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Khosravi Vahid Ardejani Faramarz Doulati Aryafar Ahmad Yousefi Saeed Karami Shawgar 《Environmental Earth Sciences》2020,79(7):1-16
The pore structure characteristics of soil are closely related to soil engineering properties. For saline soil distributed in seasonally frozen areas, existing studies have focused on the influence of freeze–thaw cycles on pore structure, while the influence of soluble salt in the soil is not well understood. This study aims to explore the influence of salt content and salt type on the pore structure of freeze-thawed soil. Soil samples with different salt contents (0–2%) and types (bicarbonate salt and sulfate salt) were subjected to 10 freeze–thaw tests, and their pore size distributions (PSDs) were obtained by mercury intrusion porosimetry tests. In addition, the PSDs were quantitatively analyzed by fractal theory. For both salts, the PSDs of the tested soil samples were bimodal after the freeze–thaw cycles, and the porosity of saline soil samples increased with increasing salt content overall. However, the contents of various types of pores in soil samples with two salt types were quite different. The variation in bicarbonate salt content mainly affected the mesopore and macropore contents in the soil samples, and their change trends were opposite to each other. For soil samples with sulfate salt, the porosity and macropore content increased significantly when the salt content exceeded 1%. In addition, the pore structures in saline soil presented fractal characteristics after the freeze–thaw cycles, and the fractal dimension was positively correlated with macropore content. This study may provide references for understanding the engineering properties of saline soil in seasonally frozen areas at the microscale. 相似文献
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Jahangoshai Rezaee Mustafa Yousefi Samuel Eshkevari Milad Valipour Mahsa Saberi Morteza 《Stochastic Environmental Research and Risk Assessment (SERRA)》2020,34(1):201-218
Stochastic Environmental Research and Risk Assessment - Organizations are continuously endeavoring to provide a healthy work environment without any incident, by Health, Safety, and Environment... 相似文献
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S. A. Alavi H. Zilouei K. Zargoosh A. Asadinezhad A. Yousefi Abdolmaleki 《International Journal of Environmental Science and Technology》2018,15(5):993-1000
Surface modification of two algal biomasses, Nizimuddinia zanardini and Stoechospermum marginatum, using 4-phenyl-3-thiosemicarbazide ligand was performed to investigate the consequences on the adsorption of heavy metals from aqueous solution. Stabilization of amino group of 4-phenyl-3-thiosemicarbazide on the surface of biomasses was confirmed using Fourier transform infrared spectroscopy. Chemical modification was found to exert significant positive effects on biosorption. Adsorption capacities for Pb(II), Cd(II) and Cr(VI) using modified N. zanardini were observed to be 19.3, 16.75 and 15.75 mg/g, respectively, compared to 17.48, 14.18 and 11.85 mg/g for raw N. zanardini biomass. Also, adsorption of Pb(II), Cd(II) and Cr(VI) by the modified S. Marginatum was found to be 17.54, 15.62 and 14.77 mg/g, respectively, in comparison with that of the raw biomass which were 16.86, 12.9 and 11.2 mg/g. The obtained results of the equilibrium adsorption were studied through different isotherm models of Langmuir, Freundlich and Temkin, where the Langmuir model was observed to agree well with the results. Prevalent kinetic models including pseudo-second order and intra-particle diffusion were applied, and the pseudo-second order was found to describe the adsorption kinetics data adequately. Intra-particle model was also utilized in order to show penetration of metal ions, where it was realized that the biosorption took place in two or three steps including film diffusion, molecular diffusion and chemical reaction. 相似文献
4.
Mohammad Parsa Abbas Maghsoudi Emmanuel John M. Carranza Mahyar Yousefi 《Natural Resources Research》2017,26(4):443-455
In this study, stream sediment geochemical data have been subjected to robust principal components analysis (RPCA) and singularity mapping (SM) to enhance and map significant multivariate geochemical anomalies (i.e., mineralization-related) in Ahar area, NW Iran. The RPCA was applied to (a) account for the compositional nature of stream sediment geochemical data using suitable log-ratio transformation, (b) modulate the effect of outliers in component estimation and (c) derive a multivariate geochemical footprint of mineralization. The SM was applied to extract anomalous patterns of the multivariate geochemical footprint of mineralization. The exploration targets were then delineated using Student’s t-statistics analysis. The correlations of mapped exploration targets with the known mineral occurrences and mineralization-related patterns were further evaluated using normalized density index and overall accuracy analyses. 相似文献
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AbstractThe main objective of this study is to investigate and monitor the landuse and morphological changes in the floodplain part of the Talar River, northern parts of Iran. In the present study, the aerial photographs have been used to produce landuse maps of the floodplain for three periods including 1968, 1994, and 2013. The quantitative analysis of the produced landuse maps showed that the floodplain has undergone substantial landuse changes. Moreover, the sediment bar and the beach area have been decreased about 97 and 90%, respectively, during the 45-year period. Substantial increases of 192 and 622% have been observed for orchards and residential areas, respectively. On the other hand, not only the forest and riparian vegetation were decreased but also the average width of river was decreased about 25.5 m. In addition, flow length of the study reach increased about 8 m. The RNCI was about ?0.7 m per year indicating sedimentation process. During the period of 1968–2013, Caspian Sea has retreated about 150 m and the delta of Talar River was changed. This study showed that morphological actions during first 26 years (1968–1994) were the stable and last 19 years had the change period, especially sedimentation (bar). 相似文献
7.
Rahman Patimar Morteza Yousefi Seyyed Morteza Hosieni 《Estuarine, Coastal and Shelf Science》2009,81(4):457-462
A total of 2256 specimens of Atherina boyeri caught in Gomishan wetland (a marsh lagoon located at the southeast Caspian Sea) during spawning season from February to August 2007 were examined for life-history attributes. The population has a 4-year life cycle. Length–weight relationship was estimated as W = 0.0053TL3.0181 for males and W = 0.0050TL3.063 for females, being allometrically positive for both sexes. The von Bertalanffy growth function fitted to back-calculated size at age data was: Lt = 155.17[1 − exp − 0.28(t + 0.738)] and Lt = 162.77[1 − exp − 0.27(t + 0.727)] for males and females respectively. The sex ratio was 1:1.30 in favor of females. The reproductive season, evaluated from GSI, extended from March to July, with a peak in March. The average absolute and relative fecundities were 2976 eggs and 874 eggs g−1 of body weight respectively. The diameter of oocytes ranged from 0.03 to 0.20 mm with a mean value of 0.68. The life-history patterns of A. boyeri in the population under study imply that the population of this species in the southeast Caspian Sea differs markedly from those of other localities of its range distribution. The differences were thought to be due to differences in geographical locations. 相似文献
8.
Kh. Zoroufchi Benis M. Shakerkhatibi R. Yousefi D. Kahforoushan S. Derafshi 《International Journal of Environmental Science and Technology》2016,13(10):2353-2362
The uncontrolled releases of volatile organic compounds (VOCs) from wastewater treatment plants (WWTPs) have been highly concerned due to the associated public health risks. In petrochemical industries, WWTPs are responsible for various organic compound emissions into the atmosphere, which can considered as the main source of VOCs emission in such industries. The typical high-strength petrochemical wastewater is generated from an acrylonitrile–butadiene–styrene (ABS) resin manufacturing plant that usually needs pretreatment before discharging to the main WWTP. The objective of this study was to investigate the emissions and fates of acrylonitrile (ACN) and styrene (STM) through wastewater pretreatment units operated in an ABS manufacturing plant. In this study, the emission rates of ACN and STM were estimated by means of EPA’s Water9 emission model. Subsequently, the emission rates were used as the input data of AERMOD model to simulate the atmospheric behaviors of emitted ACN and STM. The results of Water9 model showed that 57 and 81 % of influent ACN and STM are emitted to the air through pretreatment units, respectively. For both of them, the equalization basin had the major portion of emission to the atmosphere. The concentration distribution profiles of ACN and STM resulted from AERMOD model indicted that the concentration of STM was lower than EPA reference concentration (RfC); however, the higher concentration of ACN (higher than RfC) occurred near the WWTP as well as the neighbor ambient. 相似文献
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Index overlay and Boolean logic are two techniques customarily applied for knowledge-driven modeling of prospectivity for mineral deposits, whereby weights of values in evidential maps and weights of every evidence map are assigned based on expert opinion. In the Boolean logic technique for mineral prospectivity modeling (MPM), threshold evidential values for creating binary maps are defined based on expert opinion as well. This practice of assigning weights based on expert opinion involves trial-and-error and introduces bias in evaluating relative importance of both evidential values and individual evidential maps. In this paper, we propose a data-driven index overlay MPM technique whereby weights of individual evidential maps are derived from data. We also propose a data-driven Boolean logic MPM technique, whereby thresholds for creating binary maps are defined based on data. For assigning weights and defining thresholds in these proposed data-driven MPM techniques, we applied a prediction-area plot from which we can estimate the predictive ability of each evidential map with respect to known mineral occurrences, and we use that predictive ability estimate to assign weights to evidential map and to select thresholds for generating binary predictor maps. To demonstrate these procedures, we applied them to an area in the Kerman province in southeast Iran as a MPM case study for porphyry-Cu deposits. 相似文献
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Near-field ground-motion records affected by directivity may show unusual features in the signal resulting in low-frequency cycle pulses in the velocity time history. Current probabilistic seismic hazard analysis (PSHA) is not able to predict such effects well; recent studies thus have proposed modified frameworks to incorporate pulse effect in modified PSHA. This paper attempts to carry out the seismic hazard mapping of Tabriz city according to modified and ordinary PSHA for different return periods. Tabriz, located in northwest of Iran, is situated in the vicinity of the North Tabriz Fault, which is one of the major seismogenic faults. Disaggregation results indicate that including pulse-like effects in PSHA, increases the relative contribution of close distances and small epsilons (?). Another major probable result is the high contribution of pulse periods close to spectral period. The contributions to each earthquake scenario at long-period spectral acceleration shift to larger magnitudes with including the pulse effects. 相似文献