模拟油田采出水中H2S的脱除

采出水经处理后通常需作为地层回注水使用,由于油气生产的特殊性,常用的H2S脱除方法在使用中受到限制,探索适合于油气田生产的水处理方法十分必要。文章探讨了通常可用于油田采出水中H2S脱除的各种方法,对比了各类方法的优缺点,提出以NaClO为主要脱硫剂的水处理方法,通过对模拟采出水的室内实验,证明次氯酸法可以快速有效地去除采出水中的H2S,使H2S残留量低于1 mg/L。实验表明:经处理后的水质可以达到SY/T 5329-2012《碎屑岩油藏注水水质指标及分析方法》要求,处理成本较低。     

Reasonable Use?: The Challenges of Transboundary Groundwater Regulation in the Eastern United States

Regulating groundwater in the Eastern United States (U.S.), particularly transboundary aquifers between states, is a challenge given the patchwork quilt of common law, statutory frameworks, and agency rules. Such regulation is made more challenging by the need for better quantification of pumping and use. These dynamics are exemplified through several case studies, including the first ever U.S. Supreme Court case related to groundwater withdrawals (set in the Eastern U.S.). As dynamics such as expanded irrigation, population increases, and ecological considerations influence groundwater use across the Eastern U.S., water use will continue to be an important driver for economic activity and interaction within and between states. To effectively regulate transboundary aquifers, governance solutions must incorporate current science into decision making and be implemented at local, state, regional, and federal scales.     

Water/acid gas interfacial tensions and their impact on acid gas geological storage

Acid gas geological disposal is a promising process to reduce CO₂ atmospheric emissions and an environment-friendly and economic alternative to the transformation of H₂S into sulphur by the Claus process. Acid gas confinement in geological formations is to a large extent controlled by the capillary properties of the water/acid–gas/caprock system, because a significant fraction of the injected gas rises buoyantly and accumulates beneath the caprock. These properties include the water/acid gas interfacial tension (IFT), to which the so-called capillary entry pressure of the gas in the water-saturated caprock is proportional. In this paper we present the first ever systematic water/acid gas IFT measurements carried out by the pendant drop technique under geological storage conditions. We performed IFT measurements for water/H₂S systems over a large range of pressure (up to P = 15 MPa) and temperature (up to T = 120 °C). Water/H₂S IFT decreases with increasing P and levels off at around 9–10 mN/m at high T (≥70 °C) and P (>12 MPa). The latter values are around 30–40% of water/CO₂ IFTs, and around 20% of water/CH₄ IFTs at similar T and P conditions. The IFT between water and a CO₂ + H₂S mixture at T = 77 °C and P > 7.5 MPa is observed to be approximately equal to the molar average IFT of the water/CO₂ and water/H₂S binary mixtures. Thus, when the H₂S content in the stored acid gas increases the capillary entry pressure decreases, together with the maximum height of acid gas column and potential storage capacity of a given geological formation. Hence, considerable attention should be exercised when refilling with a H₂S-rich acid gas a depleted gas reservoir, or a depleted oil reservoir with a gas cap: in the case of hydrocarbon reservoirs that were initially (i.e., at the time of their discovery) close to capillary leakage, acid gas leakage through the caprock will inevitably occur if the refilling pressure approaches the initial reservoir pressure.     

The ratio of clay content to total organic carbon content is a useful parameter to predict adsorption of the herbicide butachlor in soils

Thirteen soils collected from 11 provinces in eastern China were used to investigate the butachlor adsorption. The results indicated that the total organic carbon (TOC) content, clay content, amorphous Fe2O3 content, silt content, CEC, and pH had a combined effect on the butachlor sorption on soil. Combination of the data obtained from the 13 soils in the present study with other 23 soil samples reported by other researchers in the literature showed that Koc would be a poor predictive parameter for butachlor adsorption on soils with TOC content higher than 4.0% and lower than 0.2%. The soils with the ratio of clay content to TOC content (RCO) values less than 60 adsorbed butachlor mainly by the partition into soil organic matter matrix. The soils with RCO values higher than 60 apparently adsorbed butachlor by the combination of the partition into soil organic matter matrix and adsorption on clay surface.     

The Ethics of Burden-Sharing in the Global Greenhouse

The Kyoto Protocol on global warming has provoked great controversy in part because it calls for heavier burdens on wealthy countries than on developing countries in the effort to control climate change. The U.S. Senate voted unanimously to oppose any agreement that does not require emissions reductions in low-income countries. The ethics of this position are examined in this paper which shows that there are good moral reasons for supporting the provisions of the Kyoto Protocol. Such a conclusion follows easily from considerations of distributive justice but can also be supported by more narrowly self-interested arguments. This revised version was published online in July 2006 with corrections to the Cover Date.     

美国应急通用任务评述与借鉴

为增强我国应急预案的实用性和有效性,改善现有的应急预案准则性强,可操作性弱的情况,笔者运用比较分析的方法,评述了3个版本的美国应急通用任务列表,从作用、结构和内容等方面比较各版本的通用任务表间的不同以及各自优缺点,并从理论和现实2个方面分析通用任务列表版本变迁的原因,为我国应急预案和应急准备的建立提供可借鉴的经验和参考,并对其未来发展提出建议。     

基于BP神经网络的污水格栅间气体监测

为实现对城市污水泵站格栅间内H₂S和CO有害气体浓度实时准确监测分析,设计气体传感器阵列监测系统,建立单隐层BP神经网络模型对气体浓度样本进行训练,确定网络隐含层数为9,训练函数为traindm,模型优化后输出的H₂S和CO气体浓度与实测值的平均相对误差分别为1.3%与0.4%。研究结果表明：采用BP神经网络模型对传感器阵列采集到的样本数据进行训练,可提高其测量精度,提升精度范围在57%～75%之间,能够满足对污水泵站有害气体监测的基本要求,所建立模型表现出良好效果。研究结果可为污水格栅间有害气体监测提供新方法。     

光照对低浓度硫化氢气体生物法净化的影响

和种进行光照和避光的对比试验表明,光照能提高微生物对硫化氢废气的净化效率,最终产物为硫酸,净化效率和液相硫酸极的浓度随光照强度的增加而增加。避光时微生物对硫化氢废气的净化效率较低,但最终产物为单质硫。根据上述结果适宜的工艺流程应是首先将硫化氢废气通入避光的生物膜填料塔,把硫化氢转化为能回收的单质硫,然后再将废气通入光照的生物膜填料塔净化,进一步降低硫化氢废气的排放浓度。     

同时产甲烷反硝化颗粒污泥中微生物群落结构

在UASB成功运行同时产甲烷反硝化小试基础上,针对反应器内颗粒污泥,通过构建古菌和细菌的16SrDNA基因文库、RADAR遗传变异分型和测序比对等技术进行了微生物系统发育关系和群落结构分析.结果表明,在颗粒污泥的古菌中,产甲烷髦毛菌和产甲烷杆菌是主要菌群,随机选出的88个古菌克隆子,这两类古菌的16SrDNA序列分别占古菌总量71.59%和22.73%;而颗粒污泥中细菌的多样性要高于古菌,低GC革兰氏阳性菌和ε变型菌纲分支的细菌是细菌的主要菌群,在随机选出的133个细菌克隆子中,这2类细菌的16SrDNA序列分别占细菌总量的49.62%和12.03%.     

脱氮硫杆菌的分离鉴定和反硝化特性研究

从土壤中分离到1株高活性自养反硝化菌TD,并对其进行了鉴定和硝酸盐还原特性研究.该菌株为革兰氏阴性短杆菌,严格自养.16S rDNA序列分析表明.该菌株与ThiobaciUus denitrificans相似性为99.85%.结合生理生化特性和16S rDNA序列分析,确定菌株TD为脱氮硫杆菌.通过对该菌的生长特性和反硝化特性的研究表明,该菌在初始pH为6.85,32.8℃培养条件下脱氮效果最佳;在初始pH为6.90,29.5℃培养条件下生长最快.该菌生长比较缓慢,没有明显的稳定期,对数生长期阶段的反硝化能力最强,反硝化速率最快,达到了2.245 mg·(L·h)-1,在培养过程中培养基pH值明显下降.较高盐度对该菌株的反硝化活性有抑制作用.该菌株的急性毒性实验结果显示,脱氮硫杆菌对健康鱼体几乎无毒,属于无毒性菌株.