Polycyclic aromatic hydrocarbons (PAHs) in soils around oil refineries; Case study: Erbil and Kirkuk refineries, Iraq- A modelling approach (original) (raw)
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Journal of Research and Applications in Agricultural Engineering, 2015
Polycyclic aromatic hydrocarbons (PAHs) are a group of organic compounds, which accumulation in arable land is highly unfavorable phenomenon due to their toxic properties and adverse effects on yield as well as growth of plants. In order to determine the degree of PAHs exposure, the research on the sorption and accumulation of PAHs in various components of the soil is indispensable. The aim of this study was to define the effect of the organic and clay fraction on the mobility of PAHs. Experiments were carried out in column systems and the following solid phases (sorbents) were applied: a quartz sand (a control), a mixture of quartz sand and humic acids, a mixture of quartz sand and clay mineral-montmorillonite and systems combined with quartz sand, montmorillonite and humic acids. As a labile phase, the aqueous solution of phenanthrene (concentration of 0,5 mg•l-1) was used. Quantification of PAHs in the eluate was carried out by a photoluminescence method. The obtained results indicate that the increase of both clay fraction and the humic acids resulted in an increase in the sorption of phenanthrene on a solid matrix. Moreover, the montmorillonite showed higher sorption than humic acids added in the form of a commercial preparation. Thus, it can be assumed that the soils characterized by favorable agronomic properties (a lot of clay fraction and organic matter) are particularly susceptible to the accumulation of organic compounds (e.g. PAHs). Additionally, this kind of soil-due to immobilization-is characterized by smaller capacity of natural bioremediation. These conclusions points to the need for monitoring of arable land, particularly areas with high emissions of PAHs to the environment.
Chemosphere, 2018
This study was carried out in order to investigate the toxicity on Lebanese soil and to show the impact of the anthropogenic activities, industrialization and urbanization, on the release of Polycyclic Aromatic Hydrocarbons (PAHs) in Lebanese soils. Hundred soil samples of different land use were screened for 17 PAHs using a UAE/GC-MS method. Detection frequency varied between 76 and 100% for most of the PAHs, where the ΣPAHs ranged from 33.5 to 4062.9 ng.g-1. Moreover, BaPeq values varied between 0.93 and 332.4 ng.g-1. BaPeq values in industrial and urban soils were 777 and 256 times higher than those in rural soil, respectively. None of the soil samples showed concentrations above the safe BaPeq value of 600 ng.g −1. Significant decrease in concentration levels of ΣPAHs was obtained in the following order: Industrial, urban, traffic and agricultural. Furthermore, the relative high contribution of Chrysene, Benzo(a)Anthracene and Benzo(k)Fluoranthene in agricultural soils indicates that open burning remains an adopted way in Lebanon for disposal of agricultural residues, while the predominance of Benzo(ghi)Perylene and Benzo(b)Fluoranthene in industrial soils suggests the broad use of diesel powered engines in the Lebanese industrial sector. The ratios of Low Molecular Weight/High Molecular Weight and fluoranthene/fluoranthene+pyrene (Fln/Fln+Pyr) showed that PAHs in soil samples are mainly pyrogenic and created during combustion of petrol, coal, wood and other biomasses.
Applied Geochemistry, 2009
Editorial handling by R. Fuge a b s t r a c t Fifty soil samples collected from agricultural land in four regions of Poland with different anthropopressure were analysed for their content of 16PAHs by GC/MS. The regions correspond to Polish administrative units (voievodeships): Podlaskie and Lubelskie are situated in the rural East part of the country and more industrialised Slaskie and Dolnoslaskie voievodeships -in the South-West part. Basic physicochemical properties as well as the content of selected potentially harmful metals (Pb and Zn) were included in the soil analysis. Overall accumulation of R16PAHs in the upper soil layer was within the range 73-1800 lg kg À1 with a geometric mean (GM) of 252 lg kg À1 , while the mean benzo(a)pyrene (BaP) load was 20 lg kg À1 . This corresponds with data for other European countries. Carcinogenic compounds contributed nearly in 50% to the total PAHs loads. In uncontaminated rural regions the mean R16PAHs and BaP contents were 113-159 lg kg À1 and 11-13 lg kg À1 , respectively. Regional conditions strongly influenced the accumulation of PAHs P4-rings, which were highly dependent (over 95%) on local anthropopressure expressed as dust and 4PAHs emission indexes. Soil acidity was the main soil parameter related to the accumulation of higher molecular weight PAHs in soils. In more contaminated regions a significant link between soil OM and PAH loads was noted. The same regions were characterised by associations between PAHs and potentially harmful metals implying common sources of pollution. Those relationships were not observed in the uncontaminated part of the country. The lower molecular weight PAHs contributed to a smaller extent (about 20%) to the total PAHs content in soils, and were less affected by anthropogenic factors.
Journal of Soils and Sediments
Purpose The objective of this study was to evaluate the mutual relations between the soil organic matter (SOM) fractions: fulvic acids (FA), humic acids (HA), humins (HN), black carbon (BC) and the polycyclic aromatic hydrocarbons (PAH) accumulation level in agricultural soils influenced by historical and actual anthropopressure. The research allowed to indicate which fractions of SOM are the major sequestration sinks for PAHs after they are naturally introduced into the soil. Materials and methods Soil samples were collected from the upper layer of agricultural soils (n = 41), and basic physicochemical properties (pH KCl , total carbon, total nitrogen and clay content) were determined. The SOM was characterised by the total organic carbon content and humic substances, including HA, FA and HN, determined by an adapted method recommended by the International Humic Substances Society. The extracts of HA and FA were analysed for carbon content using a liquid CN analyser, while HN constituted the soil carbon in the residue after FA and HA extraction. The content of BC was analysed by dry combustion at 375°C for 24 h (CTO375); the remaining carbon was determined via combustion in an elemental analyser. Results and discussion In all soils, significant positive relations between PAH concentrations and TOC content (r = 0.73, p < 0.001) as well as HN (r = 0.71, p < 0.001) and BC (r = 0.86, p < 0.001) were noted. Relations among PAHs, HN and BC were statistically significant only in soils with TOC content ≥ 12 g kg −1 , while they were not observed for soils with TOC content < 12 g kg −1. The links between HN and PAHs were stronger for low-molecular (two and three rings)-weight PAHs (r = 0.77, p < 0.05) than for high-molecular (≥ four rings) PAHs (r = 0.68, p < 0.05). Contrary to HN, the BC faction showed higher correlations with high-molecular-weight PAHs (r = 0.92, p < 0.001). FA and HA showed no significant relationship with hydrocarbons. Conclusions Different SOM fractions might possess divergent binding capabilities and dissimilar binding strengths to PAHs. The different proportions and sorption capacities of BC and HN in relation to PAHs of different molecular weight are the result of varying structure, i.e. polar and non-polar functionalities in sorption domains and pore-size structures of these fractions. The high correlation between BC and higher-molecular PAHs may be a result of their co-emission, while the stronger relationships between HN and lower-molecular PAHs are directly related to their higher mobility and easier diffusion to stable SOM fractions.
International Journal of Environmental Research and Public Health
The aim of this study was to assess the effect of long-term fertilization with manure and mineral fertilizers on the content and distribution of selected polycyclic aromatic hydrocarbons (PAHs)—the content of a sum of 16 polycyclic aromatic hydrocarbons, light and heavy PAHs in two soil layers (0–30 cm and 30–60 cm). The material for the study was composed of soil samples collected from the sixth rotation in a long-term, controlled field experiment, conducted in Bałcyny since 1986. The content of 16 polycyclic aromatic hydrocarbons was determined on a gas chromatographer coupled with an FID detector. In order to evaluate the significance of differences between the mean effects on the tested characteristics, a non-parametric Mann–Whitney U test for two independent samples was applied. A higher content of the sum (16) of PAHs was found in the 0–30 cm than in the 30–60 cm soil layer. The research results also demonstrated a higher content of the sum of light PAHs in the 30–60 cm than i...
International Journal of Environmental Research
The spatial and seasonal distribution of eight US Environmental Protection Agency priority poly aromatic hydrocarbons (PAHs); namely benzo(b)fluoranthene, benzo(a)pyrene, indeno(1,2,3-cd)pyrene, benzo(k)fluoranthene, chrysene, benzo(a)anthracene, dibenz(a,h)anthracene and fluoranthene were investigated in 35 soil samples. Gas chromatography with flame ionization detection was used for the quantification of the PAHs in the residential, roadside and industrial soil samples collected in proximity to an industrial area, including a petrochemical plant, in Cape Town. The sum of the concentrations of the detected PAHs (RPAHs) in winter ranged between nd (not detected) and 13.88 mg/kg, with a mean concentration of 4.08 mg/kg and a standard deviation of distribution of 2.64 mg/kg, while in summer, RPAHs ranged between nd and 10.43 mg/kg, with a mean concentration of 0.50 mg/kg and standard deviation of distribution 1.83 mg/kg. The presence and concentration level of the PAHs detected in the soil samples vary significantly under climatic change (p \ 0.05). The maximum concentrations of individual PAHs in the soil samples were higher in winter compared to the maximum concentrations of the PAHs detected in summer. The diagnostic ratios of selected PAH compounds showed that petrogenic processes were the most likely sources of the PAH compounds in the soil samples. In summer and winter, the total PAH concentration increased in order of residential soil \ industrial soil B roadside soil.
Fate and Transport of Organics in Soil: Model Predictions and Experimental Results
Journal of Water Pollution Control Federation, 1988
Laboratory batch reactors were used to generate quantitative information about the fate of polynuclear aromatic hydrocarbon (PNA) compounds in soil systems. First-order deg radation rates and equilibrium partition coefficients determined in laboratory studies were used in the Vadose Zone Interactive Processes (VIP) mathematical model to predict the fate and be havior of the PNA compounds as a function of time and soil depth. Predicted model results were compared with independent laboratory soil column studies for model validation. The VIP model provided a good approximation of the degradation and transport of the seven PNA compounds evaluated after 6 months of incubation in soil. Sensitive parameters in the VIP model in cluded degradation rates and initial soil concentrations. /. Water Pollut. Control Fed., 60, 1684 (1988).