Laboratory Design Criteria for Monitoring Biostimulated Bioremediation of a Crude Oil Contaminated Soil in Niger Delta Using Total Petroleum Hydrocarbon

The remediation of crude oil-impacted soil has always been a challenge in different soil environments and climatic conditions. Bioremediation technology has offered a breakthrough in restoring crude oil-impacted soil/sediment in muddy, dry soil and wetlands. Though, there have been varied environmental conditions that have hampered the success of the bioremediation process. This study has evaluated the effectiveness of a biostimulated bioremediation of crude oil-impacted soil using some design criteria—nutrient amendment (NPK fertilizer) and moisture content. Soil sample sets—A, B, C, D, E, F, and G were impacted with crude oil at a ratio of 10 g/kg and amended with varying amounts of nutrient 30, 60, and 80 g of N.P.K fertilizer. The medium for the inoculation of the nutrient was water and the volume of water applied varied from 30% to 80% saturation. The soil sample sets were harvested at an interval of 3 months for 180 days to determine the concentration of total petroleum hydrocarbon left in the soil. The analysis of the total petroleum hydrocarbon was achieved using a GC-FID with a capillary column and autosampler. Soil samples were extracted with mixed solvent dichloromethane and acetone at a 1:1 ratio. The total petroleum hydrocarbon results show that biostimulated bioremediation achieved better results in soil sample sets with low moisture content (30% water saturation) and moderate nutrient amendment. The biodegradation of the sample sets with high water saturation and a high nutrient amendment was slow with a higher amount of total hydrocarbon content at the end of the 180 days. The variability in the hydrocarbon degradation pattern of contaminated soil shows that biostimulated bioremediation achieved better results in soils with low moisture content than in soil environments with high water content (saturation). More so, nutrient overdosing of the substrate hampered the effectiveness of the remediation process.

The Impact Of Oil Spill To The Total Petroleum Hydrocarbon(Tph)Concentration In Fishes At North Coastal Of Karawang Regency,West Java Province

The coastal area is one of the areas that is quite vulnerable to the threat of pollution caused by human activities,including pollution caused by oil spills(hydrocarbons)in the sea.The incident can be caused by several factors including the explosion,leakage of petroleum pipelines on the seabed,leakage of tanks or petroleum tankers at sea and disposal of waste petroleum products into the environment.Oil spills continuously can cause environmental contamination and pollution both aquatic and terrestrial.If the petroleum hydrocarbons enter sea waters,some of them will be absorbed by aquatic organisms because the nature of the petroleum hydrocarbons is difficult to decompose in waters.The intentional and unintentional entry of hazardous and toxic substances into marine ecosystems such as petroleum hydrocarbons and chemical solvents resulting from industrial wastes has become a serious problem for human health and the environment.The purpose of this study was to determine the concentration of Total Petroleum Hydrocarbon(TPH)contained in fish in coastal waters of Karawang Regency,West Java Province.This research was conducted in September-November 2019 by taking several fish samples at Ciparage Jaya Fish Auction Place,Betok Mati and Sungai Buntu Rive with a total sample of 24 fish,and taking seawater samples in the three study sites.TPH analysis was carried out at the Integrated Chemistry Laboratory,Bogor Agricultural University.TPH values in fish at Ciparage-1,Ciparage-2,Betok Mati and Sungai Buntu stations,in general,have different mean values but are almost uniform,each at 6.82;6.82;7.45 and 5.12 mg/kg.Based on the average TPH concentration in fish,it can be said that the average TPH in fish at Betok Mati station is relatively higher compared to other stations.TPH values in all fish samples exceed the safe threshold,which is a maximum of 0.002 mg/kg.Based on the results of the Bioaccumulation factor(BAF)analysis showed that the average TPH in fish was 6.55 mg/kg and the average TPH in the waters was 11.23 mg/l,so the BAF value was 58.35 which means that the absorption rate of TPH by fish organisms against the concentration of TPH in the waters of 58.35%.The analysis shows that the value of Ecological Hazard Assessment(EHA)is 3743.33 which means that the level of influence of the hazard on ecosystems and organisms is 3743.33.This value exceeds the recommended threshold according to the European Union,which is a maximum of 0.002 mg/l.

Assessment of organic compost and biochar in promoting phytoremediation of crude-oil contaminated soil using Calendula officinalis in the Loess Plateau, China

The Loess Plateau,located in Gansu Province,is an important energy base in China because most of the oil and gas resources are distributed in Gansu Province.In the last 40 a,ecological environment in this region has been extremely destroyed due to the over-exploitation of crude-oil resources.Remediation of crude-oil contaminated soil in this area remains to be a challenging task.In this study,in order to elucidate the effects of organic compost and biochar on phytoremediation of crude-oil contaminated soil(20 g/kg)by Calendula officinalis,we designed five treatments,i.e.,natural attenuation(CK),planted C.officinalis only(P),planted C.officinalis with biochar amendment(PB),planted C.officinalis with organic compost amendment(PC),and planted C.officinalis with co-amendment of biochar and organic compost(PBC).After 152 d of cultivation,total petroleum hydrocarbons(TPH)removal rates of CK,P,PB,PC and PBC were 6.36%,50.08%,39.58%,73.10%and 59.87%,respectively.Shoot and root dry weights of C.officinalis significantly increased by 172.31%and 80.96%under PC and 311.61%and 145.43%under PBC,respectively as compared with P(P<0.05).Total chlorophyll contents in leaves of C.officinalis under P,PC and PBC significantly increased by 77.36%,125.50%and 79.80%,respectively(P<0.05)as compared with PB.Physical-chemical characteristics and enzymatic activity of soil in different treatments were also assessed.The highest total N,total P,available N,available P and SOM(soil organic matter)occurred in PC,followed by PBC(P<0.05).C.officinalis rhizospheric soil dehydrogenase(DHA)and polyphenol oxidase(PPO)activities in PB were lower than those of other treatments(P<0.05).The values of ACE(abundance-based coverage estimators)and Chao 1 indices for rhizospheric bacteria were the highest under PC followed by PBC,P,PB and CK(P<0.05).However,the Shannon index for bacteria was the highest under PC and PBC,followed by P,PB and CK(P<0.05).In terms of soil microbial community composition,Proteiniphilum,Immundisolibacteraceae and Solimonadaceae were relatively more abundant under PC and PBC.Relative abundances of Pseudallescheria,Ochroconis,Fusarium,Sarocladium,Podospora,Apodus,Pyrenochaetopsis and Schizothecium under PC and PBC were higher,while relative abundances of Gliomastix,Aspergillus and Alternaria were lower under PC and PBC.As per the nonmetric multidimensional scaling(NMDS)analysis,application of organic compost significantly promoted soil N and P contents,shoot length,root vitality,chlorophyll ratio,total chlorophyll,abundance and diversity of rhizospheric soil microbial community in C.officinalis.A high p H value and lower soil N and P contents induced by biochar,altered C.officinalis rhizospheric soil microbial community composition,which might have restrained its phytoremediation efficiency.The results suggest that organic compost-assisted C.officinalis phytoremediation for crude-oil contaminated soil was highly effective in the Loess Plateau,China.

Bioprospecting of Hydrocarbonoclastic Representative Bacteria

This study was designed and carried out to characterize hydrocarbonoclastic microbial communities in soil polluted with artisanal refined hydrocarbon at Trans Amadi, Phalga Local Government Area of Rivers State, Nigeria. Heterotrophic bacteria count ranged from 8.0 × 105 cfu/gm for sample TSAS1, and 2.1 × 106 cfu/gm for sample TSAS2 while TSAS3 was too numerous to count (TNTC). Hydrocarbon utilizing bacteria count ranged from 1.1 × 105 cfu/gm for TSAS1, and 5.9 × 104 cfu/gm for TSAS2, while TSAS3 was 5.4 × 104 cfu/gm. Physiochemical parameters of the soil were determined. The ranges obtained were pH 6.6, conductivity 125 μs/cm, temperature 27.3°C, moisture 7.72, total nitrogen 0.056%, phosphate 1.554 ppm, potassium 145.87 ppm, lead 7.02 ppm, cadmium 0.41 ppm, nickel 1.96 ppm, copper 1.14 ppm, total petroleum hydrocarbon 1487.24181 ppm, polycyclic aromatic hydrocarbon 12.85287 ppm. Isolates of hydrocarbon utilizing bacteria characterized belonged to the genera Escherichia coli, Klebsiella sp., Lactobacillus sp., Enterobacter sp., Serratia sp., and Proteus sp. The findings in this study have revealed the abilities of these groups of bacteria to be employed in bioremediation/biodegradation clean-up practices. Thus the polluted soil may harbour important genera of bacterial species that may have beneficial applications in environmental microbiology for future remediation processes.

Phytoremediation of Oil-Contaminated Soils by Combining Flowering Plant Cultivation and Inoculation with <i>Acinetobacter junii</i>Strain M-2

Oil contamination of the soil by petroleum products has become an enormous environmental problem. In this study, we examined whether remediation of oil-contaminated soils by cultivating three flowering plants (Mimosa, Gazania, and Zinnia) could be enhanced by inoculation with Acinetobacter junii strain M-2 at different plant growth stages (at sowing, at early growth, and at mid-growth). The growth of Zinnia cultivated in oil-contaminated soils inoculated at sowing was significantly superior to that in the non-inoculated soil. Although total petroleum hydrocarbon concentrations in soils inoculated at sowing were nominally lower than those in non-inoculated soils, especially in the case of Zinnia planting, the effect did not reach statistical significance. However, dehydrogenase activity was significantly higher in the soils inoculated with A. junii strain M-2 than in non-inoculated soils for all three plant species tested. These results demonstrate that a combination of ornamental plant cultivation (particularly Zinnia) and inoculation with A. junii strain M-2 increases the efficiency of oil-contaminated soil phytoremediation.

Effects of 5-Aminolevulinic Acid (ALA) on Zinnia hybrida Growth and Phytoremediation Effects in Oil-Contaminated Soil

In this study, we compared plant height, weight, soil TPH concentration, and soil DHA level after 18 weeks of Zennia hybrida cultivation with four different concentrations of 5-Aminolevulinic acid (ALA)-based liquid fertilizer: 1500-fold, 5000-fold, and 8000-fold dilutions, along with a non-treatment control of diluted ALA. The plants of ALA-treated were significantly taller than the non-treatment control. The plants of ALA-treated plants were higher in shoot fresh weight, shoot dry weight, and root dry weight than the non-treatment control. The plot of ALA-based liquid fertilizer with the 5000-fold dilution was significantly highest in shoot fresh weight, shoot dry weight, and root dry weight. ALA-treated plants were lower in the soil Total Petroleum Hydrocarbon (TPH) concentration than the non-treatment control. The plot of ALA-based liquid fertilizer with the 5000-fold was significantly lowest in the TPH concentration. In addition, ALA-treated plants were higher in the soil dehydrogenase activity (DHA) than the non-treatment control. The plot of ALA-based liquid fertilizer with the 5000-fold was significantly highest in the TPH concentration. This study indicated that ALA-applied zinnia-grown oil-contaminated soil is more effective than not. The remediation in oil-contaminated soil with ALA-based liquid fertilizer is more effective than the non-treatment control;furthermore, ALA application with 5000-fold dilution was most suitable in oil-contaminated soil among other plots.

Eco-toxicity of petroleum hydrocarbon contaminated soil

Total petroleum hydrocarbons （TPH） contaminated soil samples were collected from Shengli Oilfield of China. Toxicity analysis was carried out based on earthworm acute toxicity, plant growth experiment and luminescent bacteria test. The soil was contaminated by- petroleum hydrogcarbons with TPH concentration of 10.57%. With lethal and sub-lethal rate as endpoint, earthworm test showed that the LD50 （lethal dose 50%） values in 4 and 7 days were 1.45% and 1.37% respectively, and the inhibition rate of earthworm body weight increased with higher oil concentration. TPH pollution in the soil inhibited seed germination in both wheat and maize experiment when the concentration of petroleum was higher than 0.1%. The EC50 （effective concentration 50%） for germination is 3.04% and 2.86% in maize and wheat, respectively. While lower value of EC50 for root elongation was to be 1.11% and 1.64% in maize and wheat, respectively, suggesting higher sensitivity of root elongation on petroleum contamination in the soil. The EC50 value in luminescent bacteria test was 0.47% for petroleum in the contaminated soil. From the experiment result, it was concluded that TPH content of 1.5% is considered to be a critical value for plant growth and living of earthworm and 0.5% will affect the activity of luminescent bacteria.

In situ Remediation of Petroleum Contaminated Groundwater by Permeable Reactive Barrier with Hydrothermal Palygorskite as Medium

The permeable reactive barrier（PRB） has proven to be a costeffective technique to remediate the petro leum contaminated groundwater at a northeast field site in China. In this study, the geology, hydrogeology and con tamination characterization of the field site were investigated and the natural hydrothermal palygorskite was chosen as a reactive medium. Furthermore, the adsorption of the total petroleum hydrocarbons（TPH） in the groundwater onto hydrothermal palygorskite and the adsorption kinetics were investigated. The results indicate that the removal rates of TPH, benzene, naphthalene and phenantharene could all reach up to 90% by hydrothermal palygorskite with a diameter of 0.25-2.00 mm that had been thermally pretreated at 140 ℃. The adsorption of TPH onto hydrothermal palygorskite after pretreatment followed a pseudosecondorder kinetic model and a Langmuir adsorption isotherm, suggesting that the theoretic adsorption capacity of hydrothermal palygorskite for adsorbate could be 4.2 g/g. Scan ning electron microscopy（SEM）, infrared spectroscopy（IR）, Xray diffraction（XRD） and Xray fluorescence spec troscopy（XRF） were carried out to analyze the adsorption mechanism. The results reveal that hydrothermal palygors kite is a fibrous silicate mineral enriched in Mg and A1 with large surface area and porosity. The dense cluster acicular and fibrous crystal of hydrothermal palygorskite, and its effect polar group OH played an important role in the physical and chemical adsorption processes of it for contaminants. This study has demonstrated hydrothermal paly gorskite is a reliable reactive medium for in situ remediation of petroleum contaminated groundwater at field sites.

Merits and limitations of TiO2-based photocatalytic pretreatment of soils impacted by crude oil for expediting bioremediation

Heavy hydrocarbons （HHCs） in soils impacted by crude oil spills are generally recalcitrant to biodegrada- tion due to their low bioavailability and complex chemical structure. In this study, soils were pretreated with varying concentrations of ultraviolet radiation A （UVA） or ultraviolet radiation C （UVC） activated titanium dioxide （TiO2） （1%-5%） under varying moisture conditions （0%- 300% water holding capacity （WHC）） to enhance biodegradation of HCCs and shorten remediation time- frames. We demonstrate that pretreatment of impacted soils with UVC-activated TiO2 in soil slurries could enhance bioremediation of HHCs. Total petroleum hydrocarbon （TPH） removal after 24 h exposure to UVC （254 nm and 4.8 mW/cm2） was （19.15：1.6）% in slurries with 300% WHC and 5 wt-% TiO2. TPH removal was non-selective in the C15-C36 range and increased with moisture content and TiO2 concentration. In a 10-d bioremediation test, TPH removal in treated soil increased to （26.05：0.9）%, compared to （15.45：0.8）% for controls without photo- catalytic pre-treatment. Enhanced biodegradation was also confirmed by respirometry. This suggests that addition of UVC-activated TiO2 to soil slurries can transform recalcitrant hydrocarbons into more bioavailable and biodegradable byproducts and increase the rate of subsequent biodegradation. However, similar results were not observed for soils pretreated with UVA activated TiO2. This suggests that activation of TiO2 by sunlight and direct addition of TiO2 to unsaturated soils within landfarming setting may not be a feasible approach. Nevertheless, less than 1% of UVA （7.5 mW/cm2） or UVC （1.4 mW/cm2） penetrated beyond 0.3 cm soil depth, indicating that limited light penetration through soil would hinder the ability of TiO2 to enhance soil bioremediation under land farming conditions.

Bioremediation and detoxification of real refinery oily sludge using mixed bacterial cells

Anaerobic biotreatment of real field petroleum refinery oily sludge(PROS)was investigated under using four different organic loads(OLs)in the order ofOL4>OL3>OL2>OL1,in bench-scale bioreactors.The bioremediation of raw PROS was carried out using mixed culture biocatalyst without chemicals addition or any type of pretreatment.The results revealed a potential performance of the used biocatalyst dominated by Pseudomonas aeruginosa(class:Gammaproteo)and Staphylococcus spp.(class:Bacilli)achieving significant removal of chemical oxygen demand(COD)and total petroleum hydrocarbons(TPH).The highest organic removal rate was recorded in OL4 followed by OL3,0L2,OL1,respectively indicating a positive relationship between the percentage removal of organics and their content.Maximum removal efficiencies of 96.7%and 90%were observed for COD and TPH,respectively in OL4 within 14 days only.Analysis of polycyclic aromatic hydrocarbons(PAHs)demonstrated that acenaph-thylene and phenanthrene exhibited the maximum removal efficiency(almost complete)among the 8-priority PAHs tested in this study.However,the overall degradation of PAHs in the oily sludge was 83.3%.

Fenton treatment via oxidative mechanism and its kinetics on soil polluted with automatic gas oil

The effectiveness,viability and feasibility of applying Fenton reactants in treating soil contaminated with automatic gas oil(AGO)was investigated ex-situ.Soil was simulated to achieve 10%contamination using AGO(diesel)as the primary contaminant.Physicochemical properties and heavy metal contents were characterized using standard analytical methods,while total petroleum hydrocarbon(TPH)content was determined by molecular spectroscopy.An investigation of the soil physicochemical properties shows severe impact of the contaminant on pH,conductivity,phosphorus and(TPH)content.The optimum concentration of Fenton reactants determined from the optimization study was found to be 350,000 ppm H2O2 and 600 ppm FeSO4 at optimum room temperature range of 27e30
C and optimum pH of 4.7.The highly exothermic Fenton oxidation treatment resulted in significant decrease in TPH content by 87.6%after 6 h of periodic monitoring;breaking down the hydrocarbons into non-toxic environmental friendly products.Kinetics analysis and evaluation shows pseudo-first order mechanism for the Fenton treatment with a calculated rate constant of 0.226 h-1 and half life of 3 h 4 min.The Fenton method is found to be very effective and efficient not only for the removal of the diesel contaminant,but also for the restoration of lost physicochemical properties occasioned by the effect of the contaminant.The environmental friendliness and fast response time towards effective clean up gives the technique a cutting edge advantage over other conventional methods.It therefore presents potentials for remediation experts in outright applications on real field challenges.

A comparative study of methods for remediation of diesel-contaminated soil

Soil pollution by diesel fuels is a worldwide environmental problem,but little research has been carried out into on-site techniques for remediation of soil polluted by waste solvents.This study compared chemical oxidation and soil washing methods for their efficiency and environmental and economic impacts.Soil was spiked with 0#diesel to simulate an actual pollution level of about 1260 mg/kg total petroleum hydrocarbon(TPH).Fenton-like oxidation eliminated 90.4%of the TPH with a Fe2+׃H2O2 ratio of 1:10 in 5 d compared with 25.8%removal by the activated persulfate method under the same conditions.In washing tests,sodium dodecylbenzenesulfonate and Tween 80 were both unsuitable for TPH washing,while ultrapure water removed 36.1%of TPH in 75 min.Only the Fenton-like oxidation technique met remediation goals based on the screening values of the Guideline for Risk Assessment of Contaminated Sites.The environmental impact and economic assessment of techniques demonstrated the superiority of water washing for dealing with low-degree TPH contamination.