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1.
利用一株絮凝效果好的胶质芽胞杆菌所产的微生物絮凝剂进行了深圳市较具代表性电镀废水絮凝性实验。结果表明,微生物絮凝剂有较强的吸附作用,能降低电镀废水中重金属离子的浓度,对废水pH值有一定的调节作用。实验确定了处理综合电镀废水中重金属的条件,初步提出电镀废水的处理和回用工艺。 相似文献
2.
天然铁的硫化物净化含铬污水的新方法 总被引：16，自引：1，他引：15
天然铁的硫化物净化含铬污水的新方法鲁安怀（中国地质大学材料系,北京,１０００８３）在为确保环境质量而开展的重金属污染物防治活动中,人们特别注重含铬废水的治理,并已成为国内外环保界优先控制的项目。而含铬废水主要来源于电镀企业中镀铬漂洗水、各种铬钝化漂洗... 相似文献
3.
电镀园区废水处理过程中,由于园区企业难以做到彻底的分质分流,导致废水处理出现破络不彻底,次亚磷酸盐、氰化物等出现再络合与难降解等问题,同时,深度处理后,浓水需要进行深度处理,重金属离子浓度、总磷、总氮处理都存在难以达标的情况。本文根据企业电镀废水的典型水质和水量特征,研究设计了改进的CAFE处理工艺,详细论证了各工艺的处理过程、主要设备及相关设计参数,并将该工艺在南通某电镀园区电镀废水处理中进行了实际应用。运行的实践表明,该套设计方案污水处理运行稳定,最终出水的CODCr（化学需氧量）、NH4-N、总铬、六价铬、总镍指标的平均质量浓度分别为34.00、5.41、0.29、0.03、0.05 mg/L,均远远小于电镀废水的排放标准,达到了电镀废水的深度处理要求。 相似文献
4.
为了全面提升内蒙古大型硫铁矿的综合利用价值,尝试将其主要成分磁黄铁矿和黄铁矿分别用于处理含铬废水,找到了天然硫铁矿和改性硫铁矿处理Cr(Ⅵ)的最佳实验条件。与已有的研究相比,本研究所使用的矿样粒径减少到80~100目,用量减少了70%,所处理的含铬废水浓度增大到50 mg/m L。将处理含铬废水后的硫铁矿经XPS扫描分析后发现,天然黄铁矿在pH值分别为1.84、4.15和10.87的反应体系中处理Cr(Ⅵ)后,大部分的Cr(Ⅲ)以Cr2S3的物相出现,分别占总铬物相的77.99%、86.53和100%。天然磁黄铁矿在pH值为6.5,加热500℃改性后的黄铁矿在pH值为4.15时,也有相当量的三价铬以Cr2S3的物相出现。用已经获得的处理含铬Cr(Ⅵ)的最佳条件,直接用于处理某皮革厂高浓度的含Cr(Ⅲ)实际废水,去除率达73%。本研究为综合处理含铬废水提供了思路,成为矿山资源化的途径之一。 相似文献
5.
6.
根据陕西某汞锑选矿厂含铬废水成因及治理工艺特点，在GB7466－87标准方法的基础上，拟订了该矿区含铬废水中全铬及六价铬的测定方法。加标回收实验的回收率为99.9%－100.2%，对ρ（TCr)为216.5mg/L的样液测定10次，其RSD％为1.3，广泛适应该矿区实验室的分析测定。 相似文献
7.
颗粒炭动态吸附含Cu－EDTA电镀废水的研究 总被引：1，自引：0，他引：1
本文采用颗粒状活性炭，动态吸附处理含Ｃｕ－ＥＤＴＡ电镀废水，对动态法的工艺条件进行了系统研究．最佳工艺条件为：炭粒颗粒度８０～１００目，ｑＨ＝５．５，吸附等温方程式为ｑ＝１９．０Ｃ０．２５９，吸附容量（１５０～２００ｍｌ废水）／ｇ活性炭，过滤速率为１２ｍｌ／ｍｉｎ．结果表明，该方法具有处理效果好，易于扩大应用的优点． 相似文献
8.
氢氧化镁处理含铬废水的研究 总被引：17，自引：0，他引：17
用硫酸亚铁将废水中Ｃｒ（Ⅵ）还原成Ｃｒ（Ⅲ）,再用氢氧化镁乳液和废水中的酸,使铬离子,铁离子氢氧化物沉淀,澄清分离,这样含铬废水经处理后,铬的含量及ｐＨ值有达到排放标准,该方法操作简便,效果显著。 相似文献
9.
本文采用颗粒状活性炭，动态吸附处理含Ｃｕ－ＥＤＴＡ电镀废水，对动态法的工艺条件进行了系统研究。最佳工艺条件为：炭粒颗粒度８０－１００目，ＰＨ＝５．５，吸附等温方程为ｑ＝１９．０Ｃ＾０．２５０，吸附容量（１５０－２００ｍｌ废水）／ｇ活性炭，过滤速度为１２ｍｌ／ｍｉｎ，结果表明，该方法具有处理效果好，易于扩大应用的优点。 相似文献
10.
AMA吸附剂吸附铬(Ⅵ)的性能研究及应用 总被引：2，自引：0，他引：2
用凹凸棒石粘土改性制备了AMA吸附剂，对其吸附铬(Ⅵ)的性能进行了较系统地研究。选择了吸附铬(Ⅵ)的最佳条件，用来处理含铬(Ⅵ)废水，铬(Ⅵ)的去除率在96％以上，铬(Ⅵ)的残余浓度小于0．5mg/L，符合国家的排放标准。可以在废水治理中推广应用。 相似文献
11.
Discontinuities such as fractures or cracks are common in geo-materials. Connectivity is a comprehensive parameter that includes the influence of length, orientation and density of the discontinuities. The main objectives of this paper are to define connectivity based on the statistical geometrical parameters of a network of random discontinuities and to quantify the hydraulic properties of the network using connectivity. An analytical method is first proposed to evaluate connectivity through the density of degree of freedom (DDOF). The analytically estimated DDOF is verified using numerical analysis. DDOF increases with the increases in the mean length, relative orientation and density of the random discontinuity network. Connectivity becomes better and the permeability becomes larger with increasing DDOF. The representative element volume (REV) of a random discontinuity network can be estimated based on connectivity. When a discontinuity network is poorly connected, a REV does not exist when the size of the discontinuity network is smaller than 10 times of the mean length of the discontinuities. When a discontinuity network is normally connected, a REV exists when the REV size is smaller than 10 times of the mean length of the discontinuities. When the discontinuity network is highly connected, the REV size is only 2–4 times of the mean length of the discontinuities. The results indicate that DDOF is a good indicator to quantify the connectivity of a random discontinuity network and the relationship between connectivity and permeability. 相似文献
12.
新疆吉木萨尔大龙口非海相二叠系—三叠系界线层段古地磁特征 总被引：5，自引：0，他引：5
通过对吉木萨尔县大龙口非海相二叠系-三叠系界线上下地层磁性特征的研究,在梧桐沟组-锅底坑组共发现78个极性异常,其中以负极性为主,间隔了一系列的正极性和过渡极性.梧桐沟组上部以负极性为主,间隔了2个正极性和过渡极性.这可与巴基斯坦盐岭和四川广元上寺的大隆组下部对比,即相当于Da段.梧桐沟组顶部和锅底坑组底部,正、负极性变化频繁,极性特征可与巴基斯坦盐岭和四川广元上寺大隆组中部对比,即相当于Db段.锅底坑组下部以负极性为主,间隔了2个正极性段,可与四川广元上寺大隆组中上部对比,即相当于Dc段.锅底坑组中下部以负极性为主,上部夹1个正极性段,可与四川广元上寺大隆组上部磁性特征对比,即相当于Dd段.锅底坑组中上部以负极性为主,间隔了4个正极性段,可与四川广元上寺飞仙关组下部对比,即相当于Fa段.根据磁性段的划分对比,将二叠系三叠系界线置于Fa和Dd之间,即本次研究测制剖面的41层和42层之间.根据各岩组的古地磁特征求得岩组形成时的古地磁极:梧桐沟组79.1°N,238.1°;锅底坑组72.3°N,322.2°;下三叠统77.5°N,320.8°.古纬度基本一致,为32°～35°N. 相似文献
13.
Keitaro KUNUGIZA 《Resource Geology》1999,49(4):199-212
Abstract: Boundaries between the cpx Zn-Pb ores of the Kamioka ore deposit and host clinopyroxene granitoid in the Hida metamorphic belt were examined to decipher the incipient stage of ore formation process. The boundaries are characterized by the compositional zoning of relic clinopyroxene with outward increase of XMg from 0. 5 to 0. 75 in the host rocks, and by the incline of XMg towards the ores, passing through the boundaries, reaching up to 0. 95. In the ores, relic clinopyroxene is rimmed by hedenbergite. Both clinopyroxenes show compositional zoning with outward decrease and increase of XMg and MnO, down to 0. 02 and to 3. 2 wt%, respectively. The presence of high magnesian clinopyroxene can be explained if hydrothermal fluid flow had leached hedenbergite component of relic clinopyroxene. The incline of XMg of clinopyroxene toward the ores was attributed to the degree of dissolution of clinopyroxene, and thus the total amounts of fluid to have passed. The outward decrease of XMg of clinopyroxenes in the ores was due to crystal-fluid fractionation during precipitation. These mineralogical changes at the boundaries indicate the time-integrated phenomena of hydrothermal ore forming process. Firstly, leaching of ore components by infiltrating fluid proceeded in host rocks, and enhanced the formation of a fluid channel. The condition of fluid changes through the fluid channel in P-T space, and hence ore forming minerals precipitate at a remote place from the leaching one. This in turn caused the physicochemical change of fluid condition anyhow, and accelerated the precipitation of the minerals. This leaching-precipitation sequence appears a basic process of hydrothermal ore-forming system, and characterizes the incipient stage of ore formation process of the Kamioka Zn-Pb ore deposit. Compositional zoning of clinopyroxenes defines Z-shaped compositional trend in the Di–Hd–Jo diagram, each arm of which corresponds to the leaching and the precipitation stages, and the secondary dissolution of precipitated clinopyroxene. 相似文献
14.
贵州罗甸二叠纪末生物大灭绝事件后沉积的微生物岩时代和沉积学特征 总被引：9，自引：1，他引：8
二叠纪末期发生的显生宙以来最大的生物绝灭事件,使海洋生态系统和陆地生态系统均受到重创之后,微生物岩广泛分布于全球正常浅海地区。研究认为,扬子地台在二叠纪末期存在一次海平面降低的事件,造成研究区二叠纪地层与早三叠世微生物岩之间存在沉积间断或剥蚀,并使三叠纪牙形石混入二叠纪末期的沉积物中。二叠-三叠系界线位于微生物岩层的底界;微生物岩形成于早三叠世最早期,相当于Hindeodus parvus带,是早三叠世最早期开始的海侵事件为其提供生长所需的可容纳空间。在Isarcicella staeschei带-I. isarcica带早期再次发生相对海平面降低事件,之后海平面开始快速上升。研究区早三叠世早期的微生物岩以凝块构造发育为特征,具有斑状、层状、枝状和网状凝块构造4种典型中型构造。结合前人的工作,认为微生物群落通过生物沉积和物理沉积作用形成球状体,球状体汇聚形成不同的中型凝块构造。研究扬子地台早三叠世凝块石的确切时代和结构、构造类型特征,为准确恢复生物大灭绝事件前后的环境变迁以及生物演化事件与环境变化的相互作用关系提供重要的证据。 相似文献
15.
Alan M. Jacobs 《Mathematical Geology》1971,3(3):227-238
Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in at-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort. 相似文献
16.
A. Yu. Antonov 《Russian Journal of Pacific Geology》2007,1(2):153-175
This paper summarizes the results of long-term geological, petrological, and geochemical investigations of the Mesozoic-Cenozoic complexes of the Stanovoy Range in order to determine the main reasons for their generation and evolution. The analysis of this material showed that the compositionally variable Late Mesozoic igneous complexes of the Stanovoy Range were formed in various depth facies, from abyssal to surficial. The majority of their salic complexes show minor compositional variations, whereas the mafic complexes are more variable, especially in the southeast of the region. The southeastern Stanovoy Range comprises comparable amounts of both subalkaline and low-alkali igneous rocks, whereas the central part is dominated by subalkaline rocks, and the northwestern part contains rocks only of the shoshonite-latite series. This zoning is fundamentally different from that of typical island arcs, which are characterized by the occurrence of volcanic rocks of similar alkalinity in each zone. Extrusive and intrusive rocks with similar alkali and silica contents (and schlieren-like inclusions in the granitoids of the region) were formed from common magmas of corresponding chemical compositions. In addition, the mafic and most of the salic magmas were formed as independent melting products, whereas the magmas of intermediate composition were formed mainly by mixing of chemically contrasting liquids (i.e., salic and basic). It was shown that the available information on the magmatism of the region is best interpreted in terms of the model of mantle diapirism. In particular, mantle diapirs ascended rather slowly during the Mesozoic and occurred over the whole territory of the Stanovoy Range during the Jurassic-Cretaceous stage (J3-K1), when alkaline and subalkaline basalts were formed. During the Early-Late Cretaceous stage, mantle diapirs produced alkali-poor basalts in the central and eastern parts. During the Cenozoic, the diapir ascended rather rapidly but only in a small area in the eastern part of the region forming alkali basalts. In contrast to the Cenozoic, the Earth’s crust was strongly affected by mantle diapirs and related mafic magmas in the Mesozoic. As a result, crustal sequences were reworked by fluids and subsequently yielded tremendous volumes of compositionally corresponding salic magmas, which interacted and mixed with mafic magmas producing the corresponding chemical zoning. The maximum generation of crustal magmas was confined to the axial zones of ascending diapirs, where the highest energy effects took place, whereas the role of autochthonous gneissic granites increased away from the axis at the expense of typical intrusive complexes. 相似文献
17.
Investigation of the Upper Callovian to Lower Kimmeridgian microfossils from the Makar’yev reference section (Unzha River, East European Platform) has been carried out. The section is characterized by ammonite debris and abundant associations of benthic and planktic foraminifers. It is a perfect object for stratigraphic and paleoecological researches. The biostratigraphic distribution of foraminifers from the Makar’yev section allows one to identify standard foraminifera zones of the East European Platform, as well as to upgrade some of them. The analysis of vertical and lateral ammonites and foraminiferal distribution, completed with litho stratigraphy, has precised the stratigraphic volume and position of boundaries of several lithological units.An improved stratigraphic scheme for the Kostroma area of the Moscow Depression is proposed. Analysis of the composition, structure, and dynamic changes of the foraminiferal assemblages has been performed. The morphofunctional analysis of foraminiferal genera has for the first time identified how foraminiferal morphogroups differing in their life style and feeding strategy varied with short-term paleoenvironmental changes. These morphogroup changes allow establishing four ecostratigraphic levels. These paleoecological data have been calibrated along with geochemical factors. They have shown a crisis of foraminiferal association during the Late Oxfordian and Early Kimmeridgian. A similar crisis has also been discovered in the north of Siberia, which may be an argument for its global distribution. The analysis of the taxonomic composition and the density of foraminiferal associations, in parallel with the structure of the association, has revealed a succession of transgressive and regressive events during the Late Callovian-Early Kimmeridgian. It allows the typification of each assemblage in relation with each event and underlines the occurrence of second-order sea-level fluctuations (middle part of the Middle Oxfordian and the earliest Kimmeridgian). 相似文献
18.
The Atlas of Palaeogeography of China was published in 1955. This paper will introduce the impor- tant historical background of the compilation and publishing of the atlas. Actually it was a direct outcome of the famous Main geological structural units of China written by Huang Jiqing in 1945. Confined by the status of geological development of that stage, the atlas mainly presents the variation of the distribution of old landmasses and oceans during different geological stages. The compilation was based on facies types, palaeontological species , and features of regional fauna assemblages . The basic scale of the atlas was 1:1 000 000. There are totally 20 maps, spanning from the Sinian to Triassic of the Mesozoic. The compila-tion was finished in more than three years. The outline of landmasses and oceans, main direction of trans-gression and regression, distribution of fossils, crustal deformation, mineral deposits, as well as volcanic and glacial activities are shown with various patterns and colors 相似文献
19.
Summary Finite element analyses were conducted to investigate the magnitude of tensile strains imposed on landfill liners due to the
formation of subsurface cavities. The study incorporated the significance of using geogrids to reduce the magnitude of strains
and possibly the potential for collapse of landfill liners. Variations of key parameters included depth of overburden (D) and diameter of the cavity (B). Estimated stress distributions were compared to theoretical values obtained from a model reported in the literature.
Results indicated that, contrary to conventional wisdom, the critical area based on the mechanics of arching was above the
edge of the cavity where stress concentration occurred. Incorporation of geogrid reinforcement reduced the magnitude of tensile
strains. The tensile force in the geogrid was dependent upon the size of the cavity, the depth of the overburden, and the
applied pressure. 相似文献
20.
Horace Moo-Young Tommy Myers Barbara Tardy Richard Ledbetter Wipawi Vanadit-Ellis Tae-Hyung Kim 《Engineering Geology》2003,70(3-4):249-258
Marine sediment capping is a technique where clean sand or sediment is placed over contaminated sediment to reduce the migration of contaminants to the environment. Environmental regulations have limited the use of in situ sediment capping due to concerns about the contaminant migration through the cap. A series of centrifuge tests were conducted to simulate the effects of consolidation settlement of capped marine sediment. This study describes the testing and monitoring of the centrifuge tests. The results from the centrifuge tests are interpreted and compared to predictions made by the PSDDF computer program, which can qualitatively estimate the consolidation settlement of capped marine sediment.
Centrifuge tests were utilized to predict the consolidation of marine sediment caused by the placement of a capping layer. The centrifuge tests used the modeling of models technique to verify that correct modeling procedures were utilized. In this study, the maximum deviation between the centrifuge test results and PSDDF prediction was 20%. Thus, designers should utilize PSDDF consolidation settlement results with caution. Dye tracer studies showed the importance of consolidation-induced advective transport of contaminants. Thus, the capping layer must be appropriately designed to reduce the effects of consolidation-induced advective transport. This may be accomplished by adding a reactive barrier or geosynthetic barrier layer to the cap design. 相似文献