Subterranean microorganisms and radioactive waste disposal in Sweden

In 1987, microbiology became a part of the Swedish scientific program for the safe disposal of high level nuclear waste (HLW). The goal of the microbiology program is to understand how subterranean microorganisms will interact with the performance of a future HLW repository. The Swedish research program on subterranean microbiology has mainly been performed at two sites in granitic rock aquifers at depths ranging from 70 m down to 1240 m, the Stripa research mine in the middle of Sweden and the Äspö Hard Rock Laboratory (HRL) situated on the south eastern coast of Sweden. Some work has also been performed in cooperation with other national or international research groups in Sweden, Canada and at the natural analogue sites Oklo in Gabon and Maqarin in Jordan. The following conclusions are drawn. There is a very high probability of the existence of a deep subterranean biosphere in granitic rock. The documented presence of a deep biosphere implies that relevant microbial reactions should be included in the performance assessment for a HLW repository. A HLW repository will be situated in a subterranean biosphere that is independent of solar energy and photosynthetically produced organic carbon. The ultimate limitation for an active microbial life will be the availability of hydrogen as energy source over time, and hydrogen has indeed been found in most deep groundwaters. Sulphide producing microorganisms are active in environments typical for a Swedish HLW repository, and the potential for microbial corrosion of the copper canisters must be considered. The bentonite buffer around the copper canisters will be a hostile environment for most microbes due to the combination of radiation, heat and low water availability. Discrete microbial species can cope with each of these constraints, and it is theoretically possible that sulphide producing microbes may be active inside a buffer, although the experiments conducted thus far have shown the opposite. Microorganisms have the capability to enzymatically recombine radiolysis oxidants formed by radiation of water. It has earlier been concluded that the migration of radionuclides due to sorption on microorganisms can be neglected. The influence of microbially produced complexing agents remains to be studied at realistic conditions in deep groundwater. Microorganisms have been found in natural alkaline groundwaters, but it could not be conclusively demonstrated that they were in situ viable and growing, rather than just transported there from neutral groundwater. A possible hypothesis based on the obtained results from investigations of natural alkaline groundwaters is that fresh concrete may be a bit too extreme for active life even for the most adaptable microbe – but this remains to be demonstrated.     

Intercalation of kaolinite with acetamide

Upon intercalation of both ordered (low defect) and disordered (high defect) kaolinites with acetamide, two types of interaction are observed. Firstly, hydrogen bonding between the NH₂ groups of the acetamide with the siloxane oxygens is formed, as evidenced by the formation of two new bands at 3400 and 3509 cm^–1. Secondly, the appearance of additional bands at ∼3600 cm^–1 in both the infrared and Raman spectra of the acetamide intercalates is attributed to a second type of hydrogen bonding by the interaction of the C=O group and the inner surface hydroxyls. Changes in the intensity of the hydroxyl deformation modes in the 895 to 940 cm^–1 region are attributed to the changes in the hydrogen bonding of the kaolinite surfaces. It is proposed that the hydrogen bonding between the adjacent kaolinite layers is replaced with hydrogen bonding between both kaolinite surfaces and the acetamide molecule. Changes in the molecular structure of acetamide are observed upon intercalation. The amide 1 band is lost and replaced with a well-defined NH₂ deformation vibration. The loss of the amide 1 band is attributed the hydrogen bond formation between the amide hydrogens and the siloxane surface. The bands of the C=O group at 1680 and 1740 cm^–1 become a single band at 1680 cm^–1. The amide 2 band remains unchanged. The lack of intensity of the 1740 cm^–1 band is attributed to the formation of hydrogen bonding between the inner surface hydroxyl groups and the carbonyl group. Received: 4 February 1998/ Revised, accepted: 30 June 1998     

通过断层气氢探测新郑-太康断裂的浅层位置

新郑-太康断裂隐伏于河南省东部平原下,是一条规模较大的北西向断裂带,曾于2010年发生太康4.7级地震,确定该断裂准确的浅层位置对防震减灾具有重要意义。根据深部石油勘探资料,应用德尔格X-am 7000型多气体检测仪,在新郑地区布置2条与断裂走向近垂直的地球化学测线进行土壤氢气浓度测试,结果发现解放路和马庄村-前宫村测线异常点位处氢气浓度分别为背景值的16-33倍和40-50倍。2条H₂浓度曲线同步解释出一条倾向变化、宽约150m的走滑断裂带,位置与石油勘探资料吻合良好。此次研究表明利用断层气氢探测隐伏断裂的浅层位置在该区具有较好的可行性。     

Photoproduction of hydrogen peroxide in aqueous solution from model compounds for chromophoric dissolved organic matter (CDOM)

To explore whether quinone moieties are important in chromophoric dissolved organic matter (CDOM) photochemistry in natural waters, hydrogen peroxide (H₂O₂) production and associated optical property changes were measured in aqueous solutions irradiated with a Xenon lamp for CDOM model compounds (dihydroquinone, benzoquinone, anthraquinone, napthoquinone, ubiquinone, humic acid HA, fulvic acid FA). All compounds produced H₂O₂ with concentrations ranging from 15 to 500 μM. Production rates were higher for HA vs. FA (1.32 vs. 0.176 mM h⁻¹); values ranged from 6.99 to 0.137 mM h⁻¹ for quinones. Apparent quantum yields (Θ_app; measure of photochemical production efficiency) were higher for HA vs. FA (0.113 vs. 0.016) and ranged from 0.0018 to 0.083 for quinones. Dihydroquinone, the reduced form of benzoquinone, had a higher production rate and efficiency than its oxidized form. Post-irradiation, quinone compounds had absorption spectra similar to HA and FA and 3D-excitation–emission matrix fluorescence spectra (EEMs) with fluorescent peaks in regions associated with CDOM.     

新04号泉溶解气氢气异常特征分析

选取乌鲁木齐周围100 km范围内MS4地震和300 km范围内MS≥5地震,分析新04号泉氢气资料。结果显示,新04号泉对乌鲁木齐周围100 km范围内4级地震无明显震兆异常,对300 km范围内MS≥5地震对应情况较好,对应率为80%。     

燃烧加热污染空气对超燃冲压发动机性能影响研究

针对燃烧加热地面试验设备存在的工质污染问题,采用数值模拟方法研究了燃烧加热污染空气对氢燃料超燃冲压发动机性能的影响。以飞行马赫数Ma=6.5,当量油气比ER=0.6为计算基准状态,分别对纯净空气和污染空气来流下氢燃料超燃冲压发动机的整机流场和性能进行了对比计算分析。燃烧化学反应模拟采用了改进的H₂/O₂七组分八方程模型,湍流模型为标准的 k-ε模型,并采用直连式燃烧室试验数据进行了数值方法的验证。研究结果表明:(1)相对于纯净空气来流,污染空气来流下的超燃冲压发动机推力和比冲均有所下降。(2)采用酒精燃烧加热器的前提下,来流参数匹配静温、静压、马赫数时,发动机性能与纯净空气来流下的结果最为接近,而匹配总温、总压、马赫数时相差最大。(3)来流参数匹配总焓、静压、马赫数的前提下,采用氢燃烧加热器时发动机性能与纯净空气来流下的结果最为接近,而采用甲烷燃烧加热器时相差最大。      

Hydrachemical Characteristics at the Seismic Stations in Songyuan District,Jilin Province

The hydrochemical types and origins of underground water in Songyuan and vicinity, Liaoning Province were discussed based on the hydrochemical composition, δD and δ¹⁸O. The water samples from eight wells were collected 4 times during 2014 to 2015. The main ion concentrations of water were analyzed with an Ion Chromatography. Isotopic compositions of hydrogen and oxygen were analyzed with the Liquid Water Isotope Analyzer. The mineralization (TDS) of the water ranged from 125.4 mg/L to 19 350.9 mg/L. Values of δD and δ¹⁸O ranged from -71.7‰ to -98.1‰ and from -9.0‰ to -12.5‰, respectively. The isotopic data indicated that the water originated from meteorological precipitation. The chemical compositions of Taolaizhao phreatic water were influenced by the human activity while the other water samples collected from artesian well were less affected by the human activity. Water in Changling, Dongdashi, Taohaotai, Qianan and Ningjiang were characterized by HCO₃-Na with low TDS values. Such chemical types of water with fluctuations of Na⁺, SO42- and δ¹⁸O drift were resulted from dissolving silicate minerals and adding surfactant during oil exploitation. Fresh water in Fuyu well was Cl-Na type, which was influenced by acid injection during oil exploitation. Water in Qianguo well was characterized by Cl-Na type with TDS up to 19 350.9 mg/L, the obvious fluctuations of hydrogen and oxygen isotopes and increasing ion concentrations in the Qianguo well may be caused by the earthquakes that occurred in the sampling duration. The results will provide the background of hydrochemistry, and will be of benefit to monitoring earthquake and certificating seismic-chemical anomalies in the future.     

Origin and Distribution Factors of Sour Gases in Natural Gas Reservoirs in the Amu Darya Right Bank Block,Turkmenistan

Through the analysis of original carbon isotopes in the blocks on the right bank of the Amu Darya River, Turkmenistan, it can be firstly concluded that the carbon dioxide (CO₂) in the sour gas reservoirs belongs to the inorganic-origin gas. The origin of hydrogen sulfide (H₂S) in the Amu Darya Right Bank Block is thermochemical sulfate reduction from the detailed analysis of hydrocarbon source rocks data, reservoir characteristics, vitrinite reflectance of organic matter, and sour gas content. Then, the factors affecting the distribution of sour gases in the Amu Darya Right Bank Block were investigated by the analysis of conventional sour gas distribution factors including geological structure, fracture and fault, caprock integrity, sedimentary facies, reservoir types, lithofacies, the source of sulfur and so on. The following basic findings were achieved: ① The basement rift in the study area is conductive to the distribution of CO₂. The caprock integrity contributes to the concentration of CO₂. The gas reservoirs in the biological dike reefs, patch reefs and overthrust zones usually have medium CO₂ content. ② The geological structure and fracture caused the complexity of the distribution of H₂S. The gypsum-salt rock in upper Jurassic-Tithonian is an important sulphur source, and the main hydrocarbon source rocks are also the major sulfur source of H₂S gas reservoirs. Furthermore, the giant gypsum layers in the middle-upper Jurassic Callovian-Oxfordian and the upper Jurassic-Tithonian are conductive to preservation of H₂S, and the small openings and holes in the reservoir is also correlative to the distribution of H₂S. ③ The H₂S in the study area is mostly distributed in the formations with the geothermal temperature of higher than 100 ℃. The open platform deep-water sedimentary facies are harmful to the formation of H₂S. The patch reef and overthrust zones belong to the belts of low H₂S content, however, the biological dike reef zones belong to the belts of medium-high H₂S content. However, the origin and distribution factors of sour gases in natural gas reservoirs were obtained. At the same time, it was pointed out that more necessary and accurately quantitative research is still needed to determine the origin and distribution of acid gases in the Amu Darya Right Bank Block, Turkmenistan.