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  • 1
    Language: English
    In: Environmental Earth Sciences, 2011, Vol.63(4), pp.873-883
    Description: Organophosphate pesticides are compounds that are not only toxic to both humans and wildlife but also difficult to degrade under natural environmental conditions. In Iran, agricultural practices are strongly dependent on the use of pesticides due to climatic and soil conditions, thus posing a potential risk to groundwater quality standards. Evaluating the concentration of organophosphate pesticides namely diazinon, fenitrothion, dichlorvos, ethion, profenofos, malathion and azinphos methyl in water samples in May (low precipitation rate), December (high precipitation rate) as well as the concentration in sediments along the Haraz River is taken into consideration in this study. Generally the pesticides concentration in water samples are relatively higher in May in comparison with that in December; this fact may be due to two major reasons: the first reason is attributed to the prompt raining after the treatment period of most orchards and dry farming lands that will terminate in more wash out of such pesticides towards the branches and main river channel, while the second reason may be considered as the less river water dilution rate in May because of lower precipitation rate. Furthermore, the relatively higher concentrations in downstream stations may be contributed to more intensified agricultural (specially rice paddies), urban and rural land uses in this region in comparison with upstream areas which contain mainly dry farming, grazing lands and orchards with relatively lower loads of pesticides. Additionally, as the Henry’s law constant of all pesticides considered in this study are relatively low, volatilization may not be regarded as an important route of dissipation. Diazinon, azinphos methyl and dichlorvos showed the highest water concentrations in comparison with other pesticides that may be justified by their extended use within the basin during last decades. Based on the chemical properties as well as remarkably higher values in sediment samples in comparison with water ones, it is concluded that the two pesticides, ethion and fenitrothion, persist in the environment due to non-degradable tendencies. Although the concentration of mentioned pesticides is not so high in the water samples, more precautions must be considered in their future use. Regarding the sorption coefficient variation alongside the river, the higher values in upstream and central parts may be attributed to the higher potential of different types of erosion regarding deeper slopes and also sand, gravel and carbonate mining activities at the banks and also river bed in such regions which is considered as an anthropogenic disturbance. In case of central parts, in addition to mentioned reasons, the existence of coal outcrops in the geologic texture of the study area may also be considered as a key role in augmentation of the sorption coefficient. Finally, the dominant clayey and loamy soils containing more organics may be attributed as the major reason of sorption tendency in downstream.
    Keywords: Organophosphate pesticides ; Surface water ; Sediment ; Pollution ; Haraz River
    ISSN: 1866-6280
    E-ISSN: 1866-6299
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  • 2
    Language: English
    In: Environmental Earth Sciences, 2010, Vol.59(5), pp.1111-1117
    Description: The Haraz River flows northwards through the Iranian Alborz mountains in the central region of Mazandaran province and empties into the Caspian Sea. This area has been a rich source of minerals from times immemorial. About 45 mines (coal, limestone, sand and gravel, etc.) have been operational for the last eight decades. Towards the estuary, the river receives a discharge of industrial, agricultural and urban wastes. Eight sediment samples from the Haraz River and its main tributaries were collected and analyzed for base metals as well as Sr and Fe. The chemical partitioning of metals (Cu, Zn, As, Cd, Pb, Fe, Ni, Cr, Co and Sr) in each sample was determined in four fractions (acid-soluble, reducible, oxidizable and residual). The total content of each metal was also determined. The results showed relatively higher concentrations of Cd, As, Sr and Pb in comparison to that of shale. However, based on the chemical partitioning of metals, it is found that Pb, Co, Cd and Sr are the most mobile metals. In spite of the high As concentrations in sediments, it is not likely that this element is a major hazard for the aquatic environment, since it is found mainly in the residual fraction. Cadmium is the metal that showed the highest percentages in the acid-soluble fraction (the most labile) and the lowest in the residual fraction. However, Fe, Cr and Ni are present in the greatest percentages in the residual fraction, which implies that these metals are strongly linked to the sediments.
    Keywords: River ; Sediment ; Pollution ; Metal ; Chemical partitioning
    ISSN: 1866-6280
    E-ISSN: 1866-6299
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  • 3
    Language: English
    In: Environmental Monitoring and Assessment, 2010, Vol.171(1), pp.395-410
    Description: The Haraz River is one of the most significant rivers in the southern Caspian Sea basin. Towards the estuary, the river receives discharges of industrial, agricultural, and urban wastes. In the present investigation, bulk concentrations of Cu, Zn, As, Cd, Pb, Fe, Ni, Cr, Co, and Sr in Haraz River (Iran) bed sediments were measured from several sample locations. In addition, association of studied metals with various sedimentary phases was assessed to determine the proportions of metals in different forms. The intensity of sediment contamination was evaluated using an enrichment factor (EF), geo-accumulation index (I geo ), and a newly developed pollution index (I poll ). Both EF and I geo formulae compare present concentrations of metals to their background levels in crust and shale, respectively. In a specific area with its own geological background like Haraz River water basin where naturally high concentrations of metals may be found, such a comparison may lead to biased conclusions regarding levels of anthropogenic contamination. Accordingly, chemical partitioning results are substituted for the mean crust and shale levels in the new index (I poll ). The Pearson correlation coefficient between the anthropogenic portion of metallic pollution in Haraz river-bed sediments with I poll showed much more value in comparison with those of geochemical accumulation index and enrichment factor. The order of metals introduced by anthropogenic activities are as follows: Sr 〉 Pb 〉 Co 〉 Cd 〉 Zn 〉 Cu 〉 Ni 〉 As 〉 Cr 〉 Fe. The results showed relatively higher concentrations of Cd, As, Sr, and Pb in comparison with those of shale. However, based on the chemical partitioning of metals, it is found that Sr, Pb, Co, and Cd are the most mobile metals. In spite of the high As concentrations in sediments, it is not likely that this element is a major hazard for the aquatic environment since it is found mainly in the residual fraction. Also, Fe, Cr, and Ni are present in the greatest percentages in the residual fraction, which implies that these metals are strongly linked to the sediments.
    Keywords: Chemical partitioning ; Metal species ; Anthropogenic pollution index (I) ; River sediment
    ISSN: 0167-6369
    E-ISSN: 1573-2959
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  • 4
    Language: English
    In: Desalination, 2010, Vol.260(1), pp.264-275
    Description: Hydrochemical quality of groundwater in an aquifer in central Iran adjacent to central Kavir desert was analyzed in this study. The dominant type of groundwater in the area is Na + K_Cl + SO4 which is mainly different from the common type of fresh waters in Iran (Ca_HCO ). The spatial distribution of anions and cations as well as EC obeys an increasing pattern eastwards. Due to high concentrations of SO , Cl , K and Na all of the water samples are not categorized in suitable ranges for drinking use. Regarding agricultural use suitability of regional groundwaters, except for 4 samples in central parts of the study area which show high salinity hazard, all other samples are absolutely not applicable for agriculture due to extremely high values of EC. Illegal groundwater pumping mainly for regional agricultural use during recent years has caused groundwater quality degradation due to saline water intrusion from eastern areas (central Kavir desert and salt lake) and connate water upcoming from deeper aquifers. As the main use of water in the study area is contributed to agriculture, implementing modern mechanized irrigation techniques accompanied by planting crops with low water demand and high tolerance against salinity may be recommended.
    Keywords: Hydrochemistry ; Groundwater Quality ; Salinity ; Central Iran ; Engineering
    ISSN: 0011-9164
    E-ISSN: 1873-4464
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  • 5
    Language: English
    In: Iranian journal of environmental health science & engineering, 2013, Vol.10(1), pp.30
    Description: Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of Iran's Kurdistan province is considered. To investigate the potential risk and hazard level regarding arsenic-contaminated drinking water and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of Qorveh County were considered for evaluation of arsenic concentration in water. Sampling campaign was performed in August 2010 and arsenic concentration was measured via the Silver Diethyldithiocarbamate method. The highest and lowest arsenic concentration are reported in Guilaklu and Qezeljakand villages with 420 and 67 μg/L, respectively. None of thirteen water samples met the maximum contaminant level issued by USEPA and Institute of Standards and Industrial Research of Iran (10 ppb). The highest arsenic concentration and consequently risk and hazard levels belong to villages situated alongside the eastern frontiers of the county. Existence of volcanic activities within the upper Miocene and Pleistocene in this part of the study area may be addressed as the main geopogenic source of arsenic pollution. Quantitative risk values are varying from 1.49E-03 in Qezeljakand to 8.92E-03 in Guilaklu and may be interpreted as very high when compared by similar studies in Iran. Regarding non-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic daily intakes are greater than arsenic reference dose. Such drinking water source has the potential to impose adverse carcinogenic and non-carcinogenic effects on villagers. Accordingly, an urgent decision must be made to substitute the current drinking water source with a safer one.
    Keywords: Arsenic ; Drinking Water ; Groundwater ; Hazard ; Qorveh ; Risk
    ISSN: 1735-1979
    E-ISSN: 17352746
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  • 6
    Language: English
    In: PLoS ONE, 01 January 2018, Vol.13(1), p.e0191314
    Description: Suspended particles in rivers can act as carriers of potentially bioavailable metal species and are thus an emerging area of interest in river system monitoring. The delineation of bulk metals concentrations in river water into dissolved and particulate components is also important for risk...
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
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  • 7
    Language: English
    In: Water Resources Management, 2013, Vol.27(5), pp.1563-1579
    Description: Predicting natural phenomena like flood and drought and consequently presenting an appropriate solution for fighting such natural hazards in northwestern Iran is considered in this study through clustering the precipitation regime. To compare the reference period (past) with the simulated data, the statistics of daily precipitation in six stations of Ardebil, Ghazvin, Hamedan, Kermanshah, Sanandaj, and Tabriz, have been provided for a 30-year period (1961–1990) and compared with the simulated data of 2021–2050. The simulated data was generated by general atmosphere circulation model HADCM3, A1scenario and was downscaled using the LARS-WG model. The method for comparing precipitations was done based on clustering in the form of 5 clusters for all the stations and study periods. One of the results of this research is the greater concentration of precipitation for the cold periods of the year (winter and fall) and the increase of annual precipitation by the amount of 20.62 mm for future period. Furthermore, the normality of two coordinates of precipitation and cluster frequency percentage was evaluated. The outputs of this section demonstrate that the precipitations of cluster 3 which have the features of light rain with average intensity, fall on this normal line for most of the stations and study periods. On the other hand, precipitations of cluster 1 indicating very heavy and intense precipitations, have the most distance to the normal line in most cases. Therefore, the precipitations of the third cluster need optimal exploitation management while those of the first cluster need required risk and crisis management.
    Keywords: Climatic change ; Clustering ; Downscaling ; Scenario
    ISSN: 0920-4741
    E-ISSN: 1573-1650
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  • 8
    Language: English
    In: Environmental Engineering and Management Journal, 2014, Vol.13(1), pp.115-120
    Description: Zarshuran As-Au deposit is the major ore deposit in northwest of Iran. Having been exposed to weathering, the accumulated mining waste is consumed to deteriorate regional soil and water quality. Accordingly, 11 composite surface soil samples were collected to evaluate the metallic pollution. Mean concentration of elements As, Sb, Hg and Zn were measured to be 234.9, 19.6, 24.2 and 476.7 ppm, respectively. In comparison with mean earth crust and local guidelines for agricultural soil, the samples are strongly polluted by toxic elements As, Sb, Hg and Zn. The major reason of such high pollution may be contributed to the lasting gold mining activities that ease the exposure of Au-As- Sb rich minerals to the air and moisture. Detailed statistical analysis categorizes the 11 stations into two distinct groups. Stations S1 to S5 (showing lower metallic pollution) belong to the first group and are located in higher elevations than the mining site. Being located in downstream of the mining site, stations S6 to S11 (second group) manifest more severe soil quality degradation. The seasonal inundation of regional river waters plays the key role in polluting the downstream soil. Regarding extremely high concentrations of toxic elements (As, Sb, Hg and Zn) in the soil of the study area, severe threats may be posed to human health through consumption of the harvested crop.
    Keywords: Engineering;
    ISSN: 1582-9596
    E-ISSN: 1843-3707
    Source: CrossRef
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  • 9
    Language: English
    In: Environmental Geochemistry and Health, 2018, Vol.40(4), pp.1317-1328
    Description: Determining the main sources of pollution (MSP) in groundwater is crucial to improve water quality (WQ) status. Field studies were conducted in this research, where five sampling campaigns were carried out from 36 wells in the southern Tehran aquifer. In all samples, WQ parameters were measured and evaluated regarding the Iranian drinking water standard (IDWS). Finally, by using the principal component factor analysis (PCFA), the probable MSP in the aquifer were determined. The results showed that all ions, total hardness, and total dissolved solids were above the IDWS. To analyze the PCFA results, only the first four of twenty rotated principal factors (RPFs) that conserved a high percentage of the variance of the data (about 90%) were considered. The results of the first PRF revealed that the geological structure was the MSP in the aquifer. Furthermore, the second RPF was mainly affected by nutrients (nitrate and orthophosphate) and microbial parameters (fecal and total coliforms), indicating the importance of agricultural activities and sewage effluents as another MSP in the aquifer. Finally, the remarkable share of heavy metals and pH in formation of the third and fourth RPFs, respectively, reflected the role of industrial activities as a probable MSP of groundwater.
    Keywords: Tehran ; Groundwater quality ; Source of pollution ; PCFA
    ISSN: 0269-4042
    E-ISSN: 1573-2983
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  • 10
    Language: English
    In: Iranian Journal of Science and Technology, Transactions of Civil Engineering, 2017, Vol.41(2), pp.229-239
    Description: Nowadays, with the ever-increasing growth of the population and the development of various industries, we are experiencing an increase in man-made leachates such as urban solid wastes, chemicals, and wastewater. Generally, the groundwater in aquifers is contaminated by these pollutants seeping through the above-ground sediment. The vulnerability of groundwater to contaminants can be assessed, which means those areas with lower vulnerability can be distinguished from those areas with high vulnerability. Hydrogeological parameters are presented in a modified DRASTIC method which assesses depth to groundwater surface ( D ), recharge ( R ), soil media ( S ), topography ( T ), impact of vadose zone ( I ), conductivity of aquifer, hydraulic capabilities ( C ), and the effect of land use activity ( L ). This study aims at zoning the pollution potential of the Mashhad aquifer by using the modified DRASTIC method and GIS to assess the old and new landfill sites. The results show that new and existing (old) landfill sites for solid waste disposal in Mashhad site selections should be closed down due to their location in high vulnerability zones where the risk of groundwater pollution is high.
    Keywords: Groundwater vulnerability ; Pollution ; Landfill ; Modified DRASTIC method
    ISSN: 2228-6160
    E-ISSN: 2364-1843
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