Catalytic ozonation of volatile organic compounds(ethyl acetate)at normal temperature

Catalytic treatments of VOCs at normal temperature can greatly reduce the cost and temperature of processing,and improve the safety factor in line with the requirements of green chemistry.Activated carbon fiber(ACF)was pretreated with 10%H_(2)SO_(4)by single factor optimization to increase specific surface area and pore volume obviously.The catalytic ozonation performance of ACF loaded with Au,Ag,Pt and Pd noble metals on ethyl acetate was investigated and Pd/ACF was selected as the optimal catalyst which had certain stability.Pd is uniformly distributed on the surface of ACF,and Palladium mainly exists in the form of Pd0 with a amount of Pd+2.The specific surface area of the catalysts gradually decreases as the loading increases.The activation energy of ethyl acetate calculated by Arrhenius equation is 113 kJ mol 1.With 1%Pd loading and the concentration ratio of ozone to ethyl acetate is 3:1,catalytic ozonation performance is maximized and the conversion rate of ethyl acetate reached to 60%in 3050℃Cat 15,00030,000 h^1.

The Character of Normal Temperature Straw-Rotting Microbial Community

In order to study degradation capability and optimal condition of produced endoglucanase （CMCcase）, the microbial community with efficient cellulose degrading ability in 28℃ was studied. Microbial community came from rotted rice straw which was enriched and domesticated by improved Mandels medium. The standard cellulase activity assays were used to determine cellulase activity, degradation products were analyzed by gas chromatography mass spectrometry （GC/MS）, and denaturing gradient gel electrophoresis （DGGE） was used to identify the composition dynamic of the community. The results showed that the microbial community could degrade 39.6% of rice straw gross weight within 6 d. When culture medium volume was 1/5 and pH = 6 on day 5, the CMCcase activity reached the highest of 14 IU mL-L During the fermentation, more than ten products were detected using GCMS. The microbial changed lots in different fermentation periods which detected by DGGE. Phylogenetic tree derived from 16S rDNA sequence found that the community composed of bacteria, and the closest relative were belong to Clostridium sp., Brevibacillus sp. and Bacterium sp. This microbial community could accelerate rice straw rotting and decomposed products could promote organic matter increase of soil

Meridional Distributions of Historical Zonal Averages and Their Use to Quantify the Global and Spheroidal Mean Near-Surface Temperature of the Terrestrial Atmosphere

The zonal averages of temperature (the so-called normal temperatures) for numerous parallels of latitude published between 1852 and 1913 by Dove, Forbes, Ferrel, Spitaler, Batchelder, Arrhenius, von Bezold, Hopfner, von Hann, and Börnstein were used to quantify the global (spherical) and spheroidal mean near-surface temperature of the terrestrial atmosphere. Only the datasets of Dove and Forbes published in the 1850s provided global averages below 〈T〉=14°C, mainly due to the poor coverage of the Southern Hemisphere by observations during that time. The global averages derived from the distributions of normal temperatures published between 1877 and 1913 ranged from 〈T〉=14.0°C (Batchelder) to 〈T〉=15.1°C (Ferrel). The differences between the global and the spheroidal mean near-surface air temperature are marginal. To examine the uncertainty due to interannual variability and different years considered in the historic zonal mean temperature distributions, the historical normal temperatures were perturbed within ±2σ to obtain ensembles of 50 realizations for each dataset. Numerical integrations of the perturbed distributions indicate uncertainties in the global averages in the range of ±0.3°C to ±0.6°C and depended on the number of available normal temperatures. Compared to our results, the global mean temperature of 〈T〉=15.0°C published by von Hann in 1897 and von Bezold in 1901 and 1906 is notably too high, while 〈T〉=14.4°C published by von Hann in 1908 seems to be more adequate within the range of uncertainty. The HadCRUT4 record provided 〈T〉≌?13.7°C for 1851-1880 and 〈T〉=13.6°C for 1881-1910. The Berkeley record provided 〈T〉=13.6°C and 〈T〉≌?13.5°C for these periods, respectively. The NASA GISS record yielded 〈T〉=13.6°C for 1881-1910 as well. These results are notably lower than those based on the historic zonal means. For 1991-2018, the HadCRUT4, Berkeley, and NASA GISS records provided 〈T〉=14.4°C, 〈T〉=14.5°C, and 〈T〉=14.5°C, respectively. The comparison of the 1991-2018 globally averaged near-surface temperature with those derived from distributions of zonal temperature averages for numerous parallels of latitude suggests no change for the past 100 years.

A new extraction process of refractory gold arsenosulfide concentrates

A new hydrometallurgical process for the refractory gold arsenosulfideconcentrates under normal temperature and pressure was presented. The experimental results of arefractory gold concentrate show that the total consumption of NaOH in alkaline leaching is only 40%of those theoretically calculated under the conditions of full oxidization at the same oxidation ofarsenic to ar-senate and sulfur to sulfate. After alkaline leaching, cyanidation and adsorptionwere carried out for 24 h. The dissolution of gold by NaCN is increased to 95.3% from 12.8% beforepretreatment, and meanwhile 99.3% of the adsorption of gold by activated charcoal. The consumptionof NaCN for one ton ore is 10 kg, which is 1.2 times less than that before pretreatment. As it iscarried out under normal temperature and pressure, the investment of installations is alsodecreased.

异质结NiO/Fe_(2)O_(3)纳米片在温和条件下实现PET高选择性光降解

通过传统技术降解聚对苯二甲酸乙二醇酯(PET)塑料的过程往往需要消耗大量能量且所得到的产物种类复杂.鉴于此,我们报道了一种新颖的PET降解策略,即在温和条件下、纯水溶液中利用面内异质结NiO/Fe_(2)O_(3)纳米片实现了PET塑料的100%选择性光降解.其中,我们通过高分辨透射电子显微镜、X射线近边吸收谱和X射线光电子能谱证实了所制备的NiO/Fe_(2)O_(3)纳米片为Z-scheme异质结;通过光致发光光谱证实了此Z-scheme异质结的构建有利于促进反应过程中光生电子-空穴对的分离,从而提高了PET塑料的光降解效率.此外,我们通过多种原位表征技术和标记实验证实了PET塑料被光生空穴降解成二氧化碳,同时氧气被光生电子还原为水的反应机理.总之,该工作为解决白色污染危机提供了一种有前景的解决方案.