Treatment of a Trifluraline Effluent by Means of Oxidation‐Coagulation with Fe(VI) and Combined Fenton Processes     

Ayrton F. Martins  Carla da S. Frank  Marcelo L. Wilde 《洁净——土壤、空气、水》2007,35(1):88-99

The amination water (AW) effluent stream from the industrial production of the trifluraline herbicide was submitted to an oxidation‐coagulation treatment with potassium ferrate, combined with advanced oxidation processes. The experimental results obtained by analysis of variance (ANOVA) for the oxidation‐coagulation‐Fenton process, evaluating the variables pH (A), Fe(VI) concentration (B), and H₂O₂ concentration (C), demonstrated that the regression equation resulting from the Response Surface Methodology (RSM) experimental design, for the quadratic model, was η_Abs (%) = 36.9– 21.58A + 8.37A² + 1.36B + 0.92B² + 1.08C + 1.52C² + 1.27AB – 1.34AC + 1.33BC. The maximum absorptiometric color reduction occurred at pH 3, with corresponding maximum amounts of iron and hydrogen peroxide. The absorptiometric color and COD reduction were 96% and 57%, respectively. For the oxidation‐coagulation‐photo‐Fenton process, the analyzed variables were pH (A), Fe(VI) concentration (B), H₂O₂ concentration (C), and temperature (D). The regression equation resulting from the quadratic model was η_Abs (%) = 38.3 – 20.2A + 8.12A² – 0.27B + 3.73B² + 0.3C + 3.6C² + 1.67D + 3.1D² + 1.72AB + 0.51AC – 1.82AD + 0.74BC – 1.11BD + 0.03CD. The ANOVA response showed that the highest absorptiometric color reduction occurred at pH 3, with respective maximum amounts of iron and hydrogen peroxide at 60°C. The maximum efficiencies achieved by the proposed treatment process for the trifluraline effluent stream were 95% and 85%, for absorptiometric color and COD reduction, respectively.  相似文献   

Local Tsunami Warning in the Pacific Coastal United States   总被引：2，自引：1，他引：1  

Mark?DarienzoEmail author  Al?Aya  George?L.?Crawford  David?Gibbs  Paul?M.?Whitmore  Tyree?Wilde  Brian?S.?Yanagi 《Natural Hazards》2005,35(1):111-119

Coastal areas are warned of a tsunami by natural phenomena and man-made warning systems. Earthquake shaking and/or unusual water conditions, such as rapid changes in water level, are natural phenomena that warn coastal areas of a local tsunami that will arrive in minutes. Unusual water conditions are the natural warning for a distant tsunami. Man-made warning systems include sirens, telephones, weather radios, and the Emergency Alert System. Man-made warning systems are normally used for distant tsunamis, but can be used to reinforce the natural phenomena if the systems can survive earthquake shaking. The tsunami warning bulletins provided by the West Coast/Alaska and Pacific Tsunami Warning Centers and the flow of tsunami warning from warning centers to the locals are critical steps in the warning process. Public knowledge of natural phenomena coupled with robust, redundant, and widespread man-made warning systems will ensure that all residents and tourists in the inundation zone are warned in an effective and timely manner.  相似文献   

中国东北麻山杂岩晚泛非期变质的锆石SHRIMP年龄证据及全球大陆再造意义   总被引：43，自引：1，他引：43  

Simon A Wilde  吴福元  张兴洲 《地球化学》2001,30(1):35-50

中国东北地区佳木斯地块南部麻山杂岩正、副片麻岩 7个样品的锆石 SHRIMP年龄数据首次明确地表明 ,东北地区存在 500 Ma的晚泛非期高级变质作用事件。峰期麻粒岩相变质导致柳毛地区 (502± 10)Ma (2σ )深熔花岗岩的形成。正、副片麻岩变质年龄的一致性表明它们已在变质前发生了构造叠置。西麻山副片麻岩中含有在后期麻粒岩相变质过程中未重结晶的碎屑锆石，由此形成从协和一致的 550 Ma到弱不一致 1 900 Ma的较大 207Pb/206Pb年龄变化范围，表明其原岩具有从新元古代到中元古代-古元古代的年龄。柳毛地区变质的片麻状闪长岩中所含的古老锆石的 207Pb/206Pb年龄为 546～ 1 460 Ma表明，该闪长岩大约在 1 400 Ma就位，并受到 500 Ma变质事件的影响，从而说明柳毛地区存在中元古代基底。然而，与以前的认识相反，麻山杂岩不存在具有太古宙基底的同位素证据。晚泛非期变质事件年龄的确定对重塑晚前寒武纪-显生宙早期麻山杂岩和佳木斯地块的古地理位置具有重要意义。根据目前获得的有关证据，认为佳木斯地块可能曾经位于冈瓦纳大陆北缘的华北克拉通附近。  相似文献   

Reply to the comment by B. A. Hofmann     

P. Wilde  M. S. Quinby-Hunt 《Mineralium Deposita》1993,28(4):285-286

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The provenance of low-calcic black shales   总被引：2，自引：0，他引：2  

M. S. Quinby-Hunt  P. Wilde 《Mineralium Deposita》1991,26(2):113-121

The elemental concentration of sedimentary rocks depends on the varying reactivity of each element as it goes from the source through weathering, deposition, diagenesis, lithification, and even low rank metamorphism. However, non-reactive components of detrital particles ideally are characteristic of the original igneous source and thus are useful in provenance studies. To determine the source of detrital granitic and volcanic components of low-calcic (<1% CaCO₃) marine black shales, the concentrations of apparently non-reactive (i.e. unaffected by diagenetic, redox and/or low-rank metamorphic processes) trace elements were examined using standard trace element discrimination diagrams developed for igneous rocks. The chemical data was obtained by neutron activation analyses of about 200 stratigraphically well-documented black shale samples from the Cambrian through the Jurassic. A La-Th-Sc ternary diagram distinguishes among contributions from the upper and bulk continental crust and the oceanic crust (Taylor and McLennan 1985). All the low-calcic black shales cluster within the region of the upper crust. Th-Hf-Co ternary diagrams also are commonly used to distinguish among the upper and bulk continental crust and the oceanic crust (Taylor and McLennan 1985). As Co is redox sensitive in black shale environments, it was necessary to substitute an immobile element (i.e. example Rb) in the diagram. With this substitution of black shales all cluster in the region of the upper continental crust. To determine the provenance of the granitic component (Pearce et al. 1984), plots of Ta vs Yb and Rb vs Yb + Ta shows a cluster at the junction of the boundaries separating the volcanic arc granite (VAG), syn-collision granite (syn-COLG), and within-plate granite (WPG) fields. The majority fall within the VAG field. There are no occurrences of ocean ridge granite (ORG). The minimal contribution of basalts to marine black shales is confirmed by the ternary Wood diagram Th-Hf/3-Ta (Wood et al. 1979). The black shales plot in a cluster in a high Th region outside the various basalt fields, which suggests contribution from the continental crust.  相似文献   

Petrogenesis of an Alkali Syenite-Granite-Rhyolite Suite in the Yanshan Fold and Thrust Belt, Eastern North China Craton: Geochronological, Geochemical and Nd-Sr-Hf Isotopic Evidence for Lithospheric Thinning   总被引：6，自引：0，他引：6  

Yang  Jin-Hui; Wu  Fu-Yuan; Wilde  Simon A.; Chen  Fukun; Liu  Xiao-Ming; Xie  Lie-Wen 《Journal of Petrology》2008,49(2):315-351

The Yanshan Fold and Thrust Belt in eastern China has been intrudedby a series of alkalic igneous rocks, ranging in compositionfrom granite and rhyolite to syenite and trachyte. Laser ablationinductively coupled plasma mass spectrometry U–Pb analysesof zircon from three alkaline suites yield Early Cretaceousages of 130–117 Ma. Three groups of rocks have been identifiedbased on their mineralogical, geochemical and Sr–Nd–Hfisotope characteristics. The alkali granites and rhyolites areferroan and have low Al₂O₃, MgO, CaO, Sr, Ba and Eu concentrationsand high SiO₂, total Fe₂O₃, K₂O, Nb, Ga, Ta, Th and heavy rareearth element abundances and Ga/Al ratios. Geochemical dataand Sr-, Nd- and zircon Hf-isotopic compositions [(⁸⁷Sr/⁸⁶Sr)_i= 0·7050–0·7164, _Nd(t) = –8·4to –13·6 and _Hf(t) = –5·7 to –16·8]indicate that they were probably generated by shallow dehydrationmelting of biotite- or hornblende-bearing granitoid crustalsource rocks and then mixed with contemporaneous magma froma mantle and/or lower crustal source. Ferroan syenites havedistinct geochemical features from those of the alkaline granitesand rhyolites, suggesting that they were produced by clinopyroxeneand plagioclase fractionation of melt derived from an enrichedmantle source, mixed with lower and upper crustal-derived magmas.The magnesian syenites and trachytes have Sr-, Nd- and zirconHf-isotopic compositions that are distinct from those of theferroan syenites. They were mainly derived from partial meltingof lower crustal materials, mixed with enriched mantle-derivedalkali basaltic magma. The emplacement of an alkali syenite–granite–rhyolitesuite, coeval with the formation of metamorphic core complexesand pull-apart basins in eastern China, indicates they formedin an extensional setting, possibly as a result of lithosphericthinning. KEY WORDS: alkaline rocks; zircon U–Pb dating; petrogenesis; crustal extension; Yanshan Fold and Thrust Belt; North China Craton  相似文献   

Major tectonic units of the North China Craton and their Paleoproterozoic assembly   总被引：28，自引：0，他引：28  

赵国春  孙敏  Simon A.Wilde 《中国科学D辑(英文版)》2003,46(1)

In the last decade, Chinese geologists have made a remarkable progress in studies on thelithology, structural style, metamorphic evolution, geochemistry and geochronology of the North China Craton, including recognition of numerous tonalitic-trondhjemitic…  相似文献   

Monterey Fan: Growth pattern control by basin morphology and changing sea levels     

William R. Normark  C. E. Gutmacher  T. E. Chase  Pat Wilde 《Geo-Marine Letters》1983,3(2-4):93-99

Monterey Fan is the largest modern fan off the California shore. Two main submarine canyon systems feed it via a complex pattern of fan valleys and channels. The northern Ascension Canyon system is relatively inactive during high sea-level periods. In contrast, Monterey Canyon and its tributaries to the south cut across the shelf and remain active during high sea level. Deposition on the upper fan is controlled primarily by the relative activity within these two canyon systems. Deposition over the rest of the fan is controlled by the oceanic crust topography, resulting in an irregular fan shape and periodic major shifts in the locus of deposition.  相似文献   

Turbidity currents generated by Hurricane Iwa     

A. T. Dengler  P. Wilde  E. K. Noda  W. R. Normark 《Geo-Marine Letters》1984,4(1):5-11

Off southwest Oahu, Hawaii, an array of current sensors recorded four successive episodes of downslope displacement associated with high-speed near-bottom currents of up to 200 cm/s and elevated water temperatures. These episodes coincided with the maximum storm effects of hurricane Iwa. Sensors from four moorings recorded increases in depth of as much as 220 m, implying downslope movement of as much as 2.4 km at speeds up to 300 cm/s. A succession of slope failures at or above the 110-m shelf break, each resulting in a turbidity current event, is the favored explanation.We dedicate this work to Gil Van Dyke, who lost his life in an accident during deployment of the current meter moorings.  相似文献   

New palynology-based astronomical and revised 40Ar/39Ar ages for the Eocene maar lake of Messel (Germany)     

Olaf K. Lenz  Volker Wilde  Dieter F. Mertz  Walter Riegel 《International Journal of Earth Sciences》2015,104(3):873-889

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