Showing 12 results for Soil Pollution
Afsaneh Alinezhadian, Ahmad Karimi, Jahangard Mohammadi, Farzaneh Nikookhah, Mathias Niuman. Anderson,
Volume 6, Issue 3 (12-2013)
Abstract
Background and Objectives: In arid and semi-arid regions, wastewater reuse has become an important element in agriculture. However, irrigation with this resource can be either beneficial or harmful, depending on the wastewater characteristics. The aim of this research was to investigate the soil bacterial and crops quality irrigated with treated wastewater.
Material and Methods: This research was conducted on a maize field near the wastewater treatment plant in Shahr-e-kord in summer,2011. Plots were arranged in a randomized complete block design in 3 replications and 2 treatments, well water (W1) with fertilizer and effluent (W2).
Results: At the end of growth season, soil samples were collected from depth of 0-5 and 5-15 cm and plant samples consisting of old and new leaves and seeds were collected for bacteriological analysis. According to bacteriological analysis, total number of positive lactose bacteria, total and fecal coliforms in depth of 0-5 cm was 42% more than depth of 5-15 cm. In the case of old leaves, total number of coliform and fecal coliform was 88 and 40 MPN/100 mL respectively. Moreover, for new leaves, it was 38 and 2 MPN/100 ml respectively.
Conclusion: According the results, number of indicator bacteria in soil is decreased (about 35%) by passing time.
S. Jorfi, A. Rezaee, N. Jaafarzadeh Haghighifard, G.a Moheb-Ali,
Volume 7, Issue 3 (5-2014)
Abstract
Background and objectives: Because of problems dealing with bioremediation including being time consuming, low efficiency and toxicity to biota, application of advanced oxidation processes with higher efficiency and shorter remediation time have been considered for removal of hydrophobic hydrocarbons from contaminated soils. A great interest has been directed to Fenton oxidation because of its simplicity and high oxidation potential. The objective of this study was to determine the Fenton-like oxidation efficiency for pyrene removal from soil using iron nano oxides and Fe2+. Material and Methods: The H2O2/Fe molar ratios of unadjusted with native Fe content of soil, 10, and 20 H2O2 concentrations of 0 – 500 mM pH 3, 5, and 7 and soil samples containing Fe2+, native iron and iron nano oxides were investigated for removal of 100 mg/kg pyrene according to Taguchi experimental design. Results: Fe2+, H2O2/Fe molar ratio of 20, pH 3 and H2O2 concentration of 500 mM were determined as optimum conditions. Under optimum conditions, S/N ratio increased to 39.322 and the pyrne removal reached to 86 % for Fe2+ and 83 % for Fe3+ respectively, after 2 hours of reaction time and pH 3. Conclusion: Fenton oxidation using iron nano oxides under defined optimum conditions and neutral pH, can be a suitable alternative to conventional Fenton for remediation of soils contaminated with pyrene.
L Tabande, M Taheri,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: The contamination of soils and plants with heavy metals is a serious and growing problem. The present study aimed to determine the concentration of heavy metals in soil and some agricultural products and the probability of risks due to their consumption.
Materials and Methods: This cross-sectional descriptive study was performed using random sampling at harvest time in 2014 on 205 samples of vegetable crops (Leek, chard, parsley, watermelon, melon, tomatoes, cucumber, potatoes, onion, garlic, radish, green peas, and broad bean) and 129 samples of soils under cultivation. Concentrations of Cu, Zn, Cd, and Pb in soil and plant samples were determined by an atomic absorption instrument and the data was analyzed using SPSS software.
Results: There were significant differences between the mean concentrations of Pb, Cu, and Zn for different vegetables (P<0.001), but no significant difference was observed for Cd. The highest mean levels of Pb, Cd, Cu, and Zn were detected in parsley, chard, broad bean, and leek respectively. However, there was no heavy metal pollution in the remainder of the vegetables and soil samples (with the exception of agricultural soils adjacent to the lead mine of Mahneshan area) studied. Hazard probability (HQ) of each element for cancerous diseases was less than unit and the intake of heavy metals was lower than the Provisional Tolerable Daily Intake (PTDI).
Conclusion: The results of this study indicated that major accumulation of heavy metals was obtained in leafy vegetables. Therefore, much attention should be paid to consumption of leafy vegetables, especially vegetables grown in the surrounding industrial areas.
Ah Baghaie,
Volume 11, Issue 2 (9-2018)
Abstract
Background and Objective: Today, landfill management of municipal waste and soil pollution with heavy metals are major environmental problems. This research was conducted to evaluate the effect of Shazand municipal waste compost and Saveh pomegranate peel biochar on decreasing Pb availability in soil and sorghum plant.
Materials and Methods: Treatments consisted of applying Shazand municipal waste compost (0, 10 and 20 ton/ha) and Saveh pomegranate peel biochar (0 and 15 g/kg) in a Pb polluted soil (0, 600, 800 and 1000 mg Pb/kg soil). After 8 weeks of sorghum planting (Kimya CV.), the soil physio-chemical properties and soil and plant Pb concentration were measured.
Results: Applying 20 ton/ha municipal waste compost with 15 g/kg biochar increased soil pH by 0.4 units and decreased soil Pb availability by 11%. The similar results were observed for the root and shoot Pb concentrations, when the same amount of manure in a Pb polluted soil was applied (1000mg Pb/kg soil) that decreased the root and shoot Pb concentration by 1.8 and 2.2 times, respectively.
Conclusion: The result of this experiment showed that applying Shazand municipal waste compost and biochar can increase soil sorption properties and decrease soil or plant Pb concentration. However, the role of these organic amendments on supplying plant nutritional needs cannot be ignored.
Bahareh Ghoreishi, Hassan Aslani, Mohammad Shaker Khatibi, Sepideh Nemati Mansur, Mohammad Mosaferi,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Application of sewage sludge contaminated with heavy metals may cause health and ecological concern. Ecological risk and heavy metals content of sewage sludge from wastewater treatment plants of East Azerbaijan province were evaluated in the present study.
Materials and Methods: Nine composite samples were taken and analyzed for heavy metals. The geo-accumulation index (Igeo), contamination factor(CF) , and potential ecological risk index were calculated.
Results: Variation of the heavy metals concentrations were in the following order: Zn>Cu>Pb>Cr>Ni>As>Hg>Cd. The contents of some heavy metals were several order of magnitude higher than the crustal average (CA) values. Considering the Maximum Permissible Standards (MPS) and the Muller's index, the Cd, Cu, and Zn pollution were found to be in the moderate range, whereas As and Pb were in strongly polluted category; and Hg was in extremely polluted category. Considering MPS, the single-factor pollution index (PI) and the Nemerow’s synthetic pollution index (PN) were lower than 1 and 0.7 respectively. This indicated that the sludges were unpolluted with most heavy metals and could be safely applied for agricultural uses. However, a high potential ecological risk for As and Cd; very high risk for Pb; and extremely high risk for Hg were calculated when considering the CA values. There were significant differences between the levels of heavy metals and MPS (p <0.05).
Conclusion: Although the metal concentrations were below the MPS according to the US EPA regulations, sludge samples showed a high degree of potential ecological risk for the environment in comparision with the CA values,. Periodic monitoring of sludge quality are strongly recommended.
Mohsen Mohammadi Galangash, Rezvan Ghasemi Zolpirani, Mohammad Naimi Joubani,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: Contamination of roadside soils with heavy metals is a serious threat to soil ecosystems and organisms and human health. Therefore, the purpose of this study was to determine the concentration of heavy metals in the roadside soils of the Rasht-Qazvin old road.
Materials and Methods: 10 out-of-town sampling sites were selected via the field observation of the entire area. surface soil sampling with three replicates was performed around the Rasht-Qazvin old road. Heavy metals concentrations were measured using ICP-OES following samples preparation and acid digestion. The pollution level of heavy metals was assessed using geoaccumulation index (Igeo) and potential ecological risk index (PERI).
Results: The results showed that the average concentrations of Zn, Cu, Ni and Pb in the roadside soils were 58.07, 19.96, 20.26 and 23.21 mg/kg, respectively. The findings showed that concentration of Zn and Ni were higher than background values and the amount of Zn exceeded WHO standard limit. The potential ecological risk index (PERI) with an average value of 86.24, indicated low level of pollution for all of the studied metals. The results of geoaccumulation index (Igeo) revealed moderately contamination level of Ni.
Conclusion: Old roads are generally known as one of the sources of pollution for the surrounding lands. Although the concentration of pollutants around the road is expected to be very high, we did not detect elevated levels of heavy metals. This fact can be explained by the current road repairs and widening, agricultural activities on marginal lands and wind blows in mountainous regions which leads to the dispersion of the soil pollutants.
Shahla Karimian, Sakine Shekoohiyan, Gholamreza Moussavi,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Landfills as municipal solid waste are considered as the source of pollution. The present study aimed to assess the ecological risk of heavy metals in Tehran landfill soil and the adjacent residential area.
Materials and Methods: Having consulted with the specialists and considered the waste processing facilities, 12 sampling points were selected and sampled in four seasons. Soil samples were digested using HNO3: HClO4: HCl: HF. The levels of metals were measured using ICP-OES which further applied for the calculation of ecological risk. Kolmogorov-Smirnov, Kruskal-Wallis, and Pearson correlation coefficient analyses were run to determine the significant differences between metals concentrations in various seasons and sampling points.
Results: Metal concentration showed to follow theorder: Al > Fe > Mn > Zn > Cr > Pb > Cu >Ni > Co > As > Cd. Kruskal-Wallis results and pairwise comparison showed a statistically significant difference between metal concentrations across sampling points and seasons, especially in rainy seasons. Pearson correlation coefficient displayed a strong relationship between the mean concentrations of Cu - Pb, Cu - Zn, and Pb - Zn with obtained values of 0.932, 0.874, and 0.883, respectively. Cu exhibited the highest contamination factor at the compost and fermentation sites (13.2 and 9.89, respectively). The geo-accumulation index proved the anthropogenic sources of pollution. The potential ecological risk index (ERI) for the sampling sites ranged from 67.3 to 154, with the order of Cd > Cu > Pb > Ni > As > Cr > Zn > Co > Mn.
Conclusion: Due to the obtained moderate to severe ecological risk and exceeded background concentrations of heavy metals, it can be concluded that metal changes and soil pollution are both affected by landfill activities.
Mohamad Mehdi Ghorbaninejad Fard Shirazi, Sakine Shekoohiyan, Gholamreza Moussavi, Mohsen Heidari,
Volume 15, Issue 1 (4-2022)
Abstract
Background and Objective: Among the emerging contaminants, microplastics threaten public health. This study aimed to determine microplastic and mesoplastics in soil of residential areas adjacent to Tehran Landfill and assess its ecological risk.
Materials and Methods: The present descriptive cross-sectional study was conducted on 20 shallow and deep soil samples from residential areas near the Tehran landfill in July 2021. The microplastics were floated in NaCl and ZnCl2 solutions, and the mesoplastics were separated manually. The identification of physical and chemical properties of polymers was performed by stereomicroscope and FTIR analysis, respectively.
Results: The average amount of micro-plastics in shallow and deep soils estimated 76±34.98 and 24.7±19.79 particles/kgsoil, respectively. The average amount of mesoplastics obtained 5.25±2.91 and 3.55±1.09 particles/kgsoil, in shallow and deep soils, respectively. Paired-samples T-test showed significant differences between shallow and deep soil in terms of plastic particles (p<0.001). The most abundant microplastic particles were the fragment-shaped with the particle size of 0.1-0.5 mm and LDPE polymer types with the percentage of 37.75, 44.64, and 46.15, respectively. Mesoplastic particles, the 0.5-1 cm film-shaped particles and LDPE polymer types with the percentage of 62.76, 61.46, and 50.7 were found as the most prevalent. Microplastics and mesoplastics' potential ecological risks value in all sampling points was less than 150, indicating low ecological risk.
Conclusion: Despite the low PERI of microplastics and soil mesoplastics in residential areas, the Eri index for LDPE was high. Thus, Ecological risk is probable if control measures are not taken against plastic pollution.
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.
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.
