Initial Total Petroleum Hydrocarbons Concentration Research Articles

Synergistic use of cattle bile, compost and fertilizer amendments in enhancing the bioremediation of hydrocarbon-contaminated soils

This study investigated the degradation of hydrocarbon-contaminated soil using compost, NPK 20:10:10 fertilizer, and cattle bile as biostimulants. In this study, 1000 g of homogenized contaminated soil was amended with 10.50 g of NPK fertilizer and 107.50 g of compost to achieve a nitrogen concentration of 0.2%. To establish a 0.4% nitrogen concentration, 23.90 g of NPK fertilizer, 243.54 g of compost, and 2 ml of cattle bile were used. These amendments were applied in various combinations to create the following microcosm treatments: A, B, C, D, A2, B2, C2, D2, and a control. The microcosms, along with the control were incubated for 6 weeks in triplicate. Throughout this period, several parameters were monitored every two weeks, including pH, nitrogen (N), potassium (K), phosphorus (P), moisture content, organic carbon, organic matter, total heterotrophic bacterial count (THBC), and total petroleum hydrocarbon (TPH) concentration. The results showed significant differences (p < 0.05) in TPH content across the microcosms during the four sampling periods. By the end of the 6-week incubation, the TPH residual concentration varied between 1.58 mg/kg and 20.61 mg/kg, corresponding to degradation rates of 98.43% and 79.58%, respectively, from an initial TPH concentration of 100.91 mg/kg. Microcosm B2 demonstrated the highest hydrocarbon removal efficiency (98.43%), while the control showed the lowest efficiency. The order of degradation efficiency among the microcosms was B2 > B (94.89%) > C (94.64%) > A (94.13%) > D2 (93.62%) > A2 (93.51%) > C2 (92.45%) > D (91.44%). The study also found that pH and nitrogen levels were related to the reduction in hydrocarbon content. Microcosms with a 0.4% nitrogen concentration showed a higher rate of nitrogen consumption compared to those with a 0.2% concentration. Additionally, changes in pH were observed as hydrocarbon degradation progressed. This study further applied cluster analysis, Bayesian statistics, and multiple linear regression to evaluate the effects of treatments on soil quality over time. Cluster analysis showed increasing dissimilarity between merged clusters, while Bayesian analysis revealed positive trends in parameter estimates in Weeks 2 and 4. Regression analysis indicated significant impacts of Weeks 2, 4, and 6 on Week 0, with F-statistics of 8.475 (p = 0.016), 9.804 (p = 0.004), and 3.759 (p = 0.037), though multicollinearity reduced the predictive power of individual coefficients. Overall, Microcosm B2 emerged as the most effective treatment option. The findings suggest that biostimulation using a combination of moisture, compost, NPK fertilizer, and cattle bile is an effective approach to achieving high efficiency in TPH degradation in hydrocarbon-contaminated soils.

Enhancing in situ remediation of clayey soils contaminated with total petroleum hydrocarbons by combining pneumatic fracturing, plasma blasting, and vacuum extraction: A comprehensive field investigation

Oxidant injection technology is widely used in soil remediation; however, subsurface conditions, including soil properties and permeability, significantly influence its effectiveness. In this study, the potential of the combination of pneumatic fracturing, plasma discharge, and vacuum extraction (PPV) in enhancing soil permeability and remediating field-scale silt/clayey soils contaminated by total petroleum hydrocarbon (TPH) was studied. Improved soil permeability was assessed by measuring the chlorine and H2O2 concentrations in soil samples, and the remediation efficiency of PPV was evaluated by analyzing the TPH concentrations in the soil samples. The initial highest TPH concentration was 6922 mg kg−1; after a 42-day operation period, the TPH levels decreased to 541 mg kg−1. The economic assessment of PPV revealed it to be cost-effective, with a total operating cost of US$ 3077 for remediating 265 m³ of contaminated soil, equating to US$ 11.6 per ton of soil. Since PPV requires a short operational period, is inexpensive, and is suitable for purifying low-permeability soil, it is a promising and economically advantageous approach for soil purification. Overall, PPV demonstrated the ability to enhance oxidizing agent transfer by increasing soil permeability, suggesting its potential for efficient and targeted soil remediation.

Activation of persulfate by g-C3N4/nZVI@SBC for degradation of total petroleum hydrocarbon in groundwater

In this study, we synthesized a high removal efficiency catalyst using biochar-supported nanoscale zero-valent iron and g-C3N4, denoted as g-C3N4/nZVI@SBC, to activate persulfate (PS) for the degradation of total petroleum hydrocarbon (TPH) in groundwater. We characterized the morphology and physiochemical properties of g-C3N4/nZVI@SBC with scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), BET surface area analysis, and X-ray photoelectron spectroscopy (XPS). To assess the performance of the g-C3N4/nZVI@SBC catalyst, we investigated various reaction parameters, such as the mass ratio of g-C3N4 to nZVI@SBC, PS concentration, initial pH, initial TPH concentration, and the presence of coexisting ions in the system. The results from batch experiments and repeated use trials indicate that g-C3N4/nZVI@SBC exhibited both excellent catalytic activation capability and impressive durability, making it a promising choice for TPH degradation. Specifically, when the PS concentration reached 1 mM, the catalyst dosage was 0.3 g/L, and the g-C3N4 to nZVI@SBC mass ratio was 2, we achieved a remarkable TPH removal efficiency of 93.8%. Through electron paramagnetic resonance (EPR) testing and quenching experiments, we identified sulfate radicals, hydroxyl radicals, and superoxide radicals as the primary active substance involved in the TPH degradation process. Moreover, the g-C3N4/nZVI@SBC composite proved highly effective for in-situ TPH removal from groundwater and displayed an 86% removal rate, making it a valuable candidate for applications in permeable reactive barriers (PRB) aimed at enhancing environmental remediation. In summary, by skillfully utilizing g-C3N4/nZVI@SBC, this study has made notable advancements in synthesis and characterization, presenting a feasible and innovative approach to addressing TPH pollution in groundwater.

Adsorption of total petroleum hydrocarbon in groundwater by KOH-activated biochar loaded double surfactant-modified nZVI

Introduction: Crude oil and petroleum hydrocarbon contamination is commonly found in the soil and groundwater during the various processes of mining, processing, and utilization due to issues such as inefficient environmental management, random wastewater discharge, and storage tank leakage.To address this issue, we will use corn stalk biochar (SBC) and surfactants to improve the stability and chemical reactivity of nZVI, thereby enhancing its ability to remove pollutants, and explore the adsorption effect and mechanism of composite materials for petroleum hydrocarbons.Methods: Modified corn stalk biochar (SBC) was synthesized through high-temperature carbonization and KOH activation. Subsequently, the iron/carbon composite PN-nZVI@SBC (PNMSBC) was prepared by loading nano zero-valent iron modified with dual surfactants, and it was adopted to adsorb total petroleum hydrocarbons(TPH) in groundwater. The physical and chemical properties, surface patterns, and elemental mapping of PNMSBC particles were analyzed using SEM, EDS, TEM,XRD, BET, and FTIR spectroscopy. Kinetics and isotherm tests were performed to evaluate the adsorption properties of the composites. TPH adsorption was dependent on ionic strength, initial TPH concentration, as well as pH. The adsorption mechanism combining XPS and EPR spectroscopy was explored.Results: The characterization results by SEM and TEM showed that the particle size of nZVI particles modified by surfactants became smaller, and the dispersibility was enhanced. The characterization results by XRD and FTIR confirmed the successful preparation of the composites. The BET results showed that MSBC and PNMSBC were mesoporous structures. The characterization results indicated that Polyvinylpyrrolidone (PVP) and Sodium oleate (NaOA) inhibited the oxidation of nZVI while effectively improving its reactivity. The result of the experiments on adsorption showed that the removal of TPH by PNMSBC followed Freundlich isotherm and pseudo-second-order kinetic models, thus suggesting that the main adsorption processes comprise chemisorption and multilayer heterogeneous adsorption. The adsorption capacity of PNMSBC was increased by the abundance of macro and microporous structures. To be specific, a maximum Langmuir adsorption capacity (qm) was achieved as 75.26 g/g. The result of batch experiments indicated that PNMSBC continuously removed considerable TPH under a wide pH range from 2 to 6. The adsorption mechanism of PNMSBC includes surface adsorption, oxidation, complexation, and electrostatic interaction.Discussion: In brief, PNMSBC has a promising application for the adsorption of TPH in groundwater remediation.

Biodegradation of Petroleum Sludge by Methylobacterium sp. Strain ZASH.

A bacterium was isolated from sludge-contaminated soil in a petroleum refinery and tested for its ability to degrade aliphatic hydrocarbon compounds present in petroleum sludge. The isolate was grown on minimal salt media agar supplemented with 1% (w/v) petroleum sludge. The isolate was tentatively identified as Methylobacterium s p. s t rain ZASH based on the partial 16s rDNA molecular phylogeny. The bacterium grew optimally between the temperatures of 30°C and 35°C, pH 7 and 7.5, 0.5% and 1.5% (v/v) Tween 80 as the surfactant, and between 1% and 2% (w/v) peptone as the nitrogen source. The constants derived from the Haldane equation were μmax = 0.039 hr-1, Ks = 0.385% (w/v) total petroleum hydrocarbons (TPH) or 3,850 mg/L TPH, and Ki =1.12% (w/v) TPH or 11,200 mg/L. The maximum biodegradation rate exhibited by this strain was 19 mg/L/hr at an initial TPH concentration of 10,000 mg/L. Gas chromatography analysis revealed that after 15 days the strain was able to degrade all aliphatic n-alkanes investigated with different efficiencies. Shorter n-alkanes were generally degraded more rapidly than longer n-alkanes with 90% removal for C-12 compared to only 30% removal for C-36. The addition of sawdust did not improve bacterial degradation of petroleum hydrocarbons, but it assisted in the removal of remaining undegraded hydrocarbons through adsorption.

MODELLING OF THE TOTAL PETROLEUM HYDROCARBON (TPH) DEGRADATION DURING THE BIOREMEDIATION OF CRUDE OIL POLLUTED SOIL USING COW DUNG AND WIRE CROTONS

The contamination of soil due to activities involved in crude oil exploration and production, and oil spillage emanating from pipeline vandalization, sabotage, theft, corrosion of pipeline and the enterprises of artisanal refineries pose health and ecological problems. This is especially as crude oil contains chemical compounds which are grouped into the Total Petroleum Hydrocarbons (TPH), and known to be toxic, mutagenic, and carcinogenic. Bioremediation is currently being explored as a cost effective and environmentally friendly methods of remediating the soil from this contaminant. Thus, the current work is aimed at developing a mathematical model for the bioremediation process. This was carried out while assuming that the process of degradation is a first order reaction, and the principle of the law of conservation of mass was applied. A linear model ( ) was developed relating the instantaneous concentration of TPH, initial concentration of TPH and time duration of the bioremediation. The model fitted well to the experimental data as shown by the result of the statistical analysis where the Analysis of Variance (ANOVA) showed a p-value of 0.004 suggesting that the model is statistically significant. The p-values of the model variables such as time duration of the bioremediation was 0.004, this suggested that the variable is significant. The model can be used as a supporting tool in the management of the biodegradation of TPH to predict the degradation concentration of TPH during the bioremediation process at ambient condition of temperature and pressure using cow dung, wire croton and their combination as a carbon source. KEYWORDS: Bioremediation; cow dung; wire croton; degradation; Mathematical modelling

Bench-Scale Biopile Hydrocarbons Removal Optimization Using the Response Surface Methodology and Simultaneous Optimization

Nowadays, the generation of vast volumes of oily sludges is associated with industrial operations such as production, pretreatment, processing, water separation, and storage tank maintenance. Biopiles can be more efficient than other techniques for removing hydrocarbons in sludges, but their removal efficiency depends on operating variables. The goal of this study was to determine the best operating variable ranges at the bench scale to simultaneously optimize hydrocarbons removal in a biopile prototype. This research was conducted within the framework of a Cuban project and used an experimental protocol that integrates several standardized methods and engineering procedures into a series of steps. A Box-Behnken design was implemented for three factors and two response variables: the mass of Total Petroleum Hydrocarbons (TPH) removed and the final concentration of TPH. A simultaneous optimum was obtained for an initial TPH concentration of 39 278 mg·kg-1 and contents of texturizer and moisture of 6,45 and 25,95%, respectively. The obtained variable ranges ensure a compromise solution that maximizes the mass of TPH removed and keeps the contaminant concentration under the Cuban disposal regulations. The results have been used to set up the biopiles at a pilot scale as a subsequent stage of the project.

Remediation of Lubricant Contaminated Soils by Cavitation Microjet Shock Wave Soil Washing System with Ozonation

ABSTRACT Adopting soil washing to clean up petroleum hydrocarbon contaminated soils with high sand content is considered as a fast and economical method. Cavitation microjet shock wave soil washing system (CMS) enhanced by the use of ozonation was developed for remediation of aged lubricant contaminated soil in this study. Contaminated soil with total petroleum hydrocarbon (TPH) ranging from 1890 mg/kg to 15735 mg/kg were applicable for CMS soil washing system. The impacts of factors including initial TPH concentration hydrocarbon (TPH) concentration, soil particle size, soil washing time, and ozone treatment time onto soil washing were investigated through a 21-month period of field operation. The contaminated soils with particle size between 0.074 mm and 0.25 mm, mainly very fine sand and find sand, demonstrated 31% to 98% of TPH removal by air-injected CMS and 19% to 92% of TPH removal by CMS with ozone addition. The optimal cavitation washing time was 20 minutes. The study indicated that optimal ozone concentration in the slurry was 1.08 mg/L which require air of 27 L/min for ozone produced. However, given the short contact time in the CMS system, ozone addition in the slurry did not improve TPH removal effectively. Considering the compatible TPH removal efficiency and energy cost of ozone addition in the soil washing system, use of air-injected CMS soil washing system may be considered as an alternative way.

Predictive comparison and assessment of ANFIS and ANN, as efficient tools in modeling degradation of total petroleum hydrocarbon (TPH)

Composting is an effective organic waste management practice with a sustainable environmental impact on soil. In most cases, composting materials are agricultural residues constituting a huge environmental challenge. This study investigates the composting biostimulation of total petroleum hydrocarbon (TPH) contaminated soil using organic compost prepared from palm oil mill effluent (CPOME). The performance of CPOME in TPH degradation was evaluated using the first-order kinetic model and CO₂ evolution. The artificial neural network (ANN) and adaptive neuro-fuzzy inference system (ANFIS) modelling approaches were further employed to optimize the experimental response. The experimental designs for ANFIS and ANN modelling were done using the central composite design (CCD). Statistical parameters such as RMSE, MSE, and MAE were used to evaluate model performance and comparisons. The first-order kinetic model and CO₂ released showed that TPH degradation favours contaminated soil with 40 g/L initial TPH concentration. The first-order kinetic model observed a decrease in the constant degradation rate with increasing TPH concentration. The CO₂ evolution, which measures microbial respiration/activity, also showed a decline in released CO₂ with increasing TPH concentration. Lower values of RMSE, MSE, and MAE were obtained for the ANFIS model compared with the ANN. The R² values between the experimental and model-predicted responses showed that the ANFIS (0.9349) model predictions fitted adequately compared to the ANN (0.8862). Finally, comparison and model performances showed that the ANFIS model prediction capability was considerably better than the ANN. • The compost from palm oil mill effluent proved effective in TPH degradation • ANFIS predicted TPH degradation was better than the ANN predicted • Notable organic materials in the compost includes polysaccharides, nitrogen and lignin

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.

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.

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

Remediation of oil-based drilling waste using the electrokinetic-Fenton method

The large amount of residues and pollutants left over from the drilling industry could cause irreparable damage by entering the human and animal food chain. Therefore, drilling waste management is of particular importance. Electrokinetic (EK) remediation is one of the methods used to remediate all types of soils contaminated with metal and organic pollutants, but the special conditions and properties of drilling wastes make the use of this method more complex for the treatment of this type of waste. In this study, by enhancing the EK method with Fenton technique, which is an advanced oxidation technique, and using copper and iron electrodes as anode, total petroleum hydrocarbons (TPH) were removed from the oil-based drilling waste. The best result in this study was obtained by reducing the initial concentration of TPH from 316,000 to 72,680 mg⁄kg in drilling waste. This 77 % reduction in TPH concentration was achieved using the EK method coupled with Fenton technique along with the use of copper electrode. The use of iron electrode in the EK-Fenton (EK-F) method improved the parameters affecting the removal efficiency and pollutants decomposition and resulted in 69.6 % TPH removal. These results show a 161 % (copper) and 136 % (iron) increase in TPH removal efficiency, respectively, compared to the conventional EK method, in which TPH removal was 29.4 %. These results indicate that the use of EK-Fenton method combined with copper electrode is effective in removing TPH from drilling waste. Overall, the promising results of the present study indicate that the enhanced EK technique could be considered as an effective and environmentally friendly approach for the drilling waste remediation.

Remediation of an oil-contaminated soil by two native plants treated with biochar and mycorrhizae

Soil contamination by petroleum compounds threatens the health of soil and water resources. This research was conducted with the objective of reaching an efficient technique for the removal or reduction of harmful effects caused by total petroleum hydrocarbons (TPH) in soils. In a greenhouse experiment, the effect of biochar (B), mycorrhizae (M) and combination of mycorrhizae and biochar (M + B) on the growth of two native species; clover (Trifolium arvense) and mallow (Malva sylvestris L.), and removal efficiency of TPH (16.79 mg kg-1) from an oil-contaminated soil were studied. The plant analyses after 50 days of growth period showed a significant (p ≤ 0.05) increase in shoot dry weight of mallow in B and M + B treatments but no significant effect was observed for clover compared to the control (C). The initial TPH concentration, determined by gas chromatography technique was reduced from 9.4% in unplanted soil until 56.4% (clover) and 55.9% (mallow) in M + B treatment. The relative concentration of long chain alkanes (LCAs) were also reduced when treatments were applied, in which the highest and lowest reductions was found in C21–C25 and C11–C15, respectively, though octacosane (C28) was increased or unchanged in soil. This result suggests that likely the occurrence of C28 in the mycorrhizal hyphae or the higher removal of the other alkanes increase octacosane relative concentration in soil, which more research is necessary.

Response surface optimization and effects of agricultural wastes on total petroleum hydrocarbon degradation

This study was carried out to investigate the effects of Goat manure (GM) and Palm oil mill effluent (POME) on total petroleum hydrocarbons (TPHs) degradation. Microbial respiration rates (CO2 evolution) were investigated. TPHs degradation rate constants were estimated using the first-order kinetics model. Scanning electron microscope (SEM) and infrared spectroscopy (FT-IR) were used to investigate the surface morphologies and functional groups in GM and POME. The CO2 evolution rates in TPH contaminated soil treated with GM (TPHCS-GM), TPH contaminated soil treated with POME (TPHCS-POME), and the untreated TPH contaminated soil (UTPHCS) were 497 mg/g, 440 mg/g, and 296 mg/g, respectively. TPHCS-GM showed higher TPH degradation rate with corresponding lower half-lives. Results from the physiochemical characterization indicated that GM performed better in restoring the scarce nutrient in the TPH contaminated soil. 58% and 39% of TPH were degraded at pH 8 and 4 in TPHCS-GM and TPHCS-POME, respectively. The response surface optimization process indicated the accuracy of the quadratic model (R2 value of 0.9891) in predicting TPH degradation (76.59%) with optimum independence variables of initial TPH concentration (300 g/L) and pH (6). The results obtained from this work showed the positive prospects of GM and POME as organic nutrients in TPH contaminated soil.

Hydrocarbon Degradation and Lead Solubility in a Soil Polluted with Lead and Used Motor Oil Treated by Composting and Phytoremediation.

Used lubricant oils and metals can be common soil pollutants in abandoned sites. When soil is contaminated with various hazardous wastes, the efficiency of biological treatments could be affected. The purpose of this work was to investigate the effect of combining phytoremediation and composting on the efficiency of hydrocarbon degradation and lead solubility in a soil contaminated with 31,823mg/kg of total petroleum hydrocarbon (TPH) from used motor oil and 8260mg/kg of lead. Mexican cactus (Opuntia ficus indica) and yard trimmings were added in the composting process, and lucerne (Medicago sativa) was used in the phytoremediation process. After a 9week composting process, only 13% of the initial TPH concentration was removed. The following 20 week phytoremediation process removed 48% of TPH. The highest TPH degradation percentage (66%), was observed in the experiment with phytoremediation only. This work demonstrates sustainable technologies, such as biological treatments, represent low-cost options for remediation; however, they are not frequently used because they require long periods of time for success.

Oil Recovery of Soil Contained Petroleum Oil by Using Bio surfactant of Mixed Cultures Bacteria (Brevundumonas diminuta, Pseudomonas fluorescens, Pseudomonas aeroginosa, Pseudomonas citronelis) at vary pH Conditions (5-9)

Abstract The bacteria ( Brevundumonas diminuta, Pseudomonas fluorescens, Pseudomonas aeroginosa, Pseudomonas citronelbis ) which are indigenous bacteria from Babat Toman village South Sumatra. It were isolated and identified by using Bergey's method. In the normal condition (pH 7), these bacteria could produce bio surfactant and effectively as mixed culture. The growth of mixed culture of indigenous bacteria was tested at different pH conditions (5-9). The results show that the optimum pH was obtained at pH 7, the population of bacteria was 2.14.10 7 cfu/mL. The shortest regeneration time of these bacteria were (12, 12, 9, 9) hours respectively. The initial total petroleum hydrocarbon concentration of sample was 18,4 %, it was extracted by using the bio surfactant of mixed culture with 10 % concentration at different pH conditions (5-9), the contact time as long as 168 hours. The optimal oil recovery was obtained at pH 7 as much as 20.97 %. It can be concluded that the bio surfactant effectively used in the normal condition (pH 7) and ineffectively in alkaline condition (pH 9).The GC analyses were conducted to initial crude oil and the residue. The results show that the crude oil consists of 33 components, and the residue consists of 14 components. It shows that the bio surfactant of mixed culture bacteria dissolved the hydrocarbon components with temperature fractions 150, 155, 178, 184, 190, and 197 o C.

The accelerated enzymatic biodegradation and COD removal of petroleum hydrocarbons in the SCR using active bacterial biomass capable of in-situ generating peroxidase and biosurfactants

The enzyme-accelerated biodegradation of total petroleum hydrocarbons (TPH) was investigated in a sequencing continuous-inflow reactor (SCR) at different operational parameters of H2O2/TPH ratio, initial TPH concentration and hydraulic retention time (HRT). The optimum H2O2/TPH mass ratio was determined to be 0.35 at which the complete TPH removal of inlet TPH concentrations up to 4g/L at HRT of 24h, corresponding to the loading rate of 4kgTPH/m3.d, was attained. The average COD removal efficiency at this loading rate was 96.7%. With increasing the inlet TPH concentration from 1 to 2.5g/L, the biomass bacterial activity as dehydrogenase activity (DHA) increased from 7.5 to 27.1μgTF/gbiomass.d and remained almost unchanged with further increase of TPH concentration. The peroxidase activity (PA) remained high between 382 and 410U/gbiomass. In addition, the complete removal of 1g/L TPH (88.7% COD removal) was observed at HRT of as small as 4h (corresponding to the loading rate of 6kgTPH/m3.d) under optimum H2O2/TPH mass ratio. With the decrease of HRT from 24h to 4h at the constant TPH concentration of 1g/L the value of DHA remained between 24.4 and 28.4μgTF/gbiomass.d while the PA value increased from 287.9 to 394.4U/gbiomass. Total production of biosurfactants was 131mg/L (38mg/L rhamnolipid and 93mg/L surfactin) when the SCR was operated at TPH loading rate of 6kg/m3.d.Finally, the enhanced enzymatic biodegradation of TPH by using diverse microbial consortia capable of in-situ production of peroxidase and biosurfactant generation in the SCR is a very efficient and promising technique for accelerated biodegradation and COD removal of petroleum hydrocarbons.

Treatment of petroleum drill cuttings using bioaugmentation and biostimulation supplemented with phytoremediation

ABSTRACTThis study sought to compare the effectiveness of bioaugmentation and biostimulation, as well as the combination of both techniques, supplemented with phytoremediation, in the decontamination of petroleum drill cuttings. Drill cuttings with relatively low concentration of total petroleum hydrocarbons (TPH) and metals were mixed with soil in the ratio 5:1 and treated with three different combinations of the bioremediation options. Option A entailed bioaugmentation supplemented with phytoremediation. Option B had the combination of biostimulation and bioaugmentation supplemented with phytoremediation. While biostimulation supplemented with phytoremediation was deployed in option C. Option O containing the drill cuttings–soil mixture without treatment served as untreated control. Fertilizer application, tillage and watering were used for biostimulation treatment, while spent mushroom substrate (Pleurotus ostreatus) and elephant grass (Pennisetum purpureum) were employed for bioaugmentation and phytoremediation treatment, respectively. The drill cuttings–soil mixtures were monitored for TPH, organic carbon, total nitrogen, pH, metal concentrations, and fungal counts, over time. After 56 days of treatment, there was a decline in the initial TPH concentration of 4,114 mg kg−1 by 5.5%, 68.3%, 75.6% and 48% in options O, A, B and C, respectively. Generally, higher TPH loss resulted from the phytoremediation treatment stage. The treated options also showed slight reductions in metal concentrations ranging from 0% to 16% of the initial low concentrations. The results highlight the effectiveness of bioaugmentation supplemented with phytoremediation. The combination of bioaugmentation and biostimulation supplemented with phytoremediation, however, may prove better in decontaminating petroleum drill cuttings to environmentally benign levels.

Anoxic biodegradation of petroleum hydrocarbons in saline media using denitrifier biogranules

The total petroleum hydrocarbons (TPH) biodegradation was examined using biogranules at different initial TPH concentration and contact time under anoxic condition in saline media. The circular compact biogranules having the average diameter between 2 and 3mm were composed of a dense population of Bacillus spp. capable of biodegrading TPH under anoxic condition in saline media were formed in first step of the study. The biogranules could biodegrade over 99% of the TPH at initial concentration up to 2g/L at the contact time of 22h under anoxic condition in saline media. The maximum TPH biodegradation rate of 2.6 gTPH/gbiomass.d could be obtained at initial TPH concentration of 10g/L. Accordingly, the anoxic biogranulation is a possible and promising technique for high-rate biodegradation of petroleum hydrocarbons in saline media.