Showing 51 results for Metals
M. Amini, A. Forghani,
Volume 19, Issue 71 (6-2015)
Abstract
Any change in the characteristics of air, soil, water and food that adversely affect the health of the ecosystem, activities of human and other organismsis called contamination. Heavy metal uptake by plants depends on the type and concentration of metalin soil, its bioavailability, and plant species. The use of new sciences such as geostatistics is useful for fast and simple determination of soil and leaf contamination risk. This study studied the amount of soil and leaves of Platanus orientalis contamination in order to map the lead (Pb) and cadmium (Cd) concentration in Rasht city using a geostatistic method. To achieve the goal, 126 samples of surface soil (0-30 cm) and 76 leaf samples (Platanus orientalis) were collected from city streets. Total concentrations of lead and cadmium in the soils and leaves were determined, and clay, silt and sand particle percentage, organic matters, and soil pH were measured. Average concentrations of elements in terms of mg/kg were as follows: soil’s Lead: 86.62, soil’s Cadmium: 0.6, leaf’s Lead: 8.99. For soil Pb and Cd and leaf Pb, spherical model yielded a better fit in the experimental variogram in GS+ program by using trial and error method. According to the spatial structure, Kriging and IDW estimators were used for interpolation. Kriging estimation was mapped using Arc GIS 9.2 software.
M. R. Asgharipour, B. Rahmanian Koshki,
Volume 19, Issue 71 (6-2015)
Abstract
The aim of this study was to evaluate phytoavailability of cadmium to lentils after the application of composted animal manures. In a greenhouse experiment, two lentil (Lens culinaris) cultivars were grown in the soils applied with different levels of Cd from animal manure compost, and compared with Cd applied as cadmium chloride or their combination. Phytotoxicity of Cd was determined as plant growth, Cd accumulation, and the uptake of macronutrients. Addition of Cd significantly reduced plant growth and plant weight as well as plant water content. Phytotoxicity of Cd applied through manure composts was significantly less than the same rate of Cd amended with soluble CdCl2, suggesting the lower potential hazard of composted manure-applied Cd. Plants accumulated substantial amount of Cd in different plant parts. Most of the Cd taken up was retained in roots, and lentil roots had higher concentrations of Cd than the stem. Phytotoxicity of applied Cd in Ziba was significantly greater than that in Zabol cultivar. Cadmium addition especially as metal salt reduced nutrient concentrations in the shoot, and caused more nutrient accumulation in roots, probably due to the inhibition of their translocation to plant shoots. The results of this experiment point to the fact that the Cd source and loading rate are important factors in evaluation of Cd phytoavailability.
P. Ahmadpour, M. Soleimani,
Volume 19, Issue 73 (11-2015)
Abstract
Cadmium (Cd) is a metal with high toxicity and solubility in water, which is a serious environmental threat to human health. Phytoremediation is an environment-friendly method and a promising new and cost effective technology that uses plants to clean organic and inorganic contaminated media. This study was conducted to evaluate the potential of Jatropha curcas for remediation of soils contaminated with Cd. Seedlings were planted in the soil spiked with Cd in amounts of 0, 25, 50, 75, 100 and 150 mg kg-1 (Cd0, Cd25, Cd50, Cd75, Cd100 and Cd150) for a period of five months. Biocentration factor (BCF, metal concentration ratio of plant roots to soil), translocation factor (TF, metal concentration ratio of plant shoots to soil) and removal efficiency (RE, total metal removed by plant biomass to total metal loaded in soil) were determined. Cd concentrations among plant parts were in the following trend: roots>stems>leaves. The highest total Cd concentration (up to 1100 mg kg-1) and the highest RE were found in Cd150 and Cd25, respectively. BCF and TF of the plant were more and less than 1, respectively. Hence, although this species has a potential to be used in phytostabilization of Cd-contaminated soil, more researches in the field condition are needed.
S. Molaei, H. Shirani, M. Hamidpour, H. Shekofteh , A. A. Besalatpour,
Volume 19, Issue 74 (1-2016)
Abstract
This experiment was conducted to evaluate the effect of vermicompost, pistachio kernel and shrimp shell on the immobilization and availability of Cd, Pb and Zn in corn in polluted soils. Treatments consisted of two levels of pistachio kernel, shrimp shell and vermicompost (5 and 10 % w/w). In control treatment, no amendment was added to the soil. The experiment was carried out as a completely randomized design with 3 replications. Plants grew for two months in the greenhouse. Then, all the plants were harvested and their shoots and roots were separated, washed with distilled water and oven dried at 65 °C to a constant mass. The measured characteristics were dry weight of shoots and roots, leaf area, greenness index, chlorophyll fluorescence, maximal quantum yield of PS photochemistry (Fv/Fm), performance index (PI), and total concentrations of Cd , Pb and Zn in shoots and roots. Results showed that plant growth parameters (dry weight of shoots and roots, leaf area) and photosynthetic characteristics (chlorophyll fluorescence, Fv/Fm, and PI) were higher in plants grown in vermicompost and pistachio kernel treatments as compared to those grown in control. Plants died in shrimp shell treatment after two weeks. The concentration of Cd, Zn and Pb in shoots and roots of plants grown in vermicompost and pistachio kernel treatments were lower than those grown in control.
Sh. Ahmadi Doabi, M. Afyuni, H. Khademi, M. Karami,
Volume 20, Issue 76 (8-2016)
Abstract
Heavy metals in dust can directly enter to the human body through ingestion and inhalation. They can pollute the water and soil resources via atmospheric precipitation and accumulate in the plant tissues and then enter human body through water and food. This research aimed to study the heavy metals concentration in dust in Kermanshah province and to identify their sources. 49 samples of dust were collected in the cities of Kermanshah, Songhor, Gilangharb, Ghasre-Shirin, Sahneh, Sarpolzahab, Kangavar, Paveh and Javanrood during the spring 2013. The concentration of Zn, Cu, Ni, Cr, Mn and Fe were determined using an atomic absorption spectrometer following the sample extraction with a mixture of HCL and HNO3 (3:1 ratio). The average concentrations of Zn, Cu, Ni, Cr, Mn and Fe were 182.3, 48.6, 115.3, 73.9, 428.1 and 23161 mg kg-1, respectively. Correlation, cluster and principal component analyses were used to identify probable natural and anthropogenic sources of contaminants, and the enrichment factor was used to identify probable effects of human activity on the concentration of heavy metals. The results indicated that metal concentrations, except for Fe and Mn, were higher in comparison with the world soils. Zn, Cu, Ni and Cr are mainly of anthropogenic origin, while Fe and Mn are mainly of natural origin. Zn and Cu are mainly of traffic sources and partly of industrial sources, and Ni and Cr are mainly derived from industrial sources, combustion processes, combined with traffic sources. The analysis of EF revealed moderate enrichment for Mn and Cr, and significant enrichment for Zn, Cu and Ni. Based on the results of this study, more attention should be paid to identifying and controlling the sources of contaminants such as heavy metals in dust in order to prevent their associated pollution.
K. Asgari, S. H. Tabatabaei, P. Najafi, Sh. Kiani,
Volume 20, Issue 78 (1-2017)
Abstract
Constant use of treated wastewater (TWW) for irrigation over long periods may cause buildup of heavy metals up to toxic levels for plants, animals, and entails environmental hazards in different aspects. The aim of this study was to assess the effect of using a deep emitter installation on lowering the potential heavy metal accumulation in soil and wheat grain, and health risk under drip irrigation with treated municipal wastewater. A field experiment was conducted according to a split block design with two treatments (fresh and wastewater) and three sub treatments (0, 15 and 30 cm depth of emitters) in four replicates in Esfahan, Iran. Soil samples were collected before planting (initial value) and after harvesting (final value) in each year. Elemental concentrations (Cu, Zn, Cd, Pb, Cr, and Ni) in soil and grain were determined using an atomic absorption spectrophotometer. A pollution load index (PLI) showed that there was not substantial buildup of heavy metals in the wastewater-irrigated soils compared to the freshwater-irrigated soils. Cu, Pb, Cr and Zn concentrations in wheat grain were within permissible EPA limits, but concentrations of Cr was above the safe limits of EPA. In addition, concentrations of Ni in wheat grain were several folds higher than EPA standards. A health risk index (HRI) which is usually adopted to assess the health risk to hazard materials in foods showed values higher than 1 for Cd and Cu, whereas children might also be exposed to health risk of Cd, Cu and Cr. Based on aforementioned results, it can be concluded that the depth of emitter in drip irrigation does not play a significant role in the accumulation of heavy metals from TWW in our sandy loam soil.
M. Tayebi, M. Naderi, J. Mohammadi,
Volume 21, Issue 3 (11-2017)
Abstract
The aim of this work was to study distribution of some heavy metals in different soil particle-size fractions and to assess their spatial distribution. The study was carried out in Kafe Moor (Kerman, Iran) where the Gol-Gohar Iron Mine is located. One hundred twenty composite soil samples were randomly collected and transferred to the laboratory in bags. After air-drying, the samples were fractionated into six classes including 2- 0.5, 0.5-0.25, 0.25-0.125, 0.125- 0.075, 0.075-0.05 and <0.05 mm. Elemental concentrations (Fe, Mn, Cu, Zn, Pb and Ni) were determined using acid digestion method (HNO3, 4.0 N) and an atomic absorption spectrophotometer in each class. Ordinary Kriging technique was used for predicting spatial distribution of heavy metals. The results showed that content of metals in soil increased with decreasing particle size. The results also showed that the concentration of Fe, Mn, Cu, Zn, Pb and Ni in <0.05 mm size fraction were 2.13, 1.70, 4.79,2.43, 1.42, and 3.47 times higher than in 2-0.05 mm size fraction, respectively. In addition, mapping the concentrations of heavy metals with kiriging showed that metals pollution decreased with increasing distance from mines area.
R. Samiei Fard, H. Matinfar,
Volume 21, Issue 4 (2-2018)
Abstract
Reflectance spectroscopy is a fast and safe method to predict soil physicochemical and biological properties in low cost ways. Traditional methods to determine soil properties require spending a lot of time and money so that farmers are generally reluctant to use the results of laboratory measurements in soil and water management. Reflectance spectroscopy in the spectral range of 400-2500 nm (VNIR) is an alternative method for estimating the soil properties. The aim of this study was to evaluate the results of laboratory spectrometer to estimate the concentration of Lead (Pb) and Nickel (Ni) in soils irrigated with water from treatment of urban sewage sludge of Rey city and finally to compare these results with the results of measurements of atomic absorption spectrometry. In this study, the Partial Linear Square Regression (PLSR) model was used to estimate the concentration of heavy metals and Residual Mean Square Error (RMSE) was used to evaluate the performance of this model. In this research, after spectral corrections related to elimination of the water absorption bands as well as elimination of the inefficient spectrum from heavy metals estimations, the methods of estimating these elements were studied through mathematical derivation of spectral values and also the acquisition of the continuum removal spectra. The results show that the estimated values from first derivate spectra are more consistent with the results of atomic absorption spectrometers.
F. Masoudi, M. Shirvani,
Volume 21, Issue 4 (2-2018)
Abstract
Water and soil pollution with heavy metals has become a worldwide environmental issue. Therefore, development of efficient and low-cost methods for removal of metals from water or metal stabilization in soil has been identified as priority research areas. Biochar, produced from plant biomass and agricultural wastes, has recently been used to remove heavy metals from aqueous solutions as an effective sorbent. In this study, biochars were made from pyrolysis of palm tree residues at different temperatures of 200, 400 and 600 °C. The prepared biochars were then used to remove Ni from aqueous solutions in batch systems without pH adjustment and with pH adjustment at 7. To investigate Ni sorption rate, kinetic experiments were also carried out at a Ni concentration of 10 mg/L. The results of kinetic tests showed that the biochar prepared at 600 °C had more Ni sorption rate with equilibration time of about 5 h. Power function and Elovich models were the best equations fitted the kinetic data. Langmuir and Freundlich isotherms described sorption of Ni on the sorbents very well. According to the Langmuir model predictions, the biochar produced at 600 °C and the palm raw residues had highest and the lowest capacity to sorb Ni from the solution, respectively, and the biochars produced at 200°C and 400°C were intermediate in this respect. Both the capacity and affinity of the biochars for Ni sorption increased with pH. Overall, under the experimental conditions applied in this study, the biochar prepared at 600 °C showed the highest efficiency for Ni removal from aqueous solution.
Z. Bigdeli, A. Golchin, T. Mansouri,
Volume 21, Issue 4 (2-2018)
Abstract
To assess the effects of different levels of soil lead on mineralization of organic carbon and nitrogen, a factorial pot experiment was conducted using litter bag method. The factors examined were different levels of soil lead (0, 25, 50, 100, and 200 mg kg-1soil) and incubation periods (1, 2, 3 and 4 months) in three replications. At the end of incubation periods, the litter bags were pulled out of the pots and the weights of plant residues remained in bags were measured. The plant residues were also analyzed for organic carbon and nitrogen. Organic carbon and nitrogen losses were calculated by subtracting the remaining amounts of organic carbon and nitrogen in one incubation time interval from those of former one later incubation time interval. The results showed that the losses of organic carbon from wheat residues and carbon decomposition rate constant decreased as the levels of soil lead increased over than 25 and 50 mg/kg of soil respectively. The losses of organic nitrogen was more affected by lead pollution and decreased as the levels of soil lead increased, but nitrogen decomposition rate constant decreased as the levels of soil lead increased over than 25 mg/kg. The losses of organic carbon and nitrogen in 200 mg Pb/ kg of soil were 3.2 and 11.7 % lower than control treatment. The results of this research indicate that contamination of soil by lead increases residence time of organic carbon and nitrogen in soils and slows down the cycling of these elements.
M. Karamooz, M. Hamidpour,
Volume 22, Issue 1 (6-2018)
Abstract
Siderophores are low molecular weight iron-binding ligands produced by aerobic soil microorganisms and some plants roots. They may also develop complexes with other metals such as Cd, thereby influencing the bio-availability, toxicity and mobility of Cd in the soils and aqueous environments. The main objective of this study was to investigate the effects of desferal siderophore (DFOB) on the adsorption of Cd on muscovite. The adsorption of Cd on muscovite was studied as a function of pH (Cd concentration: 5.0 mg L-1) in the range of 3.0-8.0, as a function of metal concentration (Cd concentration in the range of 1.5-10.0 mg L-1); this was done in the absence and presence of siderophore (DFOB concentration 250 μM) using a 24h batch equilibration experiment. The results of pH dependent experiments showed that the siderophore deceased the adsorption of Cd onto muscovite at pH ≥5. The results of the isotherms experiments also showed that the removal of Cd from solution was affected by siderophore in all equilibrium concentrations of Cd at both pHs. Siderophore decreased the adsorption of Cd by the mineral. The Freundlich and Langmuir isotherms described the equilibrium data satisfactorily. The values of Freundlich (KF) and Langmuir (KL) bonding constants were greater in the suspensions without siderophore, as compared to those containing siderophore, thereby indicating the low adsorption affinity of Cd on muscovite in the presence of the siderophore.
Z. Sorkheh, B. Khalili Moghaddam,
Volume 22, Issue 1 (6-2018)
Abstract
The purpose of this research was to study the effects kerosene by a factorial experiment in the nested design in three replications. The factors included region (Shush, Dezful and Bavi), plant (parsley, dill, coriander and carrot), and management practice (control, contaminated field with kerosene 1, contaminated field with kerosene 2). Heavy metals concentration (Pb, Zn, Cu and Cd) was measured in soil (DTPA extraction method) and plants samples. The results indicated that the average values of the heavy metals concentration in both soil and plants samples subjected to kerosene contaminated treatments were greater than those of the control treatment in all of the regions. The Bavi region had the highest Cd (14.29 in soil; 11.9 in Dill) and Pb (40.46 in soil; 35.53 in Coriander) and the lowest Zn (34.75 in soil ; 28.44 in Carrot) and Cu(22.30 in soil; 16.96 in Carrot) concentration values in both soil and plants subjected to kerosene contaminated treatments. Also, the lowest concentration values of Cd (9.33 in soil; 8.01 in Carrot) and Pb (30.36 in soil; 23.54 in Carrot) and the highest values of Zn (109.08 in soil; 86.33 in Dill) and Cu (47.71 in soil; 38.57 in Dill) were recorded in Shush and Dezful regions, respectively. Based on these findings, kerosene usage could lead to a significant increase in the heavy metals (Cd, Cu and Pb) uptake, exceeding the critical level for the vegetables. This might increase the transformation risk of the mentioned heavy metals in the food chain
K. Kakaei, A. Riyahi Bakhtiari,
Volume 22, Issue 1 (6-2018)
Abstract
Landfill sites are one of the most important sources of contaminant entry to the environment. In this research, the concentrations of Cu, Pb, Ni, Cd, and organic compound BPA in Hamadan landfill were evaluated to determine the status of its burial environment in 2014. Seven water samples (2 samples from spring and 5 samples from well), 2 leachate samples and 15 soil samples were collected from Hamadan landfill. Evaluation of the concentrations of Cu, Pb, Ni, Cd and the organic compound BPA was done by atomic absorption and gas chromatography with mass spectrometry. The concentrations of metals (Cu, Pb, Ni and Cd) in water samples (wells and springs) Pb <Cu <Cd <Ni, the leachate samples Cu <Pb <Ni <Cd and finally, the soil samples Cd <Cu <Pb <Ni, were obtained, respectively. Water samples (wells and springs), only in a 7W handheld water well sample (the nearest to the buried well) related to BPA 22.35 (μg /l) composition, waste leachate samples for the concentrations of BPA, 103.3 (μg /l), and soil samples for the combined concentration of BPA 5.52 (ng /g) were obtained. High concentrations of Ni, Pd and Cd and high concentrations of BPA in the samples of leachate composition, soil samples of landfill, and the 7W handheld water well samples were due to the high volume of electronic waste and plastic waste.
F. Saberinasab, S. Mortazavi,
Volume 22, Issue 1 (6-2018)
Abstract
Today, the growth of population, the excessive growth of cities and subsequently, the industries development in all parts of the planet are evident. Such development leads to the entrance of chemical martials with various compounds, particularly heavy metals, in aquatic ecosystems. In this study, the contamination of the sediments around the Mighan wetland basin with heavy metals such as lead, zinc, copper and nickel was investigated using CF indexes (contamination factor), IGeo geo-accumulation indexes, and IPOLL sediment contamination severity. The results indicated a high concentration of copper and nickel metals, in comparison to zinc and lead metals, in the studied area. Also, regarding the location of sampling stations and their proximity of the industries around the wetland, the comparison of the results related to the measured metal concentration and the sediment quality indices, indicated a high concentration of the pollutants under examination in the southern part of the wetland, thereby emphasizing the need to control the pollutants in the wetland.
S. P. Mousavi, M. A. Asghar Mokhtari, Y. Khosravi, A. Rafiee, R. Hoseinzade,
Volume 22, Issue 2 (9-2018)
Abstract
In this study, the distribution of heavy metals pollution including arsenic, antimony, nickel, copper, cadmium, cobalt, bismuth, lead and zinc in the stream sediments of Zarshuran- Aghdarreh area was investigated by using statistical techniques and the geometric integration of each sample basin. For this purpose, the degree of pollution in 154 stream sediment samples was analyzed and the distribution maps for enrichment factors were prepared by using a combination technique, pixel estimation, and statistical and geostatistical methods. The results of calculating the enrichment factors indicated that the higher enrichment was related to arsenic, antimony, bismuth, cadmium and lead. Furthermore, the concentration of zinc, copper, lead, arsenic, antimony, cadmium and bismuth in the stream sediment samples was higher than the global average. Application of the principal component analysis on the data led to the recognition of 9 main components for the dataset; the first 5 were components with eigen values greater than 1 and a cumulative percentage more than 85%. Arsenic, antimony, cadmium, lead and zinc in the first component, cobalt in the second component, bismuth in the third component, copper in the fourth component and nickel in the fifth component had the highest values.
N. Zough, M. Shirvani,
Volume 22, Issue 4 (3-2019)
Abstract
Alginate biopolymer, due to possessing a high capacity and affinity for heavy metals, is a suitable material for the removal of metals from polluted waters; however, the weak structural consistency of alginate hydogels limits the practical application of this natural polymer in water purification practices. In this study, sepiolite clay mineral was used as a solidifier of alginate hydrogel to produce hybrid materials with different clay:alginate ratios (1:2, 1:4 and 1:8). Subsequently, the sorption of Pb by the prepared hybrid materials was studied in different Pb concentrations (25 to
2000 mg/L) and temperatures (15, 25, 35 and 45 °C). The results showed that the Langmuir and freundlich equations could significantly describe Pb sorption data on the sorbents. Based on the Langmuir model estimation, alginate showed and sepiolite showed the highest and lowest capacities for Pb sorption, respectively; also, the hybrids were intermediates in this respect. The capacity and affinity of all sorbents were enhanced with increasing the temperature from 15 to 45 °C. Standard enthalpy changes (ΔH°) were found to be positive, confirming that the process of Pb sorption on the sorbents was endothermic. Positive values were also obtained for the standard entropy changes (ΔS°), suggesting increased randomness at the solid-solution interface during the sorption of Pb ions on the sorbents. The values of the standard free energy change (ΔG°) were negative for all different temperatures, thereby indicating that sorption on the sorbents was spontaneous and favorable. Overall, it could be concluded that modification of alginate with sepiolite might cause the decreased sorption capacity of alginate; however, the hybrid materials are good candidates for the Pb removal from aqueous solutions because of their high sorption capacities.
Miss M. Halil, N. Ghanavati, A. Nazarpour,
Volume 23, Issue 1 (6-2019)
Abstract
High concentrations of heavy metals in street dust are considered to be a serious risk to the human health and the environment. In this study, 30 dust samples were collected from the pavements in the main streets of Abadan to determine the level of pollution of heavy metals in the street dust. Heavy metal concentrations were analyzed by inductively coupled spectroscopy (ICP-OES) method. The level of heavy metals pollution was estimated based on enrichment factor, pollution index and Nemro Integrated Pollution Index. The average concentrations of heavy metals such as Pb, Zn, Cu, Cr, Cd, Ni, V, As and Co were 59.13, 287.50, 112.97, 50.03, 0.52, 56.77, 35.83, 7.10 and 7.53 mg/kg, respectively. Based on the average enrichment factor (EF), Ni, Cu and Pb had high levels of contamination and Zn contamination was high. According to the mean of pollution index (PI), heavy metals of Zn and Pb had a high contamination. According to the Nemro Integrated Pollution Index (NIPI), 96.66% of the samples had a high degree of contamination. The spatial distribution pattern of the heavy metals concentration showed that in the areas with high population densities, high traffic volumes and urban shopping centers, heavy metal pollution was severe.
H. Aalipour, A. Nikbakht, N. Etemadi, M. Soleimani, F. Rejali,
Volume 23, Issue 2 (9-2019)
Abstract
Trees decline is a complex physiological disease that results from the interactions between several factors, one of which is heavy metal stress that ultimately leads to the death of trees. This experiment, which was conducted during 2016-2017 at the campus facility of the Department of Horticulture at Isfahan University of Technology, was conducted to investigate the effects of inoculation with arbuscular mycorrhizal fungi (AMF) (Rhizophagus intraradices and Funneliformis mosseae inoculated, and the combination of both species) and plant growth promoting rhizobacteria (PGPR), Pseudomonas Flourescens, on the growth responses of Arizona cypress (Cupressus arizonica G) to different concentrations of cadmium (0, 5, 10, 15, 20); this was done as a factorial experiment based on a completely randomized design, with three replications. The interactions between AMF, PGPR, and cadmium on potassium and iron concentration, height, and dry weight of Arizona cypress seedlings were significant. By increasing the concentration of cadmium in most of the treatments, the colonization, phosphorus, potassium and iron concentrations, height and dry weight of the shoot Arizona cypress seedlings were decreased, while the percentage of electrolyte leakage and proline content were increased. The AMF-inoculated plants increased phosphorus, potassium and iron concentrations, Height, shoot dry weight, proline content and reduced electrolyte leakage percentage, as compared to non-mycorrhizal (control) plants. In plants inoculated with both microorganism (mycorrhizal fungi and Pseudomonas), there was a positive effect regarding the concentration of nutrients such as potassium and iron; there was also the improvement of growth characteristics such as height and dry weight of the seedlings, as well as the appearance and freshness of the plant. The results, therefore, showed that inoculation of Arizona cypress seedlings with the combination of mycorrhizal fungi and Pseudomonas fluorescens bacteria could have a positive effect on the growth and survival of this tree under Cadmium stress condition.
B. Atashpaz, S. Rezapour,
Volume 23, Issue 2 (9-2019)
Abstract
The present study was conducted to evaluate the ecological risk indices of Zn, Cu, Cd, Pb and Ni in the soils from Urmia region (Ghahramanloo village), as irrigated with treated wastewater. Accordingly, six different soil sites (five soil sites under wastewater irrigation and one soil site under well water irrigation as the control) were selected and sampled (AP horizon, 0-30 cm depth). Soil samples were air dried, passed through a 2-mm sieve, and analysed to determine the chemical properties and the studied heavy metals. The results showed that irrigation with the treated wastewater significantly increased the total elements in the order of Cd (228%)> Zn (118.5%)> Ni (81.5%)> Pb (54.2%)> Cu (23.5%). Nevertheless, with the exception of cadmium, other elements were within the admissible range based on the national and international standards. Ecological risk index (min = 125, max = 152, mean = 140) showed a considerable risk in all studied soils and Cd could be regarded as the major metal affecting the index yield.
F. Sadeghdoust, N. Ghanavati, A. Nazarpour, Dr Timoor Babaenejad, M. J. Watts,
Volume 23, Issue 3 (12-2019)
Abstract
Heavy metals in street dust, as one of the most important environmental consequences of human activities, have attracted many researchers' attention in recent years due to their toxicity and sustainability. Therefore, this study aimed to investigate the hazard of heavy metals (lead, zinc, copper, chrome, cadmium, nickel, vanadium, arsenic and cobalt) on human health in street dust in Dezful. To this end, 30 dust samples collected from sidewalks of main streets of Dezful were analyzed by Atomic Absorption (AAS). The level of heavy metals pollution was estimated based on the pollution index and Nemro Integrated Pollution Index. Moreover, the spatial pattern of the concentrations of metals in street dust was prepared in GIS. The average concentrations of heavy metals in Pb, Zn, Cu, Cr, Cd, Ni, V, As and Co were 54.2, 223.6, 50.6, 44.4, 0.4, 45.8, 37.8, 3.3 and 7.6 (mg/kg), respectively. The average concentration of all heavy metals except As, V and Co in the samples of dust in the city of Dezful was several times higher than that of the background one. Based on the average EF and PI in the target area, heavy metals of Zn and Pb have high contamination. Based on the evaluation of NIPI, 100% of samples have high degree of contamination. The results showed that the source of pollution of the studied metals such as urban transport and burning of fossil fuels was anthropogenic.
