海拉尔盆地乌尔逊凹陷含片钠铝石砂岩捕获CO_2总量的估算

为揭示CO2地质埋存过程中砂岩对于CO2以矿物形式的捕获能力,以海拉尔盆地乌尔逊凹陷下白垩统铜钵庙—南屯组含片钠铝石砂岩为研究对象,基于含片钠铝石砂岩的时空分布,结合片钠铝石的含量和分子式开展了砂岩以片钠铝石形式固存CO2总量的研究。研究表明,海拉尔盆地乌尔逊凹陷下白垩统铜钵庙—南屯组中片钠铝石资源总量约为81.9亿t,含片钠铝石砂岩捕获的CO2总量约为25.0亿t。     

Mechanical and flow behaviours and their interactions in coalbed geosequestration of CO2

Studying gas transport mechanisms in coal seams is crucial in determining the suitability of coal formations for geosequestration and/or CO₂-enhanced coal bed methane recovery (ECBM), estimating CO₂ storage capacity and recoverable volume of methane, and predicting the long-term integrity of CO₂ storage and possible leakages. Due to the dual porosity nature of coal, CO₂ transport is a combination of viscous flow and Fickian diffusion. Moreover, CO₂ is adsorbed by the coal which leads to coal swelling which can change the porous structure of coal and consequently affects the gas flow properties of coal, i.e. its permeability. In addition, during CO₂ permeation, the coal seam undergoes a change in effective stress due to the pore pressure alteration and this can also change the permeability of the coal seam. In addition, depending on the in situ conditions of the coal seam and the plan of the injection scheme, carbon dioxide can be in a supercritical condition which increases the complexity of the problem. We provide an overview of the recent studies on porous structure of coal, CO₂ adsorption onto coal, mechanisms of CO₂ transport in coalbeds and their measurement, and hydro-mechanical response of coal to CO₂ injection and identify opportunities for future research.     

Health risk analysis of volcanic SO<Subscript>2</Subscript> hazard on Vulcano Island (Italy)

Since the last eruption of the Fossa crater in 1888–1890, intense volcanic degassing has been remaining on Vulcano Island of Sicily (Italy). Toxic sulfur dioxide (SO₂) of the solfataric action in this area represents, when inhaled, a permanent natural hazard harming humans. Approximately 500 permanent residents live and 15,000 tourists visit during the summer time the Porto village in the North of Vulcano Island. A cross-disciplinary fuzzy logic risk assessment has been conducted to evaluate health risks of human individuals exposed to higher SO₂-concentrations C over certain exposure times t. The simple approach, based on fuzzy set theory, explains health risks semantically by words rather than by numbers. Advantages of this approach are, first, experts, non-experts, decision makers, or the public are able to understand and communicate risk degrees by words without using numbers. Second, in comparison to other risk definitions, the risk is not equal to the vulnerability; it is based on the hazard (SO₂-gas clouds) and vulnerability (health effects) in combination. Third, risk levels can be still estimated even when limited or no statistical information is available, e.g., high SO₂-concentrations or long exposure times. Moreover, human health risks were determined for C−t-scenarios based on threshold values of the European Union and the World Health Organization. Independently, two additional methods were used to determine the proportions of the population who are exposed to levels of SO₂ at which health effects may be expected and also safety zones for civil protection around the degassing fields. In conclusion, SO₂-gas concentrations in many parts of Vulcano Island go beyond the proclaimed alert threshold of the European Union and the World Health Organization. For example, the results show that sensitive individuals, such as asthmatics, young children, or elderly people, should not be exposed at any time to the degassing areas in Porto di Levante and at the NE-rim of the Fossa crater. In contrast, healthy non-sensitive individuals should be exposed less than 10 min to the SO₂-clouds at these degassing areas, while hiking on the crater rim.     

1981–2020 winter ozone trends,Erzgebirge, Central Europe

Tropospheric ozone (O₃) acts as greenhouse gas and air pollutant. Over the last 100 years, tropospheric O₃ levels increased above background by factor 2.5 in the northern hemisphere and by factor 3–4 across Europe. The gas poses a potential risk to forest ecosystems in many mountain areas. There, O₃ concentrations result from long-range transport and are influenced by removal processes (dry deposition, gas phase and cloud removal, reduction on wet aerosols). Most trend studies analyzed annual-mean concentrations. We focus on winter O₃ trends at high altitudes in the German/Czech Erzgebirge (period 1981–2020) to avoid major noise from photochemical reactions and to better explain recent O₃ behavior in Central Europe. Hourly air quality and meteorological data from four stations (Carlsfeld, CAR; Fichtelberg, FIB; Schwartenberg, SWB; Zinnwald, ZIW) were used to analyze O₃ trends. The data can explain the complex O₃ formation and removal behavior.Three distinct periods of O₃-concentration trends can be discerned: i) Until the late 1980s, characterized by relatively low O₃ concentrations. ii) Dramatic transformation in the 1990s with changing air pollution in Central Europe. Strong O₃-concentration increase at FIB is corroborated by data from CAR and ZIW. iii) Stabilization as of 1997/98, when O₃ concentrations remained at the same level for all four stations, despite general regional air pollution decrease. Key results are:a) Winter O₃ trends mainly depend on O₃ concentration of air masses transported to the stations and on the O₃-removal potential (ORP) of clouds, not on local formation processes.b) ORP differs between clouds and fog, depending on droplet chemical composition. Fog from the North Bohemian Basin showed the highest ORP due to reaction with liquid phase S(IV). However, O₃ reactions with O₂⁻ in fog droplets showed high ORP, too, depending on cloud-water pH values and NO_x concentrations.c) So-called “Bohemian fog” decreased, and with it related ORP, while that of clouds from westerly and northwesterly air masses remained nearly unchanged since 1997/98.d) Decreasing ORP in clouds and fog (= higher O₃ concentration) oppose decreasing O₃ concentrations in westerly air masses. Both effects lead to unchanged O₃ levels in the Erzgebirge since 1997/98.     

A remote sensing model of CO2 flux for wheat and studying of regional distribution

A model for calculating CO₂ flux in the wheat field and an algorithm for estimating CO₂ flux in the mejonal scale were presented using the remote sensing data and supplementary micpo-met~orological data. First of all a-longertenn measurement wae carried out during winter wheat growing period in Yucheng Experimental Station udng the spectmradiometer system, the thermal infrared radiometer system, the Bowen-ratio device as well as the eddy-correlation device. Two kinds of issues concerning remote sensing and CO₂ flux can be obtained. Based on the obeervations a remote sensing model was estabilished. Then when the NOAA-AVHRR passed over the experimental area simultaneous measurements were carried out with the satellites. A regional distribution image for CO₂ flux over wheat canopy in North China (500×500 km²) was made using the supplementary ground data and NOAA-AVHRR remote sensing data which was calibrated by the synchronous observation. The sources and sinks for CO₂ fluxes in the region can be seen obviously. Project supported by the National Natural Science Foundation of China (Grant Nos. 49671058, 49890330)     

Degassing patterns of Tungurahua volcano (Ecuador) during the 1999–2006 eruptive period,inferred from remote spectroscopic measurements of SO2 emissions

This paper presents the results of 7 years (Aug. 1999–Oct. 2006) of SO₂ gas measurements during the ongoing eruption of Tungurahua volcano, Ecuador. From 2004 onwards, the operation of scanning spectrometers has furnished high temporal resolution measurements of SO₂ flux, enabling this dataset to be correlated with other datasets, including seismicity. The emission rate of SO₂ during this period ranges from less than 100 to 35,000 tonnes/day (t d^− 1) with a mean daily emission rate of 1458 t d^− 1 and a standard deviation of ± 2026 t d^− 1. Average daily emissions during inferred explosive phases are about 1.75 times greater than during passive degassing intervals. The total amount of sulfur emitted since 1999 is estimated as at least 1.91 Mt, mostly injected into the troposphere and carried westwards from the volcano. Our observations suggest that the rate of passive degassing at Tungurahua requires SO₂ exsolution of an andesitic magma volume that is two orders of magnitude larger than expected for the amount of erupted magma. Two possible, and not mutually exclusive, mechanisms are considered here to explain this excess degassing: gas flow through a permeable stagnant-magma-filled conduit and gas escape from convective magma overturning in the conduit. We have found that real-time gas monitoring contributes significantly to better eruption forecasting at Tungurahua, because it has provided improved understanding of underlying physical mechanisms of magma ascent and eruption.     

Sulfur dioxide emissions from Popocatépetl volcano (Mexico): case study of a high-emission rate, passively degassing erupting volcano

Popocatépetl volcano in central Mexico has been erupting explosively and effusively for almost 4 years. SO₂ emission rates from this volcano have been the largest ever measured using a COSPEC. Pre-eruptive average SO₂ emission rates (2–3 kt/d) were similar to the emission rates measured during the first part of the eruption (up to August 1995) in contrast with the effusive–explosive periods (March 1996–January 1998) during which SO₂ emission rates were higher by a factor of four (9–13 kt/d). Based on a chronology of the eruption and the average SO₂ emission rates per period, the total SO₂ emissions (up to 1 January 1998) are estimated to be about 9 Mt, roughly half as much as the SO₂ emissions from Mount Pinatubo in a shorter period. Popocatépetl volcano is thus considered as a high-emission rate, passively degassing eruptive volcano. SO₂ emission rates and SO₂ emissions are used here to make a mass balance of the erupted magma and related gases. Identified excess SO₂ is explained in terms of continuous degassing of unerupted magma and magma mixing. Fluctuations in SO₂ emission rate may be a result of convection and crystallization in the chamber or the conduits, cleaning and sealing of the plumbing system, and/or SO₂ scrubbing by the hydrothermal system.     

Adsorption–Reduction Behavior of Co(NH3) on Activated Carbon

A novel method has been put forward to retrofit the wet ammonia desulfurization process to realize the combined removal of sulfur dioxide and nitric oxide by introducing soluble cobalt(II) salt into aqueous ammonia solution. The active constituent of scrubbing NO from the flue gases is the produced by ammonia coordinating with Co²⁺. The regeneration of can be realized under the catalysis of activated carbon so as to sustain a high NO removal efficiency for a long time. In this paper, the adsorption–reduction behavior of on activated carbon has been researched using scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. A conclusion can be drawn from the results that cobalt ions in the aqueous solution are adsorbed by activated carbon and most of them are reduced to Co²⁺ ions, and some of the Co²⁺ ions are further reduced into metallic cobalt. The results also demonstrate that the functional groups on the surface of carbon take part in this redox reaction. The C? H groups on the carbon surface are oxidized into C? OH, and then some of the hydroxyl groups are further oxidized into carbonyl or carboxyl groups.     

Using Chlorine Dioxide to Remove the Fouling of Ultrafiltration Membrane and Control Disinfection By‐Products

Ultrafiltration (UF) can remove natural organic matter (NOM) effectively. Moreover, chlorine dioxide (ClO₂) has been an alternative disinfectant as it forms fewer disinfection by‐products with NOM than chlorination does. Therefore, combining ClO₂ with UF may improve conventional purification processes. In this study, feed water containing humic acid with 4.07 mg/L total organic carbon (TOC) was dosed directly with various amounts of ClO₂ (0, 2, 5, 10, and 15 mg/L) before being filtered through a 5‐kDa UF membrane. With a low dose (2 mg/L ClO₂), UF removed humic acid effectively, as TOC was not detected in the permeate, and the permeate flux increased to about 80% of the initial permeate flux by cross flow. Moreover, the concentrations of ClO, ClO, and trihalomethanes in the permeate were below the United States Environmental Protection Agency guidelines.     

柴达木盆地氯同位素组成特征

采用正热电离高精度测定Ｃｌ同位素的方法对我国柴达木盆地水体及盐类沉积的Ｃｌ同位素组成进行了精确测定，结果表明，柴达木盆地Ｃｌ同位素组成存在着明显的变化。各种水体的平均δ＾３７Ｃｌ值顺序为：河水（０．９４‰）〉咸水湖水（－０．２‰）〉油田水（－０．６２‰）〉盐湖卤水（－０．９７‰）。卤水具有低的δ＾３７Ｃｌ值，这是盐湖卤水蒸发析盐的结果。盐湖卤水与共存盐类矿物间的分馏系数为１．０００１－１．００２１