Search Results (186)

The growing use of reclaimed asphalt pavement (RAP) in hot mix asphalt (HMA) is an important practice to achieve more sustainable pavements, as it reduces the consumption and environmental impact of virgin materials. However, aging induces binder stiffening that requires effective rejuvenation to restore overall performance. This study provides a comprehensive comparative analysis of ten chemically different waste oils—waste engine oil (WEO), waste cooking oil (WCO), yellow grease (YG), waste hydraulic oil (WHO) waste electric transformer oil (WETO), slop oil (SO), sludge-derived bio-oil (SDBO), tire pyrolysis oil (TPO), plastic pyrolysis oil (PPO), and algal residue oil (ARO)—as recycled HMA mixture rejuvenators, linking oil composition to binder regeneration and mixture performance. Binder properties were determined by rotational viscosity (RV), dynamic shear rheometer (DSR) and bending beam rheometer (BBR), whereas mixture performance was assessed in terms of Superpave mechanical properties, Hamburg wheel-tracking test (HWTT) for rutting resistance and mixture BBR for low-temperature cracking resistance. Performance grade (PG) evaluations showed that WETO and WEO restored the 50% and 75% RAP binders, respectively, to a grade close to PG 64-16 at the lowest dosages. The Superpave volumetric properties of all restored mixtures were similar to those of the control mixture, denoting corrected mixture balance and compaction level. HWTT results indicated that WETO-recycled mixtures revealed the lowest rut depth at 50% RAP, while WEO-recycled mixtures exhibited the lowest rut depth at 75% RAP after 20000 passes. Additional evidence supporting these results can be found in BBR mixture data, which demonstrated that WETO at 50% RAP and WEO/WETO at 75% RAP showed the most reduction in creep stiffness and improvement in creep rate. The correlation, regression, and PI analyses were in good agreement with the experimental results, where WETO and WEO exhibited the best overall performance at 50% and 75% RAP, respectively. In summary, these results indicate that the performance of waste oil rejuvenator in recycled HMA mixtures is highly dependent on RAP content and point to WETO and WEO as feasible, environmentally friendly options for high-RAP recycled HMA. Full article

This study identified δ¹⁵N stable isotope ratios as a robust tracer for fishmeal inclusion in aquaculture feeds. δ¹⁵N and δ¹³C values from fish muscle samples derived from feeding trials with seven species (n = 3–5 fish per diet group) were evaluated (+/−0.1‰ for both δ¹⁵N and δ¹³C; ~1% relative to % N and % C) to verify whether the presence or absence of fishmeal (FM) in feeds could be detected. C and N isotopic data were also analyzed for feed in two of the trials. δ¹³C signatures did not differ consistently across diet groups for each species examined, with mean δ¹³C values for all species investigated being −20.2‰ ± 1.3. In contrast, a strong δ¹⁵N distinction was discerned between FM- and non-FM-fed fish for both muscle and feed samples, with FM-fed groups presenting higher values (p < 0.01) than non-FM-fed groups (range 0.8 to 9.5‰). Dietary ingredients other than FM (e.g., fish oil and algal oil) did not impact the δ¹⁵N isotopic fingerprint, although the addition of poultry byproduct meal to plant-based salmon diets caused an average 0.3‰ difference in δ¹⁵N values. The findings are not absolute as CN isotopes can be used to detect large but not small differences in feed components. Additional research on threshold levels, ingredient sourcing, and species differences is warranted to refine the method to enhance industry transparency and seafood consumer confidence. Full article

Seaweed-derived biostimulants are a promising strategy for improving crop performance in sustainable agriculture. In this context, this study evaluated the effects of foliar application of Kappaphycus alvarezii extracts, obtained from two Brazilian regions (São Paulo: Kal-SP and Santa Catarina: Kal-SC), at different concentrations (1%, 3%, 5%, and 7%) on the growth, biochemical profile, essential oil yield, and rhizosphere microbiome of Ocimum basilicum under field conditions. Morphological analysis indicated that the 5% and 7% concentrations increased plant height, biomass, root development, and inflorescence production, with biomass gains of up to 51% and essential oil production increases of up to 142% compared to the control. Biochemical responses varied by extract origin, with Kal-SC promoting greater increases in photosynthetic pigments, antioxidant activity, and carbon-related metabolites, whereas Kal-SP induced only minor metabolic changes. The algal biostimulant modulated essential oil yield and composition, promoting treatment-dependent shifts in major terpenoid compounds. Microbiome analysis showed no significant changes in alpha diversity, but significant shifts in beta diversity and functional groups, such as Bacillaceae, indicating rhizosphere reorganization. Overall, the effectiveness of K. alvarezii-based biostimulants depends on concentration and biomass source, highlighting their potential as sustainable agricultural bioproducts and the importance of standardized extraction for consistent outcomes. Full article

Background: Oil spills have dramatically increased, causing significant damage and pollution to marine ecosystems. The entry of petroleum hydrocarbons into the ocean may lead to the occurrence of harmful algal blooms (HABs). The amino acid changes in harmful algae after oil spills remain unclear. Methods: In order to study the effect of oil spills on the amino acid mechanism of typical causative species, the composition and relative abundance of amino acids in Heterosigma akashiwo were investigated under different water accommodated fractions (WAFs) of 180# fuel oil. Results: Random forest prediction of polycyclic aromatic hydrocarbon toxicity to microalgae identified pyrene, benzo[k]fluoranthene, and fluoranthene as significant contributors. A total of 16 species of amino acids were detected in Heterosigma akashiwo, among which alanine, proline, aspartic acid, cysteine, lysine, and histidine were the predominant ones. As the concentration of the WAF increased, alanine abundance decreased significantly, indicating that the WAF disrupted the metabolic balance of alanine, with the degree of interference being positively correlated with exposure concentration. With the increase in culture time, the abundance of cysteine increased at 1%, 3%, and 5% WAFs, whereas the cysteine increased and then decreased at 7% and 10% WAFs. The abundance of aspartic acid and lysine showed no obvious pattern with culture time under WAF stress. Significant increases in the abundance of proline and histidine were observed in the WAF treatments. Conclusions: This study investigated the impact of oil spill pressure on the amino acid content of harmful algae, providing a scientific basis for understanding the potential impact of oil spills on the occurrence of HABs. Full article

Alzheimer’s disease (AD) is a common age-related neurodegenerative disorder with extremely low drug development success rates, making nutritional intervention a promising strategy. Cerebral energy metabolism dysfunction is a core pathological feature of AD. Odd-chain fatty acids (OCFAs) can generate propionyl-CoA via β-oxidation to replenish the impaired tricarboxylic acid (TCA) cycle. This study characterized the lipid composition of OCFAs-enriched algal oil by UPC²-Q-TOF-MS, evaluated its neuroprotective effects on Caenorhabditis elegans (C. elegans) models with AD, Parkinson’s disease (PD), and Huntington’s disease (HD), and explored the metabolic mechanism of its key component pentadecanoic acid (C15:0) using untargeted metabolomics. Results showed that triglycerides (TAGs) represented the predominant lipid class, accounting for 97.3% of the total lipid content in the algal oil. Among all the identified TAG molecular species, TAGs containing C15:0/C17:0 accounted for more than 90%. OCFAs-enriched algal oil exhibited disease-selective neuroprotection. It significantly improved locomotor function in AD nematodes, moderately ameliorated PD-related deficits, whereas showed no efficacy in HD nematodes. Metabolomics revealed that C15:0 produced propionyl-CoA to rescue TCA cycle dysfunction and energy deficits, upregulated membrane phospholipids to repair membrane integrity, and reduced abnormal metabolites to restore metabolic homeostasis. KEGG analysis confirmed that C15:0 globally regulated core metabolic pathways including amino acid, cofactor, nucleotide, and carbon metabolism. OCFAs-enriched algal oil exerted selective anti-AD effects by repairing energy metabolism, remodeling membrane phospholipids, and restoring metabolic homeostasis, providing a novel nutritional candidate for AD intervention. Full article

This study aims to resolve the genetic origin of crude oils accumulated in the D Subsag and to assess the potential cross-sag hydrocarbon migration from the adjacent Haizhong Sag. The D Subsag, situated on the western margin of the Weixinan Sag in the Beibuwan Basin, is a significant petroleum province with proven reserves exceeding 10 million tons in the Weizhou Oilfield. However, the origin of these oils and the contribution from the Haizhong Sag source kitchen remain poorly constrained, hindering accurate resource assessment. To address this, we integrated organic geochemical analyses of nine source rock samples from the Haizhong Sag (Well H1) and eight crude oil samples from the D Subsag reservoirs. Bulk geochemical and biomarker signatures reveal distinct organic facies within the Paleogene succession. Type III kerogen, characterized by terrigenous higher plant input (high C₁₉₊₂₀ tricyclic terpanes and C₂₉ regular steranes, Pr/Ph > 2.5) deposited under oxic freshwater conditions, dominates source rocks from the third member of the Weizhou Formation (EWZ₃). In contrast, the second and third members of the Liushagang Formation (Els₂ and Els₃) contain mixed Type II₂-III kerogen with elevated contributions from lacustrine algae and aquatic organisms (elevated C₂₃ tricyclic terpanes and C₂₇ regular steranes). Thermal maturity assessment (with T_max of 436 to 448 °C) confirms that all source intervals are within the oil generation window. Two genetically distinct oil groups are identified in the EWZ₃ reservoirs. Group 1 oils (Well W4) exhibit a lacustrine algal signature (C₂₇/C₂₉ sterane > 1.15; low Pr/Ph 1.54–1.68) that does not correlate with the analyzed Haizhong Sag source rocks, suggesting localized, intra-sag source contributions. In contrast, Group 2 oils (Wells W6 and W6-2) display strong geochemical affinities with the Els₂ and Els₃ source rocks, evidenced by mixed terrestrial/aquatic signatures (∑nC₂₁⁻/∑nC₂₂⁺ < 1.0). These findings confirm that fault systems acted as conduits for long-distance migration from the Haizhong Sag, while also highlighting a previously unrecognized contribution from local source intervals. This refined petroleum system model provides critical constraints for delineating remaining hydrocarbon potential and reducing exploration risk in the Beibuwan Basin. Full article

This work focuses on the production of biodiesel from Nannochloropsis sp. microalgae. The study compares the effectiveness of conventional methods, such as Soxhlet extraction and the Bligh and Dyer method with a non-conventional method that uses an ionic liquid as solvent for lipid extraction. The Bligh and Dyer method demonstrated superior efficiency with a lipid yield of 8.19% compared to Soxhlet extraction. Sample parameters were optimized in a maximum lipid yield of 18.29% at a sample volume of 91.9 mL, a duration of 7 min, and a power rate of 0.62 W. We further investigated the use of ionic liquids for lipid extraction from microalgae. We synthesized ionic liquids, and 1-(4 sulphonic acid) butyl-3-Methyl imidazolium hydrogen sulphate and 1-(4 sulphonic acid) butyl pyridinium hydrogen sulphate were characterized using FTIR, NMR and TGA. This method showed lipid extraction efficiency values of 10.7% and 0.402%. Subsequent transesterification of algal oil using 1-(4 sulphonic acid) butyl-3-Methyl imidazolium hydrogen sulphate yielded 19.82% biodiesel. FTIR analysis confirmed the presence of lipids and esters in the biodiesel, and the produced biodiesel met ASTM specifications, indicating its suitability for use as biofuel. Full article

Multiple biomarker datasets and compound-specific sulfur isotopic compositions (δ³⁴S) of dibenzothiophenes (DBTs) were analyzed for crude oil from Well B6 on the Maigaiti Slope, Tarim Basin. The very low concentrations of DBTs (124.9 μg/g oil), diamondoids (92.7 μg/g oil), and thiadiamondoids (0.20 μg/g oil), together with the absence of 25-norhopane, indicate that the B6 oil has not undergone significant secondary alteration, including thermochemical sulfate reduction (TSR), extensive thermal cracking, or biodegradation. No clear evidence of oil mixing was observed either. Aliphatic and aromatic biomarker distributions suggest that the parent source rocks contain type I–II₁ kerogen, with dominant algal and bacterial organic inputs deposited under low-salinity, weakly reducing conditions, broadly comparable to those of the Upper Ordovician Lianglitag Formation source rocks (UOLS). Oil–source correlation using compound-specific δ³⁴S values of DBTs indicates that B6 oil is derived from UOLS (or similar undiscovered source rocks), not from Cambrian source rocks. This is consistent with biomarker evidence. As the first identified Ordovician-derived oil showing relatively light DBT δ³⁴S values (average ~6.41‰), close to those of Ordovician kerogen (average ~5.62‰), and with minimal secondary overprinting, B6 oil has strong potential to serve as a UOLS end-member oil. This will likely open new exploration opportunities for deep hydrocarbon from previously untapped strata in the southwestern Tarim Basin. Full article

Early Jurassic organic-rich shales deposited in fluvio-deltaic settings serve as important hydrocarbon source rocks, particularly in the highly petroliferous basins of the Middle East. The Lower to Middle Jurassic sedimentary succession of the frontier Kohat Basin, Pakistan, comprises thick sequences of shale, coaly, and carbonate rocks deposited along the northwestern margin of the Indian Plate, adjacent to the eastern Tethys Ocean, and records a crucial paleoenvironmental transition from fluvio-deltaic to shallow marine settings. Despite the economic significance of the Jurassic succession as a potential hydrocarbon source in the Kohat Basin and surrounding regions, their organic geochemical characteristics and role in the regional petroleum system remain poorly understood. This study presents an integrated organic geochemical and carbon isotopic evaluation of Jurassic source rocks using well cuttings and outcrop samples, focusing on organic matter (OM) input, depositional environment, hydrocarbon generation potential, thermal maturity, and oil–source rock correlation. Source rock characterization indicates that the Shinawari and Datta formations possess fair-to-excellent generative potential, whereas the Samana Suk Formation exhibits poor-to-marginal potential. Biomarker and isotopic evidence indicate that the Shinawari Formation is dominated by algal-derived OM, characterized by higher aquatic OM deposited under relatively reducing marine to marginal marine conditions. The relatively more depleted bulk and individual fraction δ¹³C values for the Shinwari Formation are also consistent with a stronger marine influence. In contrast, the Datta Formation shows mixed OM inputs with a greater terrestrial influence and suggests deposition in more oxic lacustrine to marginal marine settings. The thermal maturity-related parameters for both formations indicate early to peak oil window thermal maturity. The geochemical correlation of Jurassic source rock extracts with Kohat crude oils, based on published data, suggests that the Kohat oils differ significantly, exhibiting stronger terrestrial organic matter signatures, more oxic depositional conditions, and slightly higher maturity, thereby indicating no direct genetic linkage with the Jurassic source rocks. Overall, the Jurassic formations are unlikely to represent the primary source rocks for Kohat oils but may have contributed locally to a multi-source petroleum system. This underscores the need for integrated geochemical investigations combining biomarker and isotopic analyses, supported by broader source rock and crude oil datasets, to resolve uncertainties in oil–source correlations, source contributions, and hydrocarbon migration pathways, thereby better constraining the petroleum system framework. Full article

Yogurt represents a traditional fermented dairy product characteristic of the Balkan Peninsula and is widely consumed in the Republic of Bulgaria. The aim of the present study was to develop omega-3-enriched yogurt. Four yogurts were produced: one control sample and three experimental variants enriched with chia oil (0.63%), cod liver oil (1.55%), and algal oil (1.10%). Coriander essential oil (0.038%) was added to each oil formulation. The products were monitored on days 1 and 14 of storage. The oils were pre-encapsulated in alginate beads to limit oxidative processes and preserve sensory properties. Yogurt samples were evaluated for oxidative stability, fatty acid composition, microbiological parameters, physicochemical properties, textural and sensory characteristics. Titratable acidity, pH, water-holding capacity, antioxidant activity, and microbiological parameters were not significantly affected by the incorporation of encapsulated oils. In contrast, significant differences were observed in texture and sensory attributes among the enriched variants. The chia oil sample exhibited the highest oxidative stability, followed by the algal oil yogurt, whereas the lowest stability was observed in the cod liver oil variant; however, all products remained within acceptable oxidation limits up to day 14. Approximately 350 g, 260 g, and 120 g of yogurt enriched with chia, cod liver, and algal oil, respectively, were required to meet the recommended daily omega-3 intake. The developed products demonstrated potential as dairy foods enriched with omega-3 fatty acids, with improved nutritional value. Full article

A climatic transition from arid to humid conditions occurred during the deposition of the Permian Pingdiquan Formation in the Shishugou Sag, Junggar Basin, Northwest China. This study reconstructs the paleoenvironmental evolution and organic matter (OM) enrichment mechanisms recorded in six stratigraphic intervals, with emphasis on the two oil shale units formed during the transgressive system tracts (TST1 and TST2). Geochemical, elemental, and biomarker data reveal that climate, salinity, and redox conditions fluctuated significantly and jointly governed OM enrichment, with paleoclimate acting as the primary background control by regulating lake hydrology, salinity, and preservation. During the early stage (SQ1), an arid climate prevailed, the TST1 oil shale formed during a transient freshening event in a deep stratified lake. Dominant algal productivity and minimal terrigenous input favored excellent preservation, yielding the highest TOC and superior hydrocarbon potential. In contrast, during the humid stage (SQ2), the TST2 oil shale was deposited in a moderately deep, weakly reducing, and slightly saline lake. Although preservation was less efficient, enhanced primary productivity under humid conditions compensated for OM loss, producing abundant but slightly lower quality OM. These results establish two depositional models, an arid freshening model (TST1) and a humid salinization model (TST2). Both transient freshening under arid conditions and salinization during humid periods facilitated the accumulation of organic-rich source rocks through different balances between productivity and preservation. This highlights the complex response of lacustrine source rock development to climatic variability. The occurrence of similar organic-rich source rocks can be anticipated under comparable paleoenvironmental transitions, particularly in saline lakes characterized by frequent fluctuations in water salinity and paleoclimate. Full article

Biodiesel is a sustainable and promising alternative energy source produced from renewable raw materials using various methods. One effective approach is simultaneous esterification and transesterification, which relies on suitable catalysts that can be either homogeneous or heterogeneous. Homogeneous catalysts (acid or base) offer high activity but are corrosive and difficult to recover, necessitating energy-intensive processes such as aqueous quenching and neutralization, which can lead to soap formation and stable emulsions. By comparison, heterogeneous catalytic systems overcome many of these challenges due to their ease of recovery, reusability, and simplified product separation, which collectively enhance economic viability and environmental sustainability. This review highlights recent progress in the application of zeolite-based solid catalysts for biodiesel synthesis, with particular emphasis on their use in converting waste cooking oil and other low-cost feedstocks, including non-edible oils, non-food biomass sources, algal resources, and genetically engineered microorganisms. Key factors such as catalytic activity, selectivity, catalyst loading, and reusability are discussed, highlighting the advantages of zeolites due to their unique crystal structure, high thermal stability, and ease of product recovery. Overall, this review underscores the challenges and opportunities in zeolite-based catalysis to provide a comprehensive understanding of its potential to enhance the efficiency and scalability of biodiesel production. Full article

Finding a sustainable approach to rainbow trout aquaculture is very important. This study aimed to evaluate the effects of an experimental diet (D2) including artisanal fishery discards (whiting fish—Merlangius merlangus; tub gurnard—Chelidonichthys lucerne; horse mackerel—Trachurus trachurus) and feedstuffs from the fish farmer’s farmhouse (wheat and dehulled peas) in comparison to a control diet (D1) on the growth performance and fillet quality of rainbow trout—Oncorhynchus mykiss (initial mean body weight: 48 ± 3 g). In D2, fish oil was substituted with algal oil. The trial was performed in flow-through basins. An economic assessment was performed, considering the most important economic indicators, based on the cost of feed and the cost to obtain fish biomass, comparing D2 to D1. A final reduction in total ammonia nitrogen in D2 water (TAN; 0.28 ± 0.01 mg/L vs. 0.42 ± 0.03 mg/L for D2 and D1, respectively) was observed. No significant differences in growth performance were observed, although there was a slight difference in the Feed Conversion Rate. Use of algal oil as a dietary ingredient ensured high-quality omega-3 fatty acids in the fish fillets, with a significant improvement in the DHA content of D2 fish (1131.0 ± 1.8 mg/100 g) compared to their D1 counterparts (435.0 ± 0.5 mg/100 g). The economic analysis corroborates the benefit of using marine fish by-products as alternative protein sources for rainbow trout aquaculture, as the D2 feed has a lower formulation unitary cost (−15.4%) than the D1 feed, suggesting that in addition to their efficacy in growing fish, marine fish by-products are a valuable protein source from an economic standpoint. Since this experiment was implemented at the farm level, these outcomes suggest the diet can be realistically and sustainably applied in the European rainbow trout farming sector. Full article

The bio-colonization of building materials by green algae is a widespread problem. To prevent this, it is advisable to use natural substances to avoid environmental damage. This study examined the effectiveness of four essential oils (cinnamon, thyme, oregano and hop) and four oil-based substances (trans-cinnamaldehyde, thymol, carvacrol and β-caryophyllene) in preventing bio-colonization. The effectiveness of these chemicals against three algal species (Haematococcus pluvialis, Chlorella mirabilis and Stichococcus sp.) and a mixture of these species was tested. The tests were carried out under laboratory conditions over a period of 14 days. The concentrations tested were in the range of 3–200 mg/L. Growth densities were assessed spectrometrically as absorbencies at a wavelength of 750 nm. Caryophyllene, thymol, oregano oil, and hop oil did not negatively affect the growth of algal biomass. The algicidal effect increased in the following order for the other chemicals: cinnamon oil and trans-cinnamon aldehyde < thyme oil and carvacrol. Their biocidal effect was influenced by their structure, particularly their molecular weight and solubility in fat (log K_ow). H. pluvialis was a less sensitive species than the smaller S. sp and Ch. mirabilis. The artificial biofilm was sensitive to thyme oil and carvacrol, similarly to natural biofilms, as was demonstrated in previously published studies. Full article

Maternal nutrition during pregnancy plays a crucial role in fetal development and metabolic programming. Long-chain omega-3 polyunsaturated fatty acids (LC-PUFA n-3), particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known to influence mitochondrial function and cellular energy metabolism. The present preliminary study aimed to evaluate the effects of maternal omega-3 supplementation on mitochondrial bioenergetics in neonatal piglets. Pregnant sows were supplemented with either fish oil or algal oil rich in LC-PUFA n-3 (long-chain omega-3 polyunsaturated fatty acids) throughout gestation. Liver samples were collected from newborn piglets immediately after birth, and mitochondrial respiratory parameters, oxygen consumption rates, and selected oxidative stress markers were analyzed. The results indicated that maternal omega-3 supplementation was associated with improved mitochondrial respiratory parameters and enhanced oxidative phosphorylation efficiency in neonatal liver tissue. Both fish oil and algal oil supplementation showed similar trends in improving mitochondrial bioenergetic function. Although the study was exploratory and conducted on a limited number of animals, the findings suggest that maternal intake of LC-PUFA n-3 may influence mitochondrial metabolism in offspring. Further studies with larger experimental groups are required to confirm these observations and to better understand the mechanisms underlying these effects. Full article