Showing 16 results for Contamination
T. Sohrabi, A. Hosseini, K.h. Talebi,
Volume 5, Issue 1 (4-2001)
Abstract
During recent years, worldwide concern has been focused on the potential for contamination of surface waters and ground waters by agrochemicals in runoff and soil water from irrigated fields. Given this perspective, it is very important to correctly evaluate the levels of different agrochemicals in water, both from human toxicological and environmental viewpoints and to develop management strategies for reducing agrochemical loads to acceptable levels in the environment. The main objective of this study was to assess the qualitative changes of tailwater due to the use of agrochemicals and thereby to determine contamination loads. Four farms (A, B, C and D) were chosen in the Foumanat region in the F2 unit in 1996. The areas of these fields ranged from 0.22 to 0.6 ha having a number of unequal successive basins with variable inflow and outflow rates.
A quantitative analysis showed that the tailwater ratio in farms A, B, C and D ranged from 2 to 64% during the irrigation season. The outflow water was classified as C3S1. The changes in qualitative factors were not significant and did not follow any certain pattern during the irrigation season. The changes in SAR, EC, Cu, Zn, B, P, K and DO in the inflow and outflow waters were also insignificant. After fertilizer application, the increase in nitrogen concentration in the outflow was significant. The average pollution loads in the inflow and outflow were about 1618 and 1476 kg/day/ha, respectively. The remaining load in the rice fields was about 142 kg/day/ha, which was meaningful at 1% level. The fifth farm (E) located in Lahidjan was sprayed with diazinon. Water samples were analyzed each day for diazinon residues for 10 days after application. Sample analysis showed that the concentration of the insecticide was 93.08 mg/l immediately after application and gradually reduced to 0.98 mg/l ten days after spraying.
A. Erfani, G.h. Haghnia, A. Alizadeh,
Volume 6, Issue 1 (4-2002)
Abstract
A field study was conducted at the College of Agriculture, Ferdowsi University of Mashhad, to investigate the effect of irrigation with treated municipal wastewater on the yield and quality of lettuce and some soil characteristics. Five irrigation treatments were applied to a clay loam soil, classified as fine loamy mixed mesic Calcixerollic Xerochrepts, in a randomized block design with 5 replications. The treatments consisted of T1 (Irrigation with treated wastewater over all growing season), T2 (Alternate irrigation with treated wastewater and well water), T3 (Irrigation with well water and application of cattle manure), T4 (Irrigation with well water plus fertilizer N and P), and T5 (Irrigation with well water only as control). Chemical analysis of well water proved to be a suitable source for agriculture.
The results showed that the yield was higher in T1, T2, T3 and T4 as compared to the control treatment. Maximum fresh and dry yields were obtained from T3 & T1 and T1 & T3, respectively. Plant tissue analysis showed an increase in macronutrients (N, P, K) and heavy metal concentrations in shoots and roots of lettuce in the first four treatments as compared to the control. In T1, iron concentration was maximum while that of cadmium was minimum. Furthermore, microbial contamination was considerably higher in T1 and T2. Soil analysis indicated that in plots treated with wastewater, electrical conductivity, total nitrogen, available phosphorus, soluble boron and heavy metal concentration increased. However, their values were all below international standards. More experiments seem to be necessary in this regard.
A. H. Elahami Rad, F. Shahidi,
Volume 8, Issue 1 (4-2004)
Abstract
Bulk tomato paste is produced in concentrations higher than 35% (350 Brix scale) and its packaging is not hermetic. In recent years, the production of this product in our country has considerably increased. One of the most important problems in the tomato paste industry of Iran is the preservation of bulk tomato paste. Shelf-life of tomato paste depends on many factors such as initial quality of tomato paste, cooling conditions, salting, packaging, handling, and cold storage. The product factors evaluated in this study included: 1) microbial parameters such as total count, acid-resistant microorganisms, and Howard Mould Count and 2) physico-chemical parameters such as acidity, pH, amount of lactic acid (D and L forms), and total dry matter.
Experimental data showed that using high brix (35-38) in producing tomato paste along with salting the product surface and storing it at 0 ºC had only a limiting effect on microbial changes and could not prevent their growth completely. However, salting treatment had a great effect on surface growth of fungi and their ability to produce colonies and mycelia. On the basis of the results obtained from this study, cooling of bulk tomato paste in ambient temperature is critical to bulk tomato paste production process and also has an important effect on the quality and shelf-life of the product.
S Sadr, M Afyuni, N Fathian Por,
Volume 13, Issue 50 (1-2010)
Abstract
Industrial, agricultural and urban activities have contaminated soil by heavy metals that can also increase concentration of the metals in food chains. This study was carried out in Isfahan province where lots of such activities are in progress. The purpose of this study was to determine spatial variability of Arsenic )As) in Isfahan soils. In this research, the soil samples )0-20 cm) were collected in a stratified random sampling system at about 4 Km intervals in a study area of 6800 Km2. The positions of samples were recorded using a GPS. After laboratory preparation, soil samples were measured for total As. Spatial structures of total As were determined by directional variograms. Spherical model was the best model to describe spatial variability of As. Mean-square error )MSE) and correlation coefficient were used to validate variograms. Distribution map for Arsenic was prepared using the obtained information from element by point kriging method and by using Surfer software. Interpolation in blocks by dimensions of 1000×1000 m was made. The mine effective factors with high concentration of As are parent material, and direction of dominant wind has affected the spread of As in north-west of the study area.
A. Hassanpour, M. Zahedi, A. H. Khoshgoftarmanesh,
Volume 18, Issue 68 (9-2014)
Abstract
In a pot experiment, the effect of soybeans, mung beans and beans on the corn and sunflowers in a cadmium contaminated soil was studied in a completely randomized design with three replications. The treatments consisted of intercropping of corn and mung bean corn and beans, corn and soybean, sunflower and mung bean, sunflower and beans, sunflower and soybean monoculture of corn, and monoculture of sunflower. There were significant effects of cocropping of companion crops on shoot dry weigh, the concentration of cadmium and zinc and the chlorophyll content of corn and sunflower. In this study the shoot weight of corn grown with bean and soybean and that of sunflower grown with bean plants was decreased as compared to the related monocultures. The concentration of cadmium was increased in the corn grown with soybean or mungbean and in sunflower grown with soybean. Co- cropping with bean plants had no significant effects on the concentration of cadmium in corn or sunflower. Among companion crops, the concentration of cadmium was higher in bean plants compared to those of soybean and mungbean plants. The chlorophyll content in the leaves of corn plants grown with mungbean was increased with an increase in cadmium concentration. However, this trend was not observed in other treatments. The results of this study show that co- cropping with either soybean or mungbean may increase cadmium uptake by corn and sunflower which in turn may increase the risk of inflowing of toxin cadmium into the food chain. However, further study needs to re-evaluate the effect of these companion crops on the distribution of cadmium in the edible parts of corn and sunflower.
M. Barzin, H. Kheirabadi, M. Afyuni,
Volume 19, Issue 72 (8-2015)
Abstract
Soil pollution and accumulation of heavy metals in soils and crops are the most important bioenvironmental problems that threaten the life of plants, animals and humans. This study was conducted to explore contamination of heavy metals in soils of Hamadan province. A total of 286 composite surface soil samples (0-20 cm) were collected thoroughout the province. After preparation of the samples, the total contents of Zn, Pb, Cu, and Ni in soil samples were extracted using HNO3. Total contents of heavy metals were measured by ICP. Contamination factor results showed that most samples were moderately polluted and contamination factor for lead was highly polluted. Interpolated distribution map of contamination factors (CF) and pollution load index (PLI) of the heavy metals were prepared using GIS. The overlap of CF and PLI maps with geology and land use maps indicated that the concentrations of Ni, Pb, Zn, and Cu have been controlled by natural factors such as parent material, but agricultural activities according to excessive consumption of animal manure and chemical fertilizers can increase most of these elements in soil.
S. Heydari, S. Oustan, M.r. Neyshabouri, A. Reyhanitabar,
Volume 19, Issue 72 (8-2015)
Abstract
Consequences of heavy metal accumulation in soils are of great concern. One way of decontaminating heavy metals from soils is using chelating agents, particularly EDTA. In this research, three contaminated soils (with total concentration of these metals of 10.5, 55.8 and 80.6 mmol kg-1) were collected from the surface layer of the lands surrounding a zinc-lead smelting plant in Zanjan province. The extent of Zn, Pb and Cd release by Na2H2EDTA (100 mmol kg-1 of dry soil) from these soils in column leaching experiments (both continuous and pulse addition methods) assembled into half of saturated hydraulic conductivity was assessed. In preliminary experiments, the leaching was stopped due to a drop in hydraulic conductivity. Therefore, the continuous addition method was performed with calcium nitrate as the background solution and the pulse addition method was conducted using this background solution coupled with pH adjustment to 8. Based on the results, the percentage removal of Cd as well as Pb was relatively the same for the two addition methods while the removal of Zn was 13% on average higher in the continuous addition method than in the pulse addition method. For both methods, the removal efficiencies followed the order of complex stability constants (as Pb>Zn>Cd) in a limited concentration range of EDTA to complex heavy metals. Furthermore, in contrast to Cd and Pb, a direct linear relationship was found between the percentage removal of Pb and its total amount in the soils. Surprisingly, the Pb concentration was on average only about one-twentieth of the Zn concentration. The breakthrough curves of both methods showed the mobility order of Cd>Zn>Pb. In general, it seems that the removal pattern of soil heavy metals is dependent not only on the soil type but also on the removal method.
Mrs Zahra Mehrabi, Dr Hamid Reza Eshghizadeh, Mrs Afsane Nematpour,
Volume 21, Issue 1 (6-2017)
Abstract
To determine the nitrate pollution (water, soil, and tubers) in small (< 0.5 ha), medium (0.5- 1 ha) and large (> 1 ha) size of potato fields, this study was conducted in Fereidan region of Isfahan province during growing season of 2014-2015. For this purpose, the amounts of inputs and the tuber yield were recorded in each farm. Also, average nitrate-N concentration in irrigation water, soil and tubers of different potato farms were measured before planting and after harvesting. The results showed that the average soil N-nitrate concentration in small, medium and large size farms were 16.3, 17.4 and 19.9 mg kg-1 before planting and 10.3, 13.3 and 23.3 mg kg-1 after harvesting, respectively. The average N-nitrate concentration of irrigation water in small, medium and large size farms were 36.3, 27.1 and 19.5 mg L-1 before planting and 47.6, 33.1 and 16.4 mg L-1 after harvesting, respectively. At the post-harvest time, NO3-N concentration of irrigation water were below the standard range concentration (45 mg L-1) in the all large farms while 87 % of small and 85% of medium farms had more than standard concentration. The nitrate concentrations of tubers in large-sized farms were lower than others. The tuber NO3-N concentration was affected by potato cultivar. The lowest concentration of nitrate was observed in the late-season potato cultivars (Agria). that might be associated with greater tubers yield.
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.
H. Shirani, S. Shirvani, M. Moradie,
Volume 22, Issue 2 (9-2018)
Abstract
In recent years, microbial contamination of surface and groundwater is a serious problem in some countries, leading to dangerous diseases. Soil salinity and irrigation water can affect the amount of transport or survival of bacteria in soil. In this study, the effect of different levels of salinity of irrigation water with EC: 0.5, 2.5, 6 ds/m and three manures including poultry manure, cow manure and the mixture of poultry and cow manure with 10 ton ha-1 on the transport of Escherchia coli was investigated in disturbed soil columns with 30cm height and 10cm diameter under unsteady-state water conditions. The concentration of Escherchia coli was measured. The severity of the effluent contamination of the treated columns with water salinity was 6 ds/m, which was less than that with the salinity of 2.5 and 0.5 ds/m. This difference was significant at the 0.01 probability level. Also, the effluent contamination of poultry manure-treated columns was greater than the cow manure and the mixed manure, and the contamination of mixed manure was greater than that of cow manure. The interaction of different salinity treatments on the concentration of Escherchia coli in different fertilizer treatments was significant at the 0.01 probability level. The results showed that the concentration of the released bacteria was affected by irrigation water salinity and with increasing the salinity, the concentration of the bacteria was reduced.
H. Babaei, N. Ghanavati, A. Nazarpour,
Volume 22, Issue 3 (11-2018)
Abstract
Dust particles are suspended particles created from various natural and anthropogenic sources. Dust particles contain toxic metals, such as mercury (Hg), which can have harmful effects on the human health. In this study, to investigate the contamination level of Hg in the street dust in Ahvaz, 95 dust samples were collected from the pavements in the main streets. The concentration of Hg in the collected samples was determined by the atomic absorption method (ASS). The contamination level was estimated based on indicators such as contamination factor (Cf), enrichment factor (EF), geo-accumulation index (Igeo) and ecological risk index (Er). The concentration value of mercury ranged from 0.02 to 8.75 mg/kg with an average of 2.53 mg/kg. The results of pollution indicators showed that the level of Hg contamination in the street dust of Ahvaz was a high level of contamination. In addition, the results of ecological risk assessment indicated that the ecological risk of Hg in the study area was very high. Spatial distribution pattern of Hg concentration showed that in areas with high population density, high traffic volume and industrial activities, there was a high pollution level of Hg.
M. H. Rasouli-Sadaghiani, H. Karimi, S. Ashrafi Saeidlou, H. Khodaverdiloo,
Volume 22, Issue 4 (3-2019)
Abstract
Because of the undesirable effects of lead on soil properties and human health, evaluation of its remediation methods seems to be essential. In order to evaluate the effect of humic acid (HA) on the decontamination of lead (Pb) spiked-soils in the presence of wormwood plant (Artemicia absantium), an experiment was carried out in a completely randomized block design with three replications. Experiment factors including different concentrations of Pb (Pb(NO3)2 in the solid form) (0, 250, 500 and 1000 mg kg-1) and levels of HA (0, 100 and 200 mg kg-1) were considered. At the end of the growing period of plants, some soil and plant properties were measured. According to the results, BR, MBC, root and shoot dry weights, RWC and Fe and Zn concentrations in the shoot were decreased by increasing the soil Pb concentration. So, the mean values of BR and MBC in Pb1000 treatment was 60 and 51.1 percent lower than those of Pb0, respectively. Pb accumulation in the root and shoot was enhanced as a result of the increase in the soil Pb concentration. The maximum Pb concentration of shoot (37.10 mg kg-1) and root (38.1 mg kg-1) was seen in the Pb1000 treatment. Also, the results suggested that humic acid had a positive effect on the shoot of Fe, Zn and Pb concentrations. So, the concentration of these elements in HA200 treatment showed an increase 1.25, 1.64 and 1.66 times more than that of HA0, respectively. Leaf proline amount was increased significantly by elevating the soil Pb concentration; however, application of 200 mg kg-1 humic acid decreased leaf proline by 54.5 percent, as compared to the control (HA0). Therefore, humic acid effect on increasing the plant Pb uptake, improving soil biological properties, and increasing availability and dissolution of Pb showed its ability in promoting the phytoremediation efficiency. According to the obtained results of this study, woodwarm plant (Artemicia absantium) is a non-accumulator that could not be used for phytoremediation purposes.
M. Khamseh Mahabadi, M. Shirvani, M. R. Mosaddeghi,
Volume 24, Issue 1 (5-2020)
Abstract
Shortage of water resources and deterioration of water quality have urged the need to develop new technologies for the removal of contaminants from water. Heavy metals produced by municipal and industrial activities are among the most toxic contaminants present in the natural and waste waters. Different methods have been developed for the elimination of heavy metals from water resources and industrial waste waters. Adsorption is an effective and economic method for the water purification purposes. Nowadays, clays and natural polymers have been widely used as the adsorbents for heavy metals, due to their eco-friendly nature, natural abundance, low cost and high specific surface area. If these adsorbents are used as a hybrid material, some of their physical and chemical restrictions would be alleviated. In this study, polyacrylic acid–bentonite hybrids and natural bentonite were compared in terms of Pb adsorption in the batch and fixed-bed column systems. Besides, the effect of pH on Pb retention was investigated in both systems. The results of the batch studies showed that Langmuir and Freundlich isotherm models were appropriate in ing quilibrium Pb sorption data. Pb sorption by the sorbents was increased with the rise in solution of pH from 4 to 6, showing the greatest Pb sorption capacity at pH values of 4 (83.29 mg g-1) and 6 (103.3 mg g-1). Different indices of filtration and adsorption, including average relative effluent concentration, relative adsorption index, relative transmitted index, and filtration coefficient, were calculated from the break-through curves, indicating that the polyacrylic acid-bentonite nanocomposite was superior in the Pb sorbtion, as compared to bentonite. Also, a higher pH value resulted in the greater Pb removal from the solutions.
F. Mehri Yari, H. Pirkharrati, Kh. Farhadi, N. Soltanalinezhad, F. Naghshafkan,
Volume 24, Issue 1 (5-2020)
Abstract
Soil pollution by heavy metals is a serious environmental problem that threatens the human health. The present study was carried out to investigate and detect the contamination of heavy metals of arsenic, copper, lead, zinc and iron due to human and natural activities in the sediment of lake bed and the surface soils of the eastern part of Urmia Province, West Azarbaijan Province. A total of 20 soil samples and surface deposition from the depths of 0 to 30 cm were collected randomly from the studied areas. After preparing the samples, extraction was carried out to determine the concentration of the heavy metals in the soil by using hydrochloric acid and nitric acid, and the total concentration of metals was measured using ICP-OES. The results of the calculation of the contamination factor showed that copper, iron, zinc and lead in the class of low and medium pollution and arsenic in 65.5% of the samples were very high in the class. The high concentrations of copper, lead and zinc contamination in the margin of the city and the contamination of arsenic in the lake bed were observed. The analysis of the contamination factor maps and contamination index with land use and geological map showed that copper, lead and zinc were mostly affected by human activities and arsenic influenced by the maternal materials in the region.
F. Moradian, N. Ghanavat, A. Nazarpour,
Volume 24, Issue 3 (11-2020)
Abstract
Dusts contain heavy metals such as Pb, Zn, Cu, Cr, Cd and As that can threat human's health and environment. Therefore, the spatial distribution of heavy metals concentration and soil pollution monitoring and environmental quality protection seem to be essential. To assess heavy metals pollution level in Ahvaz street dust, 115 street dust samples were collected from main pedestrians. The samples were analyzed by Atomic Absorption (AAS). The pollution level was estimated based on the geo-accumulation index (Igeo), contamination factor (CF) and the enrichment factor (EF). The average concentration values of Pb, Zn, Cu, Cr, Cd and As were found to be 197.6, 150.1, 179.7, 101, 5.6 and 14.2 mg/kg, respectively. Pearson's correlation coefficient also indicated that Pb, Zn, Cu and Cr had a significant correlation showing similar possible anthropogenic sources. On the other hand, Cd and As showed a lower correlation with other metals, indicating that they belonged to the geogenic sources. The results of contamination factor, enrichment factor and geo-accumulation index also indicated that Pb, Zn, Cu and Cd had a high contamination level. Also, areas with high population density, heavy traffic volume, and industrial activities exhibited a high level of heavy metals contamination.
S. Dehghani, M. Naderi Khorasgani, A. Karimi,
Volume 26, Issue 3 (12-2022)
Abstract
Knowledge of the distribution of heavy metal concentrations in different components of soil particles is significant to assess the risk of heavy metals. The objective of this study was to evaluate some pollution indices and spatial variations in their estimation in different components of soil particle size fractions (<2000 and> 63 μm) in the Baghan watershed in the southeast of Bushehr province with an area of about 929 square kilometers. The location of 120 surficial composite soil samples (0-20 cm) was determined by using the Latin hypercube method. Soil pollution was assessed using geochemical indices of contamination factor (CF) and pollution load index (PLI). The kriging method was used in the Arc GIS software to interpolate the spatial variations of CF and PLI. Based on the results, the CF displayed the particles in the size < 2000 microns compared to all metals in moderate pollution conditions (1≤CF <3) and with the fineness of soil particles (particles with a diameter <63 microns) concerning to Cd metal shows significant contamination status and moderate pollution with other metals, respectively. CFZn, CFCu, and CFFe in particle size <2000 microns and CFPb in finer class were fitted with a spherical model and other metal contamination coefficients with an exponential model. CFCd and CFFe have the highest impact ranges at <2000 and < 63 microns, respectively. The results of this research confirm that corrective operation is needed to monitor cadmium status in the studied area.
