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This study aims at determining the chlorine and chlorine-36 fallout rates in an experimental beech forest site located in NE France (48°31′55″ N, 5°16′8″ E). A monthly record of Cl and 36Cl concentrations in rainfall samples collected above the canopy was performed during two years, from March 2012 to February 2014. The results show that the Cl concentrations mainly originate from sea-spray while the 36Cl concentrations originate from the stratosphere and therefore present a seasonal dependency. Abrupt and important inputs of 36Cl from the stratosphere indeed yield sharp increases of the recorded concentrations during the spring-summer. We also show that a too short sampling period might bias the determined 36Cl fallout rate. To smooth the seasonal and sporadic bursts of 36Cl, a minimum of 6 months sampling period is required. A mean 36Cl fallout rate of (77 ± 21) atoms m−2 s−1 can be deduced from our study, which is 45% higher than the modelled value. This discrepancy suggests more studies aiming at measuring the 36Cl fallout rate worldwide are necessary. 相似文献
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A. O. Al‐Jasser 《洁净——土壤、空气、水》2011,39(9):827-832
Maintaining acceptable quality of water transported in the transmission and distribution system requires the chlorination of water beyond the treatment plant. While flowing through pipes, the chlorine concentration decreases for different reasons. Reaction with the pipe material itself and the reaction with both the biofilm and tubercles formed on the pipe wall are known as pipe wall demand. This varies with pipe parameters. The aim of this paper was to assess the impact of the service age of pipes on the chlorine wall decay constant. One hundred and fifty three pipe sections of different sizes and four different pipe materials were collected and tested for their chlorine first‐order wall decay constants. The results showed that pipe service age was an important factor that must not be ignored. For the range of the 55 years of pipe service age used in this study, the change in the wall decay ranged from 8 to 531% of the corresponding values in the recently installed pipes. The effect of service age on the wall decay constants was most evident in steel pipes. Other important findings were reached. 相似文献
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Eight DSDP/ODP cores were analyzed for major ion concentrations and δ37Cl values of water-soluble chloride (δ37ClWSC) and structurally bound chloride (δ37ClSBC) in serpentinized ultramafic rocks. This diverse set of cores spans a wide range in age, temperature of serpentinization, tectonic setting, and geographic location of drilled serpentinized oceanic crust. Three of the cores were sampled at closely spaced intervals to investigate downhole variation in Cl concentration and chlorine isotope composition.The average total Cl content of all 86 samples is 0.26 ± 0.16 wt.% (0.19 ± 0.10 wt.% as water-soluble Cl (XWSC) and 0.09 ± 0.09 wt.% as structurally bound Cl (XSBC)). Structurally bound Cl concentration nearly doubles with depth in all cores; there is no consistent trend in water-soluble Cl content among the cores. Chlorine isotope fractionation between the structurally bound Cl− site and the water-soluble Cl− site varies from − 1.08‰ to + 1.16‰, averaging to + 0.21‰. Samples with negative fractionations may be related to reequilibration of the water-soluble chloride with seawater post-serpentinite formation. Six of the cores have positive bulk δ37Cl values (+ 0.05‰ to + 0.36‰); the other two cores (173-1068A (Leg-Hole) and 84-570) have negative bulk δ37Cl values (− 1.26‰ and − 0.54‰). The cores with negative δ37Cl values also have variable Cl− / SO42 ratios, in contrast to all other cores. The isotopically positive cores (153-920D and 147-895E) show no isotopic variation with depth; the isotopically negative core (173-1068A) decreases by ∼1‰ with depth for both the water-soluble and structurally bound Cl fractions.Non-zero bulk δ37Cl values indicate Cl in serpentinites was incorporated during original hydration and is not an artifact of seawater infiltration during drilling. Cores with positive δ37Cl values are most likely explained by open system fractionation during hydrothermal alteration, with preferential incorporation of 37Cl from seawater into the serpentinite and loss of residual light Cl back to the ocean. Fluid / rock ratios were probably low as evidenced by the presence of water-soluble salts. The two isotopically negative cores are characterized by a thick overlying sedimentary package that was in place prior to serpentinization. We believe the low δ37Cl values of these cores are a result of hydration of ultramafic rock by infiltrating aqueous pore fluids from the overlying sediments. The resulting serpentinites inherit the characteristic negative δ37Cl values of the pore waters. Chlorine stable isotopes can be used to identify the source of the serpentinizing fluid and ultimately discern chemical and tectonic processes involved in serpentinization. 相似文献
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离子色谱法测定岩石,土壤,水系沉积物等样品中的氯,溴,碘 总被引：1，自引：0，他引：1
本文采用碳酸钠一氧化锌烧结法分解样品,利用DIONEX2020i离子色谱仪,电导、电化学检测器,建立了一测定岩石等样品中氯、溴、碘的分析流程。实验表明,本方法选择性好,灵敏度高,检出限分别为:氯1.03×10~(-6)、溴0.012×10~(-6)、碘0.014×10~(-6)。 相似文献
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本文以离子膜电解氯化钾制取碳酸钾工艺产生的淡盐水为原料,系统地研究了聚四氟乙烯平板型气态膜回收氯过程中膜性能和次氯酸钠水溶液的制备。初步研究表明,次氯酸钠含量大于100g/L,氢氧化钠有效利用率为90％;聚四氟乙烯膜有传质快、对离子截留性能好、使用寿命长等优点,在工业上有较好的应用前景。 相似文献
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本世纪初到八十年代中期由于氯同位素的测试精度很低（＞１．０‰）导致氯同位素地球科学研究未获得任何进展。１９８４年Ｋａｕｆｍａｎｎ等人建立测试精度高达±０．２４‰的方法，并且首次发现了氯同位素在自然界的变异。在此以后氯同位素的测试精度不断提高，各国学者相继对海水、温泉、火山湖水、油田卤水、地下水盐湖、冰雪、环太平洋的斑岩铜矿和美国密西西比型铅锌矿床造岩矿物和造矿矿物流质包裹体中氯同位素进行了测定并对其中氯同位素的分布规律做了比较深入的研究。在此基础上对各类水体及矿床的成因与物质来源进行了有益的探索，另外还以自然界氯同位素产生分馏的原因及机理做了初步的研究。 相似文献
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Massimo Chiaradia Dave Banks Robert Cliff Robert Marschik Antoine de Haller 《Mineralium Deposita》2006,41(6):565-573
The origin of the hypersaline fluids (magmatic or basinal brine?), associated with iron oxide (Cu–U–Au–REE) deposits, is controversial. We report the first chlorine and strontium isotope data combined with Cl/Br ratios of fluid inclusions from selected iron oxide–copper–gold (IOCG) deposits (Candelaria, Raúl–Condestable, Sossego), a deposit considered to represent a magmatic end member of the IOCG class of deposit (Gameleira), and a magnetite–apatite deposit (El Romeral) from South America. Our data indicate mixing of a high δ 37Cl magmatic fluid with near 0‰ δ 37Cl basinal brines in the Candelaria, Raúl–Condestable, and Sossego IOCG deposits and leaching of a few weight percent of evaporites by magmatic-hydrothermal (?) fluids at Gameleira and El Romeral. The Sr isotopic composition of the inclusion fluids of Candelaria, Raúl–Condestable, and El Romeral confirms the presence of a non-magmatic fluid component in these deposits. The heavy chlorine isotope signatures of fluids from the IOCG deposits (Candelaria, Raúl–Condestable, Sossego), reflecting the magmatic-hydrothermal component of these fluids, contrast with the near 0‰ δ 37Cl values of porphyry copper fluids known from the literature. The heavy chlorine isotope compositions of fluids of the investigated IOCG deposits may indicate a prevailing mantle Cl component in contrast to porphyry copper fluids, an argument also supported by Os isotopes, or could result from differential Cl isotope fractionation processes (e.g. phase separation) in fluids of IOCG and porphyry Cu deposits. 相似文献
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Diana Rodriguez Ana Rodriguez Amparo Soto Alfonso Aranda Yolanda Diaz-de-Mera Alberto Notario 《Journal of Atmospheric Chemistry》2008,59(3):187-197
The reactions of three structurally similar unsaturated alcohols, 2-buten-1-ol (crotyl alcohol), 2-methyl-2-propen-1-ol (MPO221)
and 3-methyl-2-buten-1-ol (MBO321) with Cl atoms, have been investigated for the first time, using a 400 l Teflon reaction
chamber coupled with gas chromatograph-coupled with flame-ionization detection (GC-FID). The experiments were performed at
atmospheric pressure and at temperatures between 255 and 298 K, in air or nitrogen as the bath gas. The obtained kinetic data
were used to derive the Arrhenius expressions , , (in units of cm3 molecule−1 s−1). Finally, atmospheric lifetimes of those unsaturated alcohols with respect to OH, NO3, O3 and Cl have been calculated. 相似文献
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K. Mizumura Y. Kumagait H. Tsutsui T. Nishimoto T. Yamamoto 《Environmental Geology》2000,39(10):1147-1154
X-ray fluorescent spectroscope analysis easily finds ratios of geochemical elements in soil. Applying the method of ratio
matching to measured ratios, the classification of geological layers, and the flow directions of groundwater can be determined.
This method is applied to three hill slopes in Japan and the results are in good agreement with the observations and measurements
of soil cores obtained by drilling. The classification of geological layers is found to be quantitatively connected with the
rates of organic matter in soil cores.
Received: 5 February 1999 · Accepted: 7 September 1999 相似文献