Biopile Systems Research Articles

Remediation of weathered diesel-oil contaminated soils using biopile systems: An amendment selection and pilot-scale study

Weathered diesel oil (WDO) has less biodegradable and volatile characteristics, and its bioremediation could be a challenge. In this study, the effectiveness of enhanced bioremediation via biopile processes for the cleanup of WDO-contaminated soils was evaluated. Six biopiles were constructed and operated with the following six different amendments addition: red bran (12 kg), water-soluble fertilizer (20 L/week), highly oxygenated water (20 L/d, dissolved oxygen = 25 mg/L), petroleum hydrocarbon-degrading bacterial culture (20 L/week), mixture of the above amendments, and natural attenuation (no amendment). Each biopile contained 5 m3 [2.5 m (L) × 2 m (W) × 1 m (H)] of WDO-contaminated soils [initial total petroleum hydrocarbon (TPH) concentrations = 3015 to 3785 mg/kg]. Soils were mixed with amendments and tilled for air supplement twice a week with soil moisture around 25%. Metagenomics analyses were applied to determine the microbial biodiversity and strains responsible for hydrocarbon biodegradation. Results show that the biopile system with mixed supplements (mixture group) had the highest TPH removal efficiency (79% of TPH removal) followed by red bran addition group with a removal efficiency of approximately 73% during the 42-day operation. The first-order TPH decay rates in mixture and red bran biopiles were around 3.2 × 10−2 1/d, which was 4.8 times higher than that obtained from natural attenuation biopile. Biopiles with red bran and mixture supplements contained carbon substrates and nutrients, which could effectively activate microbial activities and accelerate the TPH biodegradation. High carbon number compounds (C > 20) in WDO could be biodegraded within 24 days in the biopile with mixed amendments. Results from metagenomics study indicate that Sphingomonas and Pseudomonas might cause removal of heavy components (C24–30) and light components of petroleum hydrocarbons (C10–16), respectively.

Characteristics of organic carbon metabolism and bioremediation of petroleum-contaminated soil by a mesophilic aerobic biopile system

An innovative mesophilic aerobic biopile technology was explored to improve the bioremediation efficiency of petroleum-contaminated soil. Under the suitable soil conditions (C:N:P at 100:5:1 and soil moisture content at 18%), the soil pH was hold in the range of 7.4 to 6.8 throughout the bioremediation process, the mesophilic (30 °C-40 °C) and forced aeration (3 h-on/1 h-off) conditions were the critical factors to enhancing petroleum biodegradation. The consumption of bioavailable organic carbon (BAC) which was one of the most important factors regulating microbial metabolism, was positively related (R2 = 0.85, 40 °C) with the rate of petroleum removal. The 50% threshold of BAC could be regarded as the signal for supplementing the soil nutrients in the mesophilic aerobic biopiles to favor petroleum removal. The optimal conditions (40 °C, 3 h-on/1 h-off) maximized the utilization of BAC, promoted the petroleum degradation, and remained the microbial abundance and community composition stable to the greatest extent. In addition, the accumulation of aliphatic acids affected the microbial activity, which limited the efficiency of petroleum degradation to a certain extent. Jointly considering the energy consumption, time cost and soil conditions maintenance, a cost-effective biopile technology was obtained by temperature and aeration regulation and BAC supplementation, which could be applied to engineering application.

Effective oxygen supply method for oil-contaminated soil remediation in bio-pile system using numerical analysis

Effective oxygen supply method for oil-contaminated soil remediation in bio-pile system using numerical analysis

Identification and overcome of limitations of weathered oil hydrocarbons bioremediation by an adapted Bacillus sorensis strain

Because of the high production of oil and gas in Qatar, the likelihood of oil spill occurrence is most probably susceptible to happen. Contaminated soil treatment is very expensive. Cost effective mechanisms are investigated to treat this threatening issue. For that reason, bioremediation and biotechnology tools are introduced to help accelerate and remove the pollution caused by the contamination process. This paper demonstrated the importance of optimising the treatment conditions to the indigenous bacterial strain to obtain the highest biodegradation efficiency rates. The usage of biopile system technology was used with biostimulation and bioaugmentation processes. The indigenous Bacillus sonorensis (B. sonorensis) D1 bacterium played a crucial role in the biodegradation process when introduced to optimized conditions; carbon/nitrogen/phosphorus (C/N/P) (100/10/1), temperature (37 °C), surfactant tween 80 (0.12% (v/w)), and moisture (10%). Gas chromatography (mass spectrometry/flame ionization detector) (GC- (MS/FID)), Fourier transform infrared (FTIR), and colony-forming unit (CFU) analyses were performed. The diesel range organics (DRO) and polycyclic aromatic hydrocarbons (PAH) removal (%) of the weathered oil contaminated soil reached, after 160 days, 39.2% and 32.4% simultaneously when ammonium nitrate was used as a nitrogen source. Whereas urea inhibited the oil degradation process and caused the pH to rise to 9.55.

Bioremediation of Soil Contaminated with Diesel using Biopile system

ركزت هذه الدراسة على معالجة التربة الملوثة بالمركبات النفطية (الديزل) و التي تسببت في مشاكلات بيئية خطيرة. ومن الطرق الواعدة و الأكثر فعالية لمعالجة التربة الملوثة بالنفط هي المعالجة البيولوجية بل هي الخيار الذي يوفر إمكانية تدمير الملوثات الضارة باستخدام النشاط البيولوجي. تم فحص قدرة الخليط البكتيري لمعالجة التربة الملوثة بالديزل في منظومة bio piling. ومن أجل معالجة سريعة خارج الموقع للتربة الملوثة بالديزل تم اختيار منظومة .bio pilingوقد تم إنشاء منظومتين biopiles على نطاق تجريبي (25 كيلوغراماً من التربة لكل منهما) و يحتويان على التربة الملوثة بما يقرب من 2140 ملغم / كغم من الهيدروكربونات النفطية. التربة المعدلة: (التربة الملوثة مع إضافة المغذيات واللقاح البكتيري) حيث تخلط التربة مع 1.5٪ من نشارة الخشب، ثم زودت بالمغذيات اللازمة وتُسقى يومياً لتوفير الظروف التي تعزز نمو الكائنات الحية الدقيقة. تم تحضير التربة غير المعدلة بوصفها عنصر سيطرة (التربة الملوثة بدون إضافة). جُهز كلا النظامين بالأوكسجين لتوفير الظروف الهوائية،و تم الحضن في درجة حرارة الجو وسُحبت العينات اسبوعياً خلال مدة 35 يوما. تم إزالة 75٪ من إجمالي الهيدروكربونات البترولية من التربة المعدلة و 38٪ من تربة السيطرة في نهاية مدة الدراسة. خلصت الدراسة الى أن تجربة المعالجة البيولوجية خارج الموقع هي الإجراء المفضل،وهي اقتصادية وصديقة للبيئة، وبالتالي تمثل خيارا جيدا لمعالجة التربة الملوثة بالديزل.

Bioremediation of Soil Contaminated with Diesel using Biopile system

This study was focused on biotreatment of soil which polluted by petroleum compounds (Diesel) which caused serious environmental problems. One of the most effective and promising ways to treat diesel-contaminated soil is bioremediation. It is a choice that offers the potential to destroy harmful pollutants using biological activity. The capability of mixed bacterial culture was examined to remediate the diesel-contaminated soil in bio piling system. For fast ex-situ treatment of diesel-contaminated soils, the bio pile system was selected. Two pilot scale bio piles (25 kg soil each) were constructed containing soils contaminated with approximately 2140 mg/kg total petroleum hydrocarbons (TPHs). The amended soil: (contaminated soil with the addition of nutrients and bacterial inoculum), where the soil was mixed with 1.5% of sawdust, then supplied with the necessary nutrients and watered daily to provide conditions promoting microorganism growth. Unamended soil was prepared as a control (contaminated soil without addition). Both systems were equipped with oxygen to provide aerobic conditions, incubated at atmospheric temperature and weekly sampling within 35 days. Overall 75% of the total petroleum hydrocarbons were removed from the amended soil and 38 % of the control soil at the end of study period.
 The study concluded that ex-situ experiment (Bio pile) is a preferable, economical, and environmentally friendly procedure, thus representing a good option for the treatment of soil contaminated with diesel.

Bioremediation of Soil Contaminated with Diesel using Biopile system

This study was focused on biotreatment of soil which polluted by petroleum compounds (Diesel) which caused serious environmental problems. One of the most effective and promising ways to treat diesel-contaminated soil is bioremediation. It is a choice that offers the potential to destroy harmful pollutants using biological activity. The capability of mixed bacterial culture was examined to remediate the diesel-contaminated soil in bio piling system. For fast ex-situ treatment of diesel-contaminated soils, the bio pile system was selected. Two pilot scale bio piles (25 kg soil each) were constructed containing soils contaminated with approximately 2140 mg/kg total petroleum hydrocarbons (TPHs). The amended soil: (contaminated soil with the addition of nutrients and bacterial inoculum), where the soil was mixed with 1.5% of sawdust, then supplied with the necessary nutrients and watered daily to provide conditions promoting microorganism growth. Unamended soil was prepared as a control (contaminated soil without addition). Both systems were equipped with oxygen to provide aerobic conditions, incubated at atmospheric temperature and weekly sampling within 35 days. Overall 75% of the total petroleum hydrocarbons were removed from the amended soil and 38 % of the control soil at the end of study period.
 The study concluded that ex-situ experiment (Bio pile) is a preferable, economical, and environmentally friendly procedure, thus representing a good option for the treatment of soil contaminated with diesel.

Biological Degradation of Pyrene and Fluoranthene in Porous Media and Attached Growth Systems by Biosurfactant Producing Bacteria

The dissolution and degradation of higher ring-number polycyclic aromatic compounds were tested in batch and attached growth medium using soil biopile and fixed-film bioreactor systems. Bioavailability of polycyclic aromatic hydrocarbons (PAHs) decreases with increasing ring-number. This means high ring-number compounds will survive longer in the environment and will therefore have a longer-term impact. In the current study, pyrene and fluoranthene were degraded using a biosurfactant producing culture of Pseudomonas aeruginosa grown in fixed-bed and soil biopile experiments. High ring-number PAHs prove to be recalcitrant in nature due to their hydrophobicity and poor partitioning to soil media fixed biomass in biofilm reactors. The use of biosurfactant could facilitate faster dissolution of the PAH and thus would increase bioavailability of the PAH compounds to PAH degrading bacteria. The culture used in this study was obtained from engine oil contaminated soil, that grow on HMW PAHs and are capable of degrading PAHs were enriched, isolated and characterize. The isolated microbial cultures were further characterised 16S rDNA gene sequencing and genotype fingerprinting. During baseline study, over 90 % fluoranthene was degraded as a model compound in biofilm reactor system. Over 88 % pyrene was degraded in soil biopiles. In both cases, increased biosurfactant dose improved degradation rate up to the point where the PAH concentration became inhibitory to biomass growth and PAH degradation.

Bioremediation of Soils Contaminated with Automotive Oil Used by Biopile System

En la investigacion se realizo la biorremediacion de suelo contaminado con aceites usados de talleres de servicio automotriz mediante biopilas. Se emplearon cuatro muestras de suelo proveniente de la Unidad de Manejo Ambiental (uma) «La Huella» ejido Pedro Mendez, Chiapa de Corzo, Chiapas, Mexico; las cuales se caracterizaron en laboratorios de la Universidad de Ciencias y Artes de Chiapas y El Colegio de la Frontera Sur, analizando humedad, materia organica, textura, pH, temperatura, nitrogeno total y fosforo disponible. Se construyeron cuatro biopilas, desarrollando tres tratamientos con tres repeticiones y un testigo, las cuales fueron contaminadas en concentraciones para el testigo de 30,000 ppm, para primer tratamiento 10,000 ppm, para segundo 30,000 ppm y para tercero de 50,000 ppm de hidrocarburos totales del petroleo (htp). Las cepas utilizadas fueron Acinetobacter Sp, Sphingobacterium Sp y Stenotrophomona Sp; con concentracion de 2.25 × 108 ufc para cada tratamiento. Se realizo el recuento de microorganismos el dia quince del experimento. Los tratamientos fueron monitoreados tres meses los dias 1, 15, 30, 60 y 90 en el laboratorio de biotecnologia de la Universidad Autonoma del Carmen, Campeche. Se lograron porcentajes de remocion de las fracciones alifatica de 93.7 a 87.1% y en la fraccion aromatica de 0 a 94.8 en 90 dias de tratamiento, con aplicacion de bacterias biorremediadoras e identificacion de cepas bacterianas nativas del suelo que lograron resistir el cambio en su ambiente

Hydrocarbon removal and bacterial community structure in on-site biostimulated biopile systems designed for bioremediation of diesel-contaminated Antarctic soil

Several studies have shown that biostimulation can promote hydrocarbon bioremediation processes in Antarctic soils. However, the effect of the different nutrient sources on hydrocarbon removal heavily depends on the nutrients used and the soil characteristics. In this work, using a sample of chronically contaminated Antarctic soil that was exposed to a fresh hydrocarbon contamination, we analyzed how a complex organic nutrient source such as fish meal (FM) and a commercial fertilizer (OSEII) can affect hydrocarbon biodegradation and bacterial community composition. Both amended and unamended (control) biopiles were constructed and controlled at Carlini Station and sampled at days 0, 5, 16, 30 and 50 for microbiological, chemical and molecular analyses. FM caused a fast increase in both total heterotrophic and hydrocarbon degrading bacterial counts. These high values were maintained until the end of the assay, when statistically significant total hydrocarbon removal (71 %) was detected when compared with a control system. The FM biopile evidenced the dominance of members of the phylum Proteobacteria and a clear shift in bacterial structure at the final stage of the assay, when an increase of Actinobacteria was observed. The biopile containing the commercial fertilizer evidenced a hydrocarbon removal activity that was not statistically significant when compared with the untreated system and exhibited a bacterial community that differed from those observed in the unamended and FM-amended biopiles. In summary, biostimulation using FM in biopiles significantly enhanced the natural hydrocarbon-degradation activity of the Carlini station soils in biopile systems and caused significant changes in the bacterial community structure. The results will be considered for the future design of soil bioremediation protocols for Carlini Station and could also be taken into account to deal with diesel-contaminated soils from other cold-climate areas.

Re-inoculation strategies enhance the degradation of emerging pollutants in fungal bioaugmentation of sewage sludge

The use of Trametes versicolor has been partially successful in the removal of some pharmaceuticals from sewage sludge in laboratory-scale biopile systems. The application of two strategies for the re-inoculation of biomass was assessed during the fungal bioaugmentation of non-sterile sludge (42-d treatment) as an approach to improve the elimination of pharmaceuticals and other groups of emerging pollutants. Globally, the re-inoculation of biopiles with blended mycelium exerted a major effect on the removal of pharmaceuticals (86%), brominated-flame-retardants (81%) and UV filters (80%) with respect to the re-inoculation with additional lignocellulosic substrate colonized by the fungus (69–67–22%). The performance was better than that of the analogous non-re-inoculated systems that were assayed previously for the removal of pharmaceuticals. The results demonstrate the ability of T. versicolor to remove a wide spectrum of emerging micropollutants under non-sterile conditions, while re-inoculation appears to be a useful step to improve the fungal treatment of sludge.

Pilot 규모 biopile에 의한 유류오염토양의 정화

The pilot scale biopile system was designed and operated for evaluation of bioremediation efficiency for petroleum contaminated soil. The pilot scale biopile consisted of biopile dome, aeration system and monitoring system and two biopiles were operated with nutrients and inoculum for more 100 days. The test pile A and B were analyzed with regard to pH, total carbon contents, water contents, nutrients (N, P) and TPH. The initial TPH concentrations for pile A and pile B were about 10,000 mg/kg and 2,300 mg/kg, respectively. After 100 days, the TPH contents decreased about 70% in the pile A and 30% in the pile B. Also, n-<TEX>$C_{17}$</TEX>/pristane and n-<TEX>$C_{18}$</TEX>/phytane ratios in all pile were significantly changed. The microbial densities in the pile A was increased by approximately <TEX>$10^7$</TEX> CFU/g-soil~<TEX>$10^8$</TEX> CFU/g-soil, but there was almost no changed in the pile B. The average biodegradation rates were calculated about 66.8 mg/kg-day in the pile A and 10.9 mg/kg-day in the pile B. Over the course of operation period, pile temperature was considered the major limiting factor for the efficiency of all biopiles.

Aeration Factor Used To Design The Container Type of Biopile Systems for Small-Scale Petroleum-Contaminated Soil Projects

Biopiles which offer the potential for cost-effective treatment of contaminated soils are above-ground, engineered systems that use oxygen to stimulate the growth and reproduction of aerobic bacteria for degradation of the petroleum constituents adsorbed to soil in excavated soils. This technology involves heaping contaminated soils into piles and stimulating aerobic microbial activity within the soils through the aeration and/or addition of minerals, nutrients, and moisture. Inside the biopile, microbially mediated reactions by blowing or extracting air through the pipes can enhance degradation of the organic contaminants. The influence of a aeration system on the biopile performance was investigated. Air pressure made to compare the efficiency of suction in the pipes showed that there were slightly significant difference between the two piles in the total amount of TPH biodegradation. The normalised degradation rate was, however, considerably higher in the aeration system than in the normal system without aeration, suggesting that the vertical venting method may have improved the efficiency of the biological reactions in the pile.

전과정평가(LCA)에 의한 토양오염 정화공정의 환경영향분석 및 CO2배출량 산정 - SVE 및 Biopile 시스템 중심으로 -

전과정평가(LCA)에 의한 토양오염 정화공정의 환경영향분석 및 CO₂배출량 산정 - SVE 및 Biopile 시스템 중심으로 -

Bioremediation of diesel-contaminated soil by heated and humidified biopile system in cold climates

Abstract Bioremediation is a proven and widely accepted technology for the remediation of soil contaminated with various mixtures of petroleum hydrocarbons (PHC) in temperate climates but its application in cold climates has received far less attention. Low ambient temperature is one of the main factors limiting microbial degradation of the organic contaminants in such locations. Heating the soil should therefore enhance bioremediation as laboratory studies have shown increased biodegradation rates in Arctic soils with increasing soil temperature. A biopile is one of the many bioremediation techniques to treat hydrocarbon-contaminated soil where the soil is piled over an air distribution system and aerated. The air distribution system can also be used to provide heat to the soil in order to optimize soil temperature when conditions are limiting. However, heating the soil by forced air may cause excessive drying of the soil which may inhibit microbial activity and promote volatilization of the contaminants rather than their biodegradation. During treatment of hydrocarbon contaminated soils in a biopile system, biodegradation is preferred over volatilization and should be optimized. Few field-scale studies have tested the use of heated biopile systems in cold climates. This paper examines the effect of humidifying the air for the treatment of PHC-contaminated soil by an aerated/heated biopile system. Three biopiles were constructed with soil freshly contaminated with diesel fuel (initial total petroleum hydrocarbon concentration, [TPH], ~ 11,000 mg/kg dry weight) and operated for 10 months in Kingston, ON, Canada. One biopile was heated with an aerating/heating system previously tested in the Arctic. A second biopile was also aerated and heated but received water by humidifying the air prior to entering the soil pile. A third biopile was passively aerated by pipes protruding from the soil pile. TPH, available nutrients content, and pH were monitored by periodic collection and analysis of soil samples. Volatilization of hydrocarbon compounds was measured by trapping them on activated charcoal. Temperature and moisture were monitored continuously with a datalogger. Hydrocarbon concentrations in soil and charcoal samples were measured by solvent extraction followed by gas chromatography flame ionization detection (GC/FID) analysis. Significant TPH reduction was observed in all systems. TPH reduction followed first-order kinetics for the first two-third of the treatment. The humidified system maintained optimal soil moisture content and produced significantly lower final TPH than the other two treatments (~ 300 mg/kg dry weight). Findings suggest that humidifying the air enhanced biodegradation and minimized volatilization. The removal of hydrocarbons of different carbon chain lengths was investigated by GC/FID analysis. Three hydrocarbon fractions were defined ( nC15) based on equivalent straight-chain alkane ranges. Results from this analysis showed that all fractions were removed during treatment, but the overall data suggest that biodegradation was dominant for the highest molecular weight fraction.

Fugacity modelling to predict the distribution of organic contaminants in the soil:oil matrix of constructed biopiles

Level I and II fugacity approaches were used to model the environmental distribution of benzene, anthracene, phenanthrene, 1-methylphenanthrene and benzo[ a]pyrene in a four phase biopile system, accounting for air, water, mineral soil and non-aqueous phase liquid (oil) phase. The non-aqueous phase liquid (NAPL) and soil phases were the dominant partition media for the contaminants in each biopile and the contaminants differed markedly in their individual fugacities. Comparison of three soils with different percentage of organic carbon (% org C) showed that the % org C influenced contaminant partitioning behaviour. While benzene showed an aqueous concentration worthy of note for leachate control during biopiling, other organic chemicals showed that insignificant amount of chemicals leached into the water, greatly reducing the potential extent of groundwater contamination. Level II fugacity model showed that degradation was the dominant removal process except for benzene. In all three biopile systems, the rate of degradation of benzo(a)pyrene was low, requiring more than 12 years for soil concentrations from a spill of about 25 kg (100 mol) to be reduced to a concentration of 0.001 μg g −1. The removal time of 1-methylphenanthrene and either anthracene or phenanthrene was about 1 and 3 years, respectively. In contrast, benzene showed the highest degradation rate and was removed after 136 days in all biopile systems. Overall, this study confirms the association of risk critical contaminants with the residual saturation in treated soils and reinforces the importance of accounting for the partitioning behaviour of both NAPL and soil phases during the risk assessment of oil-contaminated sites.

Neural prediction of hydrocarbon degradation profiles developed in a biopile

The biochemical and physical nature of the degradation process in biopile systems is very complex and difficult to describe analytically, thus, neural network modeling and simulation can be of great help. Predictive feedforward neural models (FFNMs) have been commonly used to capture the dynamic phenomena of biological systems by a learning process, but the large number of input/output variables and the vast connectivity of the neural network makes it very time consuming. This paper proposes the use of a recurrent neural network model (RNNM) to predict biodegradation profiles of hydrocarbons contained in an aged polluted soil. The proposed multi-input multi-output RNNM has eight inputs, five outputs, 13 neurons in the hidden layer, and global and local feedbacks. The weight update learning algorithm is a version of dynamic backpropagation. The approximation error for the last epoch of learning is below 1.25% and the total time of learning is about 101 epochs. The learning process is applied to the kinetics of residual hydrocarbons, pH, carbon dioxide, oxygen consumption and moisture obtained with different operational conditions of air flow, and temperature; the kinetics are analyzed at four heights of the columns. The low learning error approximation makes the RNNM interesting to facilitate the study of complex biological processes in a short time.

Bioremediation of Crude Oil Contaminated Soils: A Black Art or an Engineering Challenge?

A bioremediation of crude oil contaminated soils study was carried out in engineered laboratory biopile systems. In soil bioremediation, biopiles are ‘ex situ’ treatment systems that consist of excavated and aerated contaminated soils amended by addition of biological, mineral or organic material depending upon specific needs. When bacteria are added to the contaminated soil undergoing biological treatment, the latter is referred to as a bioaugmented treatment system. Such soils are arranged above ground in a pile fashion and hence the term biopile. The study has shown virtually identical trends in respiration rates when indigenous and commercial added bacteria where employed. However, the bioaugmented experiments yielded much greater respiration rates and lead to a reduction of 75% of the initial oil in just 118 days, compared to 1 year in similar studies in the literature. The benefits of engineered biopile systems include safe operations, facilitated material balance and process controllability. The benefits of bioaugmentation were clearly demonstrated and it was found that when no nutrients are added to the soil, bacteria tend to metabolize hydrocarbons into carbon dioxide and water rather than assimilate carbon in cell growth. Polyaromatics analysis of treated soil in this investigation pointed out that simpler and more bioavailable crude oil components were degraded first. A simple sigmoid model for the carbon dioxide generation was developed from the respiration data.

Neural Prediction of a Hydrocarbon Degradation Process in Biopiles

Abstract This paper proposes the use of a Recurrent Neural Network model (RNN) for modeling a hydrocarbon degradation process carried out in a biopile system. The proposed RNN model has seven inputs, five outputs and twelve neurons in the hidden layer, with global and local feedbacks. The learning algorithm is a modified version of the backpropagation through time. The approximation and generalization error is below 2%. The learning was performed in 131 epochs, 56 iterations each one