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991.
Y. Pousada-Ferradás S. Seoane-Labandeira A. Mora-Gutierrez A. Nú?ez-Delgado 《International Journal of Environmental Science and Technology》2012,9(1):21-29
The purpose of this work was to study the risks of water pollution due to the use of mixtures containing wood ash and sewage sludge. Mixtures including sludge and ash may be recycled as fertilizers, and they are economical as they do not integrate commercial limes, but Escherichia coli counts may keep significantly high in such mixtures, because their pH is not alkaline enough. In view of that, it seems interesting to study the E. coli survival in lixiviate from ash?Csludge mixtures including limes rather than from ash?Csludge mixtures alone. Two kinds of experiments were performed using laboratory column trials under saturated flow conditions. The first experiment investigated the chemical leaching behaviour of a mixture of 70% timber-industry wood ashes and 30% urban sewage sludge (% dry weight) at doses equivalent to 10 and 30?Mg/ha. The second experiment studied the survival of E. coli in lixiviates generated from 30?Mg/ha of a mixture consisting in 75% wood ash, 20% sewage sludge and 5% quicklime (% dry weight). In the first experiment, admixture of the ash and sludge achieved a stabilization of elements such as aluminium, iron, magnesium, nickle, carbon monoxide, cadmium, chromium and molybdenum that reduced their solubility compared with that in the ash or sludge alone. Significant solubilisation of heavy metals was not observed, with overall minor risk of chemical water pollution. In the second experiment, although including quicklime E. coli counts were still detected in the lixiviate, indicating risk of water contamination. 相似文献
992.
S. Govahi A. Karimi-Jashni M. Derakhshan 《International Journal of Environmental Science and Technology》2012,9(1):145-151
Continuous upflow anaerobic sludge blanket reactor performs more favorably at the higher organic loading rate than other anaerobic treatment. The treatment of municipal landfill leachate of Shiraz??s city investigated using continuous flow anaerobic reactor and subsequently aerated lagoon. Landfill leachate has chemical oxygen demand of 45,000?C90,000?mg/L and ammonia nitrogen at 1,000?C2,500 and heavy metals that can impact biological treatments. Capacity of anaerobic and aerobic reactors is 10 and 20?L that operated at detention time of 2 and 4?days, respectively. Organic loading rate of upflow anaerobic sludge blanket is between 0.5?C20?g chemical oxygen demand/L/day. Chemical oxygen demand removal efficiencies are between 57?C87, 35?C70 and 66?C94% in the anaerobic, aerobic and whole system, respectively. As the entry, leachate organic loading rate increased from 1 to 20?g/L/day, the chemical oxygen demand removal efficiency reached a maximum of 71% and 84% in the anaerobic reactor and whole system, respectively, at high organic loading rate. Ammonium removal efficiency was about 54% after the aerobic stage. 相似文献
993.
S. Kamsonlian S. Suresh V. Ramanaiah C. B. Majumder S. Chand A. Kumar 《International Journal of Environmental Science and Technology》2012,9(3):565-578
The present study deals with the biosorption of As(III) from aqueous solution using mango leaves powder (MLP) and rice husk (RH) in a batch operation. Scanning electron microscopy and Fourier transformation infrared spectrometry analysis shows the surface texture of biosorbents and metal binding of functional groups of before and after biosorption of As(III). The optimum pH was obtained at 7 and 6 with 7 and 6?g/l of dosage of MLP and RH, respectively. The adsorption of As(III) onto MLP and RH was favourably influenced by an increase in temperature. Equilibrium data were well represented by the Freundlich isotherm model. Nitric acid and ethylenediaminetetra acetic acid was found to be a better eluant for the desorption followed by hydrochloric acid and sodium hydroxide of As(III) with a maximum desorption efficiency of 69.5, 48.5 and 79.4, 86.3?%, respectively. The pseudo-second-order kinetic model was found to best fitted of the experimental data over the equilibrium time at 32?h. The positive values of heat of adsorption (23.89?kJ/mol for MLP and 52.26?kJ/mol for RH) indicate the endothermic nature of the adsorption process. The thermodynamic study showed the spontaneous nature of the sorption of As(III) onto MLP and RH. 相似文献
994.
Prof. G. Giacovazzo Dr. F. Scordari Dr. A. Todisco Prof. S. Menchetti 《Mineralogy and Petrology》1976,23(3):155-166
Summary The crystal structure of metavoltine from Sierra Gorda, Chile, has been solved from photographic X-ray data by the heavy atom method. The space group used wasP3 witha=9.575(5) andc=18.17(1)Å; cell content: K2Na6 (Fe
2+, Cu, Zn)Fe
6
3+
(SO4)12O2·18H2O. From the relatively small number and the somewhat poor quality of the X-ray data, the least squares refinement did not give very satisfactory results-especially so for the light atoms. Therefore, steric considerations and information from the Fourier maps were also used when choosing the final atomic coordinates. The salient features of the structure are clusters of Fe
3
3+
O(H2O)3(SO4)6 with Fe3+ in octahedral coordination, and Fe2+(H2O)6 octahedra. The Na+ ions show octahedral coordination, the K+ ions irregular nine coordination.
With 4 Figures 相似文献
Ein Kristallstrukturmodell für den Metavoltin von Sierra Gorda
Zusammenfassung Die Kristallstruktur des Metavoltins von Sierra Gorda (Chile) wurde aus photographischen Röntgendaten mit der Schweratommethode gelöst. Als Raumgruppe wurdeP3 mita 09,575(5) undc 0=18,17(1) Å verwendet; Zellinhalt K2Na6 (Fe 2+, Cu, Zn) Fe 6 3+ (SO4)12O2·18H2O.Wegen der relativ kleinen Zahl und der nicht sehr guten Qualität der Röntgendaten gab die Verfeinerung nach der Methode der kleinsten Quadrate keine sehr guten Ergebnissebesonders nicht für die leichten Atome. Deshalb wurden zur Festlegung der endgültigen Atomkoordinaten auch sterische Überlegungen und Informationen aus Fouriersynthesen herangezogen. Hervorstechende Züge der Struktur sind Gruppen Fe 3 3+ O(H2O)3(SO4)6 mit Fe3+ in oktaedrischer Koordination sowie Fe2+(H2O)6-Oktaeder. Die Na+-Ionen zeigen oktaedrische Koordination, die K+-Ionen unregelmäßige 9-Koordination.
With 4 Figures 相似文献
995.
Geochemistry of eocene calc-alkaline volcanic rocks from the Kastamonu area,Northern Turkey 总被引:294,自引:3,他引:294
Analytical data for Sr, Rb, Cs, Ba, Pb, rare earth elements, Y, Th, U, Zr, Hf, Sn, Nb, Mo, Ni, Co, V, Cr, Sc, Cu and major elements are reported for eocene volcanic rocks cropping out in the Kastamonu area, Pontic chain of Northern Turkey. SiO2% versus K2O% relationship shows that the analyzed samples belong to two major groups: the basaltic andesitic and the andesitic ones. High-K basaltic andesites and low-K andesites occur too. Although emplaced on continental type basement (the North Anatolian Crystalline Swell), the Pontic eocene volcanics show elemental abundances closely comparable with typical island arc calc-alkaline suites, e.g. low SiO2% range, low to moderate K2O% and large cations (Cs, Rb, Sr, Ba, Pb) contents and REE patterns with fractionated light and almost flat heavy REE patterns. REE and highly charged cations (Th, U, Hf, Sn, Zr) are slightly higher than typical calc-alkaline values. Ferromagnesian elements show variable values. Within the basaltic andesite group the increase of K%, large cations, REE, La/Yb ratio and high valency cations and the decrease of ferromagnesian element abundances with increasing SiO2% content indicate that the rock types making up this group developed by crystalliquid fractionation of olivine and clinopyroxene from a basic parent magma. Trace element concentration suggest that the andesite group was not derived by crystal-liquid fractionation processes from the basaltic andesites, but could represent a distinct group of rocks derived from a different parent magma. 相似文献
996.
JOHN S. MOTHERSILL 《Sedimentology》1976,23(4):553-565
In the nearshore area of northwestern Lake Victoria a thin strip of quartzarenite sand occurs which grades lakeward into silty clay consisting of quartz with subordinate amounts of K-feldspar, plagioclase, kaolinite, illite, vermiculite and organic matter. Varimax matrix determinations of the element concentrations in the lake-bottom sediments extractable by aqua regia indicate that: (1) there is a strong association of Cr, Cu, Zn and Ni; (2) there is a strong association of Fe, Mn and Co; (3) Cu and Ni show moderate to slight associations with organic matter; (4) Ca is relatively independent of the other elements. The general decrease in the pH values of the surface and bottom waters outward from the lake shore, with consistently higher values for the surface water relative to the bottom waters, results from decreasing levels of photosynthetic activity. 相似文献
997.
The U content of major rock-forming minerals in a suite of calc-alkaline volcanic rocks from Sardinia is very low and their partition coefficient of U (DU = CS/CL) is smaller than 0.1. The values of DU of the mineral phases decrease from basalt to dacite and, in all rocks, the bulk of U and K is present in the groundmass. The apparent close association between K and U in basic and intermediate rocks probably reflects the fact that most of their rock-forming minerals are relatively ‘inert’ with respect to both of these elements. 相似文献
998.
A metabasalt dredged at a junction of the median valley with the Atlantis fracture zone (30°01/tN, 42°04/tW) in the Mid-Atlantic Ridge shows complete recrystallization under a metasomatic condition, though the original igneous texture of a coarse-grained basalt is still recognizable. There is strong circumstantial evidence suggesting that this rock is not an ice-rafted erratic, but an authentic Mid-Atlantic Ridge rock. The 40Ar-39Ar age of this sample is 169 m.y. (Jurassic) which should represent the time of recrystallization. The initial value (87Sr/86Sr)O is 0.720, far above the values previously observed in oceanfloor basalts, including both tholeiitic and alkalic rocks (0.701–0.704). Sr with such a high isotopic ratio is considered to have been introduced by metasomatism during metamorphism by a solution coming from a continental mass or masses which were then located very close to the Mid-Atlantic Ridge. The 40Ar−39Ar age of sample AM50 may approximate the time of the commencement of the opening of the Atlantic. All these data support the possible existence of ancient rock masses in the Mid-Atlantic Ridge, as was formerly claimed by Bonatti, Melson and others. 相似文献
999.
K.S. Valdiya 《Tectonophysics》1976,32(3-4)
A large number of fractures, faults and folds trending normal and oblique to the Himalayan tectonic trend have been recognized in recent years. The tear faults of Kumaun and Nepal have caused predominant right-lateral shear movements. There are eloquent indications of tectonic and seismic activities along some of these faults. In Kumaun, some of the NNW—SSE oriented tear faults coincide with the great thrusts that have brought older Precambrian crystallines over the sedimentary rock. This phenomenon has led many workers to interpret the thrusts as high-angled faults. Significantly, these transverse and oblique faults and fractures are parallel to the great faults discovered in the basement of the Ganga Basin and in the South Indian block, implying a certain genetic connection between the two sets.Likewise, the transverse folds of mesoscopic and macroscopic dimensions superposed on earlier folds of normal Himalayan trend are parallel to the great hidden ridges in the base ment of the Ganga Basin, representing undersurface extension of the Peninsular orogenic trends such as the Satpura, Bundelkhand and Aravali.The presence in the Lesser Himalaya of transverse structures having striking parallelism with those of Peninsular India, coupled with the strong lithostratigraphic similarities between the Purana (Riphean) sedimentary formations of the Lesser Himalaya and the greater Vindhyan Basin and the occurrence in many parts of the Himalaya of coalbearing continental Gondwana and marine Permian formations, reminiscent of similar horizons of the Bihar-Madhya Pradesh borders, is a pointer to the tectonic unity of the two provinces and suggests involvement of Peninsular India in the tectonic framework of the Himalaya. 相似文献
1000.
Joel S. Leventhal 《Chemical Geology》1976,18(1):5-20
Stepwise pyrolysis-gas chromatography is used to examine and characterize the carbonaceous matter in sedimentary rocks. Low-temperature steps remove material normally volatile or extracted by benzene-methanol. Successively-higher temperature steps degrade the insoluble carbonaceous matter (kerogen) into smaller molecular pieces. The sequential pyrolysis steps have the advantage of breaking the kerogen at several temperatures which may be related to bond type or strength. The pyrolysis product chromatograms from each step can be compared. The molecular sizes (chain length) of kerogens fragments can be determined. The results presented here show the molecules in the range C11 to C23 because: (1) they can be compared to normal petroleum source rock extractables; and (2) these large molecules give a feeling for the molecular construction of the kerogen.Green River and Antrim shales show low-temperature material which is indigenous and not modified compared to the pyrolyzed kerogen fragments in the range C11C23. Kupferletten shows low-temperature material of a narrow molecular weight range of C15C19 which is probably derived from the kerogen. Monterey shale low-temperature material appears to be unrelated to the kerogen as represented by its pyrolysis products. The Pierre shale kerogen shows molecules over the range C11C23. Kerogen from the Romney shale has no molecules large than C8 in its pyrolysis products and no petroleum potential due to thermal and tectonic diagenesis. 相似文献