Total Petroleum Hydrocarbon Concentration Research Articles

Research on the effects of soil petroleum pollution concentration on the diversity of natural plant communities along the coastline of Jiaozhou bay

This study examines the 4 typical natural plant communities at the coastal waterfront of Jiaozhou Bay. Based on field survey and sampling, laboratory analysis, application of classical statistical methods and the requirements for urban ecological preservation and data restoration in IoT engineering technology, this study investigates the diversity pattern of the 4 natural plant communities, i.e. Phragmitesaustralis, Suaeda salsa, Setariaviridis and Conyzacanadensis, analyzes the characteristics of the petroleum pollution suffered by these 4 natural plant communities and the soil at the coastal waterfront of Jiaozhou Bay. By investigating the impact on the natural regulation ability of the natural ecosystem, species and habitat, this study provides the basis for protection of the natural plant communities in the petroleum polluted area and for the design of plants arrangement in ecological restoration in the site and provides the support for application of IoT technology in urban ecosystem establishment and urban ecological restoration. Findings: (1) During investigation of 30 quadrats of the plant communities in the petroleum polluted area at coastal waterfront of Qingdao, 74 plant species have been discovered.They belong to 12 families, where Chenopodiaceae, Poaceae and Compositae are dominant families and account for 9.09%, 20.45% and 38.63% respectively; Phragmitesaustralis, Suaeda salsa, Conyza canadensis and Setariaviridis communities are all herbosa, their species composition is quite simplex and most of them are in monodominant community patch; (2) The Conyzacanadensis community has the largest Shannon-Wiener diversity index, Patrick richness index and Simpson dominance index, which are 2.115, 1.930 and 1.228 respectively; in terms Pielou evenness index, the rank is Phragmitesaustralis > Conyzacanadensis > Setariaviridis > Suaeda salsa, which are 1.056, 0.907, 0.877 and 0.661; (3) According to the result of data analysis, the petroleum polluted area at coastal waterfront of Jiaozhou Bay has average total salt content 0.626%, average PH 8.067 and average petroleum hydrocarbons content 69.306 mg/kg.According to the result of difference examination of different plant communities, the total salt, PH and petroleum hydrocarbons content in the soil at the coastal waterfront Jiaozhou Bay are the main factors that affect the distribution of plant communities in that area (P < 0.05), and the petroleum hydrocarbons content in the soil has significant impact on the distribution of the communities (P < 0.01).(4) In this study, the petroleum hydrocarbon tolerance degrees of the 4 typical tolerant plant communities are ranked as Conyzacanadensis > Suaeda salsa > Setariaviridis > Phragmitesaustralis.In the soil environment with light (Level Ⅰ) and severe (Level Ⅳ) petroleum hydrocarbon pollution, the indexes of Suaeda salsa and Conyzacanadensis are optimal among the communities; the indexes of Phragmitesaustralis and Setariaviridis are optimal in the soil environment with Level Ⅱ and Level Ⅲ petroleum hydrocarbon pollution and can grow better in that environment.

Temporal (Monthly) Distribution and Variation of Total Petroleum Hydrocarbons Content in the Water and Sediments from Orashi River, Engenni, Rivers State, Nigeria

The total petroleum hydrocarbons content of the surface water and the sediments from the Orashi River were investigated between December 2019 and June 2020 at two months intervals to find out the level of contamination of the river. The total petroleum hydrocarbons were determined by GC-FID using Agilent 5890N, after following due laboratory procedures of sample pretreatment and clean-up. The results recorded from the surface water were December, 5.844±1.231 mg/L; February, 8.767±2.501 mg/L, April, 16.886±3.157 mg/L and June, 7.271±1.110 mg/L. Variation in concentration showed that April &gt; February &gt; June &gt; December. Results recorded in the sediments were December, 39.8427±13.5 mg/Kg; February, 29.5322±5.301 mg/Kg; April, 50.5040±16.813 mg/Kg and June; 16.6545±3.35 mg/Kg. The variation in concentration showed that April &gt; December &gt; February &gt; June. The variations observed in of total petroleum hydrocarbons content in the river indicated that the contamination source was primarily anthropogenic. It is therefore recommended that effective measures and adequate steps be taken by the government to mitigate the effect that may result from the accumulation of the total petroleum hydrocarbons in the river and on the aquatic inhabitants and man who depends on the river for daily living.

Pyrolysis of heavy hydrocarbons in weathered petroleum-contaminated soil enhanced with inexpensive additives at low temperatures

Pyrolysis is a promising technology for the remediation of soil contaminated with petroleum hydrocarbons. However, for weathered petroleum-contaminated soil (WPCS) with massive recalcitrant heavy hydrocarbons, pyrolysis still has the drawback of high energy consumption. To reduce energy consumption, commonly used inexpensive additives, including Fe2O3, Al2O3, K2CO3, CaO, HZSM-5, and red mud, were selected to strengthen the pyrolysis of heavy hydrocarbons in WPCS. The removal of the total petroleum hydrocarbon (TPH) content from WPCS increased as the dosage of additives increased from 1% to 5% at 400 °C for 30 min, and increased slightly or even decreased when the additive dosage was further increased to 10%. The reduction rates of the TPH content in soil treated with 5% additives of K2CO3, CaO, Fe2O3, red mud, HZSM-5, and Al2O3 increased by 26.16%, 25.65%, 25.53%, 23.93%, 23.15%, and 20.75%, respectively. Among these additives, CaO exhibited the best performance for the removal of aromatics (73.00%) and asphaltenes (72.44%), while Fe2O3 exhibited the best performance for the removal of resins (52.25%). The removal mechanisms of heavy hydrocarbons using additives during WPCS pyrolysis were proposed based on a combination of thermogravimetric analysis and the iso-conversional Flynn–Wall–Ozawa method. The reduction in the activation energy when additives were included during WPCS pyrolysis was closely related to whether the additives participated in the reaction and to the type of pyrolysis product. The soil characterization results demonstrated that the investigated additives would not severely impact further soil cultivation. The additive-assisted pyrolysis of WPCS is expected to reduce the required energy input by 34.71% compared to the traditional pyrolysis method, thus providing an energy-efficient and cost-effective method for treating petroleum-contaminated soil in future engineering applications.

Bioremediation Of Soil Of The Kola Peninsula (Murmansk Region) Contaminated With Diesel Fuel

This work focuses on the creation and use of associations of hydrocarbon-oxidizing microorganisms. Bioremediation of soils with the help of mixed cultural and associations of microorganisms provides wider adaptive possibilities than individual species. This is especially important in conditions of short northern summer. The results of field experiments showed that microbial associations based on indigenous microorganisms (bacteria Pseudomonas fluorescens, P. putida, P. baetica, Microbacterium paraoxydans and fungi Penicillium commune, P. canescens st. 1, P. simplicissimum st. 1) with mineral fertilizers reduced the content of total petroleum hydrocarbons in the Hortic Arthrosol soil of the Kola Peninsula by 82% over 120 days. Also, the microbial associations with mineral fertilizers had a positive effect on the physical properties of the soil, increasing its humidity. The bacterial-fungi associations changed the number, abundance and structure of the indigenous community of microorganisms. Penicillium canescens, which was included in the composition of fungi association, became dominant. During the rapid decomposition of hydrocarbons are released to the soil toxic intermediates or metabolites of the microbial oxidation of hydrocarbons. Hydrocarbon oxidizing microfungi suppressed the germination of test plant seeds to one degree or another. Penicillium commune fungal metabolites inhibited seed germination only by 29% for Lepidium sativum L. and 24% for Triticum aestivum L. This species can be used for bioremediation of petroleum contaminated soils.

Effectiveness of a bio-catalytic agent used in the bioremediation of crude oil-polluted seawater

Oil spillage contamination has been one of the most common and challenging problems in marine ecosystems over the years due to frequent petroleum exploitation, washing, and transportation activities. The use of nature-derived surfactants has become an attractive approach to restore the sites affected by oil spillage. Several studies have demonstrated that nutrient addition is an efficient strategy to enhance oil biodegradation since microorganisms can use petroleum hydrocarbons as their carbon and energy source, thus favoring and increasing the hydrocarbons degradation rate. This study aimed to assess the effectiveness of a commercial bio-catalytic agent used in the biological remediation of crude oil-contaminated sites through the qualitative analysis of its properties. The tests applied to this bio-catalyst showed excellent results. For instance, the emulsification (E24) and critical micellar concentration (CMC) assays displayed average values of 74.47% and 40 mg L−1, respectively. A significant reduction of Chemical Oxygen Demand (COD), turbidity, and Total Petroleum Hydrocarbon Content (TPHC) were observed in all the samples with bio-catalytic agent solution and aeration system. The best water quality was achieved by the sample with the highest concentration (10000 ppm) of bio-catalytic agent solution. It displayed a Total Petroleum Hydrocarbon removal efficiency (RTPH) of 81.537% after 30 days of the remediation time.

FITOREMEDIASI TANAH TERKONTAMINASI MINYAK BUMI DENGAN MENGGUNAKAN TANAMAN RUMPUT BAHIA (Paspalum notatum)

The increasing need for fuel derived from petroleum is also in line with the increased exploration and production activities of petroleum. Besides producing crude oil products, this activity also produces petroleum waste. This waste will pollute the soil which will have an impact on environmental damage, disruption of human health and other living things. Therefore according to Veegha (2008), an efficient and environmentally friendly method for treating petroleum waste is needed. One of the waste treatment methods is using phytoremediation method. Phytoremediation is defined as a technology for cleaning, removing or reducing harmful pollutants, such as heavy metals, pesticides, and toxic organic compounds in soil or water using the help of plants. This research was conducted for three months from September to November 2019 at the open nursery of PT. CPI with paranet shade 60%. This study aims to determine the effectiveness of bahia grass (P. notatum) in degrading Total Petroleum Hydrocarbon (TPH) in petroleum-contaminated soils in the Rokan Block PT. Chevron Pacific Indonesia and analyze the socio-economic impact of phytoremediation on local communities. The results showed that the effectiveness of Bahia (P. notatum) grass proved effective in reducing the concentration of Total Petroleum Hydrocarbon (TPH) in petroleum-contaminated soils in the Rokan Block operating area of PT. Chevron Pacific Indonesia. The percentage of effectiveness shows a decrease in value of up to 58.38%. The socio-economic impact of phytoremediation on local communities has a positive impact with the planned phytoremediation activities using bahia grass with the community as work agents for planting the grass.

Isolation and Identification of Hydrocarbons- Degrading Bacteria from Panteka Stream, Kaduna, Nigeria, and Assessment of their Potential for Bioremediation

Water bodies become hydrocarbon-polluted when petroleum and other toxic organic matters are discharged into them. Panteka, located in northern Kaduna, Nigeria, is home to Panteka market, which is an industrial hub where different kinds of automobile spare parts are sold and mechanic workshops are situated. The Panteka stream flows through an entry point at Rafin guza, through Panteka market and towards the National Eye Centre. The indiscriminate disposal of spent engine oils and the discharge of other untreated effluents from car servicing workshops into the Panteka stream can lead to hydrocarbon contamination. Consequently, there is a need to identify these hydrocarbons and determine the capability of bacteria isolated from the stream to degrade the hydrocarbon pollutants. Using the pour plate method, and Bushnell Haas agar supplemented with 1% used engine oil, five bacterial isolates with the potential to degrade hydrocarbons were identified as Streptococcus pnuemoniae, Klebsiella pneumoniae, Shigella dysenteriae, Streptococcus pyogenes and Salmonella enterica. Salmonella enterica was confirmed by 16S rRNA gene sequencing and Basic Local Alignment search tool (BLAST) with a similarity index of 99%. The ability of the bacterial isolates to tolerate the spent engine oil was determined by turbidi metry. The results show that all the five bacterial isolates were able to tolerate the 1% (v/v) concentration of the spent engine oil. The highest growth rates (O.D 0.565 and O.D 0.695) were obtained from the pure cultures of Streptococcus pyogenes and the mixed bacterial consortium, respectively. The potentials of the bacteria to degrade hydrocarbons in the stream was analysed using Gas Chromatography Flame Ionization Detector (GC-FID), and the results showed reduction of the Total Petroleum Hydrocarbon (TPH) content from 6,056 mg/ml to 100.17 mg/ml (98.3% degradation) after 28 days of treatment with the mixed bacterial culture. The hydrocarbon fractions degraded were n-Nonane, n-Decane, n-Undecane, n- Dodecane, n-Tridecane, n-Tetradecane, n-Heptadecane, Pristane, n-octadecane, Phytane, n-Eicosane, n-Tricosane, n-Tetracosane, n-Octacosane, n-Triacontane, n-Dotriacontane, n-Tritriacontane, n-Heptriacontane; while n-Pentadecane, n-Hexadecane, n-Nonadecane, n-Heneicosane, n-Docosane, n-Pentacosane, n-Hexacosane, n-Heptacosane, n-Nonacosane, n-Hentriacontane, n-Tetratriacontane, n-Pentatriacontane, and n-Hexatriacontane were not degraded. This study shows that these bacterial strains isolated from the Panteka stream have great potential for bioremediation of the hydrocarbons found in the stream.&#x0D; Keywords: Bioremediation, Panteka stream, Automobile workshop, Hydrocarbon pollution, Bacteria isolates

Assessment of the Bioaccumulation of TPH and Heavy Metals in Tissue of Selected Fishes’ Species Caught from Stream near a Petroleum Processing Plant

This article investigated the bioaccumulation of total petroleum hydrocarbon (TPH) and selected heavy metals in the tissue of selected fishes’ species from a stream near a petroleum processing plant in Rivers State, Nigeria. The concentration of TPH and Ni, Mn, Fe, Zn, Pb, Cr and Co in the fish species’ tissue were measured using standard methods. The TPH concentrations in the fish species were generally high (1.97 to 52.84 mg/kg), greater than the European Union threshold limit of 2μg/kg. Gobius sp and Periophthalmus sp recorded the highest TPH content: 52.84 mg/kg and 28.07mg/kg levelsrespectively. Tilapia sp and Sardinella sp recorded the least and highest concentration of Manganese (0.61 mg/kg and 5.90 mg/kg respectively). The levels of Fe content in the fish tissue were higher than all other metals: 8.27 mg/kg in Gobiussp to 129.7 mg/kg in Sardinella sp. Zn: 4.39 mg/kg in Mugilidae to 11.84 mg/kg in Gobius sp while Co:&lt;0.02 mg/kg in Tilapia sp and 1.51mg/kg in Calinectis sp. The concentrations of Cd:0.24 mg/kg in Pomadasys sp to 0.56 mg/kg in Gobius sp. These values are relatively high because of the metal’s high toxic response factor of 30. The levels of Pb:&lt;0.03 mg/kg in Tilapia sp and Carangidae to 2.69 mg/kg in Calinectis sp. Gobius sp recorded the highest level (3.36 mg/kg) of Ni. The concentrations of Co, Cd, Pb, and Ni in consumable fish are of great concern because of their high toxic response factors. These results implied that the petroleum processing activities (legal and illegal) are negatively impacting aquatic habitats/ food chains. This calls for caution in the consumption of the fish from this area, the audit of the legal petroleum processing facilities and stoppage of the illegal operations.

Increase in Total Petroleum Hydrocarbons Removal Rate in Contaminated Mining Soil Through Bioaugmentation with Autochthonous Fungi During the Slow Bioremediation Stage

The removal of total petroleum hydrocarbons (TPHs) from contaminated mining soil was carried out under in vitro conditions. The aerobic consumption of TPH in the slow bioremediation stage via biostimulation with native microorganisms and biostimulation-bioaugmentation with autochthonous fungal isolates was evaluated. The initial TPH concentration was 70,880 ± 975 mg TPH/kg soil, soil was amended with nutrients at a C:N:P ratio of 100:15:1, the water content was adjusted to the soil field capacity, and batch microcosm reactors were incubated at room temperature (20.5 ± 3.1°C) for 90 days. The bioaugmentation process was tested using four hydrocarbonoclastic fungal strains isolated from the same contaminated mining soil individually and a mixed culture of the four isolates. The molecular characterization of the isolated fungi was based on sequence analysis of 18S rRNA, and the fungi were identified as Aspergillus niger MT786339.1, Aspergillus fumigatus MT786338.1, Aspergillus terreus MT786341.1, and Aspergillus flavus MT786340.1. The best TPH removal was achieved by inoculation with the fungal consortium (57 ± 1.97%) at 45 days (slow stage) after initiating the biostimulation process, followed by inoculation with Aspergillus niger (49 ± 1.2%), Aspergillus terreus (44 ± 0.67%), Aspergillus fumigatus (35 ± 0.98%), and Aspergillus flavus (32 ± 0.38%), while the degradation rate achieved with native microorganisms was only 21.6 ± 1.5%; statistical analysis of the results showed significant differences.

Detailed chemical characterization of the composition and variability of soil gas at remediated residential heating oil discharges

Underground storage tanks containing petroleum or other hazardous substances are used widely for residential storage of home heating oil. Spills and leaks of fuel from these tanks are common, and resulting subsurface petroleum vapors may pose health risks. However, understanding of this risk is limited by a lack of observational data on the chemical composition of vapors from discharged fuel. We present here the composition of soil gas sampled at 66 remediated residential sites of underground heating oil discharges throughout Virginia using a newly developed data analysis technique that allows characterization of hydrocarbons by carbon number and degree of unsaturation. Measured concentrations of total petroleum hydrocarbons exceeded 100,000 μg/m3 at 12 sites, but its composition varied widely between sites. Concentrations of hydrocarbons from chemical classes differing by more than a few carbon numbers or degrees of unsaturation are found to be poorly correlated. Furthermore, differences in composition are poorly described by metrics expected to indicate subsurface weathering (e.g., discharge year, or ratio of n-heptadecane to pristane). These results suggest that the composition and magnitude of residual contamination at remediated subsurface discharges is driven by rarely documented spill characteristics (e.g., age and composition of source material, discharge rate, etc.).

Biochar and compost-based phytoremediation of crude oil contaminated soil

Objectives: To study the effect of compost and biochar on phytoremediation of crude oil-contaminated soil. Methods: An attempt was made to remediate crude oil contaminated soil, using the phytoremediation method. The soil was amended with biochar and compost. Initially, the pH, moisture content and C/N ratio of the soil and amendments were determined. A pot culture experiment was conducted to study the effect of the amendments on the degradation of the Total Petroleum Hydrocarbons (TPH) in the crude oil contaminated soil using the plant species nutgrass (Cyperus rotundus). To avoid seepage of water from the pots plastic pots were used. The initial concentration of TPH was found to be 17mg/kg soil. The experiment was conducted from January to March 2019. No microorganism was inoculated either to enhance the growth of the plant or degrade the hydrocarbon. The study was conducted with natural microflora. The pots were kept (open) under direct sunlight with 8 hours of photoperiodism. The plants were watered daily with tap water to maintain optimum moisture content. Once in 15 days, the soil samples collected from each treatment were analysed for pH, moisture content and C/N ratio. The TPH removal rate was determined for the 45th day and 60th day. Findings: The soil amended with compost (200 kg/soil) and biochar (50 kg/soil) enhanced the degradation of TPH by the plant species. The highest degradation percent of 62.2 and 77.1% was achieved on 45th and 60th day respectively in the treatment T5 (amended with biochar and compost). Further, there was an increase in shoot length (54.52 cm/plant), root biomass (0.74 g/plant) and shoot biomass (5.08g/plant) of the plants in the biochar and compost amended soil which was comparable with the results of the treatment T2 (Plants were grown in soil without crude oil contamination). Applications: Biochar and compost amendment improves the water holding capacity and nutrient status of the soil, thereby enhancing the growth of TPH degraders in soil. Hence, from the study, it is understood that biochar and compost could be used for phytoremediation of crude oil contaminated soils. Keywords: Amendments; degradation of TPH; nutgrass

Estimation of Heavy Metals and Polycyclic Aromatic Heavy Metals in Harvested Plantains from Bodo, Rivers State

A Plantain harvested from Bodo community, Gokana L.G.A Rivers state were analyzed for heavy metals and Polycyclic Aromatic Hydrocarbons (PAHs) concentrations. Physicochemical properties of the agricultural soil used for the plantain cultivation showed the following: pH (5.7) while the control experiment was seen at 7.4. Soil conductivity of 721 and 398 were obtained for both the test and control experiments, respectively. Soil mineral contents: Potassium (6.88 mg/g), phosphorus (2.63 mg/g), Magnesium (12.42 mg/g), chloride ions (1021.21 mg/g). Heavy metal analysis of the soil showed a greater proportion of copper and iron in while Hg, As and Cd were below detectable limit in both tested samples. Pb was found relatively in lower concentrations of 24.12 mg/g in the test sample, 6.23 mg/g in the control experiment. Total Oxidizable Carbon Content (TOC) and Total Petroleum Hydrocarbon (TPH) content of the soil were observed at 104.12 and 2567 mg/g respectively in the tested sample. The control experiment showed TOC and TPH concentrations of 42.85 and 1094 mg/g. Heavy metal analysis of harvested plantain from Bodoh community showed the presence of the following: Lead (Pb), Iron (Fe) and Copper (Cu) in the following order: Cu>Fe>Pb in the test sample while in the control experiment, iron (Fe) was seen greater than copper (Cu). Heavy metals of mercury, cadmium and arsenic were below detectable limit at in both the harvested plantain from Bodo community and those of the control experiment, respectively. Bioaccumulation factor of all the heavy metals identified were <1. PAHs of Acenaphthalene, Acenaphthene, chrysene, pyrene and fluranthene were not detected in the control experiment while only chrysene was not detected in the test samples. Naphthalene,methyl naphthalene, acenaphthalene, acenaphthene, benzo (k) fluranthene and flourene were relatively high in concentration than pyrene and flouranthene in the test samples. Naphthalene, methylnaphthalene, flourene and benzo(k) flouranthene were only recorded in the control experiment. Acenaphthalene (0.034 mg/g) was seen as the highest PAHs in bioaccumulation in the test sample while flourene (0.005 mg/g) recorded the highest in the control experiment.

Determination of Petroleum Hydrocarbons Content in Soils From Suplacu de Barcău, Romania

The level of pollution with petroleum compounds was evaluated in Suplacu de Barcău area based on the assessment of total petroleum hydrocarbons (TPH) concentrations in soil. As source of contamination, one active and another inactive petroleum extraction wells were chosen, and the concentrations were determined by fluorescence spectrometry. The results indicated alarming exceedances of the intervention thresholds, especially in the area where the activity is stopped, thus indicating long-term accumulation of pollutant and persistence in soil. Keywords: petroleum hydrocarbons, soil pollution, TPH, fluorescence spectrometry

Indigenous microbial strains as bioresource for remediation of chronically polluted Niger Delta soils

An increase in artisanal crude oil refining within the Niger Delta Creeks has led to colossal environmental problems occasioned by spillages and subsequent ecosystem damage. Bacteria have been shown to play key role in biogeochemical cycling and degradation of pollutants from petroleum sources. The present study investigated the degradation efficiency of a bacterial consortia recovered from heavily inundated site in Bie-Ama community, having total petroleum hydrocarbons (TPH) concentration of 22,000 mg/kg, a value higher than Department of Petroleum Resources (DPR)’s 1000 mg/kg intervention limit. Soil samples were collected at 15 cm depth with soil auger while microbial isolation was done using enrichment and vapor phase transfer methods in Bushnell Haas medium. Colorimetric method using 2, 6-dichlorophenol indophenol (DCPIP) redox indicator was employed to determine biodegradation potentials of isolates. Bacterial isolates identified using 16S rRNA gene by Sanger sequencing were further screened for biosurfactant production and aromatic hydrocarbon degradation abilities. A consortium for efficient biodegradation of crude oil was constituted from individual isolates that totally decolorized DCPIP. Total culturable heterotrophic and hydrocarbon utilizing bacterial counts were 2.07 × 106 and 1.71 × 106 CFU/g soil respectively. Bacterial strains from the genera Pseudomonas, Bacillus, Klebsiella, Enterobacter produced biosurfactants while all strains utilized aromatics (benzene and naphthalene). A combination of Pseudomonas, Bacillus, Lysinibacillus and Enterobacter was the most efficient crude oil degrading consortium with significant mean difference (p = 0.05) as evidenced by GC-analysis confirming a more than 25% reduction in total petroleum hydrocarbon (TPH) concentration of 1% crude oil within 48 h. Conclusively, the extant indigenous bacterial community in the impacted site has the natural capability to degrade hydrocarbons and could be further enhanced through biostimulation for in situ remediation.

Assessment of enhanced biodegradation potentials of animal wastes on diesel-contaminated soil

Oil spillage is a menace, crippling most oil-producing regions around the globe. The aim of this study was to access the role of poultry litter and cow dung in enhancing biodegradation of diesel-contaminated soil. The treatment sets were split into three levels of diesel pollution (50 mL, 100 mL and 150 mL) amended with poultry litters, cow dung and a mixture of both amendments. The microbiological properties-and the total petroleum hydrocarbon content was analyzed for a period of six months using the pour plate techniques and Gas Chromatography (GC-FID), respectively. Agarose gel electrophoresis was used for plasmid detection. Mean total heterotrophic bacterial counts ranged between 40.5±0.5 x104 cfu-1 and 102.0 ±4.0 x104 cfu-1, for C1 (soil with poultry litter and cow dung with 50mL diesel) and Control 2. The mean total hydrocarbonoclastic bacterial counts ranged from 42.0±2.0 x104 cfu-1 to 66.5±2.5 x104 cfu-1 for B1 (soil with cow dung with 50mL diesel) and C3 (soil with poultry litter and cow dung with 150mL diesel). Bacillus subtilis (25.7%) and Staphylococcus aureus (4.73%) were reported as the isolates with the highest and least percentage frequency of occurrence. The percentage of diesel oil degradation was highest in C1 (98.5%) and lowest in Control 1 (31.6%). Plasmid extraction studies carried revealed that two out of the five hydrocarbonoclastic bacteria had both plasmids and chromosomal genes. The result has indicated the enhanced capacity of mixed amendments relative to individual waste treatment used in this study and should be recommended for bioremediation application.

Stimulating the Rate of Phytoremediation of Chromolaena odorata in Crude Oil Contaminated Soil Using Inorganic Urea

Investigation on the use of urea in stimulating the phytoremediation of Chromolaena odorata in a crude oil contaminated soil was carried out at a crude oil spilled site at Botem-Tai, Ogoni, Nigeria. Three phytoremediation treatments labeled A – C in addition to the control (D) were used. The treatments were: A (Chromolaena odorata only), B (Chromolaena odorata + 20 g/m2 urea), C (Chromolaena odorata + 40 g/m2 urea), D (polluted soil without phytoremediation) arranged using Latin Square Design (LSD). Total petroleum hydrocarbon (TPH) and Total hydrocarbon content (THC) in soil and plant samples from the different treatment plots in addition to other soil nutrients were analyzed. The percentage reduction in TPH and THC in soil were as follows: Treatment B, {TPH (92.08%) and THC (95.37%)} &gt; treatment A {TPH (88.95%) and THC (93.37%)}&gt; C {TPH (78.78%) and THC (83.29%)} &gt; Control {TPH (14.76%) and THC (32.90%)}. Treatment C had the highest TPH (2.67 mg/kg) and THC (20.57 mg/kg) accumulation in test plant. Combining stimulant (urea) with phytoremediation also improved soil properties such as pH, Nitrogen and Potassium. With the highest reduction of TPH and THC in treatment B (phytoremediation with 20 g/m2 urea) than other treatments is an indication that low concentration of urea has a stimulatory effect on phytoremediation of crude oil by Chromolaena odorata.

Petroleum pollution and microbial community structure in the soil of Liaohe Oilfield.

We analyzed the soil physico-chemcial properties, microbial community structure, petroleum hydrocarbon contents and components in soil samples from the well sites of Shuguang, Huanxi-ling and Jinzhou oil exploitation sites in Liaohe Oilfield, with uncontaminated paddy soil as a control. The results showed that: 1) The soil around all the three oil exploitation sites were seriously polluted by petroleum with certain differences in the petroleum hydrocarbon contents and components. The average content of petroleum hydrocarbon in the soil of Shuguang and Huanxiling oil exploitation sites was two times higher than that of Jinzhou oil exploitation site. The content of resins and asphaltenes in the soil of Shuguang oil exploitation site was the highest, while the soils of Huan-xiling and Jinzhou oil exploitation sites had the highest alkane content, which accounting for more than 40% in all the sites. 2)Compared with the paddy soil, the microbial OTU numbers, Chao1 and Shannon indices in the soil of Jinzhou oil exploitation site increased. The dominant phyla and genera were similar in the soil of all oil exploitation sites but with large differences in abundance. The soil in Jinzhou oil exploitation site had higher abundance of Mycobacterium and Pseudomonas, while Sphingomonas and Nocardioides, Massilia in the soil of Shuguang oil exploitation site, and Lysobacter, Thiobacillus and Pseudomonas in the soil of Huanxiling oil exploitation site. 3) The abundances of Sphingomonas, Nocardioides, Thiobacillus, Massilia, Pseudomonas and the contents of total petroleum hydrocarbons, total organic carbon and resins and asphaltenes were significantly positively correlated, while Mycobacterium, Lysobacter and Pseudomonas were significantly positively correlated with the contents of total nitrogen and total phosphorus. This study systematically analyzed the petroleum hydrocarbon, physico-chemcial properties and microbial communities in the soil of different oil exploitation sites, and revealed the specific dominant bacterial genera and microbial communities in the soil of Liaohe Oilfield. Our results provided a theoretical basis for functional bacterium screening and microbial community construction in the remediation process of petroleum contaminated soil in Liaohe Oilfield, and a reference for efficient degradation bacteria screening in other oilfields.

Impact of oil contamination on ecological functions of peat soils from West Siberia of Russia.

For more than a century, the need for energy has exerted high demand on oil production and led to significant negative impacts on soil and water resources. The aim of our work was to assess such impacts on the ecological functions of oil-contaminated soils in West Siberia of Russia. The total petroleum hydrocarbons (PHC) content in contaminated soils varied between 3.7 and 390g kg-1 . Although peat had the ability to absorb some PHC, excess oil migrated in soil both downward and laterally. Catalase activity, soil respiration activity (basal respiration [BR], microbial biomass carbon [Cmic], and specific respiration activity [qCO2 ]), and Enchytraeus albidus survival and reproduction rates showed significant negative correlations with PHC concentrations, and thus they can be used as guides for establishing acceptable PHC limits in peat soils. Based on the Logit model, the concentration of PHC in peat soil that corresponds to ∼20% reduction on functions (worm reproduction, catalase activity, and basal respiration) is about 40-50g kg-1 . The concentrations of PHC that will result in 80% functional reductions (i.e., near-complete loss on functional activities) are worm production (177g kg-1 ), catalase activity (123g kg-1 ), and basal respiration (311g kg-1 ). This study provides quantitative understanding of the ecological impact of PHC contamination on peat soils and thus helps to establish science-based guidelines for the protection of ecological functions and services of peatland soils.

Human health risks from fish consumption following a catastrophic gas oil spill in the Chiquito River, Veracruz, Mexico

An industrial accident resulted in a gas oil spill of 11,808 barrels in the upper part of the Coatzacoalcos River watershed. After river shore cleanup, concentrations of total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) in muscle (+ skin) were determined in captured fish to evaluate human health risk due to fish consumption post-spill in the most affected communities. Data on fish consumption, body weight, and diet factor were collected by questionnaires and field observations. Using standard formulas for carcinogenic and non-carcinogenic substances, site-specific remediation levels were calculated in fish, comparing them to the real levels observed. Likewise, the levels of PAHs in fish captured pre- and post-spill were compared to determine their origin (pyrolytic vs. petrogenic). The TPH concentrations were between 119,000 and 523,000 ng/g (dry weight) and no significant difference (P > 0.05) was found pre- vs. post-spill. The concentration of total PAHs varied between 2494.83 and 35,412.23 ng/g (dry weight), with the concentrations of naphthalene (520.9 ng/g) and phenanthrene (7532.7 ng/g) being much higher than in control samples, and being from the gas oil spill (petrogenic origin). The site-specific remediation levels calculated for TPH and PAH were much higher than the maximum levels actually detected. No human health risks were found from hydrocarbons from the spill, at least after cleanup efforts and natural attenuation (six months).

Bioremediation of oily sludge by solid complex bacterial agent with a combined two-step process

In the present research, a bioremediation process was developed using solid complex bacterial agents (SCBA) through a combined two-step biodegradation process. Four isolated strains showed high efficiency for the degradation of total petroleum hydrocarbons (TPH) and the reduction of COD of the oily sludge, at 96.6% and 92.6%, respectively. The mixed strains together with bran prepared in form of SCBA exhibited improved performance compared to individual strains, all of which had an optimal temperature of around 35 °C. The use of SCBA provided advantages over commonly used liquid media for storage and transportation. The two-step process, consisting of firstly biosurfactant-assisted oil recovery and secondly biodegradation of the remaining TPH with SCBA, demonstrated the capability for treating oily sludge with high TPH content (>10 wt%) and short process period (60 days). The large-scale (5 tons oily sludge) field test, achieving a TPH removal efficiency of 93.8% and COD reduction of 91.5%, respectively, confirmed the feasibility and superiority of the technology for industrial applications.