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31.
Abdurrahman Dokuz İbrahim Uysal Wolfgang Siebel Mehmet Turan Robert Duncan Miğraç Akçay 《Contributions to Mineralogy and Petrology》2013,166(5):1443-1468
New geochemical and isotopic data for post-collisional Early Eocene and Late Miocene adakitic rocks from the eastern part of the Sakarya Zone, Turkey, indicate that slab and lower crustal melting, respectively, played key roles in the petrogenesis of these rocks. The Early Eocene Yoncal?k dacite (54.4 Ma) exhibits high Sr/Y and La/Yb ratios, low Y and HREE concentrations, moderate Mg# (44–65), and relatively high εNd and low ISr values, similar to adakites formed by slab melting associated with subduction. Geochemical composition of the Yoncal?k dacite cannot be explained by simple crystal fractionation and/or crustal contamination of andesitic parent magma, but is consistent with the participation of different proportions of melts derived from subducted basalt and sediments. Sr/Y correlates horizontally with Rb/Y, and Pb/Nd correlates vertically with Nd isotopic composition, indicating that Sr and Pb budgets are strongly controlled by melt addition from the subducting slab, whereas positive correlations between Th/Nd and Pb/Nd, and Rb/Y and Nb/Y point to some contribution of sediment melt. In addition to low concentrations of heavy rare earth elements (~2–3 times chondrite), a systematic decrease in their concentrations and Nb/Ta ratios with increasing SiO2 contents suggests that slab partial melting occurred in the garnet stability field and that these elements were mobilized by fluid flux. These geochemical and isotopic signatures are best explained by slab breakoff and fusion shortly after the initiation of collision. Although the Late Micone Tavda?? rhyolite (8.75 Ma) has some geochemical features identical to adakites, such as high Sr/Y and La/Yb ratios, low Y and HREE concentrations, other requirements, such as sodic andesite and/or dacite with relatively high MgO and Mg# (>50), relatively high Ni and Cr, low K2O/Na2O (<0.4), high Sr (>400 ppm), for slab-derived adakites are not provided. It is sodic in composition and shows no traces of fractionation from dacitic parent magma. Low Nd and high Sr isotope ratios suggest derivation by partial fusion of calc-alkaline, juvenile crust with high Sr/Y and La/Yb ratios. 相似文献
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Micropollutants cover a variety of compounds that mainly originate from the pharmaceutical and agricultural sectors. Even at trace concentrations, the discharge of micropollutants into water bodies pose a serious threat to the environment and human health. Their removal from wastewaters at treatment plants before their discharge into the environment has become one of the leading topics of research. Physical, chemical, and biological treatment methods have been listed in the literature for efficient removal of a variety of pollutants. In this study, seven micropollutants, namely 4‐tert‐octylphenol, atrazine, 2,4,6‐trichlorophenol, fluoxetine, estrone, penconazole, and di‐n‐octyl phthalate, are spiked into municipal simulated synthetic wastewater and treated by a laboratory‐scale electrooxidation (EO) system using oxidized titanium and graphite electrode as anode and cathode, respectively. Sensitive determination of the selected micropollutants by gas chromatography–mass spectrometry (GC‐MS) before and after treatment is performed after their pre‐concentration using an eco‐friendly switchable solvent liquid‐phase microextraction method (SSLPME). The pH value, applied current, and reaction period are optimized to enhance the removal efficiency of micropollutants. Results show that the highest removal efficiency of all micropollutants is obtained at pH 3, 20 min reaction period, and 3 A applied current. The operational costs are also investigated in this study. 相似文献
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Olcayto Keskinkan Oya Işık Turan Yılmaz Behzat Balcı Leyla H. Uslu Çağatayhan B. Ersü 《洁净——土壤、空气、水》2012,40(1):34-38
In this study, batch experiments were carried out to investigate simultaneous growth of Spirulina platensis and removal of hardness in the Van Lake Water (VLW). Laboratory‐scale studies showed ample Spirulina growth observed in VLW when exposed to light. Spirulina was the only algal specimen inoculated in the water during the study. VLW percentages were varied between 0.1 and 100% while pH values were 8.7–10.42 in the flasks. On a dry‐weight basis the biomass concentration was 1.18 g L?1 at pH 10 after 17 days of incubation in the VLW. The increase of pH to above 10.38 associated with Spirulina growth resulted in the precipitation of hardness causing compounds while providing 70% hardness removal from the VLW medium. Experimental results indicated that the proposed method can be used to design batch systems for producing S. platensis and removal of hardness from the VLW. 相似文献
35.
In the present study, the removal of Cu(II) was evaluated by raw and calcined phosphogypsum (PG) as an industrial product. The role of experimental factors on the removal of Cu(II) was examined by using D‐optimal and Taguchi designs. The experimental factors and their related levels were selected as initial pH of 3–6–8, adsorbent content of 5, 10, and 25 g L?1, contact time of 5, 10, and 20 min, and temperature of 20, 40, and 60°C. The results are evaluated by ANOVA test to extract important experimental factors and their levels. The performances of the suggested factorial designs were then compared and regression models that took into account the significant main and interaction effects were suggested. Taguchi design was found as a reliable solution with less number of experiments for adsorption studies with the optimized values. The resultant removal efficiency is calculated as 78.34%. The results revealed that calcined PG is an appropriate adsorbent for Cu(II) removal from leachate of industrial waste. 相似文献
36.
Trace Element Levels in the Groundwater of Mediterranean Coastal Plains – The Case of Silifke,Turkey
The Silifke plain is located near the coast of the Mediterranean Sea in Turkey. The delta in the plain is a highly fertile land that supports the agriculture of more than twenty types of crop. Some trace element content of the groundwater samples taken from the existing wells in this area are analyzed using inductively coupled plasma optical emission spectrometry (ICP‐OES). The mean levels (ppm) of boron (B), barium (Ba), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn), total chromium (TCr), cadmium (Cd), copper (Cu), aluminum (Al), and nickel (Ni) were obtained for the sampling points in the area for four seasons. Groundwater samples taken in the study area don't exhibit significantly elevated levels of these elements during a period of twelve months between December 2007 and November 2008. Furthermore, all of the elements exhibit values lower than 0.005 ppm, with the exception of B, Ba, and Fe. The results demonstrate that although these three elements produce the highest values, most are found to be appropriate for activities such as irrigation and human consumption in terms of trace elements. 相似文献
37.
Mustafa Softa Tahir Emre Hasan Sözbilir Joel Q. G. Spencer Mehmet Turan 《Geodinamica Acta》2018,30(1):249-264
The Eastern Pontides (EP), which is the under transpressional deformation zone, is an active mountain belt that has been rising rapidly since the Cenozoic era because of the Arabian-Eurasian convergence. Morphometric studies have been performed to investigate the tectonic activity of this region and better understand the characteristics of the faults geomorphologically; the faults control the mountain fronts in the drainage basin of the EP. The results show the Hypsometric Curve (HC)-Hypsometric Integral (0.37-HI-0.67), Basin-Shaped Analysis (1.2-Bs-7), Valley-Floor-Width to Height-Ratio (0.4-Vf-1.2) and Asymmetry Factor (35-AF-81) applied to 46 drainage basins together with 9 tectonically controlled geomorphic indices (1.2-Smf-1.5) and a Stream Length Gradient (30-SL-120) indicate that the EP is tectonically active, and when the areas are evaluated according to Smf and Vf analyses, the tectonic level is relatively high. According to our conceptual model for the uplifting of the EP, with respect to field studies and morphometric analysis, (i) the EP is the active deformation zone and has a “push-up” geometry in conjunction with the North Anatolian Fault; (ii) the EP is progressively uplifting at a rate of more than 0.5 mm/yr in along with the thrust faults of the Black Sea Fault (BSF) and Borjomi-Kazbegi Fault (BKF). 相似文献