Residuo de Elaeis guineensis (Arecaceae) como absorbente de combustibles para aplicación pasiva en ingeniería contra incendios / Elaeis guineensis (Arecaceae) residue as a fuel sorbent for passive application in fire-fighting engineering

Resumen Introducción: Los vertidos de líquidos inflamables pueden producir accidentes graves, principalmente en plantas industriales y en carretera. Para prevenir la dispersión de derrames, se utilizan diversas formas de recolecta, como la absorción con sólidos porosos. Residuos agroindustriales pueden ser aprovechados como materiales sorbentes de líquidos inflamables. Objetivo: Determinar la capacidad de absorción de las biomasas residuales del pedúnculo de la palma aceitera (Elaeis guineensis) y del endocarpio del fruto de coyol (Acrocomia sp.) para cuatro líquidos orgánicos inflamables. Métodos: Las biomasas residuales de E. guineensis y de Acrocomia sp. se evaluaron como sorbentes para combustibles derramados (diésel, queroseno de aviación, queroseno comercial y gasolina). Se midió la cantidad de líquido absorbida por las biomasas a 24 ºC durante una semana, y su cinética de desorción a 50 ºC, usando balanzas de secado. Resultados: La propiedad sorbente del material de Acrocomia sp. no fue satisfactoria, comparada con el pedúnculo de E. guineensis, debido a diferencias en arquitectura residual del material orgánico. Esta última biomasa muestra una capacidad de absorción para los combustibles de 2.4 ± 0.2 cm3 g-1 a 24 ºC. La diatomita absorbe mayor cantidad de los combustibles estudiados, pero la difusión de estos fluidos a 50 ºC por la matriz mineral es solo 0.26 ± 0.09 veces lo observado para el material de E. guineensis, como resultado del mayor grado de tortuosidad de los poros de la diatomita. Conclusiones: El pedúnculo de palma aceitera (E. guineensis) mostró un adecuado potencial desempeño para la aplicación pasiva en la mitigación de los riesgos de incendio, con respecto a la diatomita. El endocarpio del fruto de Acrocomia sp. no resultó útil para esta operación de recuperación.

Abstract Introduction: Spills of flammable liquids can lead to serious accidents, mainly in industrial plants and on roads. To prevent the spread of spills, various forms of collection are used, such as absorption with porous solids. Agroindustrial waste can be used as sorbent materials for flammable liquids. Objective: To determine the sorption capacity of the residual empty-fruit bunch of oil-palm (Elaeis guineensis) and the macaw palm (Acrocomia sp.) nutshell for four organic flammable liquids. Methods: The residual biomasses of E. guineensis and Acrocomia sp. were assessed as sorbents for spilled fuels (diesel, jet fuel, commercial kerosene, and gasoline). Volumetric measurement of liquid-fuel absorption at 24 ºC was taken during a week. Desorption was measured at 50 ºC as the drying kinetics, by using moisture scales. Results: The sorption capacity of the Acrocomia sp. material was not satisfactory, compared to the E. guineensis residual material, due to differences in the residual architecture of the organic material. This last can absorb 2.4 ± 0.2 cm3 g-1 at 24 ºC, during a one-week period. Diatomite absorbs greater quantities of the organic liquids but, the fluids diffusion at 50 ºC is 0.26 ± 0.09 times more slowly in the mineral matrix, because of the greater pore tortuosity in this mineral matrix. Conclusions: The oil-palm empty fruit bunch of E. guineensis, showed lesser but adequate performance than the sorbing behavior for fire hazard mitigation of diatomite. The nutshell of macaw palm (Acrocomia sp.) did not prove to be useful for this recovery operation.

Radon deficit technique applied to the study of the ageing of a spilled LNAPL in a shallow aquifer.

A recent diesel spill (dated January 2019 ± 1 month) in a refilling station is investigated by the Radon deficit technique. The primary focus was on quantifying the LNAPL pore saturation as a function of duration of ageing, and on proposing a predictive model for on-site natural attenuation. A biennial monitoring of the local fluctuating shallow aquifer has involved the saturated zone nine times, and the vadose zone only once. Rn background generally measured in external and upstream wells is elaborated further due to the site characteristics, using drilling logs and phreatic oscillations. Notably, this study marks the first application of the Rn deficit method to produce a detailed Rn background mapping throughout the soil depth. Simultaneously, tests are performed on LNAPL surnatant samples to study diesel ageing. In particular, they are focused on temporal variations of LNAPL viscosity (from an initial 3.90 cP to 8.99 cP, measured at 25 °C, after 34 months), and Rn partition coefficient between the pollutant and water (from 47.7 to 80.2, measured at 25 °C, after 14 months). Rn diffusion is also measured in different fluids (0.092 cm2 s-1, 1.14 × 10-5 cm2 s-1, and 2.53 × 10-6 cm2 s-1 at 25 °C for air, water and LNAPL, respectively) directly. All parameters and equations utilized during this study are introduced, discussing their influence on Radon deficit technique from a theoretical point of view. Experimental findings are used to mitigate the effect of LNAPL ageing and of phreatic oscillations on determination of LNAPL saturation index (S.I.LNAPL). Finally, S.I.LNAPL dataset is discussed and elaborated to show the pollutant attenuation across subsurface over time, induced by natural processes primarily. The proposed predictive model for on-site natural attenuation suggests a half-removal time of one year and six months. The significance of such models lies in their capability to assess site-specific reactions to pollutants, thereby enhancing the effectiveness of remediation efforts over time. These experimental findings may offer a novel approach to application of Rn deficit technique and to environmental remediation of persistent organic compounds.

Data set of production of castor oil and characterization of cotton and castor mixed seed oil additives with diesel fuel.

An important energy source for industry and transportation is diesel fuel. Nonetheless, the use of diesel fuel has been connected to a number of environmental problems, such as climate change and air pollution. The purpose of this data set research is to extract oil from castor seeds and cottonseeds using a mechanical press method to use as lubricant. The oil is refined to remove impurities and improve its quality once it is extracted. The next step was determining the fatty acid content of castor oil, cottonseed oil, and cottonseed oil (50%) mixed with castor seed oil (50%) using gas chromatography (Agilent 7890B) with a mass spectroscopy detector (Agilent 5977A MSD, USA) and the European standard (EN 14103:2011). There were thirteen (13) significant methyl esters of fatty acids found. Furthermore, to make sure they met the specifications needed for dependable engine operation, the reference diesel and the diesel fuel with 0.25%, 0.50%, 0.75%, and 1% bio additives (mixed cottonseed oil, 50%; and caster seed oil, 50%) were characterized. It was subsequently determined that the physicochemical properties, including density, kinematic viscosity, calorific value, and total sulfur, complied with stated ASTM requirements. The results of the investigation showed that the fatty acid profile of combined cotton and caster has the advantage of both oils' quality, with all of its physicochemical properties falling within the ASTM recommendations for diesel fuel. In order to improve lubricity in diesel engines, 50% of caster seed oil and 50% of mixed cottonseed oil were used as bio-additives.

Assessment of diesel fuel quality.

Diesel is an essential energy source in the transportation and industrial sectors worldwide; hence, the quality of this commodity is crucial. This study compares various fuel samples to understand the quality of the fuels in terms of sulphur content, density, surface tension, viscosity, and calorific value. The properties of diesel fuel samples from eight (8) Filling Stations (Marketing Companies (MC)) were examined and compared with GSA 141:2022 and ISO 8217:2017 standards. Fuel from two companies, MC-A and MC-G had slightly lower densities than the standard, indicative of a possible contamination with lower-density fuels such as kerosene. The surface tension of all samples, except one was within the standard range. The only sample with the lower than the standard value also displayed high sulphur content. Although all the fuel samples met the minimum requirement for calorific value, the viscosities of the fuels from three companies were slightly higher than the specified standard value which can potentially result in higher emissions. In the case of sulphur content, fuel samples from only three companies were in compliance with the maximum 50 ppm standard. This means 62.5 % of the diesel fuel within the study area at the time contained more than the acceptable amount of sulphur. The findings in this research highlight the need to re-examine the quality of fuels along the distribution chain.

The content and composition of organic compounds in the bottom sediments of the Norilsk-Pyasina water system one year after the accidental spill of diesel fuel.

One year after the emergency diesel fuel spill in Norilsk, hydrocarbon concentrations in bottom sediments of the Norilsk-Pyasina water system decreased. However the average concentrations of hydrocarbons in surface sediments decreased in the same sequence (µg/g) as in 2020: the mouth of the Ambarnaya R. (835, σ = 1788) > Bezymyanny Cr.-the Daldykan R.-the Ambarnaya R. (306, σ = 273) > the Pyasina R. (23, σ = 20) > the Pyasino Lake (12, σ = 8). Concentrations decreased due to degradation of low molecular weight hydrocarbons. The content of polycyclic aromatic hydrocarbons in 2021 also changed in a smaller range (0-1027 ng/g) than in 2020 (0-3865 ng/g). Petroleum origin of polycyclic aromatic hydrocarbons in the sediments of the Ambarnaya R. (including the mouth), Bezymyanny Cr. and the Daldykan R. is confirmed by the dominance of alkylated naphthalene homologues in their composition. Hydrocarbons accumulation in some layers of the sedimentary column is caused not only by the spill of diesel fuel, but also by the organic matter from the surrounding swamps, from wetlands and floodplain lakes, as well as by the burial of the surface layer by the 2021 flood.

The Role of Catalyst Promotive Additives and Temperature in the Hydroisodewaxing Process.

One of the valuable fractions of paraffinic oils is the diesel fraction, which can be used as a commercial fuel. However, the high content of alkanes of normal structure (~10-40%) in the diesel fraction leads to a deterioration in the performance characteristics of the fuel and, as a result, the inability to use the diesel fraction without additional processing in the cold season at lower temperatures, which is critical for many regions with cold winters. The process of catalytic dewaxing is one of the most promising ways to improve the low-temperature characteristics of diesel fractions. This work is devoted to studying the activity of promoted Ni, Mo, and Ni-Mo catalysts based on mesoporous aluminosilicate and pre-activated bentonite in dewaxing diesel fractions. The effect of the nature and content of promoting additives on the activity of bifunctional catalysts in the process of hydroisodewaxing of diesel fraction in a flow-type reactor in the temperature range of 260-340 °C, pressure of 2 MPa and feed space velocity of 1 h-1 was studied. It is shown that the synthesized bifunctional catalysts based on mesoporous aluminosilicate and pre-activated bentonite from the Tagan field (Ni/MAS-H-bentonite, Mo/MAS-H-bentonite, and Ni-Mo/MAS-H-bentonite) have the necessary balance of Lewis and Bronsted acid centers strengths. It allows them to selectively conduct the hydroisodewaxing process. It has been established that the use of the synthesized 5% Ni-1% Mo/MAS-H-bentonite bifunctional catalyst in the diesel fractions hydroisodewaxing process under optimal process conditions makes it possible to obtain diesel fuel with low-temperature characteristics that meet the requirements for cold climate fuels: cold filter plugging point (CFPP)-minus 33 °C, flash point in a closed cup-39 °C and pour point-minus 36 °C.

A sustainable management of polycyclic aromatic hydrocarbons to synthesize microporous organic polymers for adsorptive desulphurization of fuels.

A sustainable management of carcinogenic polycyclic aromatic hydrocarbons (PAHs) to synthesize a series of high surface area (SABET of 563-1553 m2 g-1) microporous polymeric adsorbents is reported. The products with high yield (>90%) were obtained within only 30 min at a low temperature of 50 °C using a microwave-assisted approach with 400 W microwave power followed by 30 min of ageing by raising the temperature to 80 °C. The synthesized adsorbents are used for removing another category of carcinogenic pollutants i.e., polycyclic aromatic sulphur heterocycles (PASHs) from model and real fuels. Adsorptive desulphurization experiment in batch mode could reduce the sulphur from high concentrated model (100 ppm) and real (102 ppm) fuels to 8 ppm and 45 ppm respectively. Similarly, desulphurization of model and real fuels with ultralow sulphur concentrations of 10 and 9 ppm, respectively, reduced the final concentration of sulphur to 0.2 and 3 ppm, respectively. Adsorption isotherms, kinetics, and thermodynamic studies have been conducted using batch mode experiments. Adsorptive desulphurization using fixed bed column studies show the breakthrough capacities of 18.6 and 8.2 mgS g-1, for the same high concentrated model and real fuels, respectively. The breakthrough capacities of 1.1 and 0.6 mgS g-1 are estimated for the ultralow sulphur model and real fuels, respectively. The adsorption mechanism, based on the spectroscopic analysis (FTIR and XPS) demonstrates the role of π-π interactions between the adsorbate and adsorbent. The adsorptive desulphurization studies of model and real fuels from batch to fixed bed column mode would offer an in-depth understanding to demonstrate the lab-scale findings for industrial applications. Thus, the present sustainable strategy could manage two classes of carcinogenic petrochemical pollutants, PAHs and PASHs, simultaneously.

The combined effect of EGR and hydrogen addition on a Syzygium cumini (jamun) liquid biofuel engine.

Rapid depletion of fossil fuels required the development of alternate and sustainable fuel sources that could replace conventional fuel while having no negative environmental impact. Combining hydrogen induction with biodiesel ensures strict emission standards and lowers energy consumption compared to conventional fuels. In this study, the performance, emissions, and combustion of a CI engine for Syzygium cumini (B20) were assessed and compared to diesel fuel while using a fixed amount of hydrogen flow rate (6L/m). Throughout the experiment, an exhaust gas recirculation (EGR) technology of 10% and 20% and a constant engine speed of 1500 rpm at varying engine load circumstances were used. When hydrogen is added to B20, it decrease the emissions of carbon monoxide (CO), unburned hydrocarbons (UHC), brake thermal efficiency (BTE), and brake specific energy consumption (BSEC). At maximum load, the use of the EGR system decreased the exhaust gas temperature (EGT) by 13.4% and nitrogen oxide (NOX) emission by 25%, but it had a negative impact on BTE, BSEC, as well as other emission parameters including CO and UHC. Therefore, using hydrogen in dual fuel mode in a CI engine enhances performance and lowers exhaust emissions, while using the EGR approach reduces NOX emissions.

Synthesis of Polyvinyl Alcohol/Coal Fly Ash Hybrid Nano-Fiber Membranes for Adsorption of Heavy Metals in Diesel Fuel.

Some studies have shown that the heavy metal emissions (HMEs) emitted from diesel engines can seriously threaten human health. HMEs are mainly related to the content of heavy metal ions in diesel fuel. Therefore, in order to reduce HMEs from diesel engines, a nano-fiber membrane filtration technology for diesel fuel was investigated. Herein, coal fly ash (CFA) from coal-fired power plants combined with polyvinyl alcohol (PVA) was successfully fabricated into nano-fibrous membranes using green electrospinning technology. In order to evaluate the adsorption properties, various hybrid membranes with different mixing ratios (PVA/CFA = 10/0, 10/1, 10/3, 10/5, and 10/7 by weight) were fabricated. The results show that eight metal ions with different concentrations are found in the diesel fuel, including Pb, Cu, Zn, Al, Fe, Cr, Ba, and Ni. All PVA/FA membranes have different adsorption capacities for metal ions, following the order: Cu > Fe > Pb > Al > Zn > Cr > Ba > Ni. In addition, the adsorption capacity of CFA3 (PVA/CFA = 10/3) is the largest. The super lipophilicity of the PVA/FA membranes also provide more adsorption sites for the contact of HMs with the membranes. The above research results provide guidance for development of ultra-fine filters in the future.

The relationship between microbial community vitality and ATP bioburden in bottom waters under fuel microcosms.

Adenylate energy charge (AEC) - computed from the ATP, ADP and AMP concentrations in a specimen - reflect the net physiological state of the microbial population in that specimen. Previous research has demonstrated that healthy microbial populations maintain AEC≥0.8. As populations are subjected to stresses, or - in closed systems - deplete the available nutrients, respond to the accumulation of toxic metabolites, or both, AEC decreases (often to <0.5). Aqueous-phase samples from a set of fuel-water microcosms were tested for cellular ATP (cATP) and AEC. This paper reports on the precision of the AEC test method and the relationship between cellular AEC and cATP bioburdens in the aqueous phase of fuel over aqueous-phase microcosms.

Bio-diesel Fuel Material Supply in Vietnam and Its Current and Future Potentiality with a Focus on Rubber Seed Oil.

Diesel fuel usage in Vietnam is increasing rapidly, but most of it is imported from overseas. In this study, we investigated the possibility of popularizing bio-diesel fuel (BDF) made from Vietnamese origin resources as a sustainable energy solution. The world's energy cost fluctuates significantly depending on economic or political movements, especially after the Russian invasion of Ukraine began in 2022. This caused energy prices soar, attacking the global economy in a short period and requiring a wide range of energy supply sources. We aim to promote commercial BDF production in Vietnam for future energy security and contribution to the Vietnamese economy. Eight necessary factors were investigated to choose suitable material for BDF production. The factors are as follows: 1) material with Vietnamese origin, 2) sufficient and continuous supply volume, 3) sufficient quality to run diesel engines, including common-rail diesel engines, 4) inedibility, 5) low enough freezing point, 6) ease of collection, 7) affordability, and 8) availability of valuable elements in the material. If a suitable material candidate is not stable, it may be changed over time. In this study, the focus material was rubber seed oil. Because rubber production in Vietnam is quite stable with over 900,000 ha plantation area, and there is a potentiality to collect seeds and produce about 50,000 tons of BDF annually. In addition, the quality of rubber seeds based BDF is very high, such as low enough freezing point, etc. However, most of those rubber seeds are currently not collected and used.

Recent Advances in Structured Catalytic Materials Development for Conversion of Liquid Hydrocarbons into Synthesis Gas for Fuel Cell Power Generators.

The paper considers the current state of research and development of composite structured catalysts for the oxidative conversion of liquid hydrocarbons into synthesis gas for fuel cell feeding and gives more detailed information about recent advances in the Boreskov Institute of Catalysis. The main factors affecting the progress of the target reaction and side reactions leading to catalyst deactivation are discussed. The properties of the Rh/Ce0.75Zr0.25O2/Al2O3/FeCrAl composite multifunctional catalyst for the conversion of diesel fuel into synthesis gas are described. The results of the catalyst testing and mathematical modeling of the process of diesel fuel steam-air conversion into synthesis gas are reported.

Assessing risks from fuel contamination in Antarctica: Dynamics of diesel ageing in soil and toxicity to an endemic nematode.

Fuel spills are a major source of contamination in terrestrial environments in Antarctica. Little is known of the effects of hydrocarbon contaminants in fuels on Antarctic terrestrial biota, and how these change as fuel ages within soil. In this study we investigate the sensitivity of juveniles of the endemic Antarctic nematode Plectus murrayi to diesel-spiked soil. Toxicity tests were conducted on soil elutriates, and changes in concentrations of hydrocarbons, polar compounds and PAHs were assessed as the spiked soil was artificially aged at 3 °C over a 45-week period, representing multiple summer seasons of fuel degradation. Nematodes were most sensitive to elutriates made from freshly spiked soils (LC50 419 µg/L TPH and 156 µg/L TPH-SG), with a subsequent decline in toxicity observed in the first 6 weeks of laboratory ageing (LC50 2945 µg/L TPH and 694 µg/L TPH-SG). Effects were still evident up to 45 weeks (lowest observed effect concentration 2123 µg/L TPH) despite hydrocarbons being depleted from soils with ageing (84 % loss) and elutriates becoming dominated by polar metabolites (95 % polar). Nematode sensitivity throughout the ageing period showed evidence of a relationship between LC50 and the proportions of the lighter carbon range fraction of TPH in elutriates, the F2 fraction (C10-14). This study is the first to estimate the sensitivity of Antarctic terrestrial fauna to diesel and provides novel data on the dynamics of fuel chemistry under Antarctic conditions and how this influences toxicity. Findings contribute to predicting ecological risk at existing diesel fuel spill sites in Antarctica, to the derivation of site-specific remediation targets, and to environmental guidelines to assess ecosystem health.

The light absorbing and molecule characteristic of PM2.5 brown carbon observed in urban Shanghai.

Both brown carbon (BrC) and the non-absorbing components coated on black carbon (BC) aerosols can enhance the light absorption of BC aerosols. BrC is a complicated mixture of organic compounds and not well characterized, which hinders exploring the links between BrC and optical properties. We conducted an in-depth field study on optical properties of ambient aerosols at a monitoring site in Shanghai, China via real-time monitoring and offline analysis. Results showed that BrC caused light absorption coefficients were 3.3 ± 3.3 Mm-1, 2.2 ± 5.0 Mm-1, 1.2 ± 1.2 Mm-1 at λ = 370, 470 and 520 nm, respectively, accounting for 11%, 10%, 6% of the total aerosol absorption for the corresponding wavelengths. A larger proportion of long-chain aliphatic organosulfates (OSs, CnH2n+2O4S, (CH2)nO5S, (CH2)nO6S) with double bond equivalent (DBE) values of 0 or 1 accounted for 5-20% of the light absorption (λ = 365 nm) for soluble brown carbon (BrC), which were dominating for the days with less N-containing aromatic compounds appearing. Furthermore, the structure of CnH2n+2O4S, (CH2)nO5S, (CH2)nO6S were explored using target MS/MS of HPLC-Q-ToF-MS: (CH2)nO5S series, the most abundant family of OSs, were constructed by functionalizing a saturated hydrocarbon with one sulfate and one carbonyl group. CnH2n+2O4S series were oxidized with only one sulfate group in the aliphatic chain R. (CH2)nO6S series were proposed as aliphatic OSs with one ester group. We speculated aliphatic OSs were formed via acid catalyzed perhydrolysis of hydroperoxides derived from long-chain alkanes releasing from diesel fueled vehicles, followed by the reaction with sulfate anion radicals. Therefore, relevant technologies should be further explored to reduce the impacts from vehicle emissions.

A review and evaluation of nonroad diesel mobile machinery emission control in China.

China's emission control for nonroad diesel mobile machinery (NDMM) must deal with a fast increase in stock as well as regulations that are two decades behind those for on-road vehicles. This study provides the first large-scale review and evaluation of China's NDMM policies, along with emission measurements and an investigation on diesel fuel quality. The sulfur contents of the investigated diesel declined from 430 ppm (median value) in 2011 to 6-8 ppm during the 2017-2018 period. The emission control of NOx and PM greatly improved with the shift from the China II to China IV standards, as demonstrated by engine tests and field NOx measurements. However, the NOx emission factors for non-type-approved engines were approximately twice the limits of the China II standards. Emission compliance based on bench tests was not sufficient to control actual emissions because the field-measured NOx emission factors of all machinery ranged from 24% to 225% greater than the respective emission limits for the engines. These circumstances adversely affected the effectiveness of the regulations and policies for China's emission control of NDMM. Nevertheless, the policies on new and in-use NDMM, as well as diesel fuel quality, prevented NOx and PM emissions amounting to 4.4 Tg and 297.8 Gg during the period 2008-2017, respectively. The emission management strategy contributed to enhancing the international competitiveness of China's NDMM industries by promoting advanced technologies. For effective NDMM emission control in the future, portable testing and noncontact remote supervision should be strengthened; also, the issue of noncompliant diesel should be addressed through rigorous control measures and financial penalties.

Automotive Diesel Fuel Internal Stability Testing with the Use of UV and Temperature as Degradation Factors.

Diesel fuel stability can be considered from many points of view, of which the two considered most important are stability in contact with the environment and internal stability. Fuel stability in touch with the environment is often defined as oxidation stability, of which measurement procedures are well developed. The presented paper shows that fuel's internal stability can also be important. The internal stability of diesel fuel with the local use of thermal and ultraviolet radiation (UV) as degradation factors and fluorescence signals as a probe is presented in this paper. We show that the internal degradation of fuel with temperature use differs from that with UV and simultaneous both factors use. Our study shows that using temperature as a degradation factor introduces significant fluorescence fading. Moreover, the fluorescence signal restores significantly later than the sample stabilizes at room temperature. The novelty proposed based on examination is hybrid degradation and an examination cycle that enables the simultaneous use of degradation factors and fluorescence reading. For this purpose, a dedicated measurement setup of signal control and processing was constructed and programmed. The measurement procedure of the data series for specific wavelength enables calculation of signal shifts that allow the internal stability classification of diesel fuel samples in less than 30 min with the cost of a single disposable capillary probe and one polymer plug. Premium and regular fuel examination results show that internal fuel stability can be related to polycyclic aromatic hydrocarbons (PAH) concentrations and can be modified with dedicated additives.

Physiological changes and rate of resistance of Acrosiphonia arcta (Dillwyn) Gain upon exposure to diesel fuel.

The changes in the morpho-physiological state of green alga Acrosiphonia arcta upon exposure to diesel fuel (DF) at concentrations of 20; 100; 1,000; 2,000; 3,000 of maximum permissible concentrations (MPC) were studied. The main physiological stress markers, such as enzymes of the antioxidant system (AOS), non-enzymatic antioxidants (carotenoids) and free amino acids (as components of plant metabolome) were measured. In general, all concentrations of the petroleum product used changed the activity of the antioxidant system, changed the intensity of physiological processes (photosynthesis, free amino acid synthesis) and also affected the structure of microbiomes inhabiting the surface of algae. It was shown that the concentration of DF within 1 mg/l (20 MPC) was not lethal as plants were able to maintain physiological activity and the observed changes were reversible. Although DF exposure caused decreases in superoxide dismutase (SOD) activity, proline concentration and photosynthetic rate, increases in catalase activity and pigment concentration were observed. After the effects of stress disappeared, most physiological parameters were restored, except for carotenoid content. Higher DF concentrations (100 MPC and higher) caused injury to cell structures and damage to the pigment apparatus. The restoration of functions after the termination of exposure to stress was not achieved. Epiphytic bacterial communities actively responded both to the introduction of a toxicant and to the changing physiological parameters of algae by the change in the numbers of cultured heterotrophic bacteria. The results of this study showed that the concentration of petroleum products in the water decreased to values not exceeding MPC in the presence of algae in the environment.

A powerful tool for near-infrared spectroscopy: Synergy adaptive moving window algorithm based on the immune support vector machine.

Traditional trial-and-error methods are time-consuming and inefficient, especially very unfriendly to inexperienced analysts, and are sometimes still used to select preprocessing methods or wavelength variables in near-infrared spectroscopy (NIR). To deal with this problem, a new optimization algorithm called synergy adaptive moving window algorithm based on the immune support vector machine (SA-MW-ISVM) is proposed in this paper. Following the principle of SA-MW-ISVM, the original problem of calibration model optimization is transformed into a mathematical optimization problem that can be processed by the proposed immune support vector machine regression algorithm. The main objective of this optimization problem is the calibration model performance; meanwhile, the constraint conditions include a reasonable spectral data value, spectral data preprocessing method, and calibration model parameters. A unique antibody structure and specific coding and decoding method are used to achieve collaborative optimization in NIR spectroscopy. The tests on four actual near-infrared datasets, including a group of gasoline and three groups of diesel fuels, have shown that the proposed SA-MW-ISVM algorithm can significantly improve the calibration performance and thus achieve accurate prediction results. In the case of gasoline, the SA-MW-ISVM algorithm can decrease the prediction error by 44.09% compared with the common benchmark partial least square (PLS). Meanwhile, in the case of diesel fuels, the SA-MW-ISVM algorithm can decrease the prediction error of cetane number, freezing temperature, and viscosity by 9.99%, 28.69%, and 43.85%, respectively, compared with the PLS. The powerful prediction performance of the SA-MW-ISVM algorithm makes it an ideal tool for modeling near-infrared spectral data or other related application fields.

Compound specific stable isotope analysis of aromatics in diesel fuel to identify potential cocktailing.

Estimates suggest billions of dollars are lost annually in the US due to fuel tax fraud. One method of fuel fraud is called "cocktailing" and involves blending products that are non-taxed, lower value, taxed at a lower rate, or unwanted/less-refined petroleum to diesel fuels. The goal of this study was to investigate compound specific isotope analysis (CSIA) using isotope ratio mass spectrometry (IRMS) for small aromatics contained in diesel fuel to determine whether this approach could be used to identify cocktailing and potentially fingerprint possible sources. However, the high chemical complexity of diesel fuels complicates CSIA owing to the need to fully separate individual compounds for effective isotope analysis. Therefore, different methods were investigated to selectively isolate aromatics for CSIA and evaluate these methods for isotopic fractionation. Analyses indicate that there is enough variability in isotopic ratios (δ2H and δ13C) between toluene samples obtained from different sources to use CSIA to differentiate/identify the origin of potential fuel adulterants. Three isolation methods were identified that provided sufficiently pure aromatic fractions for CSIA: selective solvent extraction, ionic liquid coated solid phase microextraction (SPME), and a combination of the two. However, due to the labor-intensive nature of selective solvent extraction, ionic liquid coated SPME represents the best method to quickly isolate aromatics from diesel fuel, without sacrificing selectivity or sensitivity. All methods tested can result in isotopic fractionation, but this can be compensated for by applying a correction factor. Furthermore, the chemical composition of a sample appeared to be important in the degree to which fractionation occurred during isolation. While the tested approaches for aromatic extraction from diesel showed promise, additional studies are required to refine and validate the methods prior to routine use in fuel cocktailing investigations.

Adsorption of dibenzothiophene in model diesel fuel by amarula waste biomass as a low-cost adsorbent.

The effectiveness of the adsorption process is determined by the type of adsorbent used, but some adsorbents require a significant amount of processing to achieve the desired quality, and this has become a drawback economically and environmentally. This study focused on mitigating the issue of waste management and land pollution by using amarula waste biomass, which is a low-cost adsorbent that is obtained from the industrial waste by-product. The amarula shell (AmSh) waste was found to have a higher adsorption efficiency of 30 ± 3% compared to the amarula seed (AmSe) waste and the amarula fruit (AmWa) waste, which had 19 ± 5% and 9.5 ± 0.7% efficiency, respectively. It was found that the amarula waste biomass performed better at lower adsorption temperatures. The adsorption capacity was found to decrease with an increase in the quantity of the biomass. Kinetic models were applied to the experimental data. Thermodynamic parameters were also studied to determine the spontaneity of the adsorption process. The characteristics of both the fresh and used amarula waste biomass was analyzed by using Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy with Energy Dispersive Spectroscopy (FESEM-EDS), Brunauer-Emmett-Teller (BET) and Thermogravimetric Analysis (TGA). It was then concluded that cellulose and hemicellulose structures in amarula waste biomass played a major role in reducing the content of dibenzothiophene in model diesel fuel.