Gaseous phase benzene decomposition by non-thermal plasma coupled with nano titania catalyst

Synergistic effect of atmospheric non-thermal plasma generated by dielectric barrier discharge and nano titania photocatalyst for benzene decomposition was tested. The paper indicated the effect of photocatalyst on removal efficiency of benzene, the compare of photocatalyst characteristic in different high temperatures by heat treatment, analysis of by-products. The results showed that the effect of degradation was visible by added photocatalyst in the plasma reactor. When concentration of benzene was 600 mg/m3 and electric field strength was 10 kV/cm, the removal efficiency of benzene was increased up to 81 % without photocatalyst. At the same condition, the removal efficiency was increased to 15 % higher with photocatalyst. Nano titania crystal was anatase crystal in 450 °C heat treatment which is best for benzene removal. The plasma reactor packed with photocatalyst shows a better selectivity of carbon dioxide than that without photocatalyst. By-products are mostly carbon dioxide, water and a small quantity of carbon monoxide.     

Influence of energy efficiency on VOCs decomposition in non-thermal plasma reactor

In order to promote the plasma technology for commercial application and improve the energy efficiency of non-thermal plasma, a series of experiments on energy efficiency of plasma reactor were carried out for volatile organic compounds removal. This research adopts a pipe-line reaction device with plasma generated by dielectric barrier discharge technology to examine the effects of different experimental parameters, including medium packing, electric field strength, the pollutant initial concentration, and gas velocity, on the energy efficiency. In the study, four kinds of packed materials were packed into the plasma reactor: a complex catalyst, Ba_0.8Sr_0.2Zr_0.1Ti_0.9O₃, MnO₂/γ-Al₂O₃, and γ-Al₂O₃. Through optimizing the experimental parameters, the best decomposition efficiency of toluene and the best energy efficiency were achieved. The experimental results show that the energy efficiency has a trend from increasing to decreasing with increasing pollutant gas velocity, and the energy efficiency changes from increasing to decreasing with the increasing of initial concentration of pollutants, and the decomposition efficiency and the energy efficiency have the same order from high to low with different packed materials in the plasma reactors, in turn, packed with complex catalyst, Ba_0.8Sr_0.2Zr_0.1Ti_0.9O₃, MnO₂/γ-Al₂O₃, γ-Al₂O₃ and no padding. The optimized parameters for toluene decomposition are: the gas flow rate of 2 mL/min, the initial concentration range of 1500–2000 mg/m³, the field strength intensity of 9.6 kV/cm, and the plasma reactor packed with a complex catalyst, which results in the best energy efficiency of 10 g/kWh. This research provides not only a new way to develop the plasma technology, but also a reference for the commercial application.     

Conceptual knowledge processing and graphical representation of multidimensional atmospheric ozone data

The purpose of this paper is to visualize atmospheric ozone data using a new knowledge representation method called Formal Concept Analysis. This method is based on the concept of concept and represents data in hierarchical line diagrams combining the logic of implications with statistical frequency analysis and hierarchical search methods.     

Catalytic nonthermal plasma reactor for the abatement of low concentrations of benzene

Oxidative decomposition of dilute benzene in air was carried out in a dielectric barrier discharge reactor with inner metal fiber electrode that was later modified with transition metal oxides. Typical results indicated the best performance of the designed reactor for the removal of dilute benzene, where conventional techniques may not be efficient. The introduction of transition metal oxides in the discharge zone increased the conversion of benzene and shifted the product distribution to total oxidation. The performance of the reactor was further improved on humidification of air stream. The better performance of MnO_x/SMF over CoO_x and SMF may be due to in situ decomposition of ozone that may lead to the formation of strong oxidant atomic oxygen, whereas the best performance with TiO₂/MnO_x/SMF may be assigned due to the synergy between ozone decomposition on MnO_x surface and photocatalytic action on TiO₂.     

高压线对CSAMT探测结果的影响及数据处理

以干扰严重的某工作区为例,探讨高压线对CSAMT法所测数据的影响,总结了本工作区高压线对CSAMT数据影响的特征;根据其电磁干扰特征,寻求数据处理的方法,运用插值法恢复接近正常场的磁信号,再利用原始电场信号和恢复的磁信号,计算得出视电阻率。这种方法经对比和钻探验证,效果良好。     

Decomposition and analysis by atomic absorption photospectrometry of silicate rocks

A rapid and simple method of analysis of silicate rocks using gold crucibles and fluoroboric acid as a solvent of the disintegrated material has been developed. The main elements are determined in a single treatment. The results obtained are comparable to the values recommended for samples of eleven standard rocks.     

Distribution and degradation of Alkyl benzene sodium sulfonate, and its harmful effect on carp in Dianchi Lake

Sanitary and industrial sewage is a daily serious detriment to the water quality of Dianchi Lake, Yunnan Province, China. The numerous anionic detergents contained in sanitary sewage and the large number of metallic elements such as Cu, Pb, Cd contained in industrial discharge have made an obvious harmful effect on growth of carp (Cyprinus carpio chilia Wu et al.) in the lake. At the Dianchi Lake sampling and water intake area near Dragon Gate Village, the Linear Alkyl Sulfonate content in the water is over 0.7 (mg/l). This caused the carp's incubation rate and the terateger rate to reach 85% and 28% respectively, and results in a lethality rate of young carp of about 38%. In addition, further study has been stated on the distribution and degradation rates in Dianchi Lake water and in its sediments of two isomeric anionic detergents: ABS (Alkyl Benzene Sulfonate, in short form ABS) and LAS (Linear Alkyl Sulfonate, in short form LAS), and the harmful effect of LAS to its carp. Measures for harnessing and protecting the lake's aquatic environment from pollution, and using the area to develop carp aquaculture are posed. Water quality standards for feeding carp are also covered.     

Liquid and solution treatment by thermal plasma: a review

During two last decades, numerous technologies and approaches are presented for treating contaminants in liquids and solutions. Among them, thermal plasma has shown rapid kinetic and high destruction efficiencies due to very high temperature and highly active radicals. Hence, the use of thermal plasma for treatment of the contaminants in liquids and solutions has received a lot of attention in view of its low environmental impacts. This review focuses on thermal plasma, and it describes the current status of liquid and solution treatment using this technology. A comprehensive analysis of the available scientific and technical literature on liquid and solution plasma treatment is presented, including the treatment of a variety of contaminants in liquids and solutions via different kinds of thermal plasma. The principles of thermal plasma generation and the available plasma technologies with potential applications to generate valuable products from liquid waste are presented. In addition, the results of the thermal plasma processes for the treatment of specific contaminants are investigated. In light of the investigated literature, thermal plasma is found to have a significant potential to treat the liquid wastes.     

The effect of the isotopic composition of oxygen on the non-mass-dependent isotopic fractionation in the formation of ozone by discharge of O2

The oxygen gases in a fused silica container cooled to 77K at pressures of 0.5 to 15 cm Hg were energized by an RF generator of 60 kHz to produce ozone which condensed on the cold wall. The isotopomeric compositions of the initial O₂, the O₂ remaining after the discharge, and the O₂ which was completely converted from the O₃ were measured. Oxygen gases of three different isotopic compositions were used. In addition, oxygen pressure, degree of ozone formation, and geometry of the discharge were varied. The isotopomeric data of O₂ gases after the discharge reactions showed very unusual patterns. These patterns depend mainly on the isotopic composition of the oxygen used for the reaction. We compared the data with a model based on the effect of the anharmonicity and the symmetry of the excited ozone molecules on their predissociation. The anharmonicity and symmetry effects depend on the isotopic composition of the O₂ which in turn control the isotope fractionation associated with the formation of ozone. Our data are not compatible with several models such as self-shielding and the structural symmetry of the initial oxygen gas.     

HPA—S高温高压消解铂族金属

铂族金属元素（Pt、Pd、Ir、Rh、Ru、Os）在很多重要的领域中被广泛地应用。如被用作汽车催化剂的基本组成元素,以控制车辆排气污染;在石油行业用作精炼催化剂,并且在各类材料工艺学以及珠宝行业大量被使用。     

矿物类Fenton反应降解有机污染物的研究进展

作为高级氧化工艺之一,Fenton技术能高效地氧化降解有机污染物,矿物催化类Fenton体系的建立则是对Fenton技术的发展和提升。本文在简要介绍传统Fenton技术的基础上,重点阐述了负载型非均相催化类Fenton反应和天然含铁矿物催化类Fenton反应的产生及发展现状。最后结合笔者的科研工作结果展望了天然黑（铁）电气石在矿物催化类Fenton体系中的应用前景。     

煤矿井下地震勘探资料特殊处理方法及效果

与地面地震勘探相比,煤矿井下地震勘探具有较高的分辨率,但也存在一些特殊问题,如炮间时差即为其一,需要采取特殊处理手段加以解决。针对矿用雷管引起的各炮间时差问题,采用单炮初至时间回归预测分析方法校正激发时间不一致所带来的延迟时,并引入了地表一致性振幅校正及地表一致性反褶积技术,使得煤矿井下地震信号振幅、波形不一致的问题得到了较大的改善。实际资料处理效果表明：经过以上处理后,煤矿井下地震叠加剖面效果得到明显改善,为构造解释和岩性解释创造了条件。     

Impacts of ozone on trees and crops

In this review article, we explore how surface-level ozone affects trees and crops with special emphasis on consequences for productivity and carbon sequestration. Vegetation exposure to ozone reduces photosynthesis, growth, and other plant functions. Ozone formation in the atmosphere is a product of NO_x, which are also a source of nitrogen deposition. Reduced carbon sequestration of temperate forests resulting from ozone is likely offset by increased carbon sequestration from nitrogen fertilization. However, since fertilized croplands are generally not nitrogen-limited, capping ozone-polluting substances in the USA, Europe, and China can reduce future crop yield loss substantially.     

甲烷水合物生成和分解的X射线断层扫描试验研究

通过X-射线断层扫描系统(CT)开展甲烷水合物生成和分解试验研究,结果表明:CT可以清楚地描述甲烷水合物形成和分解过程.通过生成和分解的密度图像变化和CT数频率分布以及均方差变化,能够较好地理解甲烷水合物的生成和分解过程变化,同时CT数在生成和分解过程中的变化有助于准确地判断甲烷水合物的生成和分解的相平衡条件.     

Decomposition of ilmenite by concentrated KOH solution under atmospheric pressure

A new process was provided for decomposition of ilmenite by concentrated KOH solution under atmospheric pressure. The significant effects of reaction temperature, KOH concentration, stirring speed, particle size, and alkali-to-ilmenite mass ratios on titanium extraction were studied. The temperature and initial particle size showed significant influence on titanium extraction. The experimental data of the extraction rates under the relevant operating variables were well interpreted with the shrinking core model under chemically controlled process. The apparent activation energy of the reaction was evaluated using the Arrhenius expression. Approximately 80–85% of the titanium could be leached from the ilmenite ore under the optimal conditions.     

硅酸盐样品微波加热碱熔分解方法

本文研究了硅酸盐样品在常压下，用微波炉进行碱熔分解的熔样时间，试剂用量和滴加水量等情况对分解的影响，确定了最佳实验条件，将此法用于地球化学标准参考样品ＳｉＯ２的测定，取得了满意的结果。     

苯和甲苯在土壤中的吸附行为研究

选取某采油厂不同有机碳含量的表层土壤作为吸附剂,采用批实验方法对原油中代表性组分苯和甲苯的单组分吸附和双组分竞争吸附行为进行了研究。研究表明,单组分溶液中,苯和甲苯在土壤中的吸附符合线性规律,吸附能力与土壤有机碳含量成正比;双组分溶液中,苯和甲苯共存时存在竞争吸附,土壤对它们的吸附小于单组分时的情况。竞争吸附的结果说明,除分配吸附以外,介质表面点位对苯和甲苯的吸附也起着重要的作用。     

掺铁-TiO2/膨润土复合光催化材料制备及性能

采用酸性溶胶法制备掺铁-TiO₂/膨润土复合光催化剂,利用XRD﹑IR等测试手段对其进行了表征。通过测试甲基橙溶液的脱色率和COD去除率对复合光催化剂的光催化活性进行了评价。结果表明,该催化剂有较高的催化氧化性能,在太阳光照射下,对pH=4﹑质量浓度为20 mg/L的甲基橙溶液进行降解时,其脱色率可达95%以上,COD去除率可达85%以上。该催化剂在经过200℃焙烧活化2.5 h后可多次重复利用。