The refinery of the future.

Fossil fuels-coal, oil and gas-supply most of the world's energy and also form the basis of many products essential for everyday life. Their use is the largest contributor to the carbon dioxide emissions that drive global climate change, prompting joint efforts to find renewable alternatives that might enable a carbon-neutral society by as early as 2050. There are clear paths for renewable electricity to replace fossil-fuel-based energy, but the transport fuels and chemicals produced in oil refineries will still be needed. We can attempt to close the carbon cycle associated with their use by electrifying refinery processes and by changing the raw materials that go into a refinery from fossils fuels to carbon dioxide for making hydrocarbon fuels and to agricultural and municipal waste for making chemicals and polymers. We argue that, with sufficient long-term commitment and support, the science and technology for such a completely fossil-free refinery, delivering the products required after 2050 (less fuels, more chemicals), could be developed. This future refinery will require substantially larger areas and greater mineral resources than is the case at present and critically depends on the capacity to generate large amounts of renewable energy for hydrogen production and carbon dioxide capture.

Simultaneous production of biosurfactant and extracellular unspecific peroxygenases by Moesziomyces aphidis XM01 enables an efficient strategy for crude oil degradation.

Crude oil is a hazardous pollutant that poses significant and lasting harm to human health and ecosystems. In this study, Moesziomyces aphidis XM01, a biosurfactant mannosylerythritol lipids (MELs)-producing yeast, was utilized for crude oil degradation. Unlike most microorganisms relying on cytochrome P450, XM01 employed two extracellular unspecific peroxygenases, MaUPO.1 and MaUPO.2, with preference for polycyclic aromatic hydrocarbons (PAHs) and n-alkanes respectively, thus facilitating efficient crude oil degradation. The MELs produced by XM01 exhibited a significant emulsification activity of 65.9% for crude oil and were consequently supplemented in an "exogenous MELs addition" strategy to boost crude oil degradation, resulting in an optimal degradation ratio of 72.3%. Furthermore, a new and simple "pre-MELs production" strategy was implemented, achieving a maximum degradation ratio of 95.9%. During this process, the synergistic up-regulation of MaUPO.1, MaUPO.1 and the key MELs synthesis genes contributed to the efficient degradation of crude oil. Additionally, the phylogenetic and geographic distribution analysis of MaUPO.1 and MaUPO.1 revealed their wide occurrence among fungi in Basidiomycota and Ascomycota, with high transcription levels across global ocean, highlighting their important role in biodegradation of crude oil. In conclusion, M. aphidis XM01 emerges as a novel yeast for efficient and eco-friendly crude oil degradation.

Research on the evolutionary control of unsafe behavior of construction personnel based on multi-field coupled-homogeneous analysis model.

Unsafe behavior among construction personnel poses significant risks in petroleum engineering construction projects. This study addresses this issue through the application of a multi-field coupled homogeneous analysis model. By conducting case analyses of petroleum engineering construction accidents and utilizing the WSR methodology, the influencing factors of unsafe behaviors among construction personnel are systematically categorized into organizational system factors, equipment management factors, and construction personnel factors. Subsequently, employing Risk coupling theory, the study delves into the analysis of these influencing factors, discussing their coupling mechanisms and classifications, and utilizing the N-K model to elucidate the coupling effect among them. Furthermore, a novel approach integrating coupling analysis and multi-agent modeling is employed to establish an evolutionary model of construction personnel's unsafe behavior. The findings reveal that a two-factor control method, concurrently reinforcing equipment and construction personnel management, significantly mitigates unsafe behavior. This study provides valuable insights into the evolution of unsafe behavior among construction personnel and offers a robust theoretical framework for targeted interventions. Significantly, it bears practical implications for guiding safety management practices within petroleum engineering construction enterprises. By effectively controlling unsafe behaviors and implementing targeted safety interventions, it contributes to fostering sustainable development within the petroleum engineering construction industry.

Production, characterization, and application of Pseudoxanthomonas taiwanensis biosurfactant: a green chemical for microbial enhanced oil recovery (MEOR).

Biosurfactants, as microbial bioproducts, have significant potential in the field of microbial enhanced oil recovery (MEOR). Biosurfactants are microbial bioproducts with the potential to reduce the interfacial tension (IFT) between crude oil and water, thus enhancing oil recovery. This study aims to investigate the production and characterization of biosurfactants and evaluate their effectiveness in increasing oil recovery. Pseudoxanthomonas taiwanensis was cultured on SMSS medium to produce biosurfactants. Crude oil was found to be the most effective carbon source for biosurfactant production. The biosurfactants exhibited comparable activity to sodium dodecyl sulfate (SDS) at a concentration of 400 ppm in reducing IFT. It was characterized as glycolipids, showing stability in emulsions at high temperatures (up to 120 °C), pH levels ranging from 3 to 9, and NaCl concentrations up to 10% (w/v). Response surface methodology revealed the optimized conditions for the most stable biosurfactants (pH 7, temperature of 40 °C, and salinity of 2%), resulting in an EI24 value of 64.45%. Experimental evaluations included sand pack column and core flooding studies, which demonstrated additional oil recovery of 36.04% and 12.92%, respectively. These results indicate the potential application of P. taiwanensis biosurfactants as sustainable and environmentally friendly approaches to enhance oil recovery in MEOR processes.

Structure and composition of microbial communities in the water column from Southern Gulf of Mexico and detection of putative hydrocarbon-degrading microorganisms.

This study assessed the bacterioplankton community and its relationship with environmental variables, including total petroleum hydrocarbon (TPH) concentration, in the Yucatan shelf area of the Southern Gulf of Mexico. Beta diversity analyses based on 16S rRNA sequences indicated variations in the bacterioplankton community structure among sampling sites. PERMANOVA indicated that these variations could be mainly related to changes in depth (5 to 180 m), dissolved oxygen concentration (2.06 to 5.93 mg L-1), and chlorophyll-a concentration (0.184 to 7.65 mg m3). Moreover, SIMPER and one-way ANOVA analyses showed that the shifts in the relative abundances of Synechococcus and Prochlorococcus were related to changes in microbial community composition and chlorophyll-a values. Despite the low TPH content measured in the studied sites (0.01 to 0.86 µL L-1), putative hydrocarbon-degrading bacteria such as Alteromonas, Acinetobacter, Balneola, Erythrobacter, Oleibacter, Roseibacillus, and the MWH-UniP1 aquatic group were detected. The relatively high copy number of the alkB gene detected in the water column by qPCR and the enrichment of hydrocarbon-degrading bacteria obtained during lab crude oil tests exhibited the potential of bacterioplankton communities from the Yucatan shelf to respond to potential hydrocarbon impacts in this important area of the Gulf Mexico.

Characteristics of inclusions in chang 7 member and shale oil accumulation stages in Zhijing-Ansai area, Ordos Basin.

In order to further clarify the shale oil accumulation period of the Chang 7 member of the Mesozoic Triassic Yanchang Formation in the Zhijing-Ansai area of the central Ordos Basin, Using fluid inclusion petrography analysis, microscopic temperature measurement, salinity analysis and fluorescence spectrum analysis methods, combined with the burial history-thermal history recovery in the area, the oil and gas accumulation period of the Chang 7 member of the Yanchang Formation in the Zhijing-Ansai area was comprehensively analyzed. Sixteen shale oil reservoir samples of the Mesozoic Triassic Yanchang Formation in seven typical wells in the study area were selected.The results show that the fluid inclusions in the Chang 7 member of Yanchang Formation can be divided into two stages. The first stage inclusions mainly develop liquid hydrocarbon inclusions and a large number of associated brine inclusions, which are mainly beaded in fracture-filled quartz and fracture-filled calcite. The fluorescence color is blue and blue-green, and the homogenization temperature of the associated brine inclusions is between 90-110°C. The second stage inclusions are mainly gas-liquid two-phase hydrocarbon inclusions, gas inclusions and asphalt inclusions. Most of them are distributed in the fracture-filled quartz, and the temperature of the associated brine inclusions is between 120-130°C. Fluid inclusions in Chang 7 member of the Yanchang Formation can be divided into two stages. The CO2 inclusions and high temperature inclusions in the Chang 7 member of the Yanchang Formation are mainly derived from deep volcanic activity in the crust.

Insights into the response of electroactive biofilm with petroleum hydrocarbons degradation ability to quorum sensing signals.

Bioelectrochemical technologies based on electroactive biofilms (EAB) are promising for petroleum hydrocarbons (PHs) remediation as anode can serve as inexhaustible electron acceptor. However, the toxicity of PHs might inhibit the formation and function of EABs. Quorum sensing (QS) is ideal for boosting the performance of EABs, but its potential effects on reshaping microbial composition of EABs in treating PHs are poorly understood. Herein, two AHL signals, C4-HSL and C12-HSL, were employed to promote EABs for PHs degradation. The start-times of AHL-mediated EABs decreased by 18-26%, and maximum current densities increased by 28-63%. Meanwhile, the removal of total PHs increased to over 90%. AHLs facilitate thicker and more compact biofilm as well as higher viability. AHLs enhanced the electroactivity and direct electron transfer capability. The total abundance of PH-degrading bacteria increased from 52.05% to 75.33% and 72.02%, and the proportion of electroactive bacteria increased from 26.14% to 62.72% and 63.30% for MFC-C4 and MFC-C12. Microbial networks became more complex, aggregated, and stable with addition of AHLs. Furthermore, AHL-stimulated EABs showed higher abundance of genes related to PHs degradation. This work advanced our understanding of AHL-mediated QS in maintaining the stable function of microbial communities in the biodegradation process of petroleum hydrocarbons.

Development of a green and low-cost method to determine mercury content in sediments affected by oil spill on the Brazilian coast.

Tons of crude oil were found on the Brazilian coast in 2019, and studies assessing its chemical composition are still scarce. This study aimed to develop a new and simple technique of cold vapor generation using infrared irradiation coupled with atomic absorption spectrometry to determine mercury content in sediments contaminated by crude oil. Experimental conditions were evaluated, including formic acid concentration, reactor temperature, and carrier gas flow rate. The accuracy of the method was validated by comparison with mercury contents in a certified reference material (PACS-2). The detection limit was found to be 0.44 µg kg-1. The developed method was applied to determine the total mercury content in marine sediment samples collected from beaches in Ceará State. Mercury concentrations ranged from 0.41 to 0.95 mg kg-1. The proposed method is efficient, simple, low-cost, and adequate for its purpose.

Low dose phosphorus supplementation is conducive to remediation of heavily petroleum-contaminated soil-From the perspective of hydrocarbon removal and ecotoxicity risk control.

Biostimulation by supplementing of nitrogen and phosphorus nutrients is a common strategy for remediation of petroleum-polluted soils. However, the dosage influence of exogenous nitrogen or phosphorus on petroleum hydrocarbon removal and soil ecotoxicity and microbial function remain unclear. In this study, we compared the efficiencies of hydrocarbon degradation and ecotoxicity control by experiment conducted over addition of inorganic nitrogen or phosphorus at C/N ratio of 100/10, C/N/P ratio of 100/10/1, and C/P ratio of 100/1 in a heavily petroleum-contaminated loessal soil with 12,320 mg/kg of total petroleum hydrocarbon (TPH) content. A 90-day incubation study revealed that low-dose of phosphorus addition with the C/P ratio of 100/1 promoted hydrocarbon degradation and reduced soil ecotoxicity. Microbial community composition analysis suggested that phosphorus addition enriched hydrocarbon degrader Gordonia and Mycolicibacterium genus. The key enzymes EC 5.3.3.8, EC 6.2.1.20 and EC 6.4.1.1 which referred to degradation of long-chain hydrocarbons, unsaturated fatty acids and pyruvate metabolism were abundance by phosphorus supplementation. While nitrogen addition at C/N ratio of 100/10 or C/N/P ratio of 100/10/1 inhibited hydrocarbon degradation and exacerbated soil ecotoxicity due to promoting denitrification and coupling reactions with hydrocarbons. Our results suggested that low-dose phosphorus addition served as a favorable strategy to promote crude oil remediation and ecotoxicity risk control in heavily petroleum-contaminated soil. Hence, the application of suitable doses of exogenous biostimulants is an efficient approach to restore the ecological functions of organically contaminated soils.

[Molding matrix formulation of hot-melt pressure-sensitive adhesive plaster of personalized traditional Chinese medicine preparations].

This study aims to optimize the matrix formulation for the hot-melt pressure-sensitive adhesive plaster of personalized traditional Chinese medicine(TCM) preparations and verify the applicability of the formulation. The central composite design in JMP Pro 16.1.0 was employed to optimize the dosages of styrene-isoprene-styrene triblock copolymer(SIS), hydrogenated petroleum resin, and lightweight liquid paraffin, with the fine powder of Yipifang as the model drug(drug loading of 10%) and the sensory score and objective evaluation as the comprehensive evaluation indicators. The quality evaluation system of hot-melt pressure-sensitive adhesive plaster of personalized TCM preparations was established. The applicability of the optimized matrix formulation of hot-melt pressure-sensitive adhesive plaster was verified with 16 TCM preparations for external application. Furthermore, the applicability of the matrix formulation was investigated with different drug loadings. The general molding matrix formulation was SIS∶hydrogenated petroleum resin∶lightweight liquid paraffin 3∶3∶5. The optimized matrix formulation showed good molding properties and high quality scores for 16 TCM preparations and were suitable for the plastering of finely powdered decoction pieces with a loading capacity of 10% to 30%. The results suggest that the optimized matrix formulation has good applicability and is suitable for TCM preparations. The findings lay a foundation for the application and promotion of the hot-melt pressure-sensitive adhesive plasters of personalized TCM preparations.

Diversity links to functionality: Unraveling the impact of pressure disruption and culture medium on crude oil-enriched microbial communities from the deep Eastern Mediterranean Sea.

Mesopelagic water from the deep Eastern Mediterranean Sea (EMS) was collected under disrupted (REPRESS) or undisturbed (HP) pressure conditions and was acclimated to oil (OIL) or dispersed-oil (DISPOIL) under in situ pressure and temperature (10 MPa, 14 °C). Decompression resulted in oil-acclimatised microbial communities of lower diversity despite the restoration of in situ pressure conditions during the 1-week incubation. Further biodiversity loss was observed when oil-acclimatised communities were transferred to ONR7 medium to facilitate the isolation of oil-degrading bacteria. Microbial diversity loss impacted the degradation of recalcitrant oil compounds, especially PAHs, as low-abundance taxa, linked with PAH degradation, were outcompeted in the enrichment process. Thalassomonas, Pseudoalteromonas, Halomonas and Alcanivorax were enriched in ONR7 under all experimental conditions. No effect of dispersant application on the microbial community structure was identified. A. venustensis was isolated under all tested conditions suggesting a potential key role of this species in hydrocarbons removal in the deep EMS.

Binary mixture of ionic liquid and span 80 for oil spill remediation: Synthesis and performance evaluation.

The synthesis of new surfactants helps to mitigate the environmental and financial effects of oil spills by providing efficient cleanup options. Herein, this study provides the development of a binary mixture of Span 80 and Choline myristate [Cho][Mys], a surface-active ionic liquid (SAIL) as green dispersant for oil spill remediation. The synergistic interaction at a 60:40 (w/w) ratio significantly lowered the critical micelle concentration (cmc) to 0.029 mM. Dispersion efficiency tests with Arab crude oil showed optimal performance at a 60:40 ratio of Span 80 and [Cho][Mys] (1:25 dispersant to oil ratio, v/v), achieving 81.16 % dispersion effectiveness in the baffled flask test. The binary mixture demonstrated superior emulsion stability (6 h) and the lowest interfacial tension (1.12 mN/m). Acute toxicity experiments revealed the dispersant's practical non-toxicity with an LC50 value of 600 mg/L. Overall, this environmentally benign surfactant combination shows promise as a safe and effective oil spill dispersant.

Genome-wide DNA methylation changes in Oryzias melastigma embryos exposed to the water accommodated fraction of crude oil.

The water accommodated fraction (WAF) of crude oil exerts considerable impacts on marine fish during embryonic stage. Clarifying changes in epigenetic modifications is helpful for understanding the molecular mechanism underlying the toxicity of embryonic WAF exposure. The aim of this study was to explore genome-wide DNA methylation changes in Oryzias melastigma embryos after exposure to the nominal total petroleum hydrocarbon concentration of 500 µg/L in WAF for 7 days. Whole-genome bisulfite sequencing revealed that 8.47 % and 8.46 % of all the genomic C sites were methylated in the control and WAF-exposed groups, respectively. Among the three sequence contexts, methylated CG site had the largest number in both the two groups. The sequence preferences of nearby methylated cytosines were consistent between the two groups. A total of 4798 differentially methylated regions (DMRs) were identified in the promoter region. Furthermore, Gene Ontology analysis revealed that DMR-related genes were enriched mainly for functions related to development and nervous system. Additionally, the Kyoto Encyclopedia of Genes and Genomes pathways enriched in DMR-related genes were related to nervous system and endocrine system. These novel findings provide comprehensive insights into the genome-wide DNA methylation landscape of O. melastigma following embryonic WAF exposure, shedding light on the epigenetic regulatory mechanisms underlying WAF-induced toxicity.

Break oily water emulsion during petroleum enhancing production processes using green approach for the synthesis of SnCuO@FeO nanocomposite from microorganisms.

The aim of this work was to synthesize a green nanoparticle SnCuO@FeO nanocomposite core-shell to break oily water emulsions during petroleum-enhancing production processes as an alternative to chemical and physical processes. In this study, eight bacterial isolates (MHB1-MHB8) have been isolated from tree leaves, giant reeds, and soil samples. The investigation involved testing bacterial isolates for their ability to make FeO nanoparticles and choosing the best producers. The selected isolate (MHB5) was identified by amplification and sequencing of the 16S rRNA gene as Bacillus paramycoides strain OQ878685. MHB5 produced the FeO nanoparticles with the smallest particle size (78.7 nm) using DLS. XRD, FTIR, and TEM were used to characterize the biosynthesized nanoparticles. The jar experiment used SnCuO@FeO with different ratios of Sn to CuO (1:1, 2:1, and 3:1) to study the effect of oil concentration, retention time, and temperature. The most effective performance was observed with a 1:1 ratio of Sn to CuO, achieving an 85% separation efficiency at a concentration of 5 mg/L, for a duration of 5 min, and at a temperature of 373 K. Analysis using kinetic models indicates that the adsorption process can be accurately described by both the pseudo-first-order and pseudo-second-order models. This suggests that the adsorption mechanism likely involves a combination of film diffusion and intraparticle diffusion. Regarding the adsorption isotherm, the Langmuir model provides a strong fit for the data, while the D-R model indicates that physical interactions primarily govern the adsorption mechanism. Thermodynamic analysis reveals a ∆H value of 18.62 kJ/mol, indicating an exothermic adsorption process. This suggests that the adsorption is a favorable process, as energy is released during the process. Finally, the synthesized green SnCuO@FeO nanocomposite has potential for use in advanced applications in the oil and gas industry to help the industry meet regulatory compliance, lower operation costs, reduce environmental impact, and enhance production efficiency.

Synergistic algal/bacterial interaction in membrane bioreactor for detoxification of 1,2-dichloroethane-rich petroleum wastewater.

The study addressed the challenge of treating petroleum industry wastewater with high concentrations of 1,2-dichloroethane (1,2-DCA) ranging from 384 to 1654 mg/L, which poses a challenge for bacterial biodegradation and algal photodegradation. To overcome this, a collaborative approach using membrane bioreactors (MBRs) that combine algae and bacteria was employed. This synergistic method effectively mitigated the toxicity of 1,2-DCA and curbed MBR fouling. Two types of MBRs were tested: one (B-MBR) used bacterial cultures and the other (AB-MBR) incorporated a mix of algal and bacterial cultures. The AB-MBR significantly contributed to 1,2-DCA removal, with algae accounting for over 20% and bacteria for approximately 49.5% of the dechlorination process. 1,2-DCA metabolites, including 2-chloroethanol, 2-chloro-acetaldehyde, 2-chloroacetic acid, and acetic acid, were partially consumed as carbon sources by algae. Operational efficiency peaked at a 12-hour hydraulic retention time (HRT) in AB-MBR, enhancing enzyme activities crucial for 1,2-DCA degradation such as dehydrogenase (DH), alcohol dehydrogenase (ADH), and acetaldehyde dehydrogenase (ALDH). The microbial diversity in AB-MBR surpassed that in B-MBR, with a notable increase in Proteobacteria, Bacteroidota, Planctomycetota, and Verrucomicrobiota. Furthermore, AB-MBR showed a significant rise in the dominance of 1,2-DCA-degrading genus such as Pseudomonas and Acinetobacter. Additionally, algal-degrading phyla (e.g., Nematoda, Rotifera, and Streptophyta) were more prevalent in AB-MBR, substantially reducing the issue of membrane fouling.

Phenotypic and genetic characterization of a lipolytic Ralstonia mannitolilytica isolate from petroleum-contaminated soil in Iraq.

BACKGROUND: Lipases play a crucial role in various industrial applications, and microbial lipases, particularly those from bacteria, possess significant properties. With increasing concerns about the environmental and health impacts of hydrocarbons from pipelines and refineries, there is a growing need to mitigate the risks associated with these compounds. METHODS: In this study, 40 bacterial isolates were recovered from contaminated soil samples collected from multiple refineries across Iraq. Using the Vitek system, bacterial isolates were identified up to the species level, revealing that only 12 isolates exhibited lipase-producing capabilities. RESULTS: Among the lipase-producing isolates, Ralstonia mannitolilytica demonstrated the highest extracellular lipase activity, as determined by an olive oil plate assay supplemented with rhodamine B. Confirmation of the species identity was achieved through 16S rRNA gene sequencing, with the obtained sequence deposited under accession number LC772176.1. Further sequence analysis revealed single nucleotide polymorphisms (SNPs) in the genome of Ralstonia mannitolilytica strain H230303-10_N19_7x_R2 (CP011257.1, positions 1,311,102 and 1,311,457). Additionally, the presence of the lipase gene was confirmed through amplification and sequencing using a thermocycler PCR. Sequence analysis of the gene, aligned using Geneious Prime software, identified SNPs (CP010799, CP049132, AY364601, CP011257, and CP023537), and a phylogenetic tree was constructed based on genetic characterization. CONCLUSION: Our findings highlight the potential of Ralstonia mannitolilytica as a promising candidate for lipase production and contribute to our understanding of its genetic diversity and biotechnological applications in hydrocarbon degradation and industrial processes.

An efficient method of preparing Si-Fe-Al-Ca alloy from coal gasification fine slag via plasma smelting and alternating current magnetic field.

It is of great significance to solve the environmental problems caused by the unreasonable treatment of coal gasification slag. This study successfully produced Si-Fe-Al-Ca alloy from low-carbon fine slag with petroleum coke as reducing agent in a plasma furnace with an alternating current magnetic field, which solved the problem of the high reactivity requirement of carbon reductant for plasma smelting. The optimum carbon content of the mixed low-carbon fine slag and petroleum coke is 105% of the theoretical value. As the strength of the alternating current magnetic field increased (from 0% to 100% of the maximum power), the yield of the alloy (from 25.46% to 58.19%) and the recovery ratios of each element (Si, Fe, Al, Ca, Ti) increased. In addition, as the magnetic field strength increased, the pores inside the alloy became smaller, the composition of the alloy became more homogeneous, and a better separation of the alloy from the slag was observed. The main composition of the alloy at the strongest alternating current magnetic field is Si: 51.14 wt%, Fe: 28.41 wt%, Al: 9.14 wt%, Ca: 7.15 wt%, Ti: 2.03 wt%. We attribute the enhanced smelting effect of the alternating current magnetic field to the resistive heat and Lorentz force produced by the induced current. In addition, the skin effect concentrated the induced current on the surface of the oxide particles and carbon particles, which increased the temperature of the reaction interface and promoted the carbothermal reduction reaction.

Biofilm of petroleum-based and bio-based microplastics in seawater in response to Zn(II): Biofilm formation, community structure, and microbial function.

Microplastic biofilms are novel vectors for the transport and spread of pathogenic and drug-resistant bacteria. With the increasing use of bio-based plastics, there is an urgent need to investigate the microbial colonization characteristics of these materials in seawater, particularly in comparison with conventional petroleum-based plastics. Furthermore, the effect of co-occurring contaminants, such as heavy metals, on the formation of microplastic biofilms and bacterial communities remains unclear. In this study, we compared the biofilm bacterial community structure of petroleum-based polyethylene (PE) and bio-based polylactic acid (PLA) in seawater under the influence of zinc ions (Zn2+). Our findings indicate that the biofilm on PLA microplastics in the late stage was impeded by the formation of a mildly acidic microenvironment resulting from the hydrolysis of the ester group on PLA. The PE surface had higher bacterial abundance and diversity, with a more intricate symbiotic pattern. The bacterial structures on the two types of microplastics were different; PE was more conducive to the colonization of anaerobic bacteria, whereas PLA was more favorable for the colonization of aerobic and acid-tolerant species. Furthermore, Zn increased the proportion of the dominant genera that could utilize microplastics as a carbon source, such as Alcanivorax and Nitratireductor. PLA had a greater propensity to harbor and disseminate pathogenic and drug-resistant bacteria, and Zn promoted the enrichment and spread of harmful bacteria such as, Pseudomonas and Clostridioides. Therefore, further research is essential to fully understand the potential environmental effects of bio-based microplastics and the role of heavy metals in the dynamics of bacterial colonization.

WTI, Brent or implied volatility index: Perspective of volatility spillover from oil market to Chinese stock market.

This study investigates the impact of oil market uncertainty on the volatility of Chinese sector indexes. We utilize commonly used realized volatility of WTI and Brent oil price along with the CBOE crude oil volatility index (OVX) to embody the oil market uncertainty. Based on the sample span from Mar 16, 2011 to Dec 31, 2019, this study utilizes vector autoregression (VAR) model to derive the impacts of the three different uncertainty indicators on Chinese stock volatilities. The empirical results show, for all sectors, the impact of OVX on sectors volatilities are more economically and statistically significant than that of realized volatility of both WTI and Brent oil prices, especially after the Chinese refined oil pricing reform of March 27, 2013. That implies OVX is more informative than traditional WTI and Brent oil prices with respect to volatility spillover from oil market to Chinese stock market. This study could provide some important implications for the participants in Chinese stock market.

Nitrate and oxygen significantly changed the abundance rather than structure of sulphate-reducing and sulphur-oxidising bacteria in water retrieved from petroleum reservoirs.

Sulphate-reducing bacteria (SRB) are the main culprits of microbiologically influenced corrosion in water-flooding petroleum reservoirs, but some sulphur-oxidising bacteria (SOB) are stimulated when nitrate and oxygen are injected, which control the growth of SRB. This study aimed to determine the distributions of SRB and SOB communities in injection-production systems and to analyse the responses of these bacteria to different treatments involving nitrate and oxygen. Desulfovibrio, Desulfobacca, Desulfobulbus, Sulfuricurvum and Dechloromonas were commonly detected via 16S rRNA gene sequencing. Still, no significant differences were observed for either the SRB or SOB communities between injection and production wells. Three groups of water samples collected from different sampling sites were incubated. Statistical analysis of functional gene (dsrB and soxB) clone libraries and quantitative polymerase chain reaction showed that the SOB community structures were more strongly affected by the nitrate and oxygen levels than SRB clustered according to the sampling site; moreover, both the SRB and SOB community abundances significantly changed. Additionally, the highest SRB inhibitory effect and the lowest dsrB/soxB ratio were obtained under high concentrations of nitrate and oxygen in the three groups, suggesting that the synergistic effect of nitrate and oxygen level was strong on the inhibition of SRB by potential SOB.