil-treated microcosms within 11 days after oil was added. However, the overall plant biomass was diminished by oil over 48 days. Results indicate that the shift of oiled ecosystems from autotrophic to heterotrophic domination was caused by increased availability of reduced carbon (i.e. oil) to the heterotrophs and by decreased nutrient availability to autotrophs due to nutrient uptake by oil degrading heterotrophs, rather than toxic effects of the oil on photoautotrophs.     

Cement-lime stabilization of crude oil contaminated kaolin clay

The present study examines the effect of stabilization on the geo-environmental properties of crude oil contaminated kaolin clay.Lime and cement were mixed in a ratio of 1:2 and added to the simulated crude oil contaminated kaolin clay at different percentages(5%,10%,15%,and 20%) as a stabilizing binder.Parameters investigated include consistency limits,unconfined compressive strength(UCS),and direct shear,and compressibility and leaching characteristics of the untreated and stabilized soils.The experimental testing reveals a decrease in the consistency limits with addition of the stabilizing binder.Maximum UCS values occurred for 15% cement-lime stabilized kaolin clay at different curing periods(i.e.0 d,7 d,14 d,and 28 d).By increasing the cement-lime content from 5% to 15%,the UCS values of the stabilized clay increase from 185 kPa to 350 kPa and from 785 kPa to 1160 kPa for uncured and 28 dcured samples,respectively.Both the compression and recompression indices of the contaminated kaolin clay from the consolidation test decrease by 40% and 50%,respectively,with 20% stabilizing binder addition.The leachability of the contaminated clay also reduces with incorporation of cement and lime.According to the scanning electron microscope(SEM) test,addition of stabilizing binder transforms the dispersed structure of contaminated kaolin clay into a knitted flocculated structure.The study shows the effectiveness of cement-lime mix in stabilizing the contaminated kaolin clay and the possible use of stabilized contaminated kaolin clay as an alternative construction material.