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11.
Specification and prediction of nickel mobilization using artificial intelligence methods 总被引：1，自引：0，他引：1
Raoof Gholami Mansour Ziaii Faramarz Doulati Ardejani Shahoo Maleki 《Central European Journal of Geosciences》2011,3(4):375-384
Groundwater and soil pollution from pyrite oxidation, acid mine drainage generation, and release and transport of toxic metals are common environmental problems associated with the mining industry. Nickel is one toxic metal considered to be a key pollutant in some mining setting; to date, its formation mechanism has not yet been fully evaluated. The goals of this study are 1) to describe the process of nickel mobilization in waste dumps by introducing a novel conceptual model, and 2) to predict nickel concentration using two algorithms, namely the support vector machine (SVM) and the general regression neural network (GRNN). The results obtained from this study have shown that considerable amount of nickel concentration can be arrived into the water flow system during the oxidation of pyrite and subsequent Acid Drainage (AMD) generation. It was concluded that pyrite, water, and oxygen are the most important factors for nickel pollution generation while pH condition, SO4, HCO3, TDS, EC, Mg, Fe, Zn, and Cu are measured quantities playing significant role in nickel mobilization. SVM and GRNN have predicted nickel concentration with a high degree of accuracy. Hence, SVM and GRNN can be considered as appropriate tools for environmental risk assessment. 相似文献
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Haniyeh Jalayeri Faramarz Doulati Ardejani Reza Marandi Saeed Rafiee pur 《Arabian Journal of Geosciences》2013,6(10):3847-3852
Phenol is one of the aromatic hydrocarbons. Phenol and its derivatives are highly toxic. These pollutants can be observed in the effluents of many industries. This research investigates the removal of phenol by the use of activated sludge in a batch system. The effects of influencing factors on biodegradation efficiency have been evaluated. The main factors considered in this study were the volume of acclimatized activated sludge inoculation, pH, temperature, and initial concentration of phenol. The inoculation volumes of 1, 3, and 5 mL of acclimatized activated sludge were taken into account. Different pH values of 3, 5, 7, 9, and 11 were examined. The experiments were conducted for temperatures of 25, 30, 35, and 40 °C and initial phenol concentrations of 400, 800, 1,000, and 1,500 ppm. The results show that the acclimatized activated sludge has a high capacity for the removal of phenol. From a 100-mL aqueous solution was removed 1,500 ppm of phenol after 80 h. Furthermore, maximum phenol removal was observed for an inoculation volume of 5 mL for three different phenol concentrations of 100, 400, and 800 ppm. The best pH was 7 for the biodegradation process, and the optimum temperature was 30 °C. It was further found that an increase in the phenol concentration increased its removal time. Moreover, the activated sludge could effectively remove about 99.9 % of phenol from a synthetic aqueous solution in a batch system. 相似文献
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Response of nonlinear soil‐MDOF structure systems subjected to distinct frequency‐content components of near‐fault ground motions 
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下载免费PDF全文 This paper is devoted to investigate the effects of near‐fault ground motions on the seismic responses of nonlinear MDOF structures considering soil‐structure interaction (SSI). Attempts are made to take into account the effects of different frequency‐content components of near‐fault records including pulse‐type (PT) and high‐frequency (HF) components via adopting an ensemble of 54 near‐fault ground motions. A deep sensitivity analysis is implemented based on the main parameters of the soil‐structure system. The soil is simulated based on the Cone model concept, and the superstructure is idealized as a nonlinear shear building. The results elucidate that SSI has approximately increasing and mitigating effects on structural responses to the PT and HF components, respectively. Also, a threshold period exists above which the HF component governs the structural responses. As the fundamental period of the structure becomes shorter and structural target ductility reduces, the contribution of the HF component to the structural responses increases, elaborately. Soil flexibility makes the threshold period increase, and the effect of the PT component becomes more significant than the HF one. In the case of soil‐structure system, slenderizing the structure also increases this threshold period and causes the PT component to be dominant. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Azadeh Agah Faramarz Doulati Ardejani Hossein Ghoreishi 《Arabian Journal of Geosciences》2013,6(6):1933-1944
This paper presents a two-dimensional finite volume model to predict multi-species reactive transport processes in the saturated zone of a simulated semi-confined aquifer. A multipurpose commercial software called PHOENICS was used to solve model equations numerically. Capability of the present model was first confirmed using experimental data and the results obtained by a published one-dimensional finite element reactive transport model by other researchers taking different scenarios into consideration. The model was then expanded to a two-dimensional case to simulate reactive transport of BTX compounds with discontinuous source in the saturated zone of the groundwater flow system. In addition to the physical transport processes, the two-dimensional model also incorporates linear and nonlinear adsorption isotherms, first order and Monod kinetics. The two-dimensional model considers both static and dynamics modes into account. The results show that considering chemical reactions during reactive transport of contaminants could successfully predict the contaminated zone. The results of such studies can be used for monitoring of contaminated areas, designing methods to control pollution transport, and minimize its harmful effects on aquifer systems. 相似文献
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R-mod factor analysis, a popular multivariate statistical technique to evaluate water quality in Khaf-Sangan basin, Mashhad, Northeast of Iran 总被引：1，自引：0，他引：1
Water quality data are required in order to compare chemical water analyses and identify water masses. R-mode factor analysis, a popular multivariate statistical tool, has been effectively used for groundwater quality studies. In this paper, the R-mode factor analysis was applied to 50 groundwater samples collected from pumping wells in the Sangan-Khaf basin which is located in the southeast of Mashhad, northeast Iran. The groundwater samples were analysed for chemical parameters. The factor analysis was then performed on the chemical data set. It can be suggested that four factors in R-mode analysis explain more than 94.31% of the total variance. The contribution of each factor at sample points, factor score, was calculated. The spatial distribution of the factor scores for each factor was mapped separately. Since the Sangan iron mine south of the study area probably affects groundwater aquifer, therefore, such studies can be used to manage the groundwater quality in the study area. 相似文献
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Aminroayaei Yamini Maryam Tutti Faramarz Aminoroayaei Yamini Mohammad Reza Ahmadian Jamshid Wan Bo 《Mineralogy and Petrology》2017,111(5):747-759
Mineralogy and Petrology - The chloritization of biotite and stable isotopes of silicate have been studied for the Zafarghand porphyry copper deposit, Ardestan, Iran. The studied area, in the... 相似文献
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Shabnam Hasani Omid Asghari Faramarz Doulati Ardejani Saeed Yousefi 《Environmental Earth Sciences》2017,76(15):532
Mining activities and resulting wastes can be considered as one of the most important sources of hazardous elements in the environment. Knowledge of the spatial distribution of toxic elements in waste dump systems is necessary to assess environmental hazard and strategy. To achieve this goal, this paper investigates spatial distribution of toxic elements using statistical and geostatistical analysis. A total of 58 soil samples were collected, and the amount of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb and Zn was then determined at “Sarcheshmeh” copper mine waste dumps. In order to evaluate the presence of multivariate outliers, Mahalanobis distance technique (D 2) was applied and the multivariate outlier samples were removed. This resulted in an increase in correlation coefficient. To reduce dimension of data set, principal component analysis was applied and four principal components were determined which indicate 83.463% of the total variance of data set. Estimated PCs together with the toxic elements maps based on the ordinary kriging display aggregation of toxic elements in some parts, and validity of predictions was evaluated using the leave-one-out cross-validation method. The regression coefficients of estimated and observed values presented the reliability of the kriging estimates. Sequential Gaussian simulation method was applied for principal components due to similar results of estimated principal components and toxic elements. The results of simulation maps are almost identical to estimated outcomes. 相似文献
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Hydrous pyrolysis (HP) practiced on type-II kerogen-bearing oil shale samples from the Sargelu Formation in the Ghali-Kuh Area, western Iran, using a specially designed apparatus was performed at different temperatures (250–350°C), with hydrocarbon generation evaluated at each temperature. For comparison, the samples subjected to Rock-Eval pyrolysis before proceeding to HP resulted in Tmax = 418°C, HI = 102, and TOC = 4.33%, indicating immaturity and hence remarkable hydrocarbon (especially oil) generation potential, making them appropriate for HP. Moreover, the samples were deposited in a low-energy reductive marine environment, with maximum oil and gas generation (739 mg and 348 mg out of 50 g of rock sample, respectively) observed at 330°C and 350°C, respectively. The oil generated at 330°C was subjected to gas chromatography (GC) and isotopic analyses to assess hydrocarbon quality and composition. The hydrocarbon generation data was devised to estimate kinetic indices of the Arrhenius equation and to investigate the gas–oil ratio (GOR) and overall conversion yield. Based on the producible hydrocarbon quantity and quality, the findings contribute to the economic assessment of oil shales across the study area. The developed kinetic model indicates the history of hydrocarbon generation and organic matter (OM) maturity. 相似文献
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Ghorbanzadeh Mohammad Khoshnoudian Faramarz Taghikhany Touraj 《Bulletin of Earthquake Engineering》2022,20(2):997-1026
Bulletin of Earthquake Engineering - The main objective of this study is to employ a probabilistic approach to determine the appropriate value of the strong column-weak beam ratio (SCWBR) for three... 相似文献