Diesel Concentration Research Articles

Lean homogenous combustion of E-diesel using external mixture formation technique

For the past one hundred years, lots of easily accessible petroleum fuel has been burned out by humankind in inefficient engines. In this regard, present-day engine researchers face a formidable challenge to achieve the goal of significant improvements in both thermal efficiency and fuel economy. Although the direction to reach this target is critical, homogenous charge compression ignition (HCCI) is just another combustion concept to achieve this target. By the way, this work investigates the combustion phenomena of the HCCI engine by external mixture formation technique. In a nut-shell, an endeavor has been made in this work to prepare homogeneous mixture outside the combustion chamber using a fuel vaporizer system to form a uniform fuel–air mixture. The fundamental research experiments were carried out with vaporized diesel and vaporized e-diesel blends (10% and 20% ethanol substitution by volume), and the results were compared with conventional diesel engine operation. In HCCI mode, the maximum rate of pressure rises and the maximum rate of heat-release significantly reduced with increase of ethanol concentration in diesel. The experimental outcomes exposed that when HCCI engine is operated with e-diesel blend, smooth engine operation is apparent.

The Ratio of Plant Numbers to the Total Mass of Contaminant as One Factor in Scaling-up Phytoremediation Process

A toxicity test is carried out to select the contaminant concentration that a plant can tolerate in phytoremediation. We focused on the ratio of plant numbers to the total mass of contaminant as the factor for selection of contaminant concentration, nature of soil type and plant species in a diesel phytoremediation project. Based on the results of a preliminary test, Scirpus grossus could survive when the ratio of plant numbers to the total mass of diesel was more than 0.15 for 3% (Vdiesel/Vwater) after 14 days of exposure in a sub–surface flow system (SSF) containing 780 mL of diesel contaminated water with 33% percentage of withered plants. In a phytotoxicity test containing 7 L of diesel contaminated water, S. grossus could also survive with the ratio more than 0.07 for 2% (Vdiesel/Vwater) for 72 days of exposure with 36% percentage of withered plants. Based on the results of the preliminary and phytotoxicity tests, selection of diesel concentration in pilot scale containing 500 L of diesel contaminated water with 50 plants was fixed. Based on a minimum ratio of 0.05 from the preliminary and phytotoxicity tests, three diesel concentrations were selected to be 0.1, 0.175 and 0.25% to evaluate the performance of pilot reed bed to remediate diesel. Through the pilot study, the concentrations have resulted 10, 20 and 30% withered plants in the respective diesel concentration. The ratio of plant numbers to the total mass of contaminant must be considered as one factor to determine the phytotoxicity effects of the contaminant concentration in scaling-up a reed bed system for phytoremediation process.

Effect of concentration gradients on biodegradation in bench-scale sand columns with HYDRUS modeling of hydrocarbon transport and degradation.

The present research investigated to what extent results obtained in small microcosm experiments can be extrapolated to larger settings with non-uniform concentrations. Microbial hydrocarbon degradation in sandy sediments was compared for column experiments versus homogenized microcosms with varying concentrations of diesel, Syntroleum, and fish biodiesel as contaminants. Syntroleum and fish biodiesel had higher degradation rates than diesel fuel. Microcosms showed significantly higher overall hydrocarbon mineralization percentages (p < 0.006) than columns. Oxygen levels and moisture content were likely not responsible for that difference, which could, however, be explained by a strong gradient of fuel and nutrient concentrations through the column. The mineralization percentage in the columns was similar to small-scale microcosms at high fuel concentrations. While absolute hydrocarbon degradation increased, mineralization percentages decreased with increasing fuel concentration which was corroborated by saturation kinetics; the absolute CO2 production reached a steady plateau value at high substrate concentrations. Numerical modeling using HYDRUS 2D/3D simulated the transport and degradation of the investigated fuels in vadose zone conditions similar to those in laboratory column experiments. The numerical model was used to evaluate the impact of different degradation rate constants from microcosm versus column experiments.

Diesel exposure of Tympanotonus fuscatus and its effects on enzyme activity

The effect of mild concentrations of diesel (10.40,15.60,21.00 and 26.00 mg/l) on some biochemical parameters such as Aspartate transaminase (AST), Alanine transaminase (ALT), and Alkaline phosphatase (ALP), in the tissue of periwinkle (tympanotonus fuscatus) were examined using a renewal static bioassay for six days. The activities of the enzymes were measured on 120 specimens of periwinkle of size between 4.5-5.5cm lengths. The result of AST activity in the muscle showed either an increased or decreased activity against the control. The activity of ALT showed significant (p=0.05) decrease in all the test concentrations. ALT also showed significant difference (p=0.05) which were either higher or lower than the control value. In the viscera, activity of AST significantly increased(p=0.05) than that of the control. ALT activity was significantly increased (p=0.05) above the control except at 10.40ml/L where a significant decrease (p=0.05) was observed. Significant increase (p=0.05) was observed in the activity of ALP above the control value except at 10.40ml/L. The result of the tissue enzyme activities indicated alteration in the biochemistry of tympanotonus fuscatus and therefore could be used as a biomarker of aquatic pollution and toxicities.KEYWORDS: Diesel, Tympanotonus fuscatus, Enzyme, Toxicity, pollution

Effect of Waste Cooking Oil Biodiesel on the Emissions of a Diesel Engine

Abstract This paper is focused on investigating the gaseous and particulate emissions of a 4-cyclinder natural-aspirated direct-injection diesel engine fueled with different mixed concentrations of biodiesel and diesel fuel, including pure diesel fuel, B10 (diesel containing 10%vol of biodiesel), B20, B30 and pure biodiesel. Experiments were conducted with five engine loads, corresponding to brake mean effective pressures of 0.165, 0.33, 0.496, 0.661 and 0.753 MPa at a constant speed of 1800 rpm. The results show that biodiesel leads to reduction of HC, CO and particulate mass concentrations and number concentrations but an increase in NO x . In addition, particulate samples were collected from the diluted exhaust and analyzed using thermogravimetric analyzer/differential scanning calorimetry (TGA/DSC). The TGA results show that with increasing biodiesel in the fuel or decreasing engine load, the volatile mass fraction of the particulate increases and the ignition temperature of the soot decreases.

Response of autochthonous microbiota of diesel polluted soils to land-farming treatments

This study investigated the response of autochthonous microorganisms of diesel polluted soils to land-farming treatments. Inorganic NPK (nitrogen, phosphorous, and potassium) fertilizer and Ivey surfactant were applied alone or in combination as biostimulating agents. The study was carried out in experimental separated land-farming plots performed with two soils: a sandy clay soil with low biological activity and a sandy clay soil with higher biological activity, contaminated with two concentrations of diesel: 10,000 and 20,000mgkg−1. Bacterial growth, dehydrogenase activity and CO2 production were the biological parameters evaluated. Non-metric multidimensional scaling analysis proved that moisture content showed a tendency related to microbial growth and that heterotrophic and degrading microorganisms had the best relationship. Initial biological activity of soil influenced the response with 11.1% of variability attributed to this parameter. Soils with low activity had higher degree of response to nutrient addition.

Effect of diesel leakage in circulating cooling water system on preponderant bacteria diversity and bactericidal effect of biocides

Petroleum products leakage results in adverse effect on the normal operation of a circulating cooling water system. However, relatively little research has been done to explore the effect of petroleum products leakage on circulating cooling water quality and biofilm preponderant bacteria diversity. Also, normal biocides application modes cannot fulfil the need for biofilm control. In this study, diesel oil was used as the experimental subject representing leaking petroleum products; the effect of diesel addition on biofilm preponderant bacteria diversity and the bactericidal effect of chlorine dioxide and tetradecyl dimethyl benzyl ammonium chloride (1427) was investigated. Bacterial community structures were examined by PCR-denaturing gradient gel electrophoresis and PCR cloning of 16S rDNA genes. Except for 100 mg/L diesel, increasing diesel concentration enhanced the biofilm detachment ratio compared with the control test. The microstructure of biofilm samples with 0, 300 and 900 mg/L diesel addition was observed. The species of preponderant bacteria in the biofilm sample with 300 mg/L diesel addition were more and the bacterial distribution was more uniform than those in the biofilm sample with 900 mg/L diesel addition. With ClO2 and 1427 addition, chemical oxygen demand increased, lipid phosphorus and bacterial count first decreased and then remained stable, and the bactericidal ratio first increased and then remained stable. Diesel addition variation has more obvious effect on ClO2 than 1427.

Phytodegradation of total petroleum hydrocarbon (TPH) in diesel-contaminated water using Scirpus grossus

Phytoremediation using the perennial plant Scirpus grossus has been suggested as an environmentally friendly and economical method for treating contaminated water. In this study, a pilot-scale constructed wetland with a sub-surface batch system was adapted for the phytoremediation of contaminated water with different diesel concentrations, i.e., 0%, 0.1%, 0.175%, and 0.25% (Vdiesel/Vwater), using S. grossus for a period of 72 days under greenhouse conditions. The degradation of total petroleum hydrocarbons (TPH) from the water by S. grossus after 72 days of diesel exposure was recorded as 81.5%, 71.4%, and 66.6% for 0.1%, 0.175%, and 0.25% diesel (v/v) treatments, respectively. S. grossus was extracted, and the results show that the maximum TPH was 223.56mgkg−1 in stem+leaf samples with 93.72% n-alkanes C20–C34. In the batch biodegradation experiment, the rhizobacteria of S. grossus played a role in diesel degradation in the rhizosphere zone. Hence, a sub-surface batch constructed wetland using S. grossus could be a promising solution for the phytoremediation of industrial contaminated water with diesel.

The National Environmental Respiratory Center (NERC) experiment in multi-pollutant air quality health research: I. Background, experimental strategy and critique

The National Environmental Respiratory Center Program was initiated as an experiment to explore strategies for identifying the components of complex air pollution mixtures that cause health effects associated statistically with air pollution. A strategy involving multivariate analysis of a composition-concentration-response database was adopted. A novel database was created by exposing rodents daily for up to six months to one of four combustion-related mixtures and measuring respiratory, cardiovascular and general toxicological responses after one week or six months of exposure. The mixtures included multiple concentrations of diesel and gasoline engine exhaust, hardwood smoke and simulated downwind coal combustion emissions. After reporting the biological effects of each mixture and comparing effects among them, 47 significant effects were selected for multiple additive regression tree analysis to identify putative causal components. Although the four mixtures provided a database marginally sufficient for the analysis, the results suggested the putative causes of 19 significant effects with acceptable confidence. This article describes and critiques the Program and its strategy. The integrated results are presented in two accompanying papers, and mixture-specific results were presented in preceding papers, which are cited. The experiment demonstrated the potential utility of the general approach and identified certain cause–effect relationships for confirmatory studies. A follow-up study provided support for causation by the components implicated for one of those relationships. The advantages and disadvantages of the Program’s management and funding strategies are discussed.

Effect of palmitic acid on remediation of Scripus triqueter and enzymes activities of the rhizosphere soil in the simulated diesel-spiked wetland

Scripus triqueter (ST), an oil tolerant plant in the wetland of Huangpu-Yangtze river estuary (HYRE) can be used for phytoremediation. As a dominant root exudate of the ST, palmitic acid was examined for its impact on the ST and the rhizosphere soil enzymes of simulated diesel-spiked wetland. Pot experiment showed that palmitic acid inhibited the growth (height, stem weight, root weight) of the ST and the activities of soil enzymes. The activities of superoxide dismutase (SOD) and catalase (CAT) in the root and stem of the ST decreased in diesel-spiked soil planted with ST and inoculated with 400 mg kg−1 of palmitic acid (STDP) compared with those in the diesel-spiked soil planted with ST (STD). It was found that the activities of polyphenol oxidase (PPO) and dehydrogenase (DHG) were lower in the STDP than those in the STD throughout the experiment. Compared to the STD, the concentration of residual diesel in the STDP was significantly higher, indicating that inhibited degradation abilities of soil microbes and plants. The results suggested palmitic acid might act as an allelochemicals to the ST and the rhizosphere soil enzymes in the simulated diesel-spiked wetland.

Modeling the growth curves of Acinetobacter sp. strain DRY12 grown on diesel

Diesel is a toxic xenobiotic. However, some bacteria are capable of using diesel as a carbon source for energy and growth. At high diesel concentration, an inhibition to the growth curves is seen. The study of the growth inhibitory properties of diesel on bacterium has often been carried out through the modelling of the specific growth rates obtained from the linearization of thegrowth curves of bacterium. Since there exists a variety of models for obtaining a more accurate specific growth rates from bacterial growth curves such as logistic, Gompertz, Richards, Schnute, Baranyi-Roberts, Von Bertalanffy, Buchanan three-phase and more recently Huang models, theuse of these models over the simplification through linearization is needed. The modified Gompertz model gave the best fitting based on statistical test with the lowest values for RMSE and corrected Akaike Information Criteria, the highest value for adjusted R2 and the closest values to unity for both Accuracy and Bias factors. The modified Gompertz model is thus the best model to obtain specific growth rates from the growth curves of Acinetobacter sp. strain DRY12grown on diesel.

The Monod and a biphasic biodegradation kinetics of diesel hydrocarbons by a biofilm of Pseudomonas and the potential electromotive force involved

AbstractBACKGROUNDTwo kinetic models for diesel degradation in a continuous‐flow reactor at a retention time of 1.5 h were compared. One model included the Monod equation and the other, a biphasic model, did not involve Monod parameters. The experiment included two Pseudomonas species. A thermodynamic study on the nitrate‐reducing degradation of diesel was performed in addition to a BOD5 /COD ratio to evaluate the biodegradability of both the diesel components and their residual concentrations.RESULTSThe Monod model revealed that both μmax,h and for the C10–C18 chains were 2.5‐fold and 11‐fold, respectively, lower than those of chains C20–C22. The biphasic model failed to detect the influent concentration range at which the biofilm slowed down processing the substrates. The shifts of the influent‐to‐effluent BOD5/COD ratios from 0.67 to 0.80 and from 0.80 to 0.95, for the lowest and highest substrate concentrations, respectively, confirmed that residuals in the effluent can be degraded. Stoichiometric calculations for C10–C22 revealed theoretical spontaneous release of Gibbs free energies from –6.89 to –70.27 kJ, and electromotive forces from 4.4 to 45.51 mV for both the lowest and highest diesel concentrations, respectively.CONCLUSIONThe influent diesel concentration interval of 1008–1344 mg L−1 was the range over which the maximum utilization rates of chains C10–C22 decreased from 1.12 to 0.57 vss−1 due to the inhibitory action of chains C10–C18 (P&lt;0.05). Following the degradation of diesel, the organic residuals left in the effluent can be easily assimilated. The nitrate‐reducing degradation was able to produce an electromotive force spontaneously. © 2014 Society of Chemical Industry

Modified Fenton oxidation of diesel fuel in arctic soils rich in organic matter and iron

Modified Fenton (MF) chemistry was tested in the laboratory to treat three diesel fuel-contaminated soils from the Canadian arctic rich in soil organic matter (SOM) and Fe oxides. Reactors were dosed with hydrogen peroxide (HP), and treatment was compared in reactors with SOM as the only chelate vs. reactors to which ethylenediaminetetraacetate (EDTA) was added. Concentrations of diesel fuel and HP were measured over time, and the oxidation of both diesel fuel and SOM were quantified in each soil. A distinct selectivity for oxidation of diesel fuel over SOM was observed. Reactors with EDTA showed significantly less diesel fuel oxidation and lower oxidant efficiency (diesel fuel oxidized/HP consumed) than reactors with SOM as the only chelate. The results from these studies demonstrate that MF chemistry can be an effective remedial tool for contaminated arctic soils, and challenge the traditional conceptual model that SOM reduces the efficiency of MF treatment through excessive scavenging of oxidant.

Optimized conditions for phytoremediation of diesel by Scirpus grossus in horizontal subsurface flow constructed wetlands (HSFCWs) using response surface methodology

This study investigated the optimum conditions for total petroleum hydrocarbon (TPH) removal from diesel-contaminated water using phytoremediation treatment with Scirpus grossus. In addition, TPH removal from sand was adopted as a second response. The optimum conditions for maximum TPH removal were determined through a Box-Behnken Design. Three operational variables, i.e. diesel concentration (0.1, 0.175, 0.25% Vdiesel/Vwater), aeration rate (0, 1 and 2 L/min) and retention time (14, 43 and 72 days), were investigated by setting TPH removal and diesel concentration as the maximum, retention time within the given range, and aeration rate as the minimum. The optimum conditions were found to be a diesel concentration of 0.25% (Vdiesel/Vwater), a retention time of 63 days and no aeration with an estimated maximum TPH removal from water and sand of 76.3 and 56.5%, respectively. From a validation test of the optimum conditions, it was found that the maximum TPH removal from contaminated water and sand was 72.5 and 59%, respectively, which was a 5 and 4.4% deviation from the values given by the Box-Behnken Design, providing evidence that S. grossus is a Malaysian native plant that can be used to remediate wastewater containing hydrocarbons.

Diesel effects on root hydraulic conductivity and morphological changes of the vascular cylinder in Medicago sativa

The effects petroleum hydrocarbons (PH) on the morphological and physiological responses of roots have not been well studied. This research evaluated the root hydraulic responses of Medicago sativa seedlings exposed to diesel. Seeds were germinated in test tubes with 1% water-agar contaminated with diesel (3000, 6000, 9000, 12000, 15000, 18000 and 21000μLL−1), and uncontaminated test tubes were used as controls (0μLL−1). Ten days-old roots were detached to determine root anatomy, hydraulic conductivity (Kh), specific hydraulic conductivity (Ks), percentage of loss conductivity (PLC), and leaf water potential (Ψlw). Root morphological changes were related to the loss of tetrarch arrangement; however, the number of metaxylem vessels increased in response to diesel. Increasing diesel concentrations resulted in diminished Kh and Ks values, as well as enhanced PLC values. Diesel contamination resulted in the accumulation of superoxide and hydrogen peroxide in root cells, as determined by confocal microscopy.

Photocatalytic Degradation of Diesel Pollutants in Seawater by Using Nano Li-Doped Zinc Oxide under Visible Light

Zinc Oxide (ZnO) is a potential semiconductor as photocatalyst. Nevertheless, its main absorbance wavelength is in the range of UV light, which consist only a small proportion of solar. In order to utilizing the large proportion of solar light, pure ZnO and Li-doped ZnO nanoparticles with different Li loading (1.0, 2.0, 3.0 and 4.0 at%) and various calcination temperature (300, 500, 700, 900°C) were synthesized through a co-precipitation method and characterized by XRD and TEM techniques. The photocatalytic abilities of photocatalysts are evaluated in simulated experiments of removing diesel pollutants in seawater under visible illumination. Six factors, Li loadings, calcination temperature, dosage of photocatalyst, reaction time, diesel initial concentration, and pH value of seawater, were taken into consideration in the process of phtotcatalytic degradation of diesel experiments under visible light. An orthogonal experiment was implemented to investigate the best combination of five factors (the factor of reaction time was excluded) which can lead to the highest diesel removal rate. The characterization of as-prepared nano-particles showed that Li element was doped into ZnO, and all particles were of hexagonal wurtzite structure. The average crystal sizes of Li-doped ZnO with various calcination temperature (300, 500, 700 and 900°C) are 15.03, 25.97, 48.63 and 55.48nm, respectively, and consequently, higher calcination temperature will contribute to the aggregation of particles. Doping Li appropriately can improve the photocatalystic ability of ZnO under visible light, which can deduce from the single-factor experiments. Calcination temperature is also an evident factor to affect the photocatalytic ability of photocatalyst. The influence order of factors in decreasing order can also be obtain through the orthogonal experiment and the result was as follows: calcination temperature &gt; Li loading ≈ pH value &gt; initial concentration of diesel &gt; photocatalyst dosage. The best combination of the five factors is as follows, the dosage of catalyst 2.5g/L, initial concentration of diesel 1.5g/L, Li loading of catalyst 1.0 at%, calcinations temperature 900oC and pH value 8.25, the removal rate of diesel pollutants in seawater is expected to reach 77.31%.

Production of indole acetic acid by a novel bacterial strain of Planomicrobium chinense isolated from diesel oil contaminated site and its impact on the growth of Vigna radiata

A novel bacterial strain of Planomicrobium chinense (B6) degrading diesel oil [2.5% (v/v)] within 96 h was evaluated for influencing the growth of Vigna radiata under increasing concentrations of diesel from 0.5 to 2.5% (v/v). The strain was investigated for the production of plant growth promoting factors viz., Indole acetic acid, ammonia and phosphate solubilization under the influence of diesel oil. The IAA activity was augmented at 0.75 mM tryptophan and low concentrations of diesel oil [0.5–1.5% (v/v)]. The seeds treated with P. chinense (seed imbibement) as well as by soil inoculation showed significant enhancement of plant biomass and hydrocarbon degradation as compared to control treatment. However, seeds grown on soil previously inoculated with the organism performed better than those applied by seed imbibement. Increase in plant biomass were optimized at low concentrations of diesel oil [0.5–1% (v/v)]. Gas chromatography of the bacterial inoculated soil revealed degradation of most of the linear chain alkanes along with a simultaneous increase in the plant biomass. Production of plant growth promoting factors and increase in plant biomass yield in the presence of diesel oil provides a conception of the efficiency of P. chinense for plant growth promotion activities besides hydrocarbon degradation in diesel contaminated sites.

Toxic effect of diesel and kerosene on growth and biochemical composition of spirulina platensis.

Spirulina platensis is a photosynthetic, filamentous, spiral shaped, multicellular and blue-green microalga. Diesel and kerosene are used in great amount for different purposes causing environmental pollution. In the present study, the effect of diesel and kerosene were tested on Spirulina platensis at the concentrations of 0.5,1,2,5 and 10%. Growth rate were observed for both diesel and kerosene and compared with control samples. Protein content, carbohydrate content and chlorophyll-a content were also determined. There was dramatic change in the growth and population increment. The day wise study was carried out and it was found that with increase in time span the growth decreases and concentration of diesel and kerosene also affected its growth. It was concluded that diesel is more toxic than kerosene.

Biodegradation potential of petroleum hydrocarbons by bacteria and mixed bacterial consortium isolated from contaminated sites

The aim of this study was to isolate, characterize, and evaluate the potential of petroleum hydrocarbon (PHC)-degrading bacterial strains from oil-contaminated soil in the Meerut region. Among 59 oil-degrading bacterial cultures isolated from the oil-contaminated soil samples, 1 Bacillus species, 2 species of Pseudomonas, and 1 species of Micrococcus, identified on the basis of biochemical and 16s rDNA sequencing, were found to have the ability to utilize PHCs such as benzene, diesel, toluene, anthracene, and naphthalene. These strains were selected for further study to measure the quantitative determination of PHC metabolization. Along with these selected strains, a mixed bacterial consortium was formulated and used for PHC degradation. Among the individual strains, Pseudomonas sp. APHP9 performed better than the other bacterial isolates. Maximum biodegradation of benzene and toluene was done by the bacterial consortium. The mean growth rate constant (K) of soil isolates also increased with a successive increase in PHC concentration. Moreover, Bacillus sp. APHP6, Pseudomonas sp. APHP9, Pseudomonas sp. APBP1, Micrococcus sp. APIO4, and the consortium resulted in a 54.8%, 60.2%, 40.9%, 32.5%, and 66.2% decrease in benzene concentration and a 61.2%, 68.4%, 53.7%, 39.3%, and 75.4% decrease in diesel concentration, respectively, after 6 days of incubation as estimated by HPLC analysis.

Characterization of A Diesel-Degrading Strain Isolated From A Local Hydrocarbon-Contaminated Site

A diesel-degrading bacterium has been isolated from a primary school soil. The isolate was tentatively identified as Serratia sp. Strain DRY5 based on the carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Isolate 5 showed an increase cellular growth with respect to diesel concentrations from 0% until 2% where the optimum growth occurring at 2% (v/v) diesel concentration and was able to tolerate up to 8% (v/v) diesel. Based on the optimization studies using different nitrogen sources, Ammonium chloride proved to be the best nitrogen source. Ammonium chloride was optimum at 7.7 gl-1 and concentrations higher than that resulted with inhibiton of the cellular growth. The optimal temperature and the optimal pH that supported the growth of this bacterium was between 23 to 40 oC and pH 7.5 to pH 8.5 respectively. Diesel components was proven to be completely removed from the reduction in the hydrocarbon peaks monitored by Solid Phase Microextraction Gas Chromatography analysis after 7 days of incubation.All of these characteristics suggest that this bacterium is the right bacterium for bioremediation of diesel spills and pollution in the tropics.