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Zn-粘土催化剂对染料废水的O3氧化降解性能的影响 总被引：16，自引：0，他引：16
对于生物难降解性有机染料废水,用矿物催化剂进行复合催化氧化获 得了比较理想 的实验处理效果。以粘土为载体加载金属锌氧化物制成的可重复使用的固体催化剂,对人工模拟的染料废水进行复合催化臭氧氧化实验,获得了满意的效果。该法进一步提高了臭氧的降解效果,降低了处理成本。 相似文献
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包裹缓释外壳的缓释氧材料的性能影响分析 总被引：1，自引：0，他引：1
针对地下水水质原位生物修复过程中由于缺乏氧气导致的生物活性降低、修复作用受抑等问题,以过氧化镁(MgO2)为释氧原料,塑性剂、缓冲剂、造孔剂为载体材料,采用共混滚动造粒技术,分别制备出包裹和不包裹缓释外壳的释氧材料(ORC)并进行材料性能对比分析。扫描电镜和静态实验研究表明:粒径在0.6～0.8 cm之间未添加缓释外壳的ORC材料,其机械强度约为14～18 N,固液比投加量2 g/L时,氧释放系数K为0.005 89,氧平衡浓度Cm为10.641 mg/L,材料在实验四个月后溶解氧含量达到峰值后开始逐渐下降;粒径在0.6～0.8 cm之间添加缓释外壳的ORC材料,其机械强度达到30～70 N,液固比投加量2g/L时,氧释放系数K为0.004 66,氧平衡浓度Cm为10.57 mg/L,八个月后溶解氧浓度开始逐渐下降。分析结果表明,添加缓释外壳的ORC材料其强度和释氧周期都有提高。 相似文献
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Field methods for amending marine sediment with activated carbon and assessing treatment effectiveness 总被引：1，自引：0，他引：1
Cho YM Smithenry DW Ghosh U Kennedy AJ Millward RN Bridges TS Luthy RG 《Marine environmental research》2007,64(5):541-555
Previous laboratory studies have shown reductions in PCB bioavailability for sediments amended with activated carbon (AC). Here we report results on a preliminary pilot-scale study to assess challenges in scaling-up for field deployment and monitoring. The goals of the preliminary pilot-scale study at Hunters Point Shipyard (San Francisco, USA) were to (1) test the capabilities of a large-scale mixing device for incorporating AC into sediment, (2) develop and evaluate our field assessment techniques, and (3) compare reductions in PCB bioavailability found in the laboratory with well-mixed systems to those observed in the field with one-time-mixed systems. In this study we successfully used a large-scale device to mix 500kg of AC into a 34.4m(2) plot to a depth of 1ft, a depth that includes the majority of the biologically active zone. Our results indicate that after 7 months of AC-sediment contact in the field, the 28-day PCB bioaccumulation for the bent-nosed clam, Macoma nasuta, field-deployed to this AC-amended sediment was approximately half of the bioaccumulation resulting from exposure to untreated sediment. Similar PCB bioaccumulation reductions were found in laboratory bioassays conducted on both the bivalve, M. nasuta and the estuarine amphipod, Leptocheirus plumulosus, using sediment collected from the treated and untreated field plots one year after the AC amendment occurred. To further understand the long-term effectiveness of AC as an in situ treatment strategy for PCB-contaminated sediments under field conditions, a 3-year comprehensive study is currently underway at Hunters Point that will compare the effectiveness of two large-scale mixing devices and include both unmixed and mixed-only control plots. 相似文献
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Experiments were conducted in a Mars simulation chamber (MSC) to characterize the survival of endospores of Bacillus subtilis under high UV irradiation and simulated martian conditions. The MSC was used to create Mars surface environments in which pressure (8.5 mb), temperature (-80, -40, -10, or +23 degrees C), gas composition (Earth-normal N2/O2 mix, pure N2, pure CO2, or a Mars gas mix), and UV-VIS-NIR fluence rates (200-1200 nm) were maintained within tight limits. The Mars gas mix was composed of CO2 (95.3%), N2 (2.7%), Ar (1.7%), O2 (0.2%), and water vapor (0.03%). Experiments were conducted to measure the effects of pressure, gas composition, and temperature alone or in combination with Mars-normal UV-VIS-NIR light environments. Endospores of B. subtilis, were deposited on aluminum coupons as monolayers in which the average density applied to coupons was 2.47 x 10(6) bacteria per sample. Populations of B. subtilis placed on aluminum coupons and subjected to an Earth-normal temperature (23 degrees C), pressure (1013 mb), and gas mix (normal N2/O2 ratio) but illuminated with a Mars-normal UV-VIS-NIR spectrum were reduced by over 99.9% after 30 sec exposure to Mars-normal UV fluence rates. However, it required at least 15 min of Mars-normal UV exposure to reduce bacterial populations on aluminum coupons to non-recoverable levels. These results were duplicated when bacteria were exposed to Mars-normal environments of temperature (-10 degrees C), pressure (8.5 mb), gas composition (pure CO2), and UV fluence rates. In other experiments, results indicated that the gas composition of the atmosphere and the temperature of the bacterial monolayers at the time of Mars UV exposure had no effects on the survival of bacterial endospores. But Mars-normal pressures (8.5 mb) were found to reduce survival by approximately 20-35% compared to Earth-normal pressures (1013 mb). The primary implications of these results are (a) that greater than 99.9% of bacterial populations on sun-exposed surfaces of spacecraft are likely to be inactivated within a few tens of seconds to a few minutes on the surface of Mars, and (b) that within a single Mars day under clear-sky conditions bacterial populations on sun-exposed surfaces of spacecraft will be sterilized. Furthermore, these results suggest that the high UV fluence rates on the martian surface can be an important resource in minimizing the forward contamination of Mars. 相似文献
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This article describes the Cancer Atlas Viewer: free, downloadable software for the exploration of United States cancer mortality data. We demonstrate the software by exploring spatio-temporal patterns in colon cancer mortality rates for African-American and white females and males in the southeastern United States over the period 1970–1995. We compare the results of two cluster statistics: the local Moran and the local G*, through time. Overall, the two statistics reach similar conclusions for most locations. Where they disagree reveals functional differences in the kinds of local spatial variation to which the statistics are sensitive and identifies some interesting patterns in the data. There are only two persistent clusters of colon cancer mortality through time, and these are clusters of low values.This project was funded by grant CA92669 from the National Cancer Institute to BioMedware, Inc. The perspectives stated in this article are those of the authors and do not necessarily represent the official views of the National Cancer Institute. Constructive criticism from Heidi Durbeck of BioMedware, Peter Rogerson of SUNY-Buffalo, and three anonymous reviewers helped us improve the interpretation and presentation of these results. 相似文献
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丝光沸石岩/水镁石在臭氧化染料废水体系中的增效作用机理研究 总被引：2，自引：0，他引：2
本文针对有机染料废水臭氧化后水体严重酸化、导致臭氧化效率显著降低的问题,提出利用矿物材料改善臭氧化水体酸度,进一步提高臭氧化效率的思路。一方面采用高比表面积丝光沸石岩加载铜的氧化物作为吸附剂提高臭氧化效率,同时引入天然矿物水镁石,解决有机染料废水臭氧化后水体严重酸化的难题,进一步提高臭氧化效率。实验结果表明,Cu_丝光沸石岩/水镁石岩(复配方案为Cu_丝光沸石岩与碱性矿物质量比分别为2∶1和1∶1)可以改善染料废水臭氧化后水体的pH值,提高臭氧化效率。其中复配方案为1∶1的水体COD去除率与单独臭氧化相比提高近30%。经详细分析对比,提出矿物材料体系染料废水臭氧化反应中存在Cu_丝光沸石岩表面吸附作用反应机理、与水镁石溶解有关的碱催化机理及Mg2 与有机酸根络合反应机理。 相似文献
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V.S.ROSE R.M.HYDE Department of Physical Sciences Wellcome Research Laboratories South Eden Park Ro Beckenham Kent BR BS U.K.H.J.H.MACFIE AFRC Institute of Food Research Reading Laboratory Shinfiel Reading RG AT U.K. 《地理学报(英文版)》1990,(5)
A survey of members of the U.K.QSAR Discussion Group has been made to determine the extent ofuse and development of chemometric and artificial intelligence(AI)methods in the analysis ofmultivariate quantitative structure-activity relationship(QSAR)data in the U.K.Chemometric methodswere found to be well established in both industrial and educational establishments and there wassignificant method development occurring.AI methods were not employed to any great extent and thegeneral level of interest in these techniques was low compared to chemometric methods.A requirementfor more education in multivariate statistical methods and regression methods was indicated.A need fora user-friendly,comprehensive,commercially available multivariate statistical package containingmultivariate stability testing and regression diagnostic methods was identified. 相似文献
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地质环境与农产品质量 总被引：2，自引：0，他引：2
农业地质学(Agrogeology)作为一门边缘科学,本世纪初就问世。但由于对农业地质工作的重要意义认识不足,因此有关农业地质学的一些基本问题一直研究不足;它作为一门应用科学发展缓慢。但在当今农业生产发展速度远低于地球上人口增长速度的严峻形势下,各国(特别是苏、美)开始重视农业地质工作,增加对农业地质的投资,促进了农业地质学的发展。农业地质学的研究内容概括起来包括:(1)土壤的形成、变化及其改良;(2)农 相似文献