Feasibility of CO₂/SO₂ uptake enhancement of calcined limestone modified with rice husk ash during pressurized carbonation

The calcination/carbonation cycle using calcium-based sorbents appears to be a viable method for carbon dioxide (CO?) capture from combustion gases. Recent attempts to improve the CO?/SO? uptake of a calcium-based sorbent modified by using rice husk ash (RHA) in the hydration process have succeeded in enhancing its effectiveness. The optimal mole ratio of RHA to calcined limestone (M(Si/Ca)) was adjusted to 0.2. The cyclic CO? capture characteristics and the SO? uptake activity of the modified sorbent were evaluated in a calcination/pressurized carbonation reactor system. Scanning electron microscope (SEM) images and X-ray diffraction (XRD) spectrum of the sorbent were also taken to supplement the study. The results showed that the carbonation conversion was greatly increased for the sorbent with M(Si/Ca) ratio of 0.2. For this sorbent formulation the optimal operating conditions were 700-750 °C and 0.5-0.7 MPa. CO? absorption was not proportional to CO? concentration in the carbonation atmosphere, but was directly related to reaction time. The CO? uptake decreased in the presence of SO?. SO? uptake increased, and the total calcium utilization was maintained over multiple cycles. Analysis has shown that the silicate component is evenly or well distributed, and this serves as a framework to prevent sintering, thus preserving the available microstructure for reaction. The sorbent also displayed high activity to SO? absorption and could be used to capture CO? and SO? simultaneously.     

油田采出水微波处理技术探讨

微波应用于油田采出水处理,具有辅助絮凝、杀菌、降低腐蚀的作用。实验表明:应用微波处理油田采出水,可使PAC(聚合氯化铝)加量减少20%、PAM(聚丙烯酰胺)减少30%,处理时间仅为常规工艺的1/4,微波处理60s可将采出水中的TGB(腐生菌)、FEB(铁细菌)、SRB(硫酸盐还原菌)杀死99%以上,与常规工艺相比,微波处理后水质腐蚀率可下降20%以上。     

石油开发对辽河油田湿地景观格局变化的影响分析

通过对1989-2009年20年间景观格局的空间分布、变化特征以及变化趋势分析,揭示了造成双台子河自然保护区环境变化的主要驱动力是人类活动和社会经济发展的影响,定量计算了石油开发对研究区域景观格局变化的影响。结果显示:1989-2009年双台河口自然保护区的土地利用类型发生了很大的变化,景观破碎度明显增加,人类活动导致保护区内的土地利用和景观格局也发生了明显变化,但油田开发在总的土地利用变化中的贡献率仅为4.6%。     

Responses of antioxidant systems and LPO level to benzo(a)pyrene and benzo(k)fluoranthene in the haemolymph of the scallop Chlamys ferrari

The effects of benzo(a)pyrene (BaP), benzo(k)fluoranthene (BkF) and their mixture on antioxidant enzyme activities and lipid peroxidation (LPO) levels of haemolymph of scallop (Chlamys ferrari) were studied. The superoxide dismutase (SOD) activities of 0.5 microg/L and 1.0 microg/L were significantly higher than controls (P<0.05), while it increased at beginning and then dropped (lower than controls) in the end at 10.0 microg/L and 50.0 microg/L PAHs groups. The catalase (CAT) activities were very little during the whole experimental time. The glutathione peroxidase (GPx) activities in each PAHs group all increased significantly (P<0.05). LPO levels all increased significantly (P<0.05) with time at each PAHs group except for the 0.5 microg/L group of less than hour 12. The toxicity of PAHs in a descending order was BaP>BkF>mixture of BaP and BkF. The changes in antioxidant enzyme activities and LPO level in haemolymph could reflect the detoxification functions and damage levels of whole organism.     

Modification of light utilization for skeletal growth by water flow in the scleractinian coral <Emphasis Type="Italic">Galaxea fascicularis</Emphasis>

In this study, we tested the hypothesis that the importance of water flow for skeletal growth (rate) becomes higher with increasing irradiance levels (i.e. a synergistic effect) and that such effect is mediated by a water flow modulated effect on net photosynthesis. Four series of nine nubbins of G. fascicularis were grown at either high (600 μE m⁻² s⁻¹) or intermediate (300 μE m⁻² s⁻¹) irradiance in combination with either high (15–25 cm s⁻¹) or low (5–10 cm s⁻¹) flow. Growth was measured as buoyant weight and surface area. Photosynthetic rates were measured at each coral’s specific experimental irradiance and flow speed. Additionally, the instantaneous effect of water flow on net photosynthetic rate was determined in short-term incubations in a respirometric flowcell. A significant interaction was found between irradiance and water flow for the increase in buoyant weight, the increase in surface area, and specific skeletal growth rate, indicating that flow velocity becomes more important for coral growth with increasing irradiance levels. Enhancement of coral growth with increasing water flow can be explained by increased net photosynthetic rates. Additionally, the need for costly photo-protective mechanisms at low flow regimes could explain the differences in growth with flow.     

Empirical analysis on contribution share of safety investment to economic growth: A case study of Chinese mining industry

Insufficient investment in safety is one of the most important reasons which lead to frequent accidents in Chinese mining industry. Safety input has long been regarded as a ‘sunk cost’, lacking output, and little attention from mining companies was focused on increasing safety input according to technical codes or technical requirements due to the narrow understanding on safety input. So, the empirical analysis on the contribution share of safety investment to economic growth is very important. In this paper, a new set of production safety indexes including six 1-level indexes for describing the safety level of mining production in China was constructed on the basis of Granger causality test. Meanwhile, a mining economic growth model was constructed on the basis of the new production safety indexes with co-integration theory and dynamic modeling system. The empirical results show that the production safety factor in the short term indeed drives the GDP growth in the mining industry although labor and capital input remain the major factors impacting mining economic growth, and its long term contribution share is 7.7%. Principal Component Analysis (PCA) of production safety indexes, shows that the safety level of mining production increased more than 21-fold during 1991–2009, and the investment in mining technology development capability, mining safety production environment and mechanized level of mining should be the direction to focus for improving the safety level of mining production.     

Reliability analysis of subsea blowout preventer control systems subjected to multiple error shocks

Two configurations of subsea blowout preventer (BOP) distributed control systems, which are triple modular redundancy (TMR) control system and double dual modular redundancy (DDMR) control system, are presented. With respect to common-cause failures, the performances of the two systems are evaluated by using Markov method with multiple error shock model. Due to the complexity, each system is split into three independent modules, and the corresponding Markov models are proposed subsequently. The probability of failure on demand, availability and reliability of the systems are evaluated by merging the independent Markov modules by Kronecker product approach. The results indicate that a same safety integrity level of SIL3 can be attained for the two configurations, which satisfies the requirement of subsea BOP control system, even though both of them have some advantages and shortcomings. In addition, for TMR control system, the effects of multiplicity distribution of multiple error shock and mean time to repair on reliability performances are studied.     

常州垃圾填埋场工程全寿命期管理理念探析

以常州城市垃圾填埋场项目建设为例,分析了全寿命期管理理念在垃圾填埋场管理中的应用,进而提出了全寿命期管理理念可以有效控制填埋场项目的质量、费用、时间等目标,并能产生巨大的社会效益。     

Performance analysis and life cycle greenhouse gas emission assessment of an integrated gravitational-flow wastewater treatment system for rural areas

Environmental Science and Pollution Research - Due to the lack of appropriate wastewater treatment facility in rural areas, the discharging of wastewater without sufficient treatment results in...     

加油站气液比检测方法及其影响

气液比(A/L)是加油站油气回收系统的一项重要控制指标,利用A/L测试仪、光离子化VOCs检测仪和油气排放因子测试装置,研究了不同A/L检测连接方式对A/L检测结果、检测人员暴露浓度、油气排放和油气回收效率等的影响。结果表明,不同连接方式和是否预先向检测油桶注油会导致A/L检测结果不一致,如果油桶与流量计不连接,A/L检测值将是实际A/L的1.04倍,当按照A/L=1.00~1.20调整加油枪A/L时,实际A/L将在0.96~1.15之间;按照国标GB20952-2007连接方式检测A/L可以减少检测过程中约80%的加油油气排放,夏季检测人员暴露油气浓度将由451×10-6(体积浓度)下降至91×10-6(体积浓度),油气排放因子将由1 056 mg/L下降至242 mg/L,更可减少因油罐吸入空气造成额外的汽油挥发排放,但不能减少倒油油气排放。