Bioremediation of petroleum refinery wastewater by fungal stains isolated from the fishing harbour of Bizerte (Mediterranean Sea)

The study was conducted in order to explore the potential of fungi isolated from surface and bottom seawater collected from the fishing harbour of Bizerte on the bioremediation of industrial effluent (IE) contaminated by petroleum hydrocarbon. Among the 128 fungal isolates, 11 were isolated from surface seawater and 7 from bottom seawater, representing 18 taxa in total. The gas chromatography mass spectrometry (GC-MS) was used for the determination of hydrocarbon compounds in IE. An initial screening of fungal growth using six concentrations ranged between 20 and 70% (v/v) IE has allowed the identification of the optimal concentration for fungal growth as well as selection of species able to tolerate high amounts of hydrocarbon. Colorimetric test employing 2,6-dichlorophenol indophenol and gravimetric method was applied for the assessment of fungal growth using 20% EI. By checking the phylogenetic affiliation of the high-performing stains as identified using ITSr DNA sequence, a dominance of Ascomycetes was detected. Indeed, Aspergillus terreus and Penicillium expansum may degrade 82.07 and 81.76% of residual total petroleum hydrocarbon (TPH), respectively. Both species were collected from surface seawater. While, Aspergillus niger, Colletotrichum sp and Fusarium annulatum displayed comparable degradation rates 40.43%, 41.3%, and 42.03%, respectively. The lowest rate of degradation 33.62% was detected in Emericellopsis phycophila. All those species were isolated from bottom seawater, excepting A. niger isolated from surface water. This work highlighted the importance of exploring the potential of fungi isolated from the natural environment on the bioremediation of industrial effluent. Our results promoted the investigation of the potential of the high-performing isolates A. terreus and P. expansum on the bioremediation of IE at pilot-scale and then in situ.

Photochemical loss with consequential underestimation in active VOCs and corresponding secondary pollutions in a petrochemical refinery, China

The photochemical loss of volatile organic compounds (VOCs) significantly alters the capturing source profiles in high-reactivity VOC species and results in an underestimation of secondary pollutants such as ozone (O3) and secondary organic aerosol (SOA). Utilising speciated VOC data from large petrochemical refineries, the research assesses the photochemical loss of various VOC species. Air samples from multiple sites revealed over 99 VOCs, with initial concentrations estimated via a photochemical age-based parameterisation method. The comparative analysis of initial and measured VOC values provided insights into the VOCs' photochemical degradation during transport. Findings highlight that the average photochemical loss of total VOCs (TVOCs) across different refinery process areas varied between 4.9 and 506.8 ppb, averaging 187.5 ± 128.7 ppb. Alkenes dominated the consumed VOCs at 83.1 %, followed by aromatic hydrocarbons (9.3 %), alkanes (6.1 %), and oxygenated VOCs (OVOCs) at 1.6 %. The average consumption-based ozone formation potential (OFP) and SOA formation potential (SOAP) were calculated at 1767.3 ± 1251.1 ppb and 2959.6 ± 2386.3 ppb, respectively. Alkenes, primarily isoprene, 1,3-butadiene, and acetylene, were the most significant contributors to OFP, ranging from 19.9 % to 95.5 %. Aromatic hydrocarbons, predominantly monocyclic aromatics like toluene, xylene, styrene, and n-dodecane, were the primary contributors to SOAP, accounting for 5.0 % to 81.3 %. This research underscores the significance of considering photochemical losses in VOCs for accurate secondary pollution assessment, particularly in high-reactivity VOC species. It also provides new detection methods and accurate data for the characterization, source analysis and chemical conversion of volatile organic compounds in the petroleum refining industry.

Performance of electro-Fenton process for the treatment of synthetic sulphidic spent caustic waste stream generated from petroleum refineries

Sulphidic spent caustic (SSC) is an alkaline waste stream which is generated during caustic scrubbing of liquefied petroleum gas and ethylene products. Due to presence of high concentrations of sulphides and phenols, the waste stream requires proper treatment before mixing with the low strength wastewater streams produced from other refinery operations. Electrochemical process is an emerging treatment method that can work efficiently at ambient conditions. The present study reports performance of electro-Fenton (EF) process for the treatment of synthetic SSC wastewater (sulphides = 10 g L-1, phenol = 2 g L-1 and pH = 12.9). The EF runs were carried out for 2 h duration in a reactor equipped with iron electrodes. The effects of H2O2 dose (0.26-1.3 M), current density (1-20 mA cm-2), pH (4.5-12.9) and stirring speed (100-1000 rpm) were investigated on removal of pollutants. The H2O2 was rapidly consumed in initial 30 min during which the significant fraction of the pollutants was degraded or removed. The optimum conditions for EF process were found to be as follows: pH = 4.5, H2O2 dose = 1.05 M, current density = 5 mA cm-2 and stirring speed = 500 rpm. At these conditions, the maximum sulphide and phenol removals from the wastewater were 98% and 91%, respectively. The results will be helpful to the wastewater treatment plant operators worldwide dealing with high concentrations of such pollutants.

Assessment of the internal and external exposure risks to methylsiloxanes in communities near a petroleum refinery

Methylsiloxanes (MSs) are widely used in industrial production and have attracted much attention due to their potential health risks to humans. MSs are present in emissions from petroleum refining, and it is therefore important to assess the health risks to residents living near refineries. In this study, we evaluated the pollution characteristics and human exposure risks of three cyclic MS (CMS) oligomers (D4-D6) in areas upwind and downwind of a petroleum refinery. The concentrations of total CMSs were 4-33 times higher in the downwind than upwind areas. At the same sampling site, the concentrations of CMSs were higher indoors than outdoors. The maximum concentration of CMSs was found in the indoor environment 200 m downwind of the petroleum refinery (75 μg/m3 in air and 2.3 μg/g in dust). The concentrations and detection rates of CMSs in plasma samples were higher in the downwind than upwind residents. Although residents living downwind of the petroleum refinery were a non-occupationally exposed population, they should be considered a highly CMS-exposed population because of their extremely high internal exposure doses. Inhalation exposure was the main source of CMSs in the plasma of these residents. When different exposure pathways were investigated, inhalation exposure was the major contributor to the average daily dose in residents of locations near the petroleum refinery, whereas the dermal absorption of personal care products was the major contributor at other sites. Although the overall risks of exposure to total CMSs were below the chronic reference dose for all exposure pathways, the combined joint toxic effects of various CMSs remain unclear. Further studies are therefore required to determine the exposure risks and subsequent health effects of CMSs for the residents of these areas.

Residential exposure to petroleum refining and stroke in the southern United States

BACKGROUND

The southern United States (U.S.) sustains a disproportionate burden of incident stroke and associated mortality, compared to other parts of the U.S. A large proportion of this risk remains unexplained. Petroleum production and refining (PPR) is concentrated within this region and emits multiple pollutants implicated in stroke pathogenesis. The relationship between residential PPR exposure and stroke has not been studied.

OBJECTIVE

We aimed to investigate the census tract-level association between residential PPR exposure and stroke prevalence for adults (≥18 years) in seven southern U.S. states in 2018.

METHODS

We conducted spatial distance- and generalized propensity score-matched analysis that adjusts for sociodemographic factors, smoking, and unmeasured spatial confounding. PPR was measured as inverse-distance weighted averages of petroleum production within 2.5km or 5km from refineries, which was strongly correlated with measured levels of sulfur dioxide, a byproduct of PPR.

RESULTS

The prevalence of self-reported stroke ranged from 0.4% to 12.7% for all the census tracts of the seven states. People with low socioeconomic status and of Hispanic ethnicity resided closer to petroleum refineries. The non-Hispanic Black population was exposed to higher PPR, while the non-Hispanic White population was exposed to lower PPR. Residential PPR exposure was significantly associated with stroke prevalence. One standard deviation increase in PPR within 5km from refineries was associated with 0.22 (95% confidence interval: 0.09, 0.34) percentage point increase in stroke prevalence. PPR explained 5.6% (2.4, 8.9) of stroke prevalence in the exposed areas. These values differed by states: 1.1% (0.5, 1.7) in Alabama to 11.7% (4.9, 18.6) in Mississippi, and by census tract-level: 0.08% (0.03, 0.13) to 25.3% (10.6, 40.0).

CONCLUSIONS

PPR is associated with self-reported stroke prevalence, suggesting possible links between pollutants emitted from refineries and stroke. The increased prevalence due to PPR may differ by sociodemographic factors.

Research on accounting and detection of volatile organic compounds from a typical petroleum refinery in Hebei, North China

A volatile organic compound (VOC) emissions inventory of the petroleum refinery in Hebei was established. This refinery emits 1859.2 tons of VOCs per year, with wastewater collection and treatment system being the largest emissions source, accounting for 59.6% individually, followed by the recirculating cooling water system (13.4%), storage tanks (11.1%), and equipment leaks (9.4%). Organized and fugitive samples were collected simultaneously for different processes of each emissions source. A total of 100 VOC species were characterized and quantified using a gas chromatography-mass spectrometry/flame ionization detection system. The VOC emissions concentrations and chemical composition of each process were quite different. Most of the processes used alkanes as the main chemome. We concluded from the composite source profile weighted by the amount of VOC emissions that the characteristic species of this petroleum refinery were ethane (15.4%), propylene (11.7%), propane (8.5%), iso-pentane (8.3%), and toluene (4.7%). The ozone (O₃) formation potential (OFP) and secondary organic aerosol formation potential (SOAP) were evaluated, and the results indicated that alkenes (mainly propylene) and aromatics (mainly toluene) were the priority control compounds. This study clarifies the current status of VOC emissions in the refinery in terms of emissions intensity, emissions components, and O₃ and SOA reactivity. The key emissions sources and species screened provide scientific support for reducing refined emissions from the petrochemical industry.

Control of the temperature in a petroleum refinery heating furnace based on a robust modified Smith predictor

The robust control of the crude oil outlet temperature uniformity in a heating furnace of a petroleum refinery is addressed. A reliable dynamic model of the nominal process has been attained using a system identification procedure based on real-time data. This procedure yields a second order model with a dominant time-delay. A PI controller embedded in a modified Smith predictor structure is therefore proposed. Sensitivity and robustness properties of this control system are analytically obtained. Based on that, a tuning procedure is developed for this control system which has lower sensitivity to disturbances than the standard Smith predictor while guaranteeing the system stability when plant parameters change. Simulations are carried out of the proposed control system and other well-known linear advanced process control systems. The comparison of the obtained results shows the superior performance of our control system in most cases, both in rejecting a variety of disturbances and in maintaining the closed-loop stability when the process parameters change.

Source profiles, emission factors and associated contributions to secondary pollution of volatile organic compounds (VOCs) emitted from a local petroleum refinery in Shandong

An in-depth study was conducted to quantify and characterize VOC emissions from a petroleum refinery located in Shandong, China. The VOC emission inventory established in this study showed that storage tanks were the largest emission source, accounting for 56.4% of total emissions, followed by loading operations, wastewater collection and treatment system, process vents, and equipment leaks. Meanwhile, the localization factors for refining, storage tanks and loading operations were calculated, which were 1.33, 0.75 and 0.31g VOCs/kg crude oil refined. Furthermore, the characteristics of fugitive and organized emissions were determined for various processes and emission sources using a gas chromatography-mass spectrometry/flame ionization detection (GC-MS/FID) system. Most samples contained mainly alkanes, but the total VOC concentrations and key species varied greatly among processes. The source profile of the refinery, synthesized using the weighted average method, indicated that cis-2-butene (14.5%), n-pentane (10.2%), n-butane (7.4%), isopentane (6.5%) and MTBE (5.9%) were the major species released by this refinery. Assessment of O₃ and secondary organic aerosol formation potentials were completed, and the results indicated that cis-2-butene, m/p-xylene, toluene, n-pentane, isopentane, benzene, o-xylene and ethylbenzene were the active species for which treatment should be prioritized.

A quantitative sustainability assessment framework for petroleum refinery projects

Petroleum refinery industry (PRI) projects are inherently unsustainable for the most part, because of their environmentally and socially negative potential effects; nonetheless, their development is inevitable due to their deep positive impact on economic development for stakeholders and the society at large. With these competing realities, it is extremely important to develop tools that can quantify the level of sustainability of various alternatives, so managers can make informed decisions about how to go forward with these projects. Due to the complexity of life cycle and sustainability assessment of PRI projects, in addition to their complicated multidisciplinary nature, indicator-based approaches are used oftentimes as sustainability assessment tools. In this paper, an indicator-based sustainability framework is proposed based on the literature review at the qualitative level to cover the pillars of sustainability (which is social, economic, and environmental). Then, a quantitative set of sustainability assessment factors is developed which tries to address global sustainability concerns and to reinforce the understanding of sustainability by utilizing quantitative means. UN sustainability indicators were used as the basis for the study, and the framework was developed further to reflect the specifics of PRI projects; the result of this step is 140 quantitative sustainability factors. To realize the highly relevant global concerns regarding sustainability assessment factors to be applied to PRI projects, the screening process has been done by Delphi technique in combination with Fuzzy set theory, to select the most important as well as relevant indicators which results in 101 relevant quantitative sustainability factors; then, a panel of experts has converted the screened quantitative factors to meaningful ones for PRI projects. The expert panel has then interpreted the list of factors, according to expert judgments. Finally, a comparative study has been done to see how the results will compare with those of frequently used systems. The results of the study are of primary importance due to their applicability in sustainable decision-making, as well as for future studies. The reinforced indicator-based sustainability framework will make a core, not only to assess existing plants with various characteristics but also for new refineries that are going to be developed based on sustainability principles.

Emission losses and dispersion of volatile organic compounds from tank farm of petroleum refinery complex

Emission characteristics of volatile organic compounds (VOC) emitted from the tank farm of petroleum refinery were evaluated in this study in order to analyze for the potential impacts on health and odor nuisance problems. Estimation procedures were carried out by using the U.S.EPA TANK 4.0.9d emission model in conjunction with direct measurements of gas phase of each stored liquid within aboveground storage tanks. Results revealed that about 61.12% of total VOC emitted from the tank farm by volume were alkanes, in which pentane were richest (27.4%), followed by cyclopentane (19.22%), propene (19.02%), and isobutene (14.22%). Mostly of pentane (about 80%) were emitted from the floating roof tanks contained crude oil corresponded to the largest annual throughput of crude oil as compared with other petroleum distillates. Emission data were further analyzed for their ambient concentration using the AERMOD dispersion model in order to determine the extent and magnitude of odor and health impacts caused by pentane. Results indicated that there was no health impact from inhalation of pentane. However, predicted data were higher than the odor threshold values of pentane which indicated the possibility of odor nuisance problem in the vicinity areas of the refinery. In order to solve this problem, modification of the type of crude oil storage tanks from external floating roof to domed external floating roof could be significant success in reduction of both emissions and ambient concentrations of VOC from petroleum refinery tank farm.

Evaluation of adsorbent and ion exchange resins for removal of organic matter from petroleum refinery wastewaters aiming to increase water reuse

The oil refinery industry seeks solutions to reduce its water uptake and consumption by encouraging the reuse of internal streams and wastewater from treatment systems. After conventional treatment the petroleum refinery wastewater still contains a considerable quantity of recalcitrant organics and the adsorption on activated carbon is currently used in Brazilian refineries, although it is still expensive due to the difficulty of its regeneration. This study evaluated the use of adsorbent and ion exchange resins for the removal of organic matter from refinery wastewater after conventional treatment in order to verify its feasibility, applying successive resin regenerations and comparing the results with those obtained for activated carbon process. Adsorption isotherms experiments were used to evaluate commercial resins, and the most efficient was subjected to column experiments, where absorbance (ABS) and total organic carbon (TOC) removal were measured. The adsorption isotherm of the best resin showed an adsorptive capacity that was 55% lower than that of activated carbon. On the other hand, the column experiments indicated good removal efficiency, and the amount of TOC in the treated wastewater was as good as has been reported in the literature for activated carbon. The regeneration efficiency of the retained organics ranged from 57 to 94%, while regenerant consumption ranged from 12 to 79% above the amount recommended by the resin supplier for the removal of organic material from natural sources, showing the great resistance of these recalcitrant compounds to desorption. Finally, an estimate of the service life of the resin using intermediate regeneration conditions found it to be seven times higher than that of activated carbon when the latter is not regenerated.

Adaption and use of a quadcopter for targeted sampling of gaseous mercury in the atmosphere

We modified a popular and inexpensive quadcopter to collect gaseous mercury (Hg) on gold-coated quartz cartridges, and analyzed the traps using cold vapor atomic fluorescence spectrometry. Flight times averaged 16 min, limited by battery life, and yielded > 5 pg of Hg, well above the limit of detection (< 0.2 pg). We measured progressively higher concentrations upon both vertical and lateral approaches to a dish containing elemental Hg, demonstrating that the method can detect Hg emissions from a point source. Using the quadcopter, we measured atmospheric Hg near anthropogenic emission sources in the mid-south USA, including a municipal landfill, coal-fired power plant (CFPP), and a petroleum refinery. Average concentrations (± standard deviation) immediately downwind of the landfill were higher at ground level and 30 m compared to 60 and 120 m (5.3 ± 0.5 ng m^-3, 5.4 ± 0.7 ng m^-3, 4.2 ± 0.7 ng m^-3, and 2.5 ± 0.3 ng m^-3, respectively). Concentrations were also higher at an urban/industrial area (Memphis) (3.3 ± 0.9 ng m^-3) compared with a rural/background area (1.5 ± 0.2 ng m^-3). Due to airspace flight restrictions near the CFPP and refinery, we were unable to access near-field (stack) plumes and did not observe differences between upwind and downwind locations. Overall, this study demonstrates that highly maneuverable multicopters can be used to probe Hg concentrations aloft, which may be particularly useful for evaluating Hg emissions from remote landscapes and transient sources that are inadequately characterized and leading to uncertainties in ecosystem budgets.

Data on evolutionary relationships between hearing reduction with history of disease and injuries among workers in Abadan Petroleum Refinery, Iran

The present work examined data obtained during the analysis of Hearing Reduction (HR) of Abadan Petroleum Refinery (Abadan PR) workers of Iran with a history of disease and injuries. To this end, all workers in the refinery were chosen. In this research, the effects of history of disease and injury including trauma, electric shock, meningitis-typhoid disease and genetic illness as well as contact with lead, mercury, CO₂ and alcohol consumption were evaluated (Lie, et al., 2016) [1]. After the completion of the questionnaires by workers, the coded data were fed into EXCELL. Statistical analysis of data was carried out, using SPSS 16.

Emission characteristics of volatile organic compounds and their secondary organic aerosol formation potentials from a petroleum refinery in Pearl River Delta, China

A campaign was carried out to measure the emission characteristics of volatile organic compounds (VOCs) in different areas of a petroleum refinery in the Pearl River Delta (PRD) region in China. In the refining area, 2-methylpentane, 2,3-dimethylbutane, methylcyclopentane, 3-methylhexane, and butane accounted for >50% of the total VOCs; in the chemical industry area, 2-methylpentane, p-diethylbenzene, 2,3-dimethylbutane, m-diethylbenzene and 1,2,4-trimethylbenzene were the top five VOCs detected; and in the wastewater treatment area, the five most abundant species were 2-methylpentane, 2,3-dimethylbutane, methylcyclopentane, 3-methylpentane and p-diethylbenzene. The secondary organic aerosol (SOA) formation potential was estimated using the fractional aerosol coefficients (FAC), secondary organic aerosol potential (SOAP), and SOA yield methods. The FAC method suggests that toluene, p-diethylbenzene, and p-diethylbenzene are the largest contributors to the SOA formation in the refining, chemical industry, and wastewater treatment areas, respectively. With the SOAP method, it is estimated that toluene is the largest contributor to the SOA formation in the refining area, but o-ethyltoluene contributes the most both in the chemical industry and wastewater treatment areas. For the SOA yield method, aromatics dominate the yields and account for nearly 100% of the total in the three areas. The SOA concentrations estimated of the refining, chemical industry and wastewater treatment areas are 30, 3835 and 137μgm^-3, respectively. Despite the uncertainties and limitations associated with the three methods, the SOA yield method is suggested to be used for the estimation of SOA formation from the petroleum refinery. The results of this study have demonstrated that the control of VOCs, especially aromatics such as toluene, ethyltoluene, benzene and diethylbenzene, should be a focus of future regulatory measures in order to reduce PM pollution in the PRD region.

VOCs emission rate estimate for complicated industrial area source using an inverse-dispersion calculation method: A case study on a petroleum refinery in Northern China

This study aimed to apply an inverse-dispersion calculation method (IDM) to estimate the emission rate of volatile organic compounds (VOCs) for the complicated industrial area sources, through a case study on a petroleum refinery in Northern China. The IDM was composed of on-site monitoring of ambient VOCs concentrations and meteorological parameters around the source, calculation of the relationship coefficient γ between the source's emission rate and the ambient VOCs concentration by the ISC3 model, and estimation of the actual VOCs emission rate from the source. Targeting the studied refinery, 10 tests and 8 tests were respectively conducted in March and in June of 2014. The monitoring showed large differences in VOCs concentrations between background and downwind receptors, reaching 59.7 ppbv in March and 248.6 ppbv in June, on average. The VOCs increases at receptors mainly consisted of ethane (3.1%-22.6%), propane (3.8%-11.3%), isobutane (8.5%-10.2%), n-butane (9.9%-13.2%), isopentane (6.1%-12.9%), n-pentane (5.1%-9.7%), propylene (6.1-11.1%) and 1-butylene (1.6%-5.4%). The chemical composition of the VOCs increases in this field monitoring was similar to that of VOCs emissions from China's refineries reported, which revealed that the ambient VOCs increases were predominantly contributed by this refinery. So, we used the ISC3 model to create the relationship coefficient γ for each receptor of each test. In result, the monthly VOCs emissions from this refinery were calculated to be 183.5 ± 89.0 ton in March and 538.3 ± 281.0 ton in June. The estimate in June was greatly higher than in March, chiefly because the higher environmental temperature in summer produced more VOCs emissions from evaporation and fugitive process of the refinery. Finally, the VOCs emission factors (g VOCs/kg crude oil refined) of 0.73 ± 0.34 (in March) and 2.15 ± 1.12 (in June) were deduced for this refinery, being in the same order with previous direct-measurement results (1.08-2.65 g VOCs/kg crude oil refined). An inverse-dispersion calculation method was applied to estimate VOCs emission rate for a petroleum refinery, being 183.5 ton/month (March) and 538.3 ton/month (June).

Trace metal exposure is associated with increased exhaled nitric oxide in asthmatic children

BACKGROUND

Children with asthma experience increased susceptibility to airborne pollutants. Exposure to traffic and industrial activity have been positively associated with exacerbation of symptoms as well as emergency room visits and hospitalisations. The effect of trace metals contained in fine particulate matter (aerodynamic diameter 2.5 μm and lower, PM2.5) on acute health effects amongst asthmatic children has not been well investigated. The objective of this panel study in asthmatic children was to determine the association between personal daily exposure to ambient trace metals and airway inflammation, as measured by fractional exhaled nitric oxide (FeNO).

METHODS

Daily concentrations of trace metals contained on PM2.5 were determined from personal samples (n = 217) collected from 70 asthmatic school aged children in Montreal, Canada, over ten consecutive days. FeNO was measured daily using standard techniques.

RESULTS

A positive association was found between FeNO and children's exposure to an indicator of vehicular non-tailpipe emissions (8.9 % increase for an increase in the interquartile range (IQR) in barium, 95 % confidence interval (CI): 2.8, 15.4) as well as exposure to an indicator of industrial emissions (7.6 % increase per IQR increase in vanadium, 95 % CI: 0.1, 15.8). Elevated FeNO was also suggested for other metals on the day after the exposure: 10.3 % increase per IQR increase in aluminium (95 % CI: 4.2, 16.6) and 7.5 % increase per IQR increase in iron (95 % CI: 1.5, 13.9) at a 1-day lag period.

CONCLUSIONS

Exposures to ambient PM2.5 containing trace metals that are markers of traffic and industrial-derived emissions were associated in asthmatic children with an enhanced FeNO response.