Release Of Hydrocarbons Research Articles

Exploring the integrated potential of pyrolysis and low-temperature wet torrefaction for typical medical waste valorization: A multifaceted approach leveraging online TG-FTIR-MS, 2D-COS, iso-conversional kinetics, and reaction mechanisms

The rapid growth of medical waste, exacerbated by the COVID-19 pandemic and advancements in healthcare, has drawn increased public scrutiny regarding its proper disposal and treatment. This research aimed to characterize the wet torrefaction of a typical medical waste biomass (MWB) composition, comprising bamboo swabs, skewers, splints, cotton balls, tongue depressors, toothpicks, and chopsticks, followed by its co-pyrolysis with medical waste plastic (MWP) including catheter bags, drapes, IV tubing, IV bags, oxygen masks, syringes, and test tubes. The study employed thermogravimetric analysis, TG-FTIR, 2D correlation spectroscopy, iso-conversional kinetics, and mass spectrometry techniques elucidated the driving factors, behaviors, products, mechanisms, and pathways involved. The pyrolysis temperature ranges were 180.15 to 400 °C for TMWB and 380.04 to 550 °C for MWP, with average activation energies of 150.22 and 221.59 kJ/mol for their respective devolatilization processes. Incorporating 20 % and 40 % MWP into the co-pyrolysis process yielded the best performance, characterized by the lowest activation energy. The co-pyrolysis process promoted the release of cyclic hydrocarbons and chain hydrocarbons, but decreased the yields of alcohols, esters, ethers, phenols, and acids, through synergistic mechanisms. Unraveling the pyrolysis pathways and dynamics of these representative medical waste streams offers valuable insights into improving energy recovery, mitigating pollution, diminishing waste volumes, and optimizing industrial thermochemical conversion processes for safely treating these hazardous materials.

High temperature and hyperkalemia increase vulnerability of navaga cod (Eleginus nawaga) cardiomyocytes to the ecotoxicant 3-methyl-phenanthrene

Oil and gas mining and transportation in the Arctic can lead to release of polycyclic aromatic hydrocarbons (PAHs) in the ocean and freshwater basins. PAHs are known for their toxic effects in fish hearts, including the inhibition of main ionic currents (IKr, INa and ICaL) in fish cardiac myocytes. The present study is the first one to assess the effect of a particular PAH abundant in crude oil and diesel, namely 3-methyl-phenanthrene (3-MP), on the electrical excitability (EE) of cardiomyocytes from navaga cod (Eleginus nawaga), commercial fish species from the Arctic. Action potentials (APs) were elicited in current-clamp experiments at 9, 15 and 21 °C, and AP characteristics and the current needed to elicit APs were examined. Also, the effects of 3 μM 3-MP were tested at 3 temperatures and in normal (3.5 mM) and high (8 mM) extracellular K+ concentrations.Elevation of temperature leads to hyperpolarization of resting membrane potential and AP shortening, but does not decrease EE. 3-MP was found to suppress EE in cardiomyocytes at 9 and 15 °C, but not at 21 °C. High extracellular K+ itself drastically decreases EE, although it does not worsen the effect of 3-MP. However, combination of hyperthermia and high K+ leads to augmentation of depressive effect of 3-MP on EE. We hypothesize that hyperthermia rescues Na+ channels from inactivation due to membrane hyperpolarization, thereby compensating for the partial inhibition of INa by 3-MP. However, elevation of extracellular K+ nullifies this protective mechanism by depolarizing the resting potential and aggravates the effect of 3-MP.

Evaluation of the reactivity of co-combustion of wheat straw and waste rubber thermolysis char

The co-combustion of wheat straw (WS) and waste rubber thermolysis char (WRTC) was examined with the perspective of utilizing WRTC as a high-calorific value fuel addition to agricultural biomass. The study investigated the effect of different proportions of WS-WRTC blends (10/15/25/49 wt% WRTC) and a maximum of 4 wt% binders, including potato starch and calcium oxide, on the reactivity of co-combustion and the distribution of products during the process. Thermogravimetric analysis with Fourier Transform Infrared Spectroscopy (TGA-FTIR) analyses was employed at a temperature range of 25–1000 ° C with a heating rate of 10 ° C/min. The kinetics of co-combustion were analyzed using the Fraser-Suzuki (FS) deconvolution method and a model-based kinetic modeling. The results indicate that a 10% addition of WRTC char reduces the intensity and rate of combustion and prolongs the combustion time. It was observed that the optimal addition to the blend is 25% WRCT, and it resulting in a reduction in activation energy and combustion indexes. However, it remains with no significant impact on process stability and efficiency. Kinetics of the decomposition of the WRTC25 mixture modeled by the deconvolution method indicates a 5-step reaction course, which is a combination of the characteristic combustion stages of both fuels. The main denoted functional group observed in the FTIR absorption spectra were C=O, C-O, O-H, and C-H related to the release of CO2, CO, H2O, CH4, aromatic compounds, and hydrocarbons.

Removal of Bunker Oil in Contaminated Seawater Using Biochar from Chicken Bones Via Slow Pyrolysis

Abstract An oil spill is the unintended or deliberate release of petroleum hydrocarbons into the environment, particularly the marine ecosystem. The disseminated oil can either evaporate or form a surface slick, disperse in the water, or submerge and deposit in the sediments. One of the standard methods is the use of sorbents. Pyrolysis is one of the simplest methods for converting biomass, and it involves heating organic material in the absence of oxygen. The natural polymeric ingredients of the process are bio-oil (condensable vapours), char (solid fraction), and non-condensable gases. Chicken bones were used to produce biochar via slow pyrolysis at varying operating temperature (400°C, 450°C and 500°C) and residence time (45min, 60min and 75min) to acquire the Chicken Bones Biochar (CBB). The CBB was used to obtain Chicken Bones Activated Biochar (CBAB) after it was subjected to KOH Activation Process. For the yield obtained, the lowest temperature and shorter residence time acquired the highest yield for both CBB and CBAB. The characterization of the products was carried out by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The products were evaluated after it was subjected to a bunker oil contaminated seawater and the adsorption capacity was determined with varying contact time (40min, 50min and 60min). A high absorbance of the CBB and CBAB indicated the feasibility of the chicken bone as an adsorbent material.

The Source of Thermophilic Bacteria in Lake Baikal Cold Sediments – Coastal Hydrotherms or Deep Fluids?

The sources of thermophilic bacteria revealed in cold Lake Baikal sediments are considered. Comparative analysis of the taxonomic position of thermophilic microorganisms from four terrestrial hot springs at Lake Baikal coast and from the bottom sediments associated with hydrocarbon discharge was carried out. The sequences of thermophilic microorganisms with the same taxonomic position were revealed both in the hot springs and bottom sediments. Some microbial species occurred only in the hydrotherm samples or only in those from the sediments. Gas-saturated fluids from the hydrocarbon generation zone at the depth of 4‒6 km are the most probable source of thermophilic microorganisms in the bottom sediments.

Survival and reproduction tests using springtails reveal weathered petroleum hydrocarbon soil toxicity in boreal ecozone.

Survival and reproduction tests were conducted using two native springtail (subclass: Collembola) species to determine the toxicity of a fine-grained (< 0.005 - 0.425 mm) soil from an industrial site located in the Canadian boreal ecozone. Accidental petroleum hydrocarbon (PHC) release continuously occurred at this site until 1998, resulting in a total hydrocarbon concentration of 12,800mg/kg (soil dry weight). Subfractions of the PHC-contaminated soil were characterized using Canadian Council of Ministers of the Environment Fractions, which are based on effective carbon numbers (nC). Fraction 2 (> nC10 to nC16) was measured at 8400mg/kg and Fraction 3 (> nC16 to nC34) at 4250mg/kg in the contaminated soil. Age-synchronized colonies of Folsomia candida and Proisotoma minuta were subject to 0%, 25%, 50%, 75%, and 100% relative contamination mixtures of the PHC-contaminated and background site soil (< 100mg/kg total PHCs) for 28 and 21days, respectively. Survival and reproduction decreased significantly (Kruskal-Wallis Tests: p < 0.05, df = 4.0) in treatments of the contaminated site soil compared to the background soil. In both species, the most significant decline in survival and reproduction occurred between the 0% and 25% contaminated soil. Toxicity responses in the two springtails were ascribed to the standardized test design, short lifespans, and high fecundity in both species. This study showed that 25 + years of soil weathering has not eliminated the toxicity of fine-grained PHC-contaminated soil on two native terrestrial springtail species. Adverse effects to springtail health were attributed to exposure to soils dominated by genotoxic PHC Fraction 2 compounds and slow weathering processes due to the cold climate at the site.

Metagenomic survey reveals hydrocarbon biodegradation potential of Canadian high Arctic beaches

BackgroundDecreasing sea ice coverage across the Arctic Ocean due to climate change is expected to increase shipping activity through previously inaccessible shipping routes, including the Northwest Passage (NWP). Changing weather conditions typically encountered in the Arctic will still pose a risk for ships which could lead to an accident and the uncontrolled release of hydrocarbons onto NWP shorelines. We performed a metagenomic survey to characterize the microbial communities of various NWP shorelines and to determine whether there is a metabolic potential for hydrocarbon degradation in these microbiomes.ResultsWe observed taxonomic and functional gene evidence supporting the potential of NWP beach microbes to degrade various types of hydrocarbons. The metagenomic and metagenome-assembled genome (MAG) taxonomy showed that known hydrocarbon-degrading taxa are present in these beaches. Additionally, we detected the presence of biomarker genes of aerobic and anaerobic degradation pathways of alkane and aromatic hydrocarbons along with complete degradation pathways for aerobic alkane degradation. Alkane degradation genes were present in all samples and were also more abundant (33.8 ± 34.5 hits per million genes, HPM) than their aromatic hydrocarbon counterparts (11.7 ± 12.3 HPM). Due to the ubiquity of MAGs from the genus Rhodococcus (23.8% of the MAGs), we compared our MAGs with Rhodococcus genomes from NWP isolates obtained using hydrocarbons as the carbon source to corroborate our results and to develop a pangenome of Arctic Rhodococcus. Our analysis revealed that the biodegradation of alkanes is part of the core pangenome of this genus. We also detected nitrogen and sulfur pathways as additional energy sources and electron donors as well as carbon pathways providing alternative carbon sources. These pathways occur in the absence of hydrocarbons allowing microbes to survive in these nutrient-poor beaches.ConclusionsOur metagenomic analyses detected the genetic potential for hydrocarbon biodegradation in these NWP shoreline microbiomes. Alkane metabolism was the most prevalent type of hydrocarbon degradation observed in these tidal beach ecosystems. Our results indicate that bioremediation could be used as a cleanup strategy, but the addition of adequate amounts of N and P fertilizers, should be considered to help bacteria overcome the oligotrophic nature of NWP shorelines.

Insights into prokaryotic communities and their potential functions in biogeochemical cycles in cold seep.

Deep-sea cold seeps are among the most productive ecosystems, sustaining unique fauna and microbial communities through the release of methane and other hydrocarbons. Our study revealed that the influence of seepage fluid on the prokaryotic community in the water column is surprisingly limited, which challenges conventional views regarding the impact of seepage fluids. In addition, we identified that different DOM compositions play a crucial role in shaping the prokaryotic community composition, providing new insights into the factors driving microbial diversity in cold seeps. Furthermore, the study highlighted Proteobacteria as key and multifaceted drivers of biogeochemical cycles in cold seeps, emphasizing their significant contribution to complex interactions and processes. These findings offer a fresh perspective on the dynamics of cold-seep environments and their microbial communities, advancing our understanding of the biogeochemical functions in deep-sea environments.

Using visible and near infrared spectroscopy and machine learning for estimating total petroleum hydrocarbons in contaminated soils

Petroleum pollution in soil is very damaging to the areas affected by the accidental release of petroleum hydrocarbons and has destructive impacts on natural resources and environmental health. Therefore, its monitoring and analysis are critical, however, due to the cost and time associated with chemical approaches, finding a quick and cost-effective analytical method is valuable. This study was conducted to evaluate the potential of using visible near infrared (Vis-NIR) spectroscopy to predict total petroleum hydrocarbons (TPH) in polluted soils around the Shadegan ponds, in southern Iran. One hundred soil samples showing various degrees of pollution were randomly collected from topsoil (0–10 cm). The soil samples were analyzed for TPH using Vis-NIR reflectance spectroscopy in the laboratory and then following application of preprocessing transformation, partial least squares PLS regression as well as two machine learning models including random forest (RF), and support vector machine (SVM) were examined. The results showed that the reflectance values at 1725 nm and 2311 nm, respectively, served as indicative TPH reflectance features, exhibiting weaker reflection with rising TPH. Among the preprocessing methods, the baseline correction method indicated the highest performance than the others. According to the evaluation model criteria in the validation dataset, the efficiency of the three selected models was observed in the following order SVM &gt; RF &gt; PLS regression. The SVM model provided the best performance in the validation dataset with r2 = 0.85, root mean of square (RMSEP = 1.59 %, and the ratio of prediction to deviation (RPD) = 2.6. Overall, this study provided strong evidence supporting the considerable potential of Visible-NIR spectroscopy as a rapid and cost-effective technique for estimating TPH levels in oil-contaminated soils, surpassing traditional chemical analytical methods. Applying the mid-infrared spectrum (MIR) in combination with Visible-NIR data is expected to provide more comprehensive and accurate results when assessing soils in polluted areas, thereby enhancing the accuracy and reliability of the results across a diverse range of soil types.

Relationship between chemical composition and VOCs emission potential of similar paving grade road bitumen

ABSTRACT Exposure to bitumen fumes of workers during road pavement is a subject of interest in the field of industrial hygiene. Improvements have been made to technical means of prevention, but recent studies have shown that exposures need to be reduced. The development of early diagnosis method able to assess the volatile organic compounds (VOCs) emission potential would therefore be useful. The objective of this study was to outline a possible relationship between the chemical composition of bitumen and VOCs emission during heating using thirteen 35/50 paving-grade bitumen samples used in France. The samples are similar regarding their physical properties, elemental and SARA compositions. Molecular analysis investigations show that they contain the same class of compounds but in different proportions. Thermal analyses revealed different capacities of volatiles release potential. The combination of these data allowed to establish a relationship between chemical composition and volatile emission, leading to the identification of two groups of samples. We suggest three parameters based on molecular weight distribution, thermogravimetric profile and hydrocarbon release capacity that may distinguish bitumen by their emission potential prior to road pavement application. They may contribute to a methodology aiming to prevent workers exposure to bitumen fumes.

Behaviour and Peculiarities of Oil Hydrocarbon Removal from Rain Garden Structures

The expansion of impervious areas in the context of climate change leads to an increase in stormwater runoff. Runoff from roads, petrol stations, and service stations is the most common form of unintentional release of petroleum hydrocarbons (PHs). Rain gardens are an important practice for removing PHs from stormwater runoff, but little data exist on the removal efficiency and behaviour of these substances within the system. The main objective of the study is to investigate the effectiveness of rain gardens in removing pollutants such as diesel fuel (DF) and used engine oil (UEO) in a laboratory setting, as well as to study the behaviours of these pollutants within the system. Eight experimental columns (7.164 dm3) were packed with soil (bulk density 1.48 kg/dm3), river sand (1.6 kg/dm3), and gravel. Plants of the Physocarpus opulifolia Diabolo species were planted in the topsoil to study their resistance to PHs. For 6 months, the columns were watered with model PHs followed by simulated rain events. The concentrations of PHs in the leachate and soil media of the columns were determined by reverse-phase high-performance liquid chromatography (RP-HPLC). The results of HPLC indicated the absence of UEO and DF components in the leachates of all experimental columns, which suggested 100% removal of these substances from stormwater. The chromatography results showed that 95% of the modelled PHs were retained in the surface layer of the soil medium due to the sorption process, which led to a change in hydraulic conductivity over time. Recommendations are proposed to increase the service life of rain gardens designed to filter PHs from stormwater.

Treatment of hydrocarbon marine pollution with cloud point extraction

AbstractThe release of hydrocarbons (HC) into the marine environment has serious consequences, both economically and ecologically. This work presents an efficient process to remove HC pollution from seawater: cloud point extraction (CPE), considered to be a reliable, inexpensive, and environmentally friendly method, using the readily biodegradable nonionic surfactants Lutensol ON30 and Tergitol 15‐S‐7. A real salt water sample with a high chemical oxygen demand (COD = 1700 mg O2/L) was thus treated. First, the phase diagrams of the binary systems (water–surfactant), and the pseudo‐binary systems (water–surfactant–HC), were determined. Second, after a 24 h settling time, considered as optimal, the extraction results, that is, residual soluble COD, residual percentage of surfactant in the dilute phase and volume fraction of coacervate at equilibrium, were expressed in terms of temperature and initial surfactant concentration. For each parameter, the results obtained were modeled using the response surface methodology and represented on three‐dimensional diagrams. They show that the COD can be reduced to 10 and 15 mg O2/L, using Lutensol ON30 and Tergitol 15‐S‐7, respectively, under seawater temperature conditions. Finally, it was shown that the surfactant can be recycled. The present work demonstrates that CPE can reduce the HC content of seawater on a laboratory scale.

Oil Spill: Their Impact, Recovery and Future Prevention - A Review

Abstract: In this modern age of technology there are many others age of transformation but the oil (petroleum oil) is still transformed with the help of ships via see. During this transformation there are sever examples of getting failure which causes the oil to be separated on the surface of sea. As oil spill is the release of a liquid petroleum hydrocarbon into the environment, especially marine areas, due to human activity, and is a form of pollution. Although spills can happen on land as well, the word is typically used to describe oil spills that happen on ships and release oil into the ocean or other coastal waters. An oil separator is the compact and mobile device which ultimately separates the oil spreaded on the surface of see. It uses a wiper which is mounted on the flywheel. That flywheel rotates by the motor and contains oil scrubber. It soaks the oil through the periphery of the crown wheel. A mechanism is attached with the clutch which press fits the wheel and separates the oil by the wheel and collect it on the tank through the oil separated pipe. This plays an important role in saving the environment. Oil spills can have disastrous consequence fir society both economical, environmentally and socially

Release and generation of polycyclic aromatic hydrocarbons during co-pyrolysis of straw and coal: A case of corn straw and brown coal

The release of polycyclic aromatic hydrocarbons (PAHs) during the pyrolysis of corn straw, brown coal, and their mixtures was investigated in this study. The mixing ratios were the essential factor in determining the release and generation of PAHs. Adjustments to the mixing ratio revealed that the activation energy reached its nadir at a corn straw proportion of 75%. As the corn straw proportion increased, PAHs’ yield and toxic equivalents decreased. Furthermore, this study elucidated the generation of PAHs in the products by integrating experiments and reaction kinetics calculations. Low-ring and medium-ring PAHs were generated more readily, while the content of high-ring PAHs and product toxicity decreased rapidly upon adding corn straw. Finally, the high oxygen content in corn straw generates oxygen radicals that reduce the concentration of hydrocarbons and benzenes, which mitigates the generation of PAHs and enhances the quality of the resultant oil.

Oil Spill: Their Impact, Recovery and future prevention

An oil spill is the release of a liquid petroleum hydrocarbon into the environment especially marine areas due to human activity. Oil is the most common pollutant in the oceans. Oil spill have a devastating and long-term impact on water ways and coastal areas around the world. Oil spill can be partially controlled by chemical dispersion, combustion, mechanical containment and adsorption. These days there are so many import and export business are going in the world. Because of expansion of business and shipping by seas in the cheapest mode it’s used on large scale due to huge cargo shipping these are so many cases of oil spill in the sea. World has witnessed big oil spill accidents into the oceans and made huge impact on the industries as well as the ecosystem. Due to these oil spills there were so many deaths if sea mammals and bird species. After oil spills creates a slick (a thick layer of oil) that ensure the sunlight and oxygen pass through water. It affects the life below the water due to lack of oxygen and sunlight. As some of the oil are dangerous and poisonous they are quite harmful for human too when it comes to physical contact with them. This paper deals with the separation of oil and water to find out the better solution for oil recovery from the water surface mixture empress oil spill to produce oil free water. There are different methods to remove the oil form the water but disc type oil skimmer is mostly used and efficient. The oil skimmer is used to separate oil, from mixture of aqua and oil. It causes highly acidic alkaline and salty environment remains a great challenge to aquatic organisms and also pollute the coastal area. Every year 706 million gallons of waste oil enter the water resources and pollute the environment. Sea water has been polluted due to oil spillage, it also affects the water bodies. It the oil spill increase it result in serious damage to environment. About 90% of contaminated oil can be removed by continuous separation of oil by skimmer.

A multigenerational study can detect the evolutionary response to BaP exposure in the non-biting freshwater midge Chironomus riparius

The release of polycyclic aromatic hydrocarbons (PAHs) into the environment is posing a threat to ecosystems and human health. Benzo(a)pyrene (BaP) is considered a biomarker of PAH exposure and is classified as a Group 1 carcinogen. However, it was not known whether BaP is mutagenic, i.e. induces inherited germline mutations. In this study, we used a recently established method, which combines short-term mutation accumulation lines (MAL) with whole genome sequencing (WGS) to assess mutagenicity in the non-biting midge Chironomus riparius. The mutagenicity analysis was supplemented by an evaluation of the development of population fitness in three successive generations in the case of chronic exposure to BaP at a high concentration (100 μg/L). In addition, the level of ROS-induced oxidative stress was examined in vivo. Exposure to the higher BaP concentration led to an increase in germline mutations relative to the control, while the lower concentration showed no mentionable effect. Against expectations, BaP exposure decreased ROS-level compared to the control and is thus probably not responsible for the increased mutation rate. Likewise, the higher BaP concentration decreased fitness measured as population growth rate per day (PGR) significantly over all generations, without signs of rapid evolutionary adaptations. Our results thus highlighted that high BaP exposure may influence the evolutionary trajectory of organisms.

Impact of oil-extraction/port activities on distribution and exchange of PAHs/APAHs/NPAHs/OPAHs in water and sediment of the Yellow River Delta, China

The Yellow River Delta (YRD) is rich in oil, natural gas, and land resources. With the expansion of an important oil production base in North China, the increased discharge of Polycyclic aromatic hydrocarbons (PAHs) and alkylated/nitrated/oxygenated PAHs (APAHs/NPAHs/OPAHs) into the Yellow River poses a potential risk to the aquatic ecosystem and human health. A total of 42 samples were gathered from trunk streams and tributaries within the YRD region during the wet and dry seasons, and 19 PAHs, 5 APAHs, 16 NPAHs, and 7 OPAHs were measured. The concentrations of ƩPAHs, ƩAPAHs, ƩNPAHs and ƩOPAHs ranged between 29 and 620 ng/L, 6.9–81 ng/L, 0.64–9.0 ng/L, and 7.2–81 ng/L in water, respectively, and 27–420 ng/g, 5.1–130 ng/g, 0.19–1.8 ng/g and 3.9–51 ng/g in sediment, respectively. The oil extraction activities resulted in an increased presence of middle-high molecular weight PAHs and APAHs in sediment, and port activities had a notable influence on the proportion of 1-Methylpyrene in both water and sediments. The fugacity fraction analysis suggested that sediments was a secondary source of OPAHs, while benzo[k]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, and 5-methylchrysene migrated from water to sediment. The main contributors to PAHs, APAHs, NPAHs, and OPAHs in water and sediment were combustion and petroleum sources. Compared to water, sediment displayed a heightened ecological risk associated with PAHs, APAHs, NPAHs, and OPAHs. And adults residing in the YRD region were at higher risk of cancer than children which deserve special attention.

Formation potential of disinfection byproducts during chlorination of petroleum hydrocarbon-contaminated drinking water

Recent leaks of underground fuel storage tanks in the Pearl Harbor region have led to direct release of un-weathered petroleum hydrocarbons (PHCs) into drinking water sources, which then directly underwent chlorination disinfection treatment. Since the control of disinfection byproducts (DBPs) traditionally focuses natural organic matters (NOM) from source water and little is known about the interactions between free chlorine and un-weathered PHCs, laboratory chlorination experiments in batch reactors were conducted to determine the formation potential of DBPs during chlorination of PHC-contaminated drinking water. Quantitative analysis of regulated DBPs showed that significant quantities of THM4 (average 3,498 μg/L) and HAA5 (average 355.4 μg/L) compounds were formed as the result of chlorination of un-weathered PHCs. Amongst the regulated DBPs, THM4, which were comprised primarily of chloroform and bromodichloromethane, were more abundant than HAA5. Numerous unregulated DBPs and a large diversity of unidentified potentially halogenated organic compounds were also produced, with the most abundant being 1,1-dichloroacetone, 1,2-dibromo-3-chloropropane, chloropicrin, dichloroacetonitrile, and trichloracetonitrile. Together, the results demonstrated the DBP formation potential when PHC-contaminated water undergoes chlorination treatment. Further studies are needed to confirm the regulated DBP production and health risks under field relevant conditions.

Acoustic evidence of hydrocarbon release associated with the Spitsbergen Transform Fault, north of the Molloy Ridge, Fram Strait

Hydrocarbon gases formed from biotic and abiotic processes are released through the seafloor at different locations around the world. They have been widely observed directly in video and photo data, and indirectly on echosounder data. Even though biotic gas generation is a very common process, abiotic gas generation is limited to regions where serpentinization of ultramafic rocks occur. Indications of abiotic gas occurrences are therefore sparse and much speculated upon. Here, we investigated the Spitsbergen Transform Fault, the Molloy Ridge, the Molloy Deep, and the Molloy Transform Fault/Fracture Zone, (a transform fault-bounded pull-a-part region offshore western Svalbard) where both processes may be active. Multiple acoustic gas flares, ∼1,770 and ∼3355 m high above the seafloor (tallest ever recorded), were observed indicating active migration and seepage of hydrocarbons. The proximity to the mid oceanic ridge and the documented high heat flow suggests the influence of high temperatures on organic-rich sedimentary deposits. Deep seismic data and other geological information available indicate that the main source of gas could be from thermal cracking of either pre- or syn-rift source rock organic material, potentially mixed with methane from serpentinization of mantle rocks (peridotites). Correlation with seismic stratigraphy from Ocean Drilling Program (ODP) Sites 910 and 912 on the adjacent Yermak Plateau suggests that the sedimentary source rocks may be present at the northern flank of the Molloy Ridge and within the deep graben along the Spitsbergen Transform Fault. The ∼3 km thick sedimentary succession in high heat flow zones within the transform fault and the active bounding faults allow generation and migration of hydrocarbons to the seafloor and sustains present day seepage.

The effect of bioturbation on the release behavior of polycyclic aromatic hydrocarbons from sediments: A sediment–seawater microcosm experiment combined with a fugacity model

The effects of two benthonic species, Perinereis aibuhitensis and Matuta planipes Fabricius, on the release of polycyclic aromatic hydrocarbons (PAHs) from sediments were investigated using a sediment–seawater microcosm. A Level IV fugacity model was used to simulate the behavior and fate of PAHs in the environment. This study revealed that both benthos significantly influenced the release of PAHs, and Matuta planipes Fabricius had a stronger disturbance effect than another. The final concentrations of Matuta planipes Fabricius group, Perinereis aibuhitensis group and the control group in the seawater phase reached 10.8, 9.94 and 7.90 μg/L, respectively. There were certain differences in the behaviour of the two benthonic species. Matuta planipes Fabricius caused more sediment resuspension, while Perinereis aibuhitensis increased the total organic carbon (TOC) content in the environment. The vertical concentration distribution of sediment indicated that vertical mixing was slightly stronger in the Matuta planipes Fabricius group than that in the Perinereis aibuhitensis group. The fugacity model effectively simulated the release behavior of PAHs, providing insight into PAH transport and distribution. The results demonstrated that bioturbation could promote the release of PAHs from seawater. The amount of PAHs released was significantly correlated with the biological habits of the benthos.