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1.

Purpose

This study predicts the optimal landfarming period for the total petroleum hydrocarbons (TPHs)-contaminated field soils that are subject to the combined landfarming and Fenton oxidation treatment.

Materials and methods

The TPHs degradation in the artificially contaminated model soils and the field-aged contaminated soils were compared in a laboratory scale. The soils were bioaugmented with the 16 petroleum hydrocarbon-degrading microbial cultures that are commercially available in Korea.

Results and discussion

The TPHs degradation by bioaugmentation in the model soils was 81?±?2% after 56 days, while it was only 27?±?2% after 74 days in the field-aged soils. The lower degradation in the field-aged soils can be attributed to the removal of a large part of the biodegradable and volatile TPHs fractions during the weathering process. The two-compartment model that can depict a fast-degradation phase followed by a slow-degradation phase predicted that the remedial goal of 475 mg kg?1 of TPHs could be achieved in the model soils within the conventional landfarming period of 60–120 days in Korea; however, the predicted period for the field-aged soils (710–4,086 days) was not practical requiring a combined biological and chemical treatment approach. Based on the kinetics study, the optimal landfarming period for the field-aged soils was 3 weeks and pre-Fenton oxidation can be used to meet the remedial goal.

Conclusions

The two-compartment model can be useful for predicting landfarming period for the combined landfarming and Fenton oxidation treatment of field-aged TPHs contaminated soils. The prediction of the optimal landfarming period could lead to the reduction in both the treatment cost and period.  相似文献   

2.
The influence of nutrient amendments on the biodegradation of a crude oil and on associated microbial populations in an agricultural soil was studied in microcosms during a 150-day experiment. Concentration and chemical composition of residual hydrocarbons (HC) were periodically monitored in series of polluted soils unfertilized and fertilized with increasing concentrations of nutrients. The decrease in HC concentration was effective in all soils over time. The maximal biodegradation extent was 62%, meanwhile the natural attenuation contributed to 47% of degradation. A permanent inhibition of hydrocarbons assimilation was recorded with a high input of nutrients. The biodegradation of saturates, aromatics and polars was respectively, permanently, temporally and not reduced by excessive fertilization in soil. Accumulation of polar metabolic by-products was demonstrated. Enumerations of total heterotrophic bacteria and hydrocarbon-adapted bacteria showed a strong stimulation in both populations. Maximum stimulation was observed with the highest input of nutrients. However, the extents of biodegradation were not concurrently improved, thus indicating that the microbial degraders were selected depending on the nutrient supply. The permanent and/or temporally inhibition of the saturated and unsaturated HC assimilation revealed that different nutrient supplies were optimum for the degradation of aliphatic and aromatic HC.  相似文献   

3.
Different cases of bioremediation technique were experimentally investigated here for decontaminating light non-aqueous phase liquid (LNAPL)-polluted groundwater collected from Panipat oil refinery situated in Haryana, India. Natural biodegradation of toluene, the selected LNAPL, was studied first under different varying substrate concentrations at room temperature (21.6?±?0.3 °C). Biostimulation was then studied by mixing the polluted groundwater with a primary treated domestic wastewater for providing nutrients and other supplementary components to the native microbial population. For studying the remaining cases, small-scale wetland having plants of Canna generalis was developed in the laboratory with and without the presence of toluene in the rhizosphere. The wetland system in the presence of toluene was used here for developing the pre-grown microbial cultures to enhance the degradation rate of the LNAPL (bioaugmentation). The plant-assisted biostimulation was studied in the third case by adding the polluted groundwater with the root zone water of the wetland system developed without the presence of toluene. In the fourth case, the biostimulation was coupled with the bioaugmentation strategy by mixing the groundwater with the root zone water of the wetland system developed in the presence of toluene. A comparative account of these four different bioremediation techniques was prepared for their respective rates of biodegradation, duration of lag phases, and the total time of degradation. It was observed that the plant-assisted bioremediation techniques had better performance over the natural biodegradation and biostimulation methods of the considered LNAPL. The plant-assisted biostimulation coupled with the bioaugmentation technique needed almost no acclimatization time and accelerated the rate of degradation almost twofold compared to the natural bioremediation and, hence, is proved to be the best one among the other bioremediation techniques for decontaminating the LNAPL-polluted groundwater. The results of the conducted experiments can be used to obtain vital information on framing the engineered bioremediation planning for LNAPL-contaminated sites.  相似文献   

4.
Three organic wastes (banana skin (BS), brewery spent grain (BSG), and spent mushroom compost (SMC)) were used for bioremediation of soil spiked with used engine oil to determine the potential of these organic wastes in enhancing biodegradation of used oil in soil. The rates of biodegradation of the oil were studied for a period of 84 days under laboratory conditions. Hydrocarbon-utilizing bacterial counts were high in all the organic waste-amended soil ranging between 10.2?×?106 and 80.5?×?106?CFU/g compared to unamended control soil throughout the 84 days of study. Oil-contaminated soil amended with BSG showed the highest reduction in total petroleum hydrocarbon with net loss of 26.76% in 84 days compared to other treatments. First-order kinetic model revealed that BSG was the best of the three organic wastes used with biodegradation rate constant of 0.3163 day?1 and half-life of 2.19 days. The results obtained demonstrated the potential of organic wastes for oil bioremediation in the order BSG?>?BS?>?SMC.  相似文献   

5.
Biological degradation rates of six pharmaceuticals and personal care products were examined in soil from a land application site and in adjacent soil with no prior history of effluent exposure. Microbial degradation rates were compared over 2 weeks under standing water or saturated conditions and draining conditions after having been saturated for 3 days. Biological degradation of 17??-estradiol exhibited rapid rates of biological degradation under both saturated and draining conditions. Half-lives for 17??-estradiol ranged from 1.5 to 4 days; 66?C97% was lost from the soils. Estriol showed a pattern of biological degradation in both saturated and draining conditions though the half-lives were longer (8.7?C25.9 days) than those observed for 17??-estradiol. Twenty-eight percent to 73% of estriol was lost over the 14 days treatment period. Estrone and 17??-ethinylestradiol exhibited slower rates of biological transformation under saturated and draining conditions. Half-lives for estrone ranged between 27.5 and 56.8 days with loss of at most 21%. 17??-ethinylestradiol exhibited half-lives of 22.6?C207 days. Half-life data for ibuprofen ranged from 30.4 to 1,706.4 days in this experiment. Losses of up to 17% were observed in draining soils. Triclosan loss was at most 10%, and half-lives were 70.9?C398.8 days. In all cases, soils that were draining from saturated conditions exhibited faster degradation rates than soils that remained saturated. Prior exposure of the soil to effluent did not always result in higher biological degradation rates.  相似文献   

6.
Hydrocarbon spills on Antarctic soils occur mainly near settlements where fuel is stored and aircraft and vehicles are refuelled. To investigate those factors that may preclude hexadecane mineralization activity in long-term hydrocarbon-contaminated soils from the Ross Sea Region, samples were collected from Scott Base, the site of former bases (Cape Evans, Marble Point, Vanda Station), and two oil spill sites in the Wright Valley (Bull Pass and Loop Moraine). The soils had low levels of nitrogen (<0.1% total N) and a high C/N ratio (>24) reflecting hydrocarbon contamination. Following soil water adjustment to 10% (v/w), the influence of nutrient addition (250 mg/kg N added as monoammonium phosphate) and inoculation (spiking with Antarctic soil containing high numbers of hydrocarbon degraders) as required on hexadecane mineralization activity was determined. Hexadecane mineralization activity occurred in contaminated soils from Marble Point, Cape Evans and one sample from Vanda Station without nutrient addition. In contrast soils from Scott Base, Cape Evans, another sample from Vanda Station and Loop Moraine required nutrients, whereas Bull Pass soil required inoculation and nutrients before hexadecane mineralization proceeded. Hydrocarbon degrader numbers were highest in coastal soils from Scott Base and Marble Point (107 per gram) and less prevalent in inland soils from Wright Valley (<105 per gram). The bacterial community structure of the soils differed between sites, but soils from the same sites tended to cluster together more closely, except for those from Vanda Station. Addition of nutrients did not cause large shifts in the soil bacterial communities. Results from this study indicate that hydrocarbon degradation may occur at some sites in summer when water is available. Long-term hydrocarbon-contaminated Antarctic soils may provide a valuable resource of hydrocarbon-degrading bacteria that can serve as inocula for more recent oil spills on land.  相似文献   

7.
The degradation of spiked anthracene (ANT), pyrene (PYR) and benzo[a]pyrene (B[a]P) in soil (3000 mg ∑ 3 PAHs kg−1 dry soil) was studied in aerobically incubated microcosms for 120 d. The applied treatments aimed at enhancing PAH removal from the heavily contaminated soils are: (i) bioaugmentation by adding aged PAH-contaminated soil (ACS) containing activated indigenous degraders; and (ii) combined bioaugmentation/biostimulation by incorporating sewage sludge compost (SSC) and decaying rice straw (DRS). The adopted treatments produced higher PAH dissipation rates than those observed in unamended PAH-spiked soils, especially for ANT and PYR in the presence of DRS or ACS (>96%). However, B[a]P was the most recalcitrant hydrocarbon to biodegradation. Extracellular enzyme investigation revealed the existence of ligninolytic activities in all soil treatments, including control but no relationship could be found with PAH dissipation. The ecotoxicological assessment indicated that regardless of applied treatment, PAH-spiked soils were chronically lethal to ostracod Heterocypris incongruens and confirmed the sensitivity of the microcrustacean to the concomitant presence of these three hydrocarbons. Lettuce root elongation inhibition was correlated with PAH level but the presence of SSC conferred a strong phytotoxic capacity to PAH-spiked soils. DRS amendment may constitute a cost-effective alternative for hydrocarbon bioremediation as it has impacted positively on soil microbial activity and enhanced PAH removal with no apparent changes in soil physico-chemical properties.  相似文献   

8.
Understanding the effects of oil contamination on the composition and function of soil microbiota entails investigation of the effects of a mixture of hydrocarbons at the community level in a complex environmental matrix. One approach to this difficult problem is to ally a community-level fingerprinting approach with bioassays that have a physiological or functional implication. Two contrasting refined oils (paraffin and motor oil) were used to contaminate soil microcosms, and a simulated bioremediation treatment with nutrient-addition was applied. The indigenous microorganisms were monitored over 103 d using complementary community-level techniques (carbon source physiological profiling using Biolog® microplates, and phospholipid fatty acid (PLFA) profiling). Changes in the toxicity of the applied oils were monitored using luminescent bacterial bioassays, including Vibrio fischeri and a hydrocarbon-degrading Pseudomonas putida strain. Distinct shifts in microbial community structure and C source utilization profiles were observed as a result of oil contamination. There was some evidence that bioremediated soils were returning to control values by the end of the experiment. This was supported by the bioassay results which showed an initial increase in toxicity as a result of the oil addition which had then decreased by the conclusion of the experiment. The two oils exhibited markedly different toxicity towards the bioassay organisms, with species-specific differences in response. This oil-specific difference was also found in the PLFA profiles which showed the two oil types selected different microbial communities.  相似文献   

9.
Biodegradation of crude oil is often dependent on the population sizes and metabolic activity of hydrocarbon-degrading microorganisms in addition to nutrient supply. Fertilization with N and P and bioaugmentation of oil-contaminated soil with hydrocarbon-degrading microorganisms may serve to enhance oil biodegradation rates. Glasshouse experiments were conducted to determine the impacts of fertilization and commercial bioremediation products on crude oil biodegradation and on changes in nutrient concentrations and populations of hydrocarbon-degrading microorganisms in salt marsh mesocosms growing Spartina alterniflora. Experiments were conducted under continuously-flooded and alternately-flooded/drained conditions with and without N and P fertilization. MaxBac, a slow-release fertilizer, was applied at a rate of 100 kg N ha-1 and 20 kg P ha-1, while additional P was applied at 20 kg P ha-1. Commercial products failed to enhance total oil or total petroleum hydrocarbon (TPH) degradation under either continuously or alternately-flooded conditions. An average of 62% of TPH was degraded by 33 d under continuously-flooded conditions, while 59% was degraded by 41 d after oil application under alternately-flooded conditions. Products generally did not increase population sizes of heterotrophs orhydrocarbon-degrading microorganisms. Concentrations of NH4 + and P decreased during experimentation, and fertilization with N and P stimulated total oil and TPH degradation under continuously-flooded, but not under alternately-flooded conditions.  相似文献   

10.
黄河三角洲土壤土著菌的石油烃降解潜力   总被引：3，自引：0，他引：3  
The bioremediation potential of bacteria indigenous to soils of the Yellow River Delta in China was evaluated as a treatment option for soil remediation. Petroleum hydrocarbon degraders were isolated from contaminated soil samples from the Yellow River Delta. Four microbial communities and eight isolates were obtained. The optimal temperature, salinity, pH, and the ratios of C, N, and P （C：N：P） for the maximum biodegradation of diesel oil, crude oil, n-alkanes, and polyaromatic hydrocarbons by indigenous bacteria were determined, and the kinetics changes in microbial communities were monitored. In general, the mixed microbial consortia demonstrated wider catabolic versatility and faster overall rate of hydrocarbon degradation than individual isolates. Our experimental results demonstrated the feasibility of biodegradation of petroleum hydrocarbon by indigenous bacteria for soil remediation in the Yellow River Delta.  相似文献   

11.
Although Phragmites australis is commonly planted in constructed wetlands, very little is known about its roots-associated bacterial communities, especially in wetlands used for the remediation of oil produced waters. Here, we describe the bacterial diversity, using molecular (illumina MiSeq sequencing) and cultivation techniques, in the rhizosphere soils of P. australis from an oil-polluted wetland in Oman. The obtained isolates were tested for their plant-growth promoting properties. Most sequences belonged to Proteobacteria, Bacteriodetes and Firmicutes. Sequences of potential hydrocarbon-degrading bacteria (e.g. Ochrobactrum, and Pseudomonas) were frequently encountered. All soils contained sequences of known sulfur-oxidizing (e.g. Thiobacillus, Thiofaba, Rhodobacter and Sulfurovum) and sulfate-reducing bacteria, although the latter group made up only 0.1% to 3% of total sequences. The obtained isolates from the rhizosphere soils were phylogenetically affiliated to Serratia, Acinetobacter, Xenorhabdus, Escherichia and Salmonella. All strains were able to solubilize phosphate and about half were capable of producing organic acids and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Around 42% of the strains had the ability to produce indole acetic acid and siderophores. We conclude that the rhizosphere soils of P. australis in oil polluted wetlands harbor diverse bacterial communities that could enhance the wetland performance through hydrocarbon degradation, nutrient cycling and supporting plant growth.  相似文献   

12.
The potential of mushroom cultivation substrate (MCS) in bioremediation was examined in polycyclic aromatic hydrocarbon (PAH)-contaminated soil. After a 60-day incubation, 32.9% dissipation of the 15 studied PAHs was observed in MCS-amended microcosms, with anthracene, benzo(a)pyrene and benzo(a)anthracene being the most degradable PAHs. MCS significantly increased the abundance and changed the community compositions of bacteria, fungi and aromatic hydrocarbon degraders. Two species belonging to the Sordariomycetes of the Ascomycota were enriched in all MCS-treated soil samples, and coupled with the unique changes in the PAH profile, this implies the involvement of laccase-like enzymes. Limited improvement was observed after adding Pleurotus ostreatus, possibly because of its poor colonization of the soil. In addition, alfalfa appeared to antagonize the bioremediation effects of MCS. The results of this study suggest that MCS can be a cost-effective and green biostimulation agent, thereby providing support for the development of MCS-based biostimulation of PAH-contaminated soil.  相似文献   

13.
The purpose of this study was to understand the dynamic conditions of soil/organic mixtures in order to contribute to the study of remediation processes at hydrocarbon spill sites. Induced polarization (IP) and physical, chemical, and microbiological parameters for uncontaminated and artificially contaminated soil samples with diesel oil were evaluated under controlled conditions (constant temperature and soil moisture) during a period of 12 months. In contaminated samples, the resistivity and IP parameters (chargeability and polarizability) decreased during 8 months and remained relatively stable between 8 and 12 months. The observed reduction on resistivity and IP parameters was related to the increase on the granular aggregation of the soil and a decrease on total porosity, caused by diesel-degrading microorganisms. The behavior of the IP parameters observed after 8 months can be explained by a reduction in the microbial activity and, consequently, a decrease of the degradation rate of diesel. In the studied loamy soil with high content of organic matter (96.16 g/kg), the results demonstrate that IP time domain measurements can be used in the evaluation of the evolution of the hydrocarbon degradation even when the concentration is not very high.  相似文献   

14.
A quasi steady state respiration test based on Fick’s law with a correction term for advective flux, for estimating petroleum hydrocarbon degradation rates, was evaluated in a full-scale (3,000 m3) biopile study. A contaminated clayey sand soil with an average TPH content of 1,421?±?260 mg kg?1 soil was treated in a biopile with a fixed venting and heating system. Temperature in the biopile ranged from 12.1 to 36.6°C and soil water content from 15.2 to 35.8 m3 H2O m?3 soil. Oxygen concentrations in the biopile showed a rapid decrease with depth, before venting and reached constant atmospheric concentration during venting. Measured oxygen consumption in the biopile ranged from ?0.04 to ?0.68 mol O2 m?3 soil day?1. Average oxygen consumption rates calculated with the quasi-steady-state method were significantly (P?<?0.05) lower then the oxygen consumption rates calculated with the transient method. It was suggested that the oxygen diffusion was underestimated by the diffusivity models used and that further research is needed to determine relative effective diffusion coefficients in biopiles. Although both respiration testing and petroleum hydrocarbon concentration showed a decrease of oxygen consumption in time, the estimated degradation rate was low compared to the actual decrease in petroleum hydrocarbon concentration. Additional work will have to be done to acquire a more precise knowledge of the relationship between respirometrically determined degradation rates and the actual change in petroleum hydrocarbon concentration in the soil.  相似文献   

15.
不同石油污染程度土壤细菌群落多样性及优势菌群分析   总被引：1，自引：0，他引：1  
  目的  探究辽河油田不同石油污染程度土壤中理化性质及细菌群落多样性和组成的变化规律,并对石油污染土壤中的石油降解菌进行分离培养和鉴定。  方法  采集了辽河油田不同石油污染程度土壤,采用高通量测序技术和化学分析法对土壤细菌群落组成和土壤理化性质进行测定,并进一步筛选出石油降解菌株。  结果  在出油口（A）、距离出油口50 m（B）和距离出油口150 m（C）采集的三个土壤样品,其土壤总石油烃含量分别为2467.44 mg kg?1、884.99 mg kg?1和141.63 mg kg?1,三个土壤样品具有不同的石油污染程度。石油污染显著提高了土壤总有机碳含量,土壤总石油烃含量与总有机碳含量呈现正相关（P < 0.001）。土壤细菌群落多样性和丰富度指数与土壤石油烃的浓度呈显著负相关（P < 0.01）。不同石油污染程度土壤具有不同的细菌群落组成和结构,土壤石油烃含量是影响细菌群落变化的主要因素。出油口石油污染土壤样品（A）中,变形菌门（Proteobacteria）为优势菌门,假单胞菌属（Pseudomonas）、假黄单胞菌属（Pseudoxanthomonas）、博代氏杆菌属（Bordetella）和伯克氏菌属（Burkholderia）为优势菌属。从出油口石油污染土壤（A）中分离出3株石油降解菌株,通过16S rRNA基因测序分别被鉴定为Pseudomonas baetica、黄褐假单胞菌（Pseudomonas fulva）和施氏假单胞菌（Pseudomonas stutzeri）,其石油降解率分别为37.2%、46.9%和57.8%。此结果与A样品高通量测序属水平组成分析相吻合,表明石油污染能够选择性富集土壤中具有石油降解能力的假单胞菌属。  结论  石油污染提高了土壤总有机碳含量,降低了土壤细菌群落多样性,富集了具有烃类降解能力的优势菌属,是造成土壤细菌群落组成和结构改变的主要因素,并筛选出具有潜在开发应用价值的石油降解假单胞菌株。  相似文献   

16.
Abstract

Linear alkylbenzene sulphonates (LASs) are anionic surfactants commonly used in commercial detergents. A potential risk associated with the recycling of sewage waste materials is the presence of LASs and their primary degradation products, which could accumulate in sludge, especially during anaerobic processing. The long‐term accumulation of these contaminants in soils and especially the potential disturbance of soil functions need to be studied in more detail. In our study, the influence of the amendment added to an agricultural soil with different organic wastes containing LASs on organic matter content and nitrogen (N) content evolution and mineralization was studied in field conditions. A completely randomized 3×3 factorial arrangement, representing two sewage sludge types (composted and uncomposted) and three levels of LAS presence (0, 15, and 30 g/m2) in treated soils, was established using field plots (7×2 m); the results are compared with untreated plots. Statistical models based on covariance analysis were used to understand the dynamics of and the main factors influencing carbon (C) and N mineralization in sewage sludge amended–soils in the presence of LAS. LAS seemed to alter nitrogen mineralization, especially the nitrate dynamics.  相似文献   

17.
The aim of this article is to present the problem of purification of 50-year-old weathered wastes (soil) from waste pits—the result of oil drilling. The soil was deeply contaminated with petroleum hydrocarbons—total petroleum hydrocarbon (TPH) level: 85,654–101,842 mg kg dry mass. This work presents results of waste pit material purification with the use of stage technology: initial reclamation, basic bioremediation, and bioaugmentation (inoculation with indigenous microorganisms). The whole process was controlled with the use of gas chromatography/flame ionization detector. This analytical method enables observation of alternation in n-alkanes content during the consecutive stages of purification. According to this method, estimation of oil hydrocarbon biodegradation degree with the use of n-C17/Pr and n-C18/F indicators can be done. The use of biomarker C30-17α(H)21β(H)-hopane to normalize the TPH concentration in laboratory research enabled the creation of the first-order mathematical model of biodegradation. It is possible to recognize the dynamics of the following purification stages due to the calculated first-order biodegradation constants. Decrease in the TPH content (63.8–65.1%) was a result of laboratory tests led in 130 days of basic bioremediation. The next stage of soil purification (130 days) included inoculation with biopreparation based on indigenous microorganisms—TPH decrease in 80.7–81.7%. Laboratory tests results enabled elaboration of purification methods applied in tested waste pits in industrial conditions (in situ). The technology of the G-44 and G-12 waste pits purification from huge petroleum hydrocarbons content, consisting of stage purification process, enables the TPH decrease to the satisfactory level in 3 years.  相似文献   

18.
Distribution of boron (B) in different fractions is still not well defined when it is applied in B-deficient alkaline calcareous soil and after harvesting of the sown crop. In the present greenhouse experiment with green gram crop, three B-deficient soils with calcium carbonate contents of 0.8 (S I), 2.1 (S II), and 4.6 (S III) percent were collected from different sites in Ludhiana and Bhatinda Districts, Punjab, India. The treatments composed of five levels of soil-applied B (0, 0.5, 0.75, 1.0, and 1.5 mg B kg?1) soil and the experiment was laid out in Completely Randomized Design (CRD) factorial design with three replications. Mean readily soluble, specifically adsorbed, and oxide-bound B fractions got increased significantly with increase in B applications. Distribution of readily soluble B was more in low calcareous soil than in high calcareous soil. Mean values of specifically adsorbed, oxide-bound, residual, and total B were significantly more in high calcareous soils as compared to low calcareous soils. At maturity, specifically adsorbed B converted into other fractions to maintain equilibrium in soil solution. Organically bound B was greater than the oxide-bound B fraction. Among all fractions, residual fraction accounted for the major portion of the total B. Available B was negatively and significantly correlated with calcium carbonate (CaCO3) content of soil (r = ?0.99*). At the same time, specifically bound B was also negatively and significantly correlated with readily soluble B (r = ?0.99*) whereas organically bound B was positively correlated with organic carbon content of soil (r = ?0.99*).  相似文献   

19.
This study investigated the use of waste amendments (green waste compost (GWC) and water treatment sludge (WTS) cake) in improving the nutrient and revegetation status of contaminated soil obtained from a former industrial site that has heavy metal and hydrocarbon contamination. The waste amendments were mixed with the contaminated soil at application rates equivalent to 90 and 180 t ha?1 (wet weight) and placed in plastic pots. The unamended soil serves as the control. Reed canary grass and white mustard were allowed to grow on the amended and unamended contaminated soil in the glass house. After a 30- day growth period, soil nutrient status was observed and was found to be higher in the amended contaminated soil than the control. In the amended soil, organic matter, total nitrogen, total potassium and soil nitrate were highest in contaminated soil amended with GWC at 180 t ha?1 and lowest in contaminated soil amended with WTS cake at 90 t ha?1. Above-ground dry mass of reed canary grass and white mustard grown on amended contaminated soil increased by 120–222% and 130–337%, respectively, as compared to the control, showing that improved fertility of contaminated soils thereafter, enhanced revegetation.  相似文献   

20.
Features and factors of the hydrocarbon status of soils developed in oil-producing karst regions were considered using an oilfield as an example. The notion of the hydrocarbon status of soils involves the proportions of the gas, bitumen, and polyarene components of the total hydrocarbons and their radial and lateral variations. The following types of soil hydrocarbon status were identified: (1) the background (reference) type; (2) the first kind of emanation type related to soil degassing (most probably, in an oilfield); (3) the technogenic type developed in the areas of oil spills, contaminated surface runoff, and industrial waste storage; and (4) the emanation type of the second kind related to the degassing and evaporation of spilled oil and other substances in underground karst caves. It was shown that the data on the hydrocarbon status of the soils can be used for the identification of hydrocarbon areas in the soil cover and the indication of the sources of pollutants deteriorating the environmental conditions in the landscape.  相似文献   

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