Search published articles


Showing 9 results for Polycyclic Aromatic Hydrocarbons
Survey of Phenantherene Biodegradation's Model inContaminated Soils by Acinetobacter SP
F Rashid Ashmagh, R Rezaei Kalantary, M Farzadkia, A Joneidy Jafari, R Nabizadeh,
Volume 2, Issue 3 (11-2009)
Abstract

Backgrounds and Objectives: Polycyclic aromatic hydrocarbons (PAHs) are a group of hazardous pollutants which have carcinogenic and mutagenic properties and accumulated in environment by different actions, therefore treatment of them is important. Biological treatments are simple and cheep technologies. This technology was recommended as a cost- effective method for treatment of these pollutants. In order to investigate the trend of pollution reduction of petroleum hydrocarbons in bioremediation, the phenanthrene biodegradation&aposs model in contaminated soils was studied.
Materials and Methods: Firstly, PAHs capable degrading bacteria was isolated from petroleum contaminated soils and then their ability for biodegradation of phenanthrene was assessed in slurry phase. After that by using Acinetobacter which have the most potential of removing phenanthrene from soil, the biodegradation model was investigated in bench scale.
Results: Phenantherene removal efficiency was obtained 99.4% for 100 mg/kg and 96 % for 500 mg/kg concentrations in 33 and 60 days biodegradation period respectively. Phenantherene reduction rate varied from 2.99 to 8.86 and 1.4 to 11.09 mg/kg/day for 100 and 500 mg/kg concentrations, respectively.
Conclusion: Rate of phenantherene removal is depended on primary concentration of contamination and by increasing of primary concentration, phenantherene removal rate was increased. Also removal efficiency followed zero and first order kinetic model with good correlation.


Ecological Risk Assessment of Polycyclic Aromatic Componds in the Surface Sediments of Anzali Wetland in 2010
Rokhsareh Azimi Yancheshmeh, Ali Reza Riyahi Bakhtiari, Samar Mortazavi,
Volume 7, Issue 2 (10-2014)
Abstract

Background & Objectives: In recent years, enterance of oil contaminants especially polycyclic aromatic hydrocarbons (PAHs) to Anzali Wetland, has seriously threatened organisms life. Therefore, the current study was conducted to determine and compare concentration of PAH compounds with multiple sediment quality assessment indice to evaluate the ecological toxicity of surface sediments of Anzali Wetland and present appropriate management strategy. Materials & Methods: We randomly collected 22 surface sediment samples each sample was dried and extracted based on the soxhlet method. Then during two-step of column chromatography the PAH compounds were separated and analyzed by gas chromatography equipped with a mass spectrometry detector (GC-MS). Results: Total concentrations of these compounds ranged from 212 to 2674 ng g-1 d.w. with the mean of 907 ng g-1 d.w. The highest concentrations of PAHs was reported from stations (3-1 and 4-1) located in the vicinity of urban areas with shipping activities. In comparison with sediment quality guidelines (SQGs) used in this study, the concentrations of most PAH compounds in the majority of stations situated in low range values of adverse biological effects. Only in a few stations (3-1, 3-2 and 5-3), the concentrations of some of PAH compounds exceeded the low range of adverse biological effects. Conclusion: In comparison with sediment quality guidelines (SQGs) used in this study, the concentrations of most PAH compounds in Anzali Wetland rarely lead to adverse biological effects. However, concentrations of some of these compounds can cause acute toxic effects. Therefore, further studies including toxicity and bioaccumulation tests and survey of benthic community composition, especially in areas exceeded SQGs are essential for proper management.


Determination of polycyclic aromatic hydrocarbons in water using an electrochemical DNA biosensor
R Manaffar, B Sehatnia, R Sabzi, A Ehsani,
Volume 8, Issue 2 (8-2015)
Abstract

Background and Objectives: Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants in aquatic environments. These contaminants are generated through oil spills, manufactory processes, and industrial wastes or naturally through the incomplete combustion of coal, oil, gas, and wood waste. Most of these compounds are noted as carcinogenic and mutagenic. Therefore, detection of these pollutants by a sensitive and inexpensive method is very important. Materials and Methods: In this study, an electrochemical DNA biosensor was used to detect PAHs due to its sensitivity, ability, and high response rate. For this purpose, the bovine thymus double-stranded DNA was fixed on a screen-printed electrode. Then, the electrodes electrochemical behavior was investigated. This electrochemical DNA biosensor works upon the difference between the electrochemical response of guanine bases in DNA structure in the presence and absence of PAH compounds. To evaluate the biosensors performance, the response of biosensor to real samples was compared with conventional pollutant determination methods like liquid-liquid chromatography. Results: Optimum conditions were examined for biosensor response including effect of activation potential and time on electrode pretreatment, applied potential for DNA immobilization, and detection potential. Under optimal conditions, the pretreatment of the electrode obtained in 1.6 V for 350s, then the DNA was immobilized on the electrode surface by applying a potential of -0.5 V to detect different PAHs in real samples in the range of micro molar. Conclusion: Electrochemical DNA biosensors are capable of detecting the sum of PAHs in water samples with high accuracy, sensitivity, and low cost compared with chromatographic methods.


Contamination, source apportionment and health risk assessment of Polycyclic Aromatic Hydrocarbons (PAHs) in soils of Bandar Abbas county central district
Sl Mousavi, A Shakeri, M Nakhaei,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) constitute a large class of organic compounds that are composed of two or more fused aromatic rings. Due to their potential mutagenic, carcinogenic and teratogenic effects on human health, PAHs have attracted particular concern. Therefore, in this study it was attempted to measure the PAHs concentration in the study area to evaluate the health risk.
Materials and Methods: 36 samples were taken from the central district in Bandar Abbas county to investigate the degree of contamination, sources and health risk  of polycyclic aromatic hydrocarbons (PAHs). Analysis of the samples was performed using gas chromatography.  خطای ترجمهAlso,  PMF Model was used to determine the possible sources.
Results: The total PAHs concentration had a mean value of 1.48 mg/kg in the soil samples. The total incremental life time cancer risk (ILCR) due to exposure to PAHs in soil is 1.06 × 10−6 for an adult and 4.95 × 10−6 for children. The results estimated for ILCR indicated that residents live in the central district of Bandar Abbas county are potentially exposed to cancer risk via both dust ingestion and dermal contact.
Conclusion: The ecological risk assessment of PAHs showed that the levels of all types of PAHs were lower than the lower value of effects range, except for dibenzo(a,h) antheracene and acenaphthene. The estimated results of ILCR indicated that Bandar Abbas county central district residents are potentially exposed to cancer risk via both ingestion and dermal contact. The PMF analysis identified four sources that were included fossil fuel combustion (14%), biomass combustion (13%), vehicular emissions (36%) and fossil fuel combustion/unburned petroleum (37%).
 

Ecological risk assessment of polycyclic aromatic hydrocarbons in the Persian Gulf surface sediments, Bushehr
F Bateni, A Mehdinia, M Seyed Hashtroudi ,
Volume 11, Issue 4 (3-2019)
Abstract
Background and Objective: This study conducted to assess ecological risk of an important group of pollutants called polycyclic aromatic hydrocarbons (PAHs) in offshore sediment of the Persian Gulf deposits in Bushehr province. The aim of this study was to model the toxicity of PAHs for aquatic organisms in the study area.
Materials and Methods: In the first step of the applied risk assessment model in this study, the unit of toxicity for each PAH and solubility were calculated by Quantitative Structure-Activity Relationships (QSAR) model. In the second step, the pore water concentration of all compounds in sediment was calculated as an available fraction. Finally, the proposed model was used to evaluate the offshore sediments of the Persian Gulf. Sediments in 19 stations and 7 transects were studied to assess the ecological risk of 21 PAHs. The extraction and clean up method was based on pressurized liquid extraction (PLE) with packed clean up cell. Compounds were analyzed by GC-MS.
Results: The toxicity and solubility of PAHs were modeled. The Pearson correlation for the predicted and measured data was more than 0.93. The amount of total toxicity was introduced as a risk index. The maximum and minimum total toxicity values for the sediments were found as 0.018 and 0.147, respectively. The results from this study indicated that although the concentration of PAHs in the sediments may not cause significant concern in the study area, they may affect benthic organism at the sub-lethal levels. According to the applied risk assessment model for 21 unsubstituted PAHs, the offshore sediments of Bushehr are in low-risk range.
Conclusion: The result of this study indicated a low risk of the sediments. The hazard index decreased as the distance from coastal and oil and gas industry increased, indicating the high impact of anthropogenic activities on the contamination of the study area.
 

Analysis of polycyclic aromatic hydrocarbons in surface soil of agricultural lands in Hamedan, Iran
Azim Rabieimesbah, Soheil Sobhanardakani, Mehrdad Cheraghi, Bahareh Lorestani,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants produced by anthropogenic activities that contaminate all environmental matrices, including soils, and can enter the food chains. Therefore, this study was conducted for the analysis of PAHs compounds content in agricultural soils of Hamedan city, west of Iran, in 2021.
Materials and Methods: a total of 36 surface soil specimens were collected from 12 sampling sites in agricultural soils and after extraction of analytes based on the soxhlet method, the gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, soil samples were further analuzed for the amounts of pH, electrical conductivity (EC), and total organic carbon (TOC). Statistical analysis was performed using SPSS software.
Results: Results showed that 16 PAHs (∑16PAHs) total concentrations ranged from 435 to 3292 µg/kg with an average value of 1806 µg/kg. PAHs with higher molecular weight (≥ 4 rings) were dominant in PAHs profiles accounting for 78%. Based on the results, the mean concentrations of all 16 PAHs were lower than MPC established by MHWaS. Furthermore, the mean concentrations of Pyr, B(a)A, Chy, B(b)F, B(k)F­, B(a)P, and B(ghi)P were higher than the MPC established by the Iranian Department of Environment.
Conclusion: Based on the results obtained, as the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
 

Bioremediation of selected polycyclic aromatic hydrocarbons by Chlamydomonas reinhardtii algae in synthetic crude oil wastewater
Navid Ahmadi, Mozhgan Ahmadi Nodushan, Mohammad Hadi Abolhasani, Seyed Abbas Hosseini,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The presence of PAHs in the environment can cause a problem as their presence has a deleterious effect on humans and animals. They also have the ability to cause tumors in humans and animals. Generally, to remove crude oil pollutants from seawater, various physicochemical and biological treatment methods have been applied worldwide. A biological treatment method using bacteria, fungi, and algae has recently gained a lot of attention due to its efficiency and lower cost. Chlamydomonas reinhardtii, microalgae have features such as a high proliferation rate, and cultivability in various water ecosystems.
Materials and Methods: In the present study, a total of 12 samples of synthetic oil wastewater were prepared at 2.5 g/L, 7.5 g/L, and 12.5 g/L that were called C1, C2 and C3.The gas chromatography/mass spectrometry (GC–MS) method was used for the determination of PAHs compounds in the samples. Furthermore, water samples were further analyzed for the amounts of biological oxygen demand (BOD), Chemical oxygen demand (COD), and total organic carbon (TOC). Chlorophyll A, biomass, amounts of nitrate, and nitrite ​​were also measured. Statistical analysis was performed using SAS 9/8 software.
Results: Results indicated that the removal rates from crude oil by C.reinhardtii microalgae were 100% on the 14th day for the three compounds of phenanthrene, fluorine, and anthracene at all concentrations, and 97.8%, 93%, and 92.7% for naphthalene compound at concentrations of 2.5 g in 1L, 7.5 g in 1L, and 12.5 g in 1 L, respectively (p<0.05). In terms of nutrients (NO-2 and NO-3), the highest amount of nitrate removal was observed at a concentration of 2.5 g/L from crude oil (C1) (p<0.05). The highest biomass was observed in the C3 treatment (p<0.05). Moreover, the greatest decline in BOD was observed in treatment C3 at 47.4%, while the greatest COD and TOC decline were observed in C1 treatment with the value of 84% and 94%, respectively (p<0.01).
Conclusion: The results showed that the cultivation of C.reinhardtii in crude oil in terms of nutrient removal potential, hydrocarbon composition, improving water quality and production of suitable biomass can be an acceptable option for exploitation in the biological treatment process.
 

Identification and determination of amounts of polycyclic aromatic hydrocarbons in the surface soil of Nuruddin Abad in Garmsar
Zahra Lotfi,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants with teratogenic, mutagenic and carcinogenic potential, which can pose potential risks to the environment and human health. Therefore, this study was conducted for the analysis of PAHs compounds content in surface soil samples of the disposal site of the wastes resulting from the activity of oil refining units (Nuruddin Abad, Garmsar) in 2022.
Materials and Methods: In this research, surface soil samples were collected from 8 sampling sites in the study area. After the extraction of analytes based on the soxhlet method, the gas chromatography/flame ionization detector (GC-FID) method was used for the determination of PAHs compounds in the samples. Statistical analysis was performed using SPSS software.
Results: The results showed that the concentrations of Naphthalene (Nap), Acenaphthene (Ace), Benzo[b]fluoranthene (BbF), Dibenz[a,h]anthracen (DBA), Benzo[g,h,i]perylene (BP) and Indeno[1,2,3‐c,d]pyren (Ind) were less than the quantification limit of the measurement method <0.01 mg/kg. total concentrations of 16 PAHs compounds ranged from 56.55 to 92.06 mg/kg.
Conclusion: The results showed that the concentrations of Acenaphthylene (Acy), Fluorene (Flu), Phenanthrene (Phen), Anthracene (Ant), Fluoranthene (Flt), Pyrene (Pyr), Chrysene (Chr), Benz[a]anthracene (BaA), Benzo[k]fluoranthene (BkF), Benzo[a]pyrene (BaP) were higher than MPC established by the Iranian Department of Environment. Also, the concentrations of Acy, Flu, Phen, Ant, Pyr, Chr, BaA, BkF, and BaP were higher than MPC established by MHWS. As the mean contents of some PAHs were higher than the MPC, therefore, periodic monitoring of soil contamination with PAHs is recommended for the environmental and human health aspects.
 

Measurement of polycyclic aromatic hydrocarbons in canned fish using multi-walled magnetized carbon nanotube and solid phase extraction method
Gholamali Sharifiarab, Mohammad Ahmadi, Nabi Shariatifar, Peiman Ariaii,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: polycyclic aromatic hydrocarbons (PAHs) are compounds with high carcinogenic and mutagenic potential. This study aims to investigate the amount of 16 of these compounds in different types of canned fish.
Materials and Methods: In this research, first, multi-walled carbon nanotubes were magnetized by the MSPE method, and then the synthesized composite was used to extract PAHs from the matrix of canned fish samples. Finally, the concentration of each of these compounds was measured by GC-MS.
Results: The results of this research showed that the highest average amount of total PAHs and PAH4 were 20.22±5.29 and 6.07±1.41 μg/kg, respectively. Also, the highest average amount of benzo[a]pyrene (BaP) found in all samples was 1.34±0.41 μg/kg, which was lower than the existing standards (EU standard for BaP in fish is 2 μg/kg). The amount of these compounds in different types of canned fish were as follows: canned in olive oil > canned with dill > simple canned fish > canned in salt water. And finally, the amount of these compounds in brand A was higher than in other brands.
Conclusion: Based on the findings of this research and since the total average of each of these compounds is lower than the existing standards in different types of canned fish, it can be said that there is no danger to the consumers.
 

Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb