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1.
Arch Microbiol ; 205(1): 50, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36598589

RESUMO

Crude oil pollution is one of the most arduous issues to address, as it is hazardous to both public health and the environment. The discovery of novel biosurfactants-producing fungi and bacteria is in high demand due to their excellent properties and wide range of applications. The aim of this research is to isolate a powerful biosurfactant-producing fungus from the crude oil site near Barauni oil refinery in Bihar, India. Standard protocols were used to collect samples from the site. An integrative taxonomic approach was used, which included morphological, molecular, and phylogenetic analysis. The use of plating samples on Bushnell-Hass (BH) media aided in the isolation of a fungal strain from an enrichment culture. Two fungal strains isolated from contaminated soils, Penicillium citrinum and Paecilomyces variotti, showed potent oil degrading activity in a single culture. For preliminary biosurfactants screening, drop collapse assays, oil spreading, and emulsification activity tests were used. The results showed that the cultures performed well in the screening test and were further evaluated for degradation capacity. Different treatment periods (0, 3, 6, 9, 12, and 15 days) were used to observe degradation in single cultures. A steady drop in pH, an alteration in optical density and an increase in carbon dioxide release showed the ability of fungal strain to degrade the crude oil in a single culture. Fungi mycelia provide a larger surface area for absorption and degradation of the pollutants in contaminated environment. They produce extracellular enzymes to degrade the oil, and at the same time absorb and utilise carbon, allowing them to remove toxic substances from the oil. Thus, they could be candidates for bioremediation of a hydrocarbon-contaminated site.


Assuntos
Eurotiales , Petróleo , Filogenia , Eurotiales/metabolismo , Biodegradação Ambiental , Petróleo/metabolismo , Hidrocarbonetos/metabolismo
2.
Environ Pollut ; 319: 120971, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603759

RESUMO

Waxy oily sludge (WOS) from petrochemical enterprises has complex components and difficult treatment. Long-term large-scale stacking has seriously threatened human health and the ecological environment. In this paper, a new rapid and effective treatment method combining dispersion and biodegradation in a semi-fluid state was developed for the WOS. The degradation mechanism of the WOS in the bioreactor was preliminarily discussed. The component analysis results showed that the compounds with large molecular weight (M ≥ 282) in the WOS accounted for more than 50%. Among all microbial consortiums, the treatment effect of the consortium FF: NY3 = 9: 1 was the best for treating the crude oil in WOS, which was significantly different from that of a single strain (p < 0.05). Under the optimal nitrogen source NH4NO3 and the concentration of rhamnolipid, the developed high-efficiency microbial consortium (FF: NY3 = 9:1) could remove 85% of the total hydrocarbon pollutants in the 20 L semi-fluid bioreactor within 9 days. The degradation characteristics of WOS components in the bioreactor showed that the developed consortium has good degradation ability for n-alkanes (about 90%), middle- (77.35%)/long-chain (72.66%) isomeric alkanes, alkenes (79.12%), alicyclic hydrocarbons (78.9%) and aromatic hydrocarbons (62.78%). The kinetic analysis results indicated that, in comparison, the middle-chain n-alkanes, middle-chain isomeric saturated alkanes, alkenes, and alicyclic hydrocarbons were most easily removed. The removal rates of long-chain n-alkanes, long-chain isomeric saturated alkanes, and aromatic hydrocarbons were relatively low. The biological toxicity test showed that the germination rate of wheat seeds in treated waxy sludge was Significantly higher than that in untreated waxy sludge (p < 0.01). These results suggest that the new method developed in this paper can treat refractory WOS quickly and effectively. This method lays the foundation for the pilot-scale treatment of the semi-fluid bioreactor.


Assuntos
Petróleo , Esgotos , Humanos , Cinética , Óleos , Hidrocarbonetos/análise , Alcanos/metabolismo , Biodegradação Ambiental , Petróleo/análise , Alcenos
3.
J Hazard Mater ; 446: 130656, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603421

RESUMO

Oil spill attenuation in Arctic marine environments depends on oil-degrading bacteria. However, the seasonally harsh conditions in the Arctic such as nutrient limitations and sub-zero temperatures limit the activity even for bacteria capable of hydrocarbon metabolism at low temperatures. Here, we investigated whether the variance between epipelagic (seasonal temperature and inorganic nutrient variations) and mesopelagic zone (stable environmental conditions) could limit the growth of oil-degrading bacteria and lead to lower oil biodegradation rates in the epipelagic than in the mesopelagic zone. Therefore, we deployed absorbents coated with three oil types in a SW-Greenland fjord system at 10-20 m (epipelagic) and 615-650 m (mesopelagic) water depth for one year. During this period we monitored the development and succession of the bacterial biofilms colonizing the oil films by 16S rRNA gene amplicon quantification and sequencing, and the progression of oil biodegradation by gas chromatography - mass spectrometry oil fingerprinting analysis. The removal of hydrocarbons was significantly different, with several polycyclic aromatic hydrocarbons showing longer half-life times in the epipelagic than in the mesopelagic zone. Bacterial community composition and density (16S rRNA genes/ cm2) significantly differed between the two zones, with total bacteria reaching to log-fold higher densities (16S rRNA genes/cm2) in the mesopelagic than epipelagic oil-coated absorbents. Consequently, the environmental conditions in the epipelagic zone limited oil biodegradation performance by limiting bacterial growth.


Assuntos
Poluição por Petróleo , Petróleo , Estuários , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Água do Mar/microbiologia , Hidrocarbonetos/metabolismo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Petróleo/metabolismo
4.
World J Microbiol Biotechnol ; 39(3): 84, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36693977

RESUMO

The coexistence of heavy metals (HMs) and petroleum hydrocarbons (PHs) exacerbates ecotoxicity and impair the drivers of eco-functionalities that stimulate essential nutrients for the productivity of the impacted environment. Profiling the bacteria that stem the ecological impact via HMs sequestration and PHs catabolism with nitrogen fixation is imperative to bioremediation of the polluted sites. The sediment of site that was consistently contaminated with industrial wastewaters was analysed for ecological toxicants and the bacterial strains that combined HMs resistance with PHs catabolism in a nitrogen-limiting system were isolated from the sediment and characterized. The geochemistry of the samples revealed the co-occurrence of the above-benchmark concentrations of HMs with the derivatives of hydrocarbons. Notwithstanding, nickel and mercury (with 5% each of the total metal concentrations in the polluted site) exhibited probable effect concentrations on the biota and thus hazardous to the ecosystem. Approx. 31% of the bacterial community, comprising unclassified Planococcaceae, unclassified Bradyrhizobiaceae, Rhodococcus, and Bacillus species, resisted 160 µmol Hg2+ in the nitrogen-limiting system within 24 h post-inoculation. The bacterial strains adopt volatilization, and sometimes in combination with adsorption/bioaccumulation strategies to sequester Hg2+ toxicity while utilizing PHs as sources of carbon and energy. Efficient metabolism of petroleum biomarkers (> 87%) and Hg2+ sequestration (≥ 75% of 40 µmol Hg2+) displayed by the selected bacterial strains portend the potential applicability of the bacilli for biotechnological restoration of the polluted site.


Assuntos
Bacillus , Mercúrio , Metais Pesados , Petróleo , Petróleo/metabolismo , Ecossistema , Metais Pesados/metabolismo , Bactérias/genética , Bactérias/metabolismo , Biodegradação Ambiental , Hidrocarbonetos/metabolismo , Bacillus/metabolismo
5.
Bull Environ Contam Toxicol ; 110(2): 46, 2023 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-36690874

RESUMO

We attempted to characterize zooplankton community response following spills of the unconventional crude oil, diluted bitumen (dilbit), into 10-m diameter, ~ 100 m3, ~ 1.5-m deep boreal lake limnocorrals, including two controls and seven dilbit treatments ranging from 1.5 to 180 L (1:100,000 to 1:1,000 v/v, dilbit:water). Community composition and abundances were monitored weekly to bi-weekly over three months. Total zooplankton biomass and abundance seemingly collapsed in all limnocorrals, regardless of treatment, though some rotifer species persisted. As a result, it was not possible to determine the impacts of dilbit. We theorize several potential non-oil-related reasons for the sudden community collapse - including elevated zinc levels, fish grazing pressures, and sampling biases - and provide guidance for future work using in-lake enclosures.


Assuntos
Petróleo , Poluentes Químicos da Água , Animais , Lagos , Zooplâncton , Poluentes Químicos da Água/análise , Hidrocarbonetos
6.
Ecotoxicol Environ Saf ; 250: 114487, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36587413

RESUMO

Atlantic salmon is an important species for Canadian culture and economy and its importance extends beyond Canada to Scandinavia and Western Europe. However, it is a vulnerable species facing decline due to habitat contamination and destruction. Existing and new Canadian pipeline projects pose a threat to salmonid habitat. The effects of diluted bitumen (dilbit), the main oil circulating in pipelines, are less studied than those of conventional oils, especially during the critical early embryonic developmental stage occurring in freshwater ecosystems. Therefore, this study aimed to compare the effects of water-accommodated fractions (WAF) of the Clearwater McMurray dilbit and the Lloydminster Heavy conventional oil on Atlantic salmon embryos exposed either from fertilization or from eyed stage. The dilbit contained the highest concentrations of low molecular weight (LMW) compounds (including BTEX and C6-C10), while the conventional oil contained the highest concentrations of PAHs. The Clearwater dilbit caused a higher percentage of mortality and malformations than the conventional oil at similar WAF concentrations. In addition, the embryos exposed from fertilization suffered a higher mortality rate, more developmental delays, and malformations than embryos exposed from the eyed stage, suggesting that early development is the most sensitive developmental stage to oil exposure. Gene expression and enzymatic activity of the detoxification phase I and II enzymes (CYP1A and GST) were measured. Data showed increases in both cyp1a expression and GST activity with increasing WAF concentrations, while gst expression was not affected by the exposures. Also, gene expression of proteins involved in the biotransformation of vitamin A and DNA damage repair were modified by the oil exposures. Overall, this study indicates that Atlantic salmon is mostly affected by oil exposure at the beginning of its development, during which embryos accumulate deformities that may impact their survival at later life stages.


Assuntos
Petróleo , Salmo salar , Poluentes Químicos da Água , Animais , Canadá , Ecossistema , Hidrocarbonetos/toxicidade , Água , Óleos , Poluentes Químicos da Água/toxicidade , Petróleo/toxicidade
7.
J Environ Manage ; 328: 117200, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36608456

RESUMO

A novel electromagnetic induction low temperature thermal desorption treatment (EMI LTTD) for petroleum hydrocarbons contaminated soil was introduced in this work. The removal rate of total petroleum hydrocarbons (TPH) under various factors, the morphology changes of soils as well as removal mechanism were investigated. Results suggested that increasing the heating temperature significantly increased the removal rate of TPH. At the beginning of 20 min, most of hydrocarbons (93.44-96.91 wt%) was removed with the temperature ranged from 200 °C to 300 °C. Besides, the initial contaminants concentration, particle size and thickness of soil slightly influenced the removal rate of TPH. Desorption kinetic study demonstrated that first-order model was well-described for desorption behavior. Response surface methodology analysis showed the temperature of 216 °C, the residence time of 21 min and the moisture content of 18% was an optimum condition recommended for potentially practical application. Under this condition, the results for the composition of hydrocarbons based on carbon number fractions indicated that the fractions of C10∼C16, C17∼C22 still existed in soil, while C23∼C28 was not detected after EMI LTTD treatment. Proposed mechanism was both hydrocarbons removed by evaporation at any temperature, while parts of heavy hydrocarbons was cracked within the soil close to induction medium, resulting in re-adsorption of light hydrocarbons. A buckwheat germination and growth test indicated that soil treated by EMI LTTD was potential in reutilization for planting.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes do Solo , Petróleo/análise , Solo/química , Poluentes do Solo/análise , Hidrocarbonetos/química , Poluição por Petróleo/análise , Biodegradação Ambiental
8.
Water Sci Technol ; 87(1): 228-238, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36640034

RESUMO

Bioaugmentation is an effective strategy used to speed up the bioremediation of marine oil spills. In the present study, a highly efficient petroleum degrading bacterium (Pseudomonas aeruginosa ZS1) was applied to the bioremediation of simulated crude oil pollution in different sampling sites in the South China Sea. The metabolic pathways of ZS1 to degrade crude oil, the temporal dynamics of the microbial community response to crude oil contamination, and the biofortification process were investigated. The results showed that the abundance and diversity of the microbial community decreased sharply after the occurrence of crude oil contamination. The best degradation rate of crude oil, which was achieved in the samples from the sampling site N3 after the addition of ZS1 bacteria, was 50.94% at 50 days. C13 alkanes were totally oxidized by ZS1 in the 50 days. The degradation rate of solid n-alkanes (C18-C20) was about 70%. Based on the whole genome sequencing and the metabolites analysis of ZS1, we found that ZS1 degraded n-alkanes through the terminal oxidation pathway and aromatic compounds through the catechol pathway. This study provides data support for further research on biodegradation pathways of crude oil and contributes to the subsequent development of more reasonable bioremediation strategies.


Assuntos
Microbiota , Poluição por Petróleo , Petróleo , Biodegradação Ambiental , Poluição por Petróleo/análise , Alcanos/metabolismo , Petróleo/análise , Bactérias/genética , Bactérias/metabolismo , Redes e Vias Metabólicas , Hidrocarbonetos/metabolismo
9.
J Environ Manage ; 329: 117015, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36584510

RESUMO

The aim of this research was to develop a sustainable and ecologically sound, non-traditional cold mix asphalt (CMA) that can be used in the construction industry. This new type of CMA incorporates wastewater sludge fly ash (UFA) and bottom ash (UBA) as a replacement filler for ordinary Portland cement and limestone. Silica fume (SF) was also used as an additional filler. The mechanical and durability characteristics of the new CMAs were examined in terms of indirect tensile stiffness modulus (ITSM), and rutting, fatigue, water and fuel resistance. The results showed that CMA with 2.1% OPC +3.9% UFA at 3 days of age, had ITSM values 11 times that of traditional CMA, while CMA with 2.1% OPC+ 3.3% UFA +0.6% UBA, had ITSM values 5 times that of traditional CMA at 28 days of age. SF activated hydration for both mixes, significantly increasing ITSM. These results indicate that CMA has a comparable mechanical performance to standard Hot Mix Asphalt (HMA) mixtures for use as surface pavement layers. This study offers a novel CMA with improved mechanical performance. It is economically effective and ecologically beneficial, compared to HMA, due to its ability to accommodate wastewater sludge ashes that are often disposed of in landfill sites.


Assuntos
Esgotos , Hidrocarbonetos , Carbonato de Cálcio , Cinza de Carvão , Gases , Dióxido de Silício
10.
Ecotoxicol Environ Saf ; 249: 114345, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36508834

RESUMO

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.


Assuntos
Nematoides , Poluentes do Solo , Animais , Regiões Antárticas , Ecossistema , Solo/química , Hidrocarbonetos/toxicidade , Poluentes do Solo/toxicidade , Poluentes do Solo/química
11.
Environ Pollut ; 319: 120911, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36549453

RESUMO

Co-composting is an efficient strategy for collaborative disposal of multiple organic wastes in rural areas. In this study, we explored the co-composting of rural sewage sludge and other organic solid wastes (corn stalks and kitchen waste), with a focus on the variation of total petroleum hydrocarbons (TPH) during this process. 12% corn-derived biochar was applied in the composting (BC), with no additives applied as the control treatment (CK). The TPH contents of piles after composting ranged from 0.70 to 0.74 mg/g, with overall removal efficiencies of 35.6% and 61.1% for CK and BC, respectively. The results indicate that the addition of 12% biochar increased the rate of TPH degradation and accelerated the degradation process. 16s rDNA high-throughput sequencing was applied to investigate the biodiversity and bacterial community succession during the composting process. Diverse bacterial communities with TPH degradation functions were observed in the composting process, including Acinetobacter, Flavobacterium, Paenibacillus, Pseudomonas, and Bacillus spp. These functional bacteria synergistically degraded TPH, with cooperative behavior dominating during composting. Biochar amendment enhanced the microbial activity and effectively promoted the biodegradation of TPH. The physicochemical properties of the compost piles, including environmental factors (pH and temperature), nutrients (nitrogen, phosphorus, potassium), and humic substances produced in composting (humic acids and fulvic acids), directly and indirectly affected the variation in TPH contents. In conclusion, this work illustrates the variation in TPH content and associated influencing factors during co-composting of rural organic solid wastes, providing valuable guidance toward the further optimization of rural organic waste management.


Assuntos
Compostagem , Petróleo , Esgotos , Resíduos Sólidos , Substâncias Húmicas , Hidrocarbonetos , Flavobacterium , Solo
12.
Mar Pollut Bull ; 186: 114435, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36493517

RESUMO

A yearlong study was conducted to assess the impact of an oil spill on macrobenthos of rocky intertidal zone of Uran, India and its recovery processes, by comparing impacted site with a reference. Immediate acute effects observed were elevated sediment hydrocarbons, absence of macroalgae and amphipods, mass mortality of macrofauna and dominance of the opportunistic nereid, Namalycastis senegalensis. As the hydrocarbons reduced at the impacted site by ~50 % within three months, gradual re-appearance of macroalgae and re-colonization of amphipods (51.4 %) and sensitive polychaetes (7 %) indicated that the recovery was well underway. The amphipod, Allomelita pellucida proved to be a potential indicator of oil contamination. BOPA correlated with sediment hydrocarbons and performed effectively as the extant macrobenthic communities had sufficient representation of Polychaeta and Amphipoda. Notwithstanding the distinct initial impacts of the oil spill, comparable macrobenthic assemblages comprised of sensitive species at both sites after a year confirmed complete recovery.


Assuntos
Anfípodes , Poluição por Petróleo , Poliquetos , Alga Marinha , Animais , Poluição por Petróleo/análise , Sedimentos Geológicos , Hidrocarbonetos , Ecossistema , Monitoramento Ambiental
13.
Mar Pollut Bull ; 186: 114377, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36493519

RESUMO

Deepwater hydrocarbon releases experience complex chemical and physical processes. To assess simplifications of these processes on model predictions, we present a sensitivity analysis using simulations for the Deepwater Horizon oil spill. We compare the buoyant multiphase plume metrics (trap height, rise time etc), the hydrocarbon mass flowrates at the near-field plume termination and their mass fractions dissolved in the water column and reaching the water surface. The baseline simulation utilizes a 19-component hydrocarbon model, live-fluid state equations, hydrate dynamics, and heat and mass transfer. Other simulations turn-off each of these processes, with the simplest one using inert oil and methane gas. Plume metrics are the least sensitive to the modeled processes and can be matched by adjusting the release buoyancy flux. The mass flowrate metrics are more sensitive. Both liquid- and gas-phase mass transfer should be modeled for accurate tracking of soluble components (e.g. C1 - C7 hydrocarbons) in the environment.


Assuntos
Poluição por Petróleo , Petróleo , Poluentes Químicos da Água , Hidrodinâmica , Poluentes Químicos da Água/análise , Poluição por Petróleo/análise , Termodinâmica , Água/análise , Fenômenos Químicos , Hidrocarbonetos/análise , Golfo do México , Petróleo/análise
14.
Mar Pollut Bull ; 186: 114473, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36512859

RESUMO

The marine coast is an important ecological transitional boundary but easily suffers from human intervention. Total petroleum hydrocarbons (TPHs) are ubiquitous along the coast. However, the influence of anthropogenic and natural factors on TPHs distribution remains unclear. This study sampled surficial sediment (N = 243) from the coasts of the largest peninsula-Leizhou Peninsula, in Southern China. We found that land-based discharge, sea traffic, and sediment type significantly (p < 0.05) drive the accumulation of TPHs. We observed that TPHs increased by 1.036 µg · g-1 (exp[αi] = exp. [0.0355]) of its original value with the addition of one more boat on the wharf. Although the average TPHs were at a moderate level (124.68, ND-1536.14, µg · g-1) and risk, 'Blue Carbon' ecosystems, i.e., mangroves (224.84, ND - 1441.13, µg · g-1, p < 0.001) were more severely polluted. Cleaner production policy should be applied to mitigate TPHs discharging trend from coastal areas.


Assuntos
Petróleo , Poluentes Químicos da Água , Humanos , Ecossistema , Petróleo/análise , Hidrocarbonetos/análise , Atividades Humanas , China , Sedimentos Geológicos , Monitoramento Ambiental , Poluentes Químicos da Água/análise
15.
Mar Pollut Bull ; 186: 114421, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36521361

RESUMO

To assess the impacts of drill cutting discharges in the Gulf of Mexico, a particle dispersion modeling study was conducted on hypothetical drilling scenarios. The goal was to assess cumulative seabed deposition, and potential hydrocarbon loading from non-aqueous drilling fluids (NADF). Cuttings drilled with NADF showed to have minimal impact on local fauna at the deep-water well simulated. A hypothetical drill site was modeled under 3 different seasonally representative met-ocean conditions. The site is located approximately 260 km from the coast in water roughly 3500 meters (m) deep. Cumulative deposition was assessed for all materials released, whereas hydrocarbon loading was assessed based on the potential for NADF fluids to be retained on cuttings. Smothering effects on the benthic community are not anticipated. Hydrocarbon deposition was also very limited, ≤165 ppm of TPH. Overall, the cuttings drilled with NADF are predicted to have minimal impact on local fauna.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Poços de Água , Hidrocarbonetos
16.
Mar Pollut Bull ; 186: 114478, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36529019

RESUMO

Barium (Ba) in recent marine sediments can originate from natural and anthropogenic sources including discharges from the oil and gas industry. In this study, we use data from the Norwegian and Barents Seas to assess whether Ba in recent marine sediments has increased due to these discharges. To account for Ba in detrital material, we normalise all samples with respect to aluminosilicate by calculating an enrichment factor. We use statistical modelling to control for parameters related to sedimentation. We present results that suggest increased Ba levels in recent sediments that coincide with the timing of hydrocarbon drilling and production. This is supported by geographical differences on a large scale that relate to proximity to hydrocarbon drilling and production. Among 243 sampling stations, we identify 73 locations exhibiting enrichment of Ba in the upper 6 of sediment. At these locations, Ba is 1.55 to 3.55 times higher than the levels that can be expected from the shale average when Ba in detrital matter is accounted for. Excess Ba is reported in sediment surface samples in areas important to fisheries like the Lofoten area and the western Barents Sea.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Bário , Monitoramento Ambiental/métodos , Oceanos e Mares , Noruega , Hidrocarbonetos
17.
Environ Res ; 219: 114955, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36495962

RESUMO

Hydrocarbon-contaminated soils are considered as one of the major environmental issues that harm human well-being, particularly in arid regions of the world. Phytoremediation is a possible mitigation measure for this issue and has been suggested as it is cost-effective compared with other remediation technologies for soil clean-up, such as soil thermal treatment and soil washing. However, there are still gaps in the literature regarding the behavior of annual and perennial desert plants and their ability to survive in hydrocarbon-contaminated soils in arid ecosystems. Therefore, this study aims to develop an integrated approach using remote sensing techniques to understand the behavior of annual and perennial desert plants over different types of oil-contaminated soils (oil tarcrete, wet-oil lake, bare soil, and vegetation cover) in the Kuwait Desert and to explore the impact of climate and physical soil properties on the regrowth of native desert plants. The Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), and ferrous iron (Fe2+) index (FI) were used to determine the changes in oil contamination and vegetation cover from 1992 to 2002, and 2013-2020. Subsequently, statistical tests were performed to determine the influence of climatic and soil physical characteristics on changes in hydrocarbon contamination and desert plant behavior. The results showed that hydrocarbon contamination was high at the study sites in the first six years (1992-1997) after contamination, and then decreased in the following years. However, vegetation cover was low in the first six years but significantly increased after 1998, reaching >65%. It was also found that annual plants had the highest distribution rate compared to perennial plants, which mainly depended on the soil type. We concluded that certain annual and perennial plants could successfully grow over tarcrete-contaminated sites, making these sites more suitable for the restoration of native desert plants than hydrocarbon-contaminated sites. We also observed that the succession process of vegetation growth over hydrocarbon-contaminated soils could be associated with vegetation growth on a clean sediment layer covering the oil layer. Additionally, we observed that the remobilization of aeolian sediment over many contaminated sites in Kuwait resulted in the accumulation of organic matter, plant seeds, and dust particles that create layers of nutrient-rich soil for the initial growth of plants.


Assuntos
Ecossistema , Poluentes do Solo , Humanos , Tecnologia de Sensoriamento Remoto , Poluentes do Solo/análise , Solo , Plantas , Biodegradação Ambiental , Hidrocarbonetos
18.
Environ Res ; 219: 115064, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36549230

RESUMO

The key to enhancing the efficacy of bioremediation of hydrocarbon-contaminated soil is the precise and highly efficient screening of functional isolates. Low screening effectiveness, narrow screening range and an unstable structure of the constructed microflora during bioremediation are the shortcomings of the traditional shaking culture (TSC) method. To improve the secondary screening of isolates and microflora implemented for alkane degradation, this work evaluated the characterization relationship between bacterial function and enzyme activity and devised an enzyme activity assay (EAA) method. The results indicated a substantial positive correlation (r = 0.97) between 24 candidate isolates and their whole enzymes, proving that whole enzyme activity properly reflects the metabolic functions of microorganisms. The functional analysis of the isolates demonstrated that the EAA method in conjunction with microbial abundance and metabolite determination could broaden the screening range of functional isolates, including aliphatic acid-metabolizing isolates (isolates H4 and H7) and aliphatic acid-sensitive isolates (isolate H2) with n-hexadecane degradation ability. The EAA method also guided the construction of functional microflora and optimized the mode of application using combinations of alkane-degrading bacteria and aliphatic acid-degrading bacteria successively (e.g., F1+H7+H7). The combinations maintained a high abundance of functional isolates and stable α diversity and community composition throughout the experiment, which contributed to more advanced alkane degradation and mineralization ability (p < 0.01). Assuming a workload of 100 tests, the screening efficiency of the EAA method is more than 16 times that of the TSC method, and the greater the quantity of isolates, the higher the screening efficiency, enabling high-throughput screening. In conclusion, the EAA method has a broad-spectrum, accurate and highly efficient screening ability for functional isolates and microflora, which can provide intensive technical support for the development of bioremediation materials and the application of bioremediation technology.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Petróleo/metabolismo , Petróleo/microbiologia , Poluentes do Solo/análise , Microbiologia do Solo , Hidrocarbonetos , Alcanos/metabolismo , Solo
19.
J Colloid Interface Sci ; 634: 983-994, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36571860

RESUMO

HYPOTHESIS: Specific ion effects govern myriad biological phenomena, including protein-ligand interactions and enzyme activity. Despite recent advances, detailed understanding of the role of ion hydrophobicity in specific ion effects, and the intersection with hydrotropic effects, remains elusive. Short chain fatty acid sodium salts are simple amphiphiles which play an integral role in our gastrointestinal health. We hypothesise that increasing a fatty acid's hydrophobicity will manifest stronger salting-out behaviour. EXPERIMENTS: Here we study the effect of these amphiphiles on an exemplar thermoresponsive polymer brush system, conserving the carboxylate anion identity while varying anion hydrophobicity via the carbon chain length. Ellipsometry and quartz crystal microbalance with dissipation monitoring were used to characterise the thermoresponse and viscoelasticity of the brush, respectively, whilst neutron reflectometry was used to reveal the internal structure of the brush. Diffusion-ordered nuclear magnetic resonance spectroscopy and computational investigations provide insight into polymer-ion interactions. FINDINGS: Surface sensitive techniques unveiled a non-monotonic trend in salting-out ability with increasing anion hydrophobicity, revealing the bundle-like morphology of the ion-collapsed system. An intersection between ion-specific and hydrotropic effects was observed both experimentally and computationally; trending from good anti-hydrotrope towards hydrotropic behaviour with increasing anion hydrophobicity, accompanying a change in hydrophobic hydration.


Assuntos
Polímeros , Cloreto de Sódio , Polímeros/química , Ânions/química , Interações Hidrofóbicas e Hidrofílicas , Hidrocarbonetos
20.
J Hazard Mater ; 443(Pt A): 130192, 2023 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-36270191

RESUMO

While extensive works focused on the enhancement of the activity of heterogeneous Fenton catalysts, little was paid attention to the inhibition of soil organic matter (SOM) and Mn minerals in soil remediation. Here, the oxidation of petroleum hydrocarbons in soils (S1: 4.28 % SOM, S2: 6.04 % SOM, S3: 10.33 % SOM) with inactivated SOM and passivated Mn oxides regulating by calcium superphosphate (Ca(H2PO4)2) was carried out. Oily sludge pyrolysis residue was used as precursors to prepare an oleophilic iron-supported solid catalyst (Fe-N @ PR). For regulated systems, under the optimal conditions of 1.8 mmol/g H2O2 and 0.05 g/g Fe-N @ PR, 72 ∼ 91 % of total petroleum hydrocarbons (TPHs: 15,616.58 mg/kg) were oxidized, which was 38 ∼ 45 % higher than that of control systems. The mechanism of efficient oxidation was proposed that the passivated Mn minerals stabilized H2O2 redistributing more H2O2 to sustainably produce •OH, and the inactivated SOM improved the relative reactivity of •OH to TPHs. Additionally, the passivation of Mn oxides was mainly related to the binding of H2PO4-, and the inactivation of SOM was realized by Ca2+ combing with -OH and C-O-C to form stable complexes. This study brought us a new perspective on soil remediation through passivating Mn minerals and inactivating SOM.


Assuntos
Petróleo , Poluentes do Solo , Solo/química , Manganês , Poluentes do Solo/análise , Oxidantes , Peróxido de Hidrogênio/química , Hidrocarbonetos , Oxirredução , Minerais , Óxidos
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