Total Petroleum Hydrocarbon Concentration Research Articles

A preliminary study on the eco-environmental geological issue of in-situ oil shale mining by a physical model

As traditional methods of oil shale production emitting high levels of pollutants, in-situ exploitation has aroused great concerns. In order to study the effect of in-situ pyrolysis products on the underground environment, an in-situ oil shale exploitation of underground environment impact laboratory simulation system was designed. Based on the hydrogeological condition of oil shale area in Nong'an City, a physical simulation test was conducted. It was found the temperature of surrounding layers continued to be perturbed after heating of the formation had stopped. The time during which the temperature was perturbed was about 4–5 times the heating period. During the simulation test, stray gas migration through fractures and faults was considered a mechanism for groundwater contamination. In the test, the maximum TOC content in aquifer was the value of 97.0 mg/L. The maximum total petroleum hydrocarbon (TPH) content of the simulated formation was 129 mg/kg after oil pyrolysis.

Toxicity of Refugio Beach Oil to Sand Crabs (Emerita analoga), Blue Mussels (Mytilus sp.), and Inland Silversides (Menidia beryllina).

Monterey formation crude oil spilled from an onshore pipeline and entered the surf zone near Refugio State Beach, Santa Barbara County, California (USA) on 19 May 2015. During this season, early life stages of many marine fish and invertebrates were present. Surf zone water and beach porewater samples were collected during the 4 mo after the spill and 2 yr later for chemical analyses. Elevated polycyclic aromatic hydrocarbon (PAH) and total petroleum hydrocarbon concentrations were observed in surf zone water and porewater near the release point, declining with distance and time. Early life stage toxicity was investigated by conducting 6- and 7-d static renewal bioassays with sand crab (Emerita analoga) post larvae (megalopae) and inland silverside larvae (Menidia beryllina), respectively, and a 48-h blue mussel (Mytilus sp.) embryo development bioassay. Dilutions of a high-energy water accommodated fraction of the Refugio Beach oil and a seawater control were prepared to simulate surf zone PAH concentrations (nominal PAH45 ; 0, 0.5, 1, 5, 10, 50, 100, and 500 µg/L). The PAH45 median lethal concentrations (LC50s), based on measured concentrations, were 381 µg/L for Mytilus sp., 75.6 µg/L for Menidia, and 40.9 µg/L for Emerita. Our results suggest that PAH concentrations in coastal waters of the spill-affected area were potentially lethal to early life stages of fish and invertebrates. Environ Toxicol Chem 2021;40:2578-2586. © 2021 SETAC.

Dynamics of bacterial functional genes and community structures during rhizoremediation of diesel-contaminated compost-amended soil

The objective of this study was to characterize the effects of organic soil amendment (compost) on bacterial populations associated with petroleum hydrocarbon (PH) degradation and nitrous oxide (N2O) dynamics via pot experiments. Soil was artificially contaminated with diesel oil at total petroleum hydrocarbon (TPH) concentration of 30,000 mg·kg-soil−1 and compost was mixed with the contaminated soil at a 1:9 ratio (w/w). Maize seedlings were planted in each pot and a total of ten pots with two treatments (compost-amended and unamended) were prepared. The pot experiment was conducted for 85 days. The compost-amended soil had a significantly higher TPH removal efficiency (51.1%) than unamended soil (21.4%). Additionally, the relative abundance of the alkB gene, which is associated with PH degradation, was higher in the compost-amended soil than in the unamended soil. Similarly, cnorB and nosZ (which are associated with nitric oxide (NO) and N2O reduction, respectively) were also highly upregulated in the compost-amended soil. Moreover, the compost-amended soil exhibited higher richness and evenness indices, indicating that bacterial diversity was higher in the amended soil than in the unamended soil. Therefore, our findings may contribute to the development of strategies to enhance remediation efficiency and greenhouse gas mitigation during the rhizoremediation of diesel-contaminated soils.

Changes in Adsorption Characteristics of Heavy Metals and Organic Pollutants Following Pyrolytic Treatment of Petroleum-Contaminated Dredged Sediment

Objectives : This study investigated the changes in adsorption characteristics of dredged sediment for heavy metals and organic pollutants after petroleum contamination followed by pyrolytic treatment.Methods : Pyrolytic treatment was conducted at two heating temperatures, 300℃ and 500℃, for 30 min using muffle furnace. Sediment spiked with No. 6 Fuel Oil at initial total petroleum hydrocarbon (TPH) concentrations of 5,000-50,000 mg/kg was used. Sorption experiments were conducted for heavy metals (Cd, Cu, Pb, Zn, Ni, Hg, As, Cr), phenanthrene and bisphenol A using clean sediment (sediment before the petroleum spiking) and pyrolyzed sediment.Results and Discussion : Pyrolytic treatment at 500℃ showed excellent TPH removal efficiency, resulting in the residual concentration of less than 50 mg/kg for all initial TPH contamination levels. High efficiencies (> 98%) were observed for the sorptive removal of Cu, Zn and Pb in the aqueous phase for both the two sediments. The removal efficiencies of Ni and Cd from the aqueous phase using pyrolyzed sediment were 31% and 24% lower than those using clean sediment, respectively, due to the reduced oxygen-containing functional group content and specific surface area after the pyrolytic treatment. The sediment-water distribution coefficient (Kd) and sediment organic carbon-water distribution coefficient (Koc) values of bisphenol A and phenanthrene in pyrolyzed sediment were considerably higher than in clean sediment due to the high organic compound sorption affinity exhibited by carbonaceous matter that was generated during the pyrolytic sediment treatment.Conclusions : The capability of pyrolytic treatment of dredged sediment to notably improve its organic compound sorption capacity may be exploited for beneficial use of the treatment product. The product may be applied as fill and backfill, soil amendment, or in-situ sediment capping materials in highly industrialized areas where mitigation measures for organic contaminant migration are necessary.

Ecological and human health risk assessment of total petroleum hydrocarbons in surface water and sediment from Woji Creek in the Niger Delta Estuary of Rivers State, Nigeria

This study was designed to assess total petroleum hydrocarbon (THP) concentrations in the surface water and sediment sampled from Woji Creek and to assess potential ecological and human health risk due to petroleum hydrocarbons along the creek. Physicochemical parameters [pH, temperature (T), electrical conductivity (EC), dissolved oxygen (DO), total dissolved solids (TDS)] were in-situ measured from sediment and surface water; hydrological parameters (width, depth and volume) were used to calculate the flow rate (discharge) at different stations of the creek. Trend of TPH in the surface water samples along the creek were as follows: St4 (3.639 ± 1.121 mg/L) > St3 (2.449 ± 0.623 mg/L) > St1 (1.457 ± 0.244 mg/L) > St2 (1.069 ± 0.228 mg/L) > St5 (1.010 ± 0.120 mg/L) Trend of TPH concentration across the creek was as follows: St1 - 8.758 ± 0.697 mg/kg > St3 - 7.675 ± 0.541 mg/kg > St5 - 5.515 ± 0.401 mg/kg > St4 - 5.075 ± 0.363 mg/kg > St2 - 3.162 ± 0.307 mg/kg. Diagnostic indices indicate that the hydrocarbon in the creek was from petrogenic source. Estimation of ecological risk indicated risk in the surface water but not in the sediment. However, human health risk assessment indicated no risk due to human ingestion of the sediment or surface water.

Biodegradation of the petroleum hydrocarbons using an anoxic packed-bed biofilm reactor with in-situ biosurfactant-producing bacteria

The present study employed an anoxic packed bed biofilm reactor (AnPBR) inoculated with in-situ biosurfactant-producing bacteria for the biodegradation of petroleum wastewater. Highly acclimated biomass decreased the start-up phase period and with increasing the initial total petroleum hydrocarbon (TPH) concentration from 1.5 to 4 g/L was accompanied by TPH and chemical oxygen demand (COD) removal efficiencies of above 99% and 96%, respectively. Decreasing hydraulic retention time (HRT) from 24 to 6 h caused an increase in the specific hydrocarbon utilization rate value from 0.45 to 1.66 gTPH/gbiomass.d. Moreover, dehydrogenase activity, surfactin, and rhamnolipid reached 31.8 μgTF/gbiomass.d, 95.1, and 27.1 mg/L, respectively. The biodegradation kinetic coefficients such as K, Ks, Kd, Y and µmax were 0.784 (d−1), 0.005 (g/L), 0.138 (d−1), 0.569 (gVSS/gCOD), and 0.446 (d−1), respectively. Dropping of bioreactor performance, especially TPH removal efficiency from 99% to 37.6% in the absence of nitrate after 10 days, indicates anoxic metabolism has been the dominant biodegradation pathway. The effluent chromatogram of gas chromatography/flame ionization detector (GC/FID) showed aliphatic, cyclic aliphatic, and aromatic hydrocarbons efficiently degraded. According to the high degradation rate of AnPBR in different operational parameters, it can be recommended for the treatment of oil-contaminated wastewater.

Effect and mechanisms of red mud catalyst on pyrolysis remediation of heavy hydrocarbons in weathered petroleum-contaminated soil

In this study, industrial waste red mud (RM)-assisted pyrolysis of weathered petroleum-contaminated soil (WPCS) was developed based on the principle of “Treating the wastes with wastes”. In contrast with WPCS treated without RM at 400 °C for 30 min, the total petroleum hydrocarbons content reduced by 23.93% in the WPCS treated with 5% RM, and the contents of saturates, aromatics, resins, and asphaltenes decreased by 6.39%, 66.79%, 37.78%, and 64.95%, respectively. X-ray photoelectron spectroscopy results showed that the percentages of pyridinic−N and thiophene compounds on the surface of soil treated with 5% RM decreased significantly. The binding of metal oxides in RM with oxygen-containing groups and deposition of graphitic C increased the CO and O−CO groups. The activation energy at petroleum hydrocarbon thermal degradation stages of WPCS pyrolyzed with 5% RM reduced by 13.53% (lighter petroleum) and 16.40% (heavier petroleum), suggesting the strong catalytic action between RM and petroleum hydrocarbons. The catalytic mechanisms of RM for the removal of heavy hydrocarbons include (1) producing Brønsted/protonic acid in the absence of water vapor; (2) producing lattice oxygen [O] in the presence of water vapor; and (3) transforming metal oxides in RM into more active forms with a higher specific surface area. Our results suggest that the RM-assisted pyrolysis of WPCS is a cost-effective and energy-saving method that can not only promote heavy hydrocarbon removal but also relieve the environmental burden by converting industrial waste to a value-added product.

Treatment of soil contaminated with petroleum hydrocarbons using activated persulfate oxidation, ultrasound, and heat: A kinetic and thermodynamic study

This study focuses on the remediation of petroleum hydrocarbons in the soil matrix. Factors such as the persulfate dosage, initial pH, temperature, ultrasonic power, and soil water ratio were investigated by using ultrasonic and thermal energy to activate persulfate. The results showed that the degradation efficiency of the total petroleum hydrocarbon (TPH) content was 78.2% and 72.64% within 72 h for the ultrasonically/thermally-activated persulfate (“US/Heat/PS”) and thermally-activated persulfate (“Heat/PS”) systems, respectively, whereas it was 56.41% for the ultrasonically-activated persulfate system. The results of the kinetics analysis suggested that the degradation of petroleum hydrocarbons well-fitted the pseudo-second-order reaction, and that the rate constants increased with increasing temperature and initial persulfate dosage but with decreasing pH over a certain range. Moreover, three reaction phases comprising two rapid phases and an intermediate phase were observed for the TPH degradation. The measured thermodynamic parameters justified the spontaneity of the degradation process. Furthermore, a possible mechanism of petroleum hydrocarbon degradation in the US/Heat/PS system was determined through gas chromatography–mass spectrometry analysis, and the degradation priority of different components was ranked as: alkenes > alcohols > esters > alkanes > aromatics.

Measuring pollution based on total petroleum hydrocarbons and total organic carbon in Tigris River, Maysan Province, Southern Iraq

In the current study, the concentrations of total petroleum hydrocarbons (TPHs) in water and total organic carbon content in sediments were measured. A number of environmental factors, including water temperature, dissolved oxygen, pH, electrical conductivity, nitrates, and phosphates, have also been measured in the Tigris River deposits and in three selected stations on its course in Maysan Province in southern Iraq during the months of November, 2014, December, 2014, and January, 2015. The highest temperature, 25 °C, was recorded at Ali Al Gharbi District Station (St1) in November, while the lowest temperature, 15°C, was recorded at Al-Amara District Station (St2) in January. Moreover, the highest value of dissolved oxygen, 9.1 mg L-1, was recorded in St1 in January, while the lowest value, 7.5 mg L-1, was recorded at the same station in December. All pH values were within the baseline trend for the duration of the study, with the highest level, 7.8, recorded at St2 in November, while the lowest level, 7.05, at Al Majar Al-Kabir District Station (St3) in the same month. The highest value for electrical conductivity was 2416 μs cm-1 at Al-Amara District Station in November, while the lowest value was 2000 μs cm-1 at the same station in December. The highest concentration of nitrate ion, 6.25 mg L-1, was recorded at St2 in November, while the lowest value, 3.8 mg L-1,at St1 in December. Moreover, the highest phosphate value, 0.59 mg L-1, was recorded at St2 in January, while the lowest, 0.049 mg L-1, at St3 in November. The highest rate of total organic carbon content was 2.15%, recorded at St2 in November, while the lowest, 1.7%, at St1 in the same month. The highest concentration of TPHs in the water was 5.22, recorded at St2 in January, while the lowest, 2.85, at St1 in November. The present study concluded that St2 was heavily contaminated with organic matter. This station had the highest concentration of total petroleum hydrocarbons, which is mainly due to the increased population density beside the station, leading to increased human activities and the introduction of various wastes. These wastes contain nutrients and organic compounds, such as compounds containing petroleum derivatives, discharging to the water and sediment. Furthermore, there was a positive correlation between the organic carbon rate (%) and the concentration of petroleum hydrocarbons.

ЭКОЛОГО–ГЕОХИМИЧЕСКАЯ ОЦЕНКА СОДЕРЖАНИЯ НЕФТЯНЫХ УГЛЕВОДОРОДОВ В ПОЧВАХ ТАЕЖНОЙ ЗОНЫ НИЖНЕГО ПРИАМУРЬЯ И СЕВЕРНОГО САХАЛИНА (ДАЛЬНИЙ ВОСТОК)

The background content of total petroleum hydrocarbons (TPH) in the most common soils of the Lower Amur region and Northern Sakhalin was determined. About 300 samples taken from the surface layers and horizons of 8 typical soil pedons were analyzed. The accumulative nature of TPH distribution in the soil profile was established, and their highest content was revealed in the organogenic horizons. The soils of eluvial landscapes (Podzols, Spodic Cambisols, Fulvic Cambisols) contain a smaller amount of TPH compared to the soils of accumulative landscapes (Histosols, Fluvisols). The maximum content of TPH was found in the Spodic Hyperalbic Technosols. The content of TPH in the anthropogenic abrasives of the Lower Amur region is estimated as acceptable, the level of pollution in the anthropogenic abrasives in Northern Sakhalin varies from low to very high. The results obtained on the background content of TPH can used for assessing of soils pollution and in conducting ecological monitoring studies.

Organic stimulants for enhancing phytoremediation of crude oil polluted soil: A study on cowpea

Petroleum hydrocarbon (PH) contamination of soils remains a major threat to environmental health and food security. A two-years phytoremediation study was conducted on a crude oil polluted soil to assess changes in soil total petroleum hydrocarbon concentration (TPHsoil) following use of pawpaw seed powder (PSP), moringa seed powder (MSP) and their combination (PSP + MSP) as organic stimulants in cowpea cultivation. The stimulants were tested at different application rates (100, 150, 200 and 250 g m−2), with the control (No stimulant) for their effectiveness in reducing TPHsoil and accelerating the removal rate (R) of PH from soil. The TPHsoil did not differ significantly (p < 0.05) among the treatments in year 1, but was highest in the control (11,600 mg kg−1) and least in 200 g m−2 PSP (7400.0 mg kg−1). In year 2, mean TPHsoil varied significantly (p < 0.05) and remained highest in control (7100 mg kg−1) but lowest in 150 g m−2 PSP (2700 mg kg−1). Application of 150 g m-2 PSP gave the highest R (78.2%), followed by 150 g m-2 PSP+MSP (77.4%), and least by the control (42.7%) over two years of study. The average fresh pod yield of cowpea over two years was highest in 250 g m−2 PSP (2416.67 kg ha−1), followed by 150 g m−2 PSP (2173.34 kg ha−1) and least in control (1302.22 kg ha−1). There was significant negative association between TPHsoil and fresh pod yield (r = −0.403; p < 0.01). However, application of 150 g m−2 PSP appeared most effective for enhanced phytoremediation of crude oil polluted soil and improvement of cowpea yield.

Integrated geophysical and geochemical methods for environmental assessment of subsurface hydrocarbon contamination.

Oil spills have become a major source of environmental pollution in Nigeria, especially in the oil-producing communities. Assessment of hydrocarbon contamination within the subsurface is a complex program and requires both field-based measurement and geochemical analysis, to give a precise definition of the extent of pollution. To ascertain the extent of contamination of the subsurface around an oil spill site which was reportedly contaminated by oil pollution, an integrated geophysical method involving 1D vertical electrical sounding (VES) and 2D, 3D electrical resistivity tomography (ERT) techniques supported with geochemical method was employed. Orthogonal set of 2D resistivity data consisting of six (6) parallel and six (6) perpendicular profiles were acquired in a 100 × 50-m2 rectangular grid using the Wenner array. Ten (10) vertical electrical soundings were also acquired in the site to supplement the 2D profiles. 2D resistivity data were processed individually using 2D Earth Imager software. The entire set of 2D resistivity data is collated into a 3D dataset using a 3D collation code and was inverted to produce a 3D resistivity structure of the subsurface, following from which contaminant plumes with high resistivity anomalies due to oil pollution were observed from 2D and 3D resistivity images. 2D resistivity tomography imaged contaminant plume to depth of 17.1 m, while 3D resistivity tomography imaged plumes of hydrocarbon contaminant to depth of 19.8 m within the subsurface. 3D depth slices imaged hydrocarbon contaminants within the third, fourth, and fifth layers at depths of 5.38-8.68 m, 8.68-12.5 m, and 12.5-16.9 m respectively. Thus, hydrocarbon contamination was evidently increasing with depth as observed in VES survey which indicated pollution to depth beyond 24 m, which goes beyond the depth to first and second aquifers in the area, indicating that the first and second aquifers have been invaded by oil pollution. Similarly, geochemical analysis of groundwater samples from three boreholes showed average concentration of total petroleum hydrocarbon (TPH) as 722.75µg/L which is higher than DPR limits indicating high contamination. Poly aromatic hydrocarbons (PAHs) concentration in the samples was summed up to 0.66µg/L in BH1, 0.68µg/L in BH2, and 0.30µg/L in BH3, which are above the DPR target limit. BTEX compounds also showed elevated concentrations in the water samples. These findings validate the result of geophysical investigation; therefore, future research should aim to proffer remediation solutions to oil spill impact on the environment within the study area. The findings of this study can help for better understanding of the subject of electrical resistivity inversion, and particularly on 3D inversion technique for delineating subsurface plumes of hydrocarbon contamination.

Simulating diluted bitumen spills in boreal lake limnocorrals - Part 1: Experimental design and responses of hydrocarbons, metals, and water quality parameters

Large-scale, in-lake enclosures (limnocorrals) were used to simulate spills of diluted bitumen (dilbit) in a boreal lake. In this study we use these simulated spills, which covered a range of sizes (oil:water ratio) representative of the upper 25% of onshore crude oil spills in North America (2008–2019), to assess the fate of dilbit-derived hydrocarbons and metals as well as the impacts of the spills on standard water quality parameters. The systems were monitored over 70 days following the application of dilbit amounts ranging between 1.5 and 179.8 L into 10-m diameter, ~100 m3 limnocorrals. The concentration of total petroleum hydrocarbons (TPH) in the water column increased rapidly over the first two weeks reaching a plateau that ranged between 200 μg/L and 2200 μg/L for the lowest and highest treatment respectively. The concentration of total polycyclic aromatic compounds (PACs) also increased over the first two weeks, prior to a slow decrease until day 70. The maximum measured concentrations in the highest treatment were 2858 ng/L for the sum of all 46 quantified PACs, 2716 ng/L for alkylated PACs and 154 ng/L for the 16 EPA priority PAHs. The concentrations of PACs in the sediment increased continuously over the study in the three highest treatments with maximum observed concentrations of 189 ng/g for ΣPAC46, 169 ng/g for ΣPACalk. No significant treatment-related changes in the 16 EPA priority PAHs were observed in the sediment. Of the 25 metals quantified in the water column, only manganese, molybdenum, and vanadium displayed a significant treatment effect with increases of 280, 76 and 25% respectively in the total fraction. These results can help us understand and predict the fate of oil-derived contaminants following a spill and characterize the exposure of freshwater organisms living within them. These results should help inform the risk assessment of future dilbit transportation projects.

Determination of Total Petroleum Hydrocarbons Concentration in Coastal Seawater of Teluk Batik Beach, Perak, Malaysia

The study aims to determine Total Petroleum Hydrocarbon (TPH) status in seawater from Teluk Batik beach seawater. In July 2018, fishing vessel sunk two nautical miles off Pematang Damar Laut, a coastal village within the town of George Town, Penang Malaysia, which also impacted the coastline of Perak State. Approximately six tons of diesel and hundreds of liters of fuel oil drifted from the Penang sea to the Perak coast. On further subsequent wave action the TPH concentrations in seawater fluctuated over time. In the coastal water of Teluk Batik Beach, Perak, Malaysia, grab samples were taken from surface seawater for determining the TPH concentrations in November and December 2019. The TPH in seawater was determined by the extractable solvent (Hexane) and the additional petroleum hydrocarbons by the Infrared (IR) method. The values of TPH ranged from 91 to 503 mg/L. Compared to the standards in Malaysian waters, the TPH levels found in this study were high, indicating serious pollution of TPH in the area under study.

A New Ciboria sp. for Soil Mycoremediation and the Bacterial Contribution to the Depletion of Total Petroleum Hydrocarbons.

A Ciboria sp. strain (Phylum Ascomycota) was isolated from hydrocarbon-polluted soil of an abandoned oil refinery in Italy. The strain was able to utilize diesel oil as a sole carbon source for growth. Laboratory-scale experiments were designed to evaluate the use of this fungal strain for treatment of the polluted soil. The concentration of total petroleum hydrocarbons (TPH) in the soil was 8,538 mg/kg. Mesocosms containing the contaminated soil were inoculated with the fungal strain at 1 or 7%, on a fresh weight base ratio. After 90 days of incubation, the depletion of TPH contamination was of 78% with the 1% inoculant, and 99% with the 7% inoculant. 16S rDNA and ITS metabarcoding of the bacterial and fungal communities was performed in order to evaluate the potential synergism between fungi and bacteria in the bioremediation process. The functional metagenomic prediction indicated Arthrobacter, Dietzia, Brachybacerium, Brevibacterium, Gordonia, Leucobacter, Lysobacter, and Agrobacterium spp. as generalist saprophytes, essential for the onset of hydrocarbonoclastic specialist bacterial species, identified as Streptomyces, Nocardoides, Pseudonocardia, Solirubrobacter, Parvibaculum, Rhodanobacter, Luteiomonas, Planomicrobium, and Bacillus spp., involved in the TPH depletion. The fungal metabolism accelerated the onset of specialist over generalist bacteria. The capacity of the Ciboria sp. to deplete TPH in the soil in treatment was also ascertained.

Remediation and optimization of petroleum hydrocarbons degradation in contaminated water using alkaline activated persulphate

This study investigated the characterization of Nigerian crude oil using gas chromatography-mass spectrometry (GC-MS) and the efficiency of alkaline activated sodium persulphate in degrading petroleum hydrocarbons in crude oil-polluted water. Hydrocarbons (aliphatics and aromatics), non-hydrocarbons, and other constituents were characterized in crude oil samples. The ratio of hydrocarbons:non-hydrocarbons/others and aliphatics:aromatics is 86:14 and 45:55, respectively. Alkylated benzenes, toluene, o-xylene, fluorene, and naphthalenic compounds were the most common aromatic compounds. The majority of aliphatic compounds were n-alkanes and cyclic hydrocarbons, including cyclohexane and heptylcyclohexane. Degradation experiments were performed with different initial concentrations of sodium persulphate (0.3 M, 0.5 M and 0.7 M) with sodium hydroxide as an activator. Runs were carried out within 8 days. The total petroleum hydrocarbons (TPH) extraction was carried out and analyzed using gas chromatography flame ionization detector (GC-FID). From an initial TPH concentration of ~137 mg L−1 in water, near-complete degradation was achieved with 0.3 and 0.5 M oxidant dosage. With 0.7 M sodium persulphate, 76% TPH was degraded within 8 days. Radical quenching using sodium thiosulphate showed that the addition of the scavenger resulted in negligible changes in TPH concentration pre-and post-degradation using all three oxidant dosages. Thus, alkaline activated persulphate is effective for the remediation of petroleum hydrocarbon contamination.

Reactivation of aerobic granular sludge for the treatment of industrial shipboard slop wastewater: Effects of long-term storage on granules structure, biofilm activity and microbial community

This work reports on reactivation of aerobic granular sludge (AGS) for the treatment of industrial recalcitrant wastewater (slop wastewater) characterized by high salinity and hydrocarbons. AGS were reactivated in two reactors, R1 and R2, to treat industrial slop wastewater after a long-term storage for 12-months at 4 °C. In R1, salt-adapted mature aerobic granules were previously subjected to a step-wise increase of hydrocarbons, whereas in R2 aerobic granules were previously cultivated in presence of salinity and hydrocarbons. After a short-term reactivation period, the slop dosage caused a simultaneous decrease of granules dimensions and proteins/polysaccharides (PN/PS) ratio down to 1.76 (R1) and 2.35 (R2). Then, the increase of granules dimensions and of the PN/PS ratio up to 5.63 (R1) and 4.22 (R2), suggested a new granulation process. The difference in total petroleum hydrocarbons (TPHs) removal efficiencies (≈87 % R1, and ≈97 % R2) was mainly due to a biodegradation effect in R2 where granules were previously cultivated with slop. This was confirmed by a simultaneous decrease of TPHs concentration in the bulk and adsorbed into granules. Based on Next Generation Sequencing of metagenomic 16S encoding genes, in R2 typical oil-polluted seawater-associated bacteria were detected, which probably played key roles in TPHs biodegradation.

Bioremediation of clay with high oil content and biological response after restoration

The clay with high oil content form soil lumps, which is hard for microbes to repair. In this paper, the bioaugmentation and biostimulation technology were applied to improve the bioremediation effect of the soil with high oil content, that modified by local cow dung and sandy soil, the ecological toxicity of the soil after restoration was further analyzed. After 53 days of bioremediation, the degradation efficiency with respect to the total petroleum hydrocarbons (TPH) content reached 76.9% ± 2.2%. The soil bacterial count of M5 group reached log10 CFU/g soil = 7.69 ± 0.03 and the results were better than other experimental groups. The relative abundances of petroleum-degrading bacteria added to M5 remained high (Achromobacter 9.44%, Pseudomonas 31.06%, and Acinetobacter 14.11%), and the proportions of some other indigenous bacteria (Alcanivorax and Paenibacillus) also increased. The toxicity of the bioremediated soil was reduced by seed germination and earthworm survival experiments.

Determination of Oil Spill Chemical Concentrations in Nearshore Matrices

ABSTRACT Marine oil spill incidents create concerns about human health risks, particularly in nearshore locations such as beaches used for recreation. To improve the timeliness of risk estimates during an oil spill, we need to expand modelling capacity for oil spill chemicals (OSCs) from predictions for chemical bulk measurements such as Total Petroleum Hydrocarbons (TPH) to predictions of individual concentrations of the more toxic Polycyclic Aromatic Hydrocarbons (PAH)s. The objective of this study is to establish a relationship for TPH and PAH nearshore sampling concentration values with the oil mass landing and TPH hindcast from a 3D Hydrodynamic Fate and Transport Model (3D-FTM) for a past oil spill. The overall goal is to use this information to expand current modeling capacities to predict concentration distributions for individual PAHs as a starting point for health risk assessment. During Phase I of this study, historic sampling data for various matrices (weathered oil, seawater and sediments) were used to evaluate PAH concentration distributions within time-space specific categories. The categories corresponded to samples collected prior to nearshore oiling, post nearshore oiling and at no time impacted by oil as predicted by historic oil spill trajectories. For matrices within each category, concentration frequency distributions and concentration patterns were generated for a subset of PAHs. Results show differences in PAH concentration patterns within each matrix and for each category. Concentration frequency distributions for most PAHs in each category were log-normally distributed. Phase II is ongoing. Here we analyze PAH and TPH concentrations measured from surface weathered oil slick samples collected at the time of the Deepwater Horizon (DWH) oil spill. Preliminary results show that concentrations for a subset of PAHs in weathered oil slicks correlate well with TPH concentrations (R2=0.76). We are collocating the historic environmental sampling data with the output from the Oil-Connectivity Modelling System (Oil-CMS). The relationship between measured and model predicted TPH is explored by comparing values for samples that coincide in time and space with the model's particles. A subsequent step is to use output of the oil-CMS in combination with the physical and chemical properties for each PAH to predict concentration distributions for individual PAHs. The overarching goal is to improve risk estimates and, therefore, better guide public health decision-making.

Environmental and socioeconomic impacts of pipeline transport interdiction in Niger Delta, Nigeria

Over the years, pipelines have been the most economic medium for transporting crude oil to production and distribution facilities in the Niger Delta area of Nigeria. However, damages to the pipelines in this area by interdiction have hampered the continuous flow of crude oil to the facilities. Consequently, the revenue of the government dwindles, and the environment is severely degraded. This study assesses the economic and environmental impacts of pipeline interdiction in the Niger Delta region. Data from National oil spills detection and response agency, Nigeria is used to map spatial distribution of oil spills using Kernel Density Estimation with Geographic Information System. Literature was assessed to synthesize the historical, socioeconomic, and environmental impacts of oil spills and pipeline interdiction. Soil samples were collected from study area to determine the types of hydrocarbon pollutants and their concentrations in comparison with uncontaminated sites in the area. Results show that the range of concentrations of total petroleum hydrocarbon (TPH) for the impacted soil (IMP) was 17.27–58.36 mg/kg; remediated soil (RS) was 11.73–50.78 mg/kg which were higher than the concentrations of 0.68 mg/kg in the control samples (CS). Polycyclic aromatic hydrocarbons (PAH) concentrations were in the range of 0.43–77.54 mg/kg for IMP, 0.42–10.65 mg/kg for RS, against CS value of 0.49 mg/kg while BTEX ranged between 0.02 – 0.38 mg/kg for IMP, 0.01–2.7 for RS against CS value of 0.01. The values of the PAH were higher than the limits of the Department of Petroleum Resources, Nigeria. This study also revealed that pipeline interdiction has affected the livelihood of the inhabitants of the study area and the revenue of the Nigerian government. The major hotspots for oil spills in the Niger Delta region are Bayelsa, Rivers and Delta states.