Leaf and fruit necroses associated with vanadium-rich ash emitted from a power plant burning fossil fuel

Necrotic brown lesions developing on leaves and fruits of lemon, and other plants, near fossil-fuel-burning power plants emitting vanadium-rich ash, were reproduced experimentally by inoculating leaves with this type of ash, which is strongly acidic. Comparable lesions were formed when drops of vanadium oxide, dissolved in NaOH, were put on leaves and fruits. Neutralizing, or adding excess H₂SO₄ (to pH 3), did not alter lesion formation. The histology of these lesions was similar to that of lesions attributed to vanadium-rich ash.     

Humic fractions of organic wastes

The distribution and composition of humic and fulvic acids have been investigated in the following organic wastes: straw, farmyard manure, sewage sludge, poultry manure, municipal refuse compost and pig slurry. Of the total organic carbon, the proportion present as humic carbon varied from about 13% in the compost to 50% in the pig slurry; the humic compounds extracted are characterized by a variable chemical composition. As compared to the natural humic substances from soil organic matter, these compounds show a lower content of acidic functional groups, lower E₄/E₆ and C/H ratios and can be classified as young forms of humic substances.     

铅锌冶炼弃渣有害特征及其浸出行为研究

铅锌弃渣是有色金属工业排出的大宗固体废物之一。其中有铅冶炼系统排铅烟花炉渣,锌系统排锌回转窑渣。铅锌弃渣一般含有多种超过排放标准而目前又尚无成熟工艺提取的有价值和稀贵金属元素。这些废渣的堆存直接影响自然景观,并有可能对环境如土壤、水体和作物等造成危害。因此,考察铅锌渣的有害特征,研究其水浸出行为与规律,对解决铅锌弃渣对环境污染,寻求同行业固体废物的治理途径具有重要的现实意义。     

Latest precambrian (Cadomian) zircon ages, Nd isotopic systematics and P-T evolution of granitoid orthogneisses of the Erzgebirge, Saxony and Czech Republic

Single zircons from two orthogneiss complexes, the Grey Gneiss and Red Gneiss, the lowermost tectonic units in the Erzgebirge, were dated. The grey Freiberg Gneiss is of igneous origin and has a ²⁰⁷Pb/²⁰⁶Pb emplacement age of 550±7 Ma. A quartz monzonite from Lauenstein contains idiomorphic zircons with a mean ²⁰⁷Pb/²⁰⁶Pb age of 555±7 Ma as well as xenocrysts ranging in age between 850 and 1910 Ma. Red gneisses from the central Erzgebirge contain complex zircon populations, including numerous xenocrysts up to 2464 Ma in age. The youngest, idiomorphic, zircons in all samples yielded uniform ²⁰⁷Pb/²⁰⁶Pb ages between 550±9 and 554±10 Ma. Nd isotopic data support the interpretation of crustal anatexis for the origin of both units. _Nd(t) values for the grey gneisses are –7.5 and –6.0 respectively, (mean crustal residence ages of 1.7–1.8 Ga). The red gneisses have a wider range in _Nd(t) values from –7.7 to –2.8 (T _DM ages of 1.4–1.8 Ga). The zircon ages document a distinct late Proterozoic phase of granitoid magmatism, similar in age to granitoids in the Lusatian block farther north-east. However, Palaeozoic deformation as well as medium pressure metamorphism ( 8 kbar/600–650° C) are identical in both gneiss units and distinguish these rocks from the Lusatian granitoids. The grey and red gneisses were overthrust by units with abundant high-pressure relicts and a contrasting P-T evolution. Zircon xenocryst and Nd model ages in the range 1000–1700 Ma are similar to those in granitoid rocks of Lusatia and the West-Sudetes, and document a pre-Cadomian basement in parts of east-central Europe that, chronologically, has similarities with the Sveconorwegian domain in the Baltic Shield.     

次级燃料还原燃烧产物内NOx的动力学特性研究

提出了在燃煤电站锅炉炉膛内添加次级燃料建立ＮＯｘ的还原区，以控制ＮＯｘ的排放，建立了描述ＮＯｘ还原动态过程的数学模型和化学动力学模型，对计算值和实测值作了比较分析。