营养限制对厌氧序批操作反应器的影响及其恢复重建过程

研究了在厌氧条件下以葡萄糖为基质的序批操作反应器(ASBR)中营养物浓度限制对基质吸收和储存的影响及其恢复重建过程。结果表明,营养物限制条件下,发酵细菌表现为过量吸收基质并储存为糖原,形成隐性增殖以维持其细胞的正常结构和代谢功能;而甲烷菌由于无储存能力,其表现为活性逐渐降低。短期营养限制条件下(1个周期),基质中无磷时,储存量增加29%;基质中无氮时,储存量增加90%;基质中既无氮也无磷时,储存量增加26%。长期(31个周期)营养限制(基质中氮磷含量减小50%)下,胞内储存糖原量可高达正常状态下的4.8倍,但甲烷活性减少为正常状态下的17.78%。营养物限制对发酵细菌影响较小,对甲烷菌影响较大。将氮磷浓度恢复正常后,反应器的产甲烷能力恢复较快,出水COD经31周期后恢复正常,而胞内糖原在85周期后恢复正常。     

火电厂液氨贮存风险评价中典型事故影响范围计算

对火电厂液氨贮存风险评价中的三类典型事故（化学爆炸、管道泄漏和贮罐整体破裂）影响范围的计算方法进行了探讨。以某火电厂2×1000MW机组为例,当发生化学爆炸事故时,爆炸冲击波损害等级1、2、3、4的影响区域半径分别为78.3、156.6、391.5和1044m;管道泄漏和贮罐整体破裂所引发的中毒事故中,后者对环境的影响较大。若事故发生后10min内得到有效控制,则在F大气稳定度、1.5m/s风速条件下,贮罐整体破裂半致死浓度的影响区域半径（r值）为344.6m,大于管道泄漏r值（205.8m）;若事故发生后不考虑控制措施,则在F大气稳定度、1.5 m/s风速条件下,贮罐整体破裂半致死浓度的影响区域半径r值为561 m。     

攀西地区干香柏容器育苗技术研究

研究了攀西地区(攀枝花市和西昌地区)采用无底营养袋与多穴容器盘培育干香柏苗木的根系状况和苗木生长状况。研究结果表明,多穴容器盘育苗能从根本上解决无导根或边缝切根的容器育苗产生的根系盘绕现象,本地区适合采用的多穴容器盘规格为导根线类多穴容器盘,容积为90—150ml以上;本地区适合采用的育苗基质配方由燥红土泥碳土和牛粪组成,体积比为5%红土、35%泥碳土和60%牛粪组成。     

Sediment Source Assessment in a Lowland Watershed Using Nitrogen Stable Isotopes1

Fox, James F., Charles M. Davis, and Darren K. Martin, 2010. Sediment Source Assessment in a Lowland Watershed Using Nitrogen Stable Isotopes. Journal of the American Water Resources Association (JAWRA) 46(6):1192–1204. DOI: 10.1111/j.1752-1688.2010.00485.x Abstract: Sediment sources and transported sediments were sampled in a lowland watershed with pronounced fine sediment storage in the streambed. Sediments were analyzed for carbon and nitrogen content and stable nitrogen isotopic composition. Analysis of the data shows that temporarily stored streambed sediments dominate the sediment load during moderate- and low-flow hydrologic events. Modeling of sediment transport and nitrogen elemental and isotopic mass balance was performed for the watershed for a 12-month time period using a continuous, conceptual-based model. The model results show that during moderate- and low-flow hydrologic events, the streambed is slowly downcutting. During very high-flow hydrologic events, deposition is pronounced in the streambed and sediment is replenished to the bed. Nitrogen model results show that elemental and isotopic nitrogen of streambed sediments vary substantially over the simulation period. In this manner, the streambed in a lowland watershed functions as a temporary storage zone that, in turn, can impact the nitrogen elemental and isotopic signature of sediments. The variation could significantly impact estimates of sediment provenance using nitrogen tracer-based methods. Future work should consider both hydrologic and biogeochemical control on the nitrogen isotopic signature of sediments in small lowland watersheds and streams where a significant portion of deposited fines are temporarily stored.     

Laboratory calibration of the seismo-acoustic response of CO2 saturated sandstones

Ultrasonic experiments were undertaken on CO₂ flooded sandstone core samples, both synthetic sandstones and core plugs from the CRC1 CO₂ injection well in the Otway Basin, Victoria, South Eastern. Australia. The aim of these laboratory tests was to investigate the effects of CO₂ as a pore fluid on the seismo-acoustic response of the sandstone and ultimately to provide an indication of the sensitivity of time-lapse seismic imaging of the eventual CO₂/CH₄ plume in the Otway, Waarre C formation.The synthetic sandstones were manufactured using both a proprietary calcium in situ precipitation (CIPS) process and a silica cementing technique. Samples were tested in a computer controlled triaxial pressure cell where pore pressures can be controlled independently of the confining pressures. The pressure cell is equipped with ultrasonic transducers housed in the loading platens. Consequently, effective pressures equivalent to those expected in the reservoir can be applied while ultrasonic testing is undertaken. Both compressional, P and shear waves, S were recorded via a digital oscilloscope at a range of effective pressure steps. Pore pressures were varied from 4 MPa to 17 MPa to represent both the gaseous and liquid phase regions of the CO₂ phase diagram. Similar experiments were conducted on core plugs from the Waarre C reservoir horizon obtained from the CRC1 injection well, but with an intervening brine-saturated step and in some cases with a CO₂/CH₄ mix of 80%/20% molar fraction which is representative of the field situation. However, the pore pressure in these experiments was held at 4 MPa. Finally, acoustic impedances and reflection coefficients were calculated for the reservoir using Gassmann theory and the implications for imaging the CO₂ plume is discussed.     

Monitoring of the microbial community composition in saline aquifers during CO2 storage by fluorescence in situ hybridisation

This study reveals the first analyses of the composition and activity of the microbial community of a saline CO₂ storage aquifer. Microbial monitoring during CO₂ injection has been reported. By using fluorescence in situ hybridisation (FISH), we have shown that the microbial community was strongly influenced by the CO₂ injection. Before CO₂ arrival, up to 6 × 10⁶ cells ml⁻¹ were detected by DAPI staining at a depth of 647 m below the surface. The microbial community was dominated by the domain Bacteria that represented approximately 60% to 90% of the total cell number, with Proteobacteria and Firmicutes as the most abundant phyla comprising up to 47% and 45% of the entire population, respectively. Both the total cell counts as well as the counts of the specific physiological groups revealed quantitative and qualitative changes after CO₂ arrival. Our study revealed temporal outcompetition of sulphate-reducing bacteria by methanogenic archaea. In addition, an enhanced activity of the microbial population after five months CO₂ storage indicated that the bacterial community was able to adapt to the extreme conditions of the deep biosphere and to the extreme changes of these atypical conditions.     

CO2SINK—From site characterisation and risk assessment to monitoring and verification: One year of operational experience with the field laboratory for CO2 storage at Ketzin, Germany

The CO₂SINK pilot project at Ketzin is aimed at a better understanding of geological CO₂ storage operation in a saline aquifer. The reservoir consists of fluvial deposits with average permeability ranging between 50 and 100 mDarcy. The main focus of CO₂SINK is developing and testing of monitoring and verification technologies. All wells, one for injection and two for observation, are equipped with smart casings (sensors behind casing, facing the rocks) containing a Distributed Temperature Sensing (DTS) and electrodes for Electrical Resistivity Tomography (ERT). The in-hole Gas Membrane Sensors (GMS) observed the arrival of tracers and CO₂ with high temporal resolution. Geophysical monitoring includes Moving Source Profiling (MSP), Vertical Seismic Profiling (VSP), crosshole, star and 4-D seismic experiments. Numerical models are benchmarked via the monitoring results indicating a sufficient match between observation and prediction, at least for the arrival of CO₂ at the first observation well. Downhole samples of brine showed changes in the fluid composition and biocenosis. First monitoring results indicate anisotropic flow of CO₂ coinciding with the “on-time” arrival of CO₂ at observation well one (Ktzi 200) and the later arrival at observation well two (Ktzi 202). A risk assessment was performed prior to the start of injection. After one year of operations about 18,000 t of CO₂ were injected safely.     

非稳定状态下除磷过程的特点研究

为了研究非稳定状态下生物除磷的特点,采用序批式间歇反应器(SBR),通过不同的进水方式(连续进水和瞬时进水),系统地考察了进水体积、NOX-N、限制曝气等因素对除磷过程的影响。结果表明,在温度为(23±0.5)℃、pH为7.0～8.0时,厌氧搅拌期连续进水的比释磷量(单位质量污泥(以MLSS计)的释磷量(以PO43-P计))比瞬时进水时高出42.11%。在运行条件相似的情况下,厌氧搅拌期的比释磷量与每周期进水体积无关。相对于连续进水,瞬时进水更有助于促进微生物利用有机底物进行自身的生长。限制曝气对连续进水和瞬时进水的释磷过程都存在明显的影响,在DO小于0.1mg/L的情况下,2者的比释磷量相对非限制曝气时分别降低了57.14%和55.56%。在连续进水时,NOX-N的反硝化结束伴随着释磷速率的突然升高。利用贮存作用并不能每次都成功地抑制丝状菌污泥膨胀。     

Intermediate storage of carbon dioxide in geological formations: A technical perspective

Enhanced oil recovery (EOR) through CO₂ flooding has been practiced on a commercial basis for the last 35 years and continues today at several sites, currently injecting in total over 30 million tons of CO₂ annually. This practice is currently exclusively for economic gain, but can potentially contribute to the reduction of emissions of greenhouse gases provided it is implemented on a large scale. Optimal operations in distributing CO₂ to CO₂-EOR or enhanced gas recovery (EGR) projects (referred to here collectively as CO₂-EHR) on a large scale and long time span imply that intermediate storage of CO₂ in geological formations may be a key component. Intermediate storage is defined as the storage of CO₂ in geological media for a limited time span such that the CO₂ can be sufficiently reproduced for later use in CO₂-EHR. This paper investigates the technical aspects, key individual parameters and possibilities of intermediate storage of CO₂ in geological formations aiming at large scale implementation of carbon dioxide capture and storage (CCS) for deep emission reduction. The main parameters are thus the depth of injection and density, CO₂ flow and transport processes, storage mechanisms, reservoir heterogeneity, the presence of impurities, the type of the reservoirs and the duration of intermediate storage. Structural traps with no flow of formation water combined with proper injection planning such as gas-phase injection favour intermediate storage in deep saline aquifers. In depleted oil and gas fields, high permeability, homogeneous reservoirs with structural traps (e.g. anticlinal structures) are good candidates for intermediate CO₂ storage. Intuitively, depleted natural gas reservoirs can be potential candidates for intermediate storage of carbon dioxide due to similarity in storage characteristics.     

Methodology for CO2 chain analysis

The paper presents a methodology for CO₂ chain analysis with particular focus on the impact of technology development on the total system economy. The methodology includes the whole CO₂ chain; CO₂ source, CO₂ capture, transport and storage in aquifers or in oil reservoirs for enhanced oil recovery. It aims at supporting the identification of feasible solutions and assisting the selection of the most cost-effective options for carbon capture and storage. To demonstrate the applicability of the methodology a case study has been carried out to illustrate the possible impact of technology improvements and market development. The case study confirms that the CO₂-quota price to a large extent influence the project economy and dominates over potential technology improvements. To be economic feasible, the studied chains injecting the CO₂ in oil reservoirs for increased oil production require a CO₂-quota price in the range of 20–27 €/tonne CO₂, depending on the technology breakthrough. For the chains based on CO₂ storage in saline aquifers, the corresponding CO₂-quota price varies up to about 40 €/tonne CO₂.