Showing 52 results for Oil
Mohsen Ansari, Mehdi Farzadkia,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: The high concentration of petroleum hydrocarbons, along with some other parameters such as aromatics, paraffin, naphthene, and heavy metals, has led to the sludge of oil sludge listed as hazardous materials with a specific source by the US Environmental Protection Agency. Therefore, the purpose of this study is to investigate the potential of oil-contaminated soil in changing the biodegradability indices of oil sludge.
Materials and Methods: Moisture, pH, total organic carbon, total nitrogen, total phosphorus, elemental analysis, and amount and type of TPH of oil sludge samples were identified. The microbial consortium was isolated from contaminated oil soil around the oil refinery and poultry manure. Finally, biodegradability indices of oil sludge were examined.
Results: The results showed that the amount of organic carbon and nitrogen in oil sludge samples were 32.65 and 0.21%, respectively. Also, iron, calcium, and potassium with 5862, 2921, and 524 mg/kg, respectively, were the most elemental components in petroleum sludge. According to the SARA analysis, the highest TPH compounds in oil sludge samples included saturated compounds, aromatics, resins, and asphaltene with 70.45%, 15.2%, 10.9%, and 3.45%, respectively.
Conclusion: According to the results of biodegradability indicators of oil sludge, it can be concluded that the isolated consortium can be proposed as a suitable tool for the treatment of petroleum sludge at the bottom of crude oil storage tanks.
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.
Masoumeh Selahvarzi, Soheil Sobhanardakani, Amir Hooman Hemmasi, Lobat Taghavi, Jamal Ghoddousi,
Volume 15, Issue 4 (3-2023)
Abstract
Background and Objective: Soil contamination with heavy metals is the most important challenge and common environmental, economic, and public health issue in the world. Therefore, this research was conducted to evaluate the contamination and source identification of Fe, Zn, Cd, and Cr in the surface soils of Khorramabad county, west of Iran in 2020.
Materials and Methods: In this descriptive study, after dividing the study area into 11 homogeneous units, a total of 65 surface soil samples were collected. After preparing the samples, the content of the elements was determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Also, enrichment factor (EF), pollution factor (CF), and Nemrow integrated pollution index (NIPI) were calculated. Statistical analyses of the data were performed using SPSS statistical software.
Results: The results showed that the average content of Fe, Zn, Cd, and Cr (mg/kg) in soil samples were 3.14, 1.13, 0.021, and 0.529, respectively. The EF values showed that the enrichment of Zn, Cd, and Cr was "extremely severe" and the average values of EF for the elements followed the descending order of Cd > Cr > Zn. The average values of CF and NIPI varied from 3.30×10-5 to 0.182 and 0.043-0.136, respectively, indicating the level of "low pollution" and quality conditions of "no pollution" in all the studied stations. Based on the results of multivariate statistical analysis (PCC, PCA and HCA), Fe has a geological origin; while, Zn, Cd, and Cr mainly originated from a combination of geological processes and anthropogenic activities.
Conclusion: Although the average values of CF and NIPI showed that the study area has an acceptable soil quality, the values of EF indicated the impact of anthropogenic activities on soil contamination. Therefore, regular and periodic monitoring of soil samples as well as management and control of pollutant emission sources is recommended for maintaining environmental and human health.
Behnaz Abdollahinejad, Hasan Pasalari, Mahdi Farzadkia,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: The purpose of this study is to identify and comprehensively evaluate international studies related to bioaugmentation and biostimulation methods for the remediation of soils contaminated with petroleum compounds.
Materials and Methods: This systematic review study was conducted in April 2022. The present systematic review study was conducted to address two main questions: 1) Is biostimulation an effective process in the bioremediation of soils contaminated with petroleum hydrocarbons; and 2) Is bioaugmentation an effective process for bioremediation of soils contaminated with petroleum hydrocarbons? Global electronic databases (PubMed, Web of Science, and Scopus) were used to identify relevant studies. After a comprehensive review of studies, 123 studies consistent with the purpose were selected.
Results: The results showed that biostimulation methods can have profound changes in bacterial, Archaebacteria, and soil fungal communities in terms of activity, frequency, and composition. In general, the nutrients and electron receptors added in the biostimulation process improve soil microbial activity, increasing the overall abundance of bacteria, and fungi and promoting selective replication of bacterial, archival, and fungal polyaromatic hydrocarbons (PHC) destroyers. The use of bioaugmentation technology in an environment contaminated with petroleum hydrocarbons has a positive effect on the refining process. However, it is necessary to precisely select the appropriate microbial strains. The most important factor in the removal of hydrocarbons in the soil is the selection of oil-decomposing microorganisms that can survive in high concentrations of pollutants.
Conclusion: Therefore, the result indicated that biostimulation and bioaugmentation can efficiently improve the THP removal efficiency in contaminated soil by considering the environmental conditions.
Sara Ghayour, Abbas Rezaee, Mohsen Heidari,
Volume 16, Issue 1 (6-2023)
Abstract
Background and Objective: Agricultural lands around Tehran may become contaminated due to their proximity to pollution sources and such pollution should be investigated. Therefore, the main objectives of this study were to determine the pollution levels of some trace elements in the agricultural soils around Tehran and to assess the attributed health risks.
Materials and Methods: In this study, 43 soil samples were collected from agricultural lands around Tehran. The soil samples were prepared and acid-digested and the concentrations of Vanadium (V), Lithium (Li), Lanthanum (La), Molybdenum (Mo), and Antimony (Sb) were measured by ICP-OES. Based on the concentrations of the elements in soil, the pollution indices and non-carcinogenic risk (based on Monte Carlo simulation) were assessed.
Results: Among the studied elements, V had the highest concentration (131 mg/kg) followed by La > Li > Sb > Mo. The values of the geoaccumulation index (Igeo) and enrichment factor (EF) were in the ranges of -1.9 to 0.8 and 0.5 to 3.1, respectively. The Nemerow integrated pollution index (NIPI) values were in the range of 1.3 to 2.0. The values of non-carcinogenic risk for Li, Mo, Sb, and V were negligible, but it exceeded the threshold limit for La.
Conclusion: This study showed that the agricultural lands around Tehran are contaminated with studied trace elements to a low to moderate extent. However, an unacceptable non-carcinogenic risk attributed to La was estimated. Therefore, it is essential to pay special attention to the La pollution of agricultural soils around Tehran.
Mohammad Javad Zoqi, Mohammad Amin Rasooli, Behnoosh Khataei, Mohammad Reza Doosti,
Volume 16, Issue 2 (9-2023)
Abstract
Background and Objective: Mining is one of the important economic activities all over the world. It causes the release of various emissions, especially heavy metals in the soil, due to the weak exploitation and improper disposal of mineral wastes. Different techniques are used for soil remediation and heavy metal extraction; including the electrokinetic method (so effective in fine-grained soils). In this research, the electrokinetic process was used to extract copper from the waste of the mine in Birjand.
Materials and Methods: In this research, a 24 cm long PVC reactor was used. The retention time was 2, 4, and 6 days and the voltage gradient was 1 V/cm. Graphite electrodes and electrolyte solutions of nitric acid and citric acid were investigated for copper extraction. The electrode polarity was alternately changed in order to pH control and improve the extraction process.
Results: According to the results, the highest removal efficiency (54%) was obtained after 6 days using 0.1 M citric acid and distilled water in the anode and cathode reservoir, respectively. Further, by 24-hour polarity reversing, the copper removal efficiency increased to about 60%.
Conclusion: The use of citric acid in anode was more effective than nitric acid, leading to more copper removal. In addition, by periodically polarity change and keeping the soil pH in the neutral range, further dissolution of the metal and reducing its sedimentation in the soil occurred. As a result, the rate of its transfer outside the treatment area and removal efficiency increased.
Maryam Fayazi,
Volume 16, Issue 4 (3-2024)
Abstract
Background and Objective: The emergence of nanotechnology and the use of nanoscale materials has made it possible to take advantage of the potential and novel applications of this technology in various fields of agriculture. Therefore, this research aims to make fertilizer for high-consumption nutrients such as nitrogen, phosphorus, and potassium (NPK) by hydrogels based on the sepiolite (Sep) clay nanostructure and starch (S).
Materials and Methods: In this study, the physical inhibition method was used to control the release of high-consumption nutrient elements of fertilizer. For this purpose, appropriate amounts of NPK salt were inserted in the structure of Sep-S hydrogels. Then, the release level of nutrients was investigated by the column elution and measuring the conductivity of the outlet solution of the column.
Results: The elution profile of the NPK fertilizer shows that the salts quickly leave the end of the column so that the conductivity of the solution at the end of the column in the first washing after consumption of 250 mL of water reaches about 12000 µS/cm. On the other hand, the elution profile of the slow-release fertilizer containing NPK salts shows that the release profile of the fertilizer in 4 times of washing with the same volume is almost similar (range 1400 µS/cm to 2300 µS/cm). Results show that the placement of fertilizer salt inside the proposed hydrogels leads to the slow release of highly consumed nutrients.
Conclusion: The release of nutrients from the structure of slow-release fertilizer based on Sep-S hydrogels has a delay, which is vital to prevent the excessive release of nutrients, and minimize negative environmental effects and excessive consumption of chemical fertilizers. Also, the materials used to make the slow-release fertilizer have a relatively low cost.
Zahra Moavi, Khoshnaz Payandeh, Mehrnosh Tadayoni,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: Heavy metals are dangerous pollutants in the environment that accumulate in food. This research was conducted with the aim of evaluating the health risks and contamination of some heavy metals in lettuce and cabbage in the cities of Hamidieh, Dezful and Ramhormoz in Khuzestan province.
Materials and Methods: The sampling was completely random, with three repetitions, and 15 samples of each of the lettuce and cabbage vegetables grown in each region were prepared. Heavy metals were measured using the Perkin Elmer 4100 atomic absorption device. Heavy metal risk assessment was conducted using soil pollution indicators and health risk assessment method.
Results: The highest amount of metal in cabbage is related to zinc (5.84±0.15 mg/kg), while the lowest amounts of chromium metal in lettuce (0.11±0.005 mg/kg) was achieved. Based on the daily absorption of heavy metals in lettuce and cabbage products, the results showed that the highest hazard index (HQ) values, related to lead metal in cabbage for children and adults, were 3.9376 and 3.4253, respectively, compared to other heavy metals. The highest value of the carcinogenicity index in children was 0.0133 for cabbage consumption. The carcinogenic index of chromium metal in lettuce and cabbage products had the lowest values (0.0003 and 0.0004). Regarding the metal enrichment factor, lead, chromium, copper and cobalt were higher in the agricultural soils of Ramhormoz compared to other regions, while nickel and zinc were higher in the soils of Hamidiyeh than in Dezful and Ramhormoz. The soil index of accumulation of chromium, zinc and copper in the soil of Dezful agricultural fields was higher, whereas lead and cobalt were higher in Hamidiyeh soils than in Dezful and Ramhormoz. Additionally, nickel was higher in Ramhormoz agricultural fields.
Conclusion: According to the soil pollution indicators, cobalt metal played an important role in the soil pollution in Dezful, Hamidiyeh and Ramhormoz, while the metals lead, nickel, chromium, copper and zinc showed minimal pollution levels in the soil of the studied areas. The health risk assessment of soil heavy metals showed that the risk index for lead, nickel, chromium, copper, zinc and cobalt was lower than 1. Additionally, the carcinogenicity index of heavy metals for both adults and children was less than 10-4. The health risk assessment of heavy metals and their risk index showed that the consumption of lettuce and cabbage in these areas can lead to various health problems in people.
Ehsan Manavipour, Akbar Eslami, Abbas Shahsavani, Ahmad Alahabadi, Reza Saeedi, Fatemeh Shokri Dariyan, Mehrnoosh Abtahi,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: In today's society, preparing healthy food has become challenging due to the variety of food production methods. Oil is produced in several ways in our country. In the cold pressing method, there is insufficient monitoring of the manufactured product. The aim of the present study is to investigate the physicochemical characteristics and the levels of heavy metals of industrial oil compared to cold-pressed oil.
Materials and Methods: In this research, 54 samples of sunflower, sesame, and canola oil produced by both cold pressing and industrial refiningmethods were prepared. Their physicochemical characteristics, including refractive index, acid value, iodine value, saponification value, peroxide value, anisidine value, as well as the concentrations of lead, iron, arsenic and copper were determined. Additionally, the effect of storage time on these characteristics was investigated.
Results: The Iodine number showed the highest deviation from the standard (61%), with an average of 136.70 gI/100g for the cold-pressed oil and 134.48 gI/100g for industrially refined oiland. The average value of the physicochemical characteristics, except for the saponification value, were higher in the cold-pressed oil samples compared to the industrially refined oil samples, but the observed difference was not statistically significant. An investigation into the effect of storage time on physicochemical properties revealed a significant increase in peroxide value (p<0.01) and anisidine (p <0.05) in both oil groups over a two-month period. The average concentration of arsenic, lead, iron and copper in the studied oils was 0.03, 0.78, 0.05 and 0.05 mg/kgoil, respectively. A deviation from the standard was observed only in one sample of cold-pressed sunflower oil, with an arsenic concentration of 0.11 mg/kgoil).
Conclusion: Based on the obtained results, the refined industrial oils exhibited more favorable chemical characteristics and stability. It is suggested that cold-pressed oils should be consumed within a short period of time. For frying purposes, refined industrial oils are preferable.
Nader Abbasi, Mohsen Mohammadi Galangash,
Volume 17, Issue 2 (9-2024)
Abstract
Background and Objective: Heavy metals are regarded as serious contaminants due to their toxicity, persistence in natural conditions, and ability to enter and accumulate (bioaccumulation and biomagnification) in food chains. The aim of this study was to investigate the concentrations of the heavy metals Pb, Cd, Cu, Zn, Cr, Fe and Ni in surface agricultural soils of the Miandoab landfill area.
Materials and Methods: In this study, 57 soil samples were collected from a depth of 0-20 cm. After preparing and digesting in the laboratory, the samples were analyzed using a inductively coupled plasma spectrometer (ICP-OES). The Ecological Risk Potential Index (EPRI), Earth Accumulation Index (Igeo), Principal Components Test (PCA) Pearson's Correlation, Cluster Analysis, and One-T-test were utilized. Statistical processing was conducted using SPSS software.
Results: According to the results of the single T-test, the average concentrations of Pb, Cd, Cu, Zn, Cr, Ni did not significantly differ from their background concentration in the soil (p≥0.05). A significant difference was pbserved only for Fe (p<0.05), indicating a geological origin for this element. The EPRI was within the low-risk range, with an average value of 46.95. PCA revealed that the first factor was positively associated with Cr, Pb and Fe; the second factor with Zn and Cu; and the third factor with Cd. Cluster analysis showed that Fe was predominantly influenced by natural resources. According to the land accumulation index, all metals, except Cu, were classified non-polluted or slightly polluted at stations 2 and 4.
Conclusion: The origin of elements is related to both natural and human factors. Specifically, Cr, Pb and Cd are more likely to originate from man-made sources, while Fe primarily comes from natural sources. The decrease in the concentration of metals can be attributed to continuous and annual ploughing, inactivity of the landfill, biological absorption by crops, soil leaching and transporting to lower depths.
Sadegh Hosseinniaee, Mohammad Jafary, Ali Tavili, Salman Zare,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: Ethylenediaminetetraacetic acid (EDTA) is known as a synthetic chelating agent used for the remediation of soils contaminated with potentially toxic elements. Marrubium cuneatum is a medicinal plant with phytoremediation capabilities. This study investigated the effect of EDTA on the morph-physiological characteristics of this species and its rhizosphere soil.
Materials and Methods: Under greenhouse conditions, M. cuneatum was grown for six months in mine-contaminated soil with different levels of EDTA (0, 1, 3, 5 mmol/kg). Subsequently, its biomass, concentration of macro- and micronutrients, and soil biochemical properties—such as organic matter content, soil enzyme activity, and microbial biomass—were measured. Additionally, a regression model was established between EDTA concentration and shoot weight to predict the plant's growth response.
Results: A concentration of 5 mmol/kg EDTA decreased the dry weight of shoots and roots by 11% and 21.9%, respectively, compared to the control. The reduction in root macronutrient content was less pronounced with EDTA application compared to that of the shoots, with the greatest decrease observed for shoot potassium (40.70% compared to the control). The potassium-to-sodium ratio also decreased significantly. Despite improvements in some soil biochemical parameters at low EDTA levels, the 5 mmol/kg dose resulted in a 30% and 10% inhibition of urease and dehydrogenase activity, respectively. The regression relationship between EDTA concentration and shoot weight indicated that the maximum dry weight was obtained at a concentration of 2.4 mmol/kg.
Conclusion: Considering the adverse effects of EDTA at concentrations of 3 mmol/kg on soil and plants, as well as the predictive model of the growth response of M. cuneatum, it is suggested to investigate EDTA levels above 2.4 mmol/kg to determine the precise dose that initiates negative effects in soil and plants.
Jawad Kadhim Noor, Atefeh Chamani, Ahmed Najm Abdallh Al-Mosawy, Narges Kargari,
Volume 17, Issue 3 (12-2024)
Abstract
Background and Objective: The pollution of trace elements in urban soil has attracted wide attention due to its detrimental environmental and health effects. Therefore, this research was conducted to evaluate of the content, pollution levels, and health risks associated with trace elements (Fe, Zn, Pb, Cd, Cu, Mn, and Mo) in the surface soil of Al-Qasim City in Babylon Governate in 2024.
Materials and Methods: This descriptive cross-sectional study involved, a total of 50 surface soil samples from a depth of 0-20 cm. The elemental content of the samples was determined using inductively coupled plasma optical spectroscopy (ICP-OES). Additionally,, the enrichment factor (EF), pollution index (PI), pollution load index (PLI), hazard index (HI), and carcinogenic risk (CR) were calculated. Statistical data analyses were done using SPSS software.
Results: The average concentrations of Fe, Zn, Cd, Cu, Mn, and Mo in the soil were 27240, 62.7, 0.302, 33.8, 570 and 0.999 mg/kg, respectively. The highest average concentrations of Fe (30,331 mg/kg), Cu (37.3 mg/kg), Mn (639 mg/kg), and Mo (1.08 mg/kg) were found in downtown areasm whilefor the highest concentrations of Zn (65.3 mg/kg) and Cd (0.332 mg/kg) were observed in rural and midtown areas.
Conclusion: The results of this research demonstrate the impact of urban activities—such astraffic, industry, and agriculture—on the trace element pollution in the soil of Al-Qasim City. Therefore, regular monitoring of trace element concentrations and identification of their pollution sources are recommended to reduce and manage associated environmental and health risks.
