Electrokinetic remediation: The use of mercury speciation for feasibility studies applied to a contaminated soil from Almadén

We have chosen the BCR (Bureau Communautaire de Référence) sequential extraction procedure as a speciation analysis to determine the mobility of mercury in the contaminated soil of the Almadén (Spain) mining district. This soil has a high mercury concentration (1000 mg kg⁻¹) in some areas. In previous works, the relationship between the weak-acid soluble fraction and the amount of contaminant recoverable by acid-enhanced electrokinetic remediation (EKR) was shown. In this study, after testing that this relationship is maintained, we test if similar relationships with chelating agents could be established. Recently, several chelating agents were tried and iodide was shown to be quite efficient for the removal of mercury. Thus we have carried out iodide-enhanced EKR experiments at the lab (16 g of soil) and semi-pilot (2 kg) scales. From these experiments it can be concluded that the amount of mercury recoverable by this technique is similar to the one recovered in the batch extraction experiments. Thus, this is another evidence that this kind of experiments can be used for the feasibility studies of the remediation technique. It is also shown that, although the removal efficiency is similar to the one obtained previously for in situ flushing, the time required to achieve this efficiency would be several orders of magnitude shorter for this soil.Nevertheless, the residual Hg present in the weak-acid soluble fraction of the speciation analysis of the soil after the EKR treatment increases with respect to the original contaminated soil, indicating a possible increase of the risks associated to the contaminated site. Therefore, a second EKR treatment is applied to the same soil, this time using acid-enhanced EKR. It is shown that, although almost no Hg was recovered with this technique for the original soil, an important amount can be recovered after the first treatment (iodide-enhanced EKR). Also it is shown that the design and operation of this second technique should be studied carefully due to the rather complex chemistry of the species involved.     

Beurteilungskriterien für sicherheitstechnische Prüfungen

Methods are presented which enable one to assess and compare the hazard potentials of different technical installations without the necessity of a detailed technical plant analysis. The basis is the energy content of the installation. In the case that energies with different impact mechanisms, e.g., pressure and heat, are to be compared, the probit method is used. In addition, the expected frequency of occurrence is included in the assessment. This is an approach which is already used in neighboring countries. It is foreseeable that it will gain importance in Germany as well. In the case of elevators the predator‐prey model is used to analyze the time series of accidents. The influence of errors in inspection and maintenance is put into evidence by comparison with the SIL classification.     

东北油气分公司推进业务外包工作的成功经验及启示

为了解决油气主体岗位不能使用劳务派遣用工的难题,规避劳务派遣用工总量超标的法律风险,经过调查研究,结合东北局实际情况,制定了业务外包工作方案,并按方案要求,清理了混岗,解决了劳务派遣员工的合理合法诉求,完成了业务外包工作,调整了用工模式,实现了规范用工管理。     

浅谈如何推进油田廉洁风险防控工作机制的建立

为了深入开展廉洁风险防控工作,作为中国石化企业都应该积极探索切实可行的廉洁风险防控机制,通过全员清权查险,全面制度预防,建立防控机制,初步形成"权责清晰、流程规范、风险明确、预警及时、监控有效"的特色廉洁风险防控体系,有力促进企业廉洁风险惩防体系的建设。     

试论钻井安全生产标准化的创建

中国石化集团江汉石油管理局钻井一公司为进一步加强企业安全生产工作,实现企业安全生产标准化,全面建立和实施以危害因素辨识、风险评估和风险控制为基础,组织完善、职责明确、具有持续改进功能的钻井一公司安全生产标准化体系,在安全标准化创建工作中,领导重视,组织落实,调动全员积极参与;按照标准化系统建设要求,建立健全了各项规章制度,从制度上保障安全标准化工作有效推进;开展了危害识别和风险评估,对辨识出的危险有害因素实施动态管理;开展了作业现场安全标准化创建;强化员工安全意识,积极开展了各类培训教育活动;开展了职业健康监护工作;开展了QHSE体系内审,指导现场标准化建设。     

浅析油田外部市场廉洁风险的有效防控

以规范权力运行和监督为主线,对油田外部市场廉洁风险防控情况进行研究,有针对性地制定和实施预警预防、制度规范、监督制约等防控措施,可以规范油田外部市场,廉洁从业环境,促进企业健康有效对外发展。     

Nongenotoxic Mechanisms Involved in Bromate-Induced Cancer in Rats

Risk assessments for bromate (BrO₃-) in drinking water are based on linear extrapolation from the total incidence of tumors in male rats. The only genotoxic effects that might result from carcinogenic doses of BrO₃- in vivo are the formation of 8-oxodeoxyguanosine (8-oxoG) in deoxyribonucleic acid (DNA) and the production of micronuclei. The mutations in tumors are consistent with the 8-oxoG adduct, and both effects are nonlinear with respect to dose. Treatment of rats with BrO₃- resulted in bromination of protein tyrosines. The accumulation of these proteins in the kidney appeared to contribute to kidney cancer in male, but not female, rats. BrO₃- increased the rate of apoptosis (programmed cell death) in the kidneys of rats of both sexes, an effect associated with increasing expression of antiapoptotic genes and proteins. Consequently, suppression of apoptosis is a likely mechanism for BrO₃- induced kidney cancer. More limited data suggest nongenotoxic modes of action for thyroid tumors and mesotheliomas. If these data are confirmed, linear extrapolation of risk to low doses is inappropriate.     

Assessing the sustainability of non-renewable brackish groundwater in feeding an RO desalination plant in Bahrain

The Rus-Umm Er Radhuma aquifer in Bahrain is a non-renewable source of brackish water (8-15 g/L), which forms a lens underlain everywhere with brines of over 100 g/L. Aquifer utilization has started in 1984 to feed a reverse osmosis (RO) desalination plant, with an economic life of 25 years (2010). Future plant upgrade strategy is formulated around boosting the plant production, which will require increasing the we llfield abstraction, in addition to a possible future rehabilitation program to extend the plant life by another 15 years (2025). The limiting factor in expanding the RO plant and its rehabilitation is the future feed water salinity, which have to be assessed before any investments are made to expand the RO plant and commission additional abstraction wells and implement the rehabilitation program. The aquifer management is based on mining a one-time brackish water reserve stored in the aquifer, the main management objective is stated as to sustain the aquifer future availability in feeding the desalination plant with a specified salinity limit of 20 g/L over the economic life of the plant of 25 years (1985-2010), and also over the plant extension period by rehabilitation (2010-2025). The stochastic analysis methodology utilizing conditional simulation is applied to conduct a risk assessment of violating these two pre-specified sustainability constraints under the proposed abstraction increase; and provided a tool to aid the decision-making process in the development and management of the aquifer under large uncertainties. Simulation results indicated that the risk of having the salinity of the wellfi eld produced water to increase due to the proposed increase in the wellfield abstraction to reach 20 g/L over the economic life of the plant (2010) is very small and minimal. However, it is questionable that the feed water salinity will be maintained under the proposed rehabilitation program to extend the plant economic life by another 15 years (2011-2025). For this option, it is recommended that model post-auditing be performed, and new updated predictions should be made as more data of potentiometry. salinity. and hydraulic parameters become available.     

Minimization of defects in Nb-doped TiO2 photocatalysts by molten salt flux

Transition metal doping is a popular pathway to improve the photocatalytic performance of TiO₂. However, most dopants are aliovalent (e.g., Nb⁵⁺, W⁶⁺, and Fe³⁺), where defects are inevitably introduced (e.g., oxygen or Ti³⁺ defects). To minimize defects and hence ensure better separation of photogenerated charges, this work incorporates an Nb dopant into TiO₂ in a flux of molten salt. The molten salt flux not only induces recrystallization of TiO₂ nanoparticles into nanowires but also allows a + 4 valence dopant in the TiO₂ lattice to inhibit formation of Ti³⁺ or oxygen defects. This minimization of defects enhances the photocatalytic activity in the degradation of gaseous acetaldehyde. This enhancement is mainly attributed to the higher crystallinity of TiO₂ and better separation of charge carriers induced by equivalent Nb-doping.     

治疗性干细胞产品的相关风险因素

近年来国内外以干细胞为主的细胞治疗研究发展迅速,在治疗退行性疾病、缺血性心脑血管疾病、肝硬化及糖尿病等领域已开展了多项临床试验研究,但作为新型治疗性产品,干细胞产品在治疗的安全性和有效性方面还存在若干风险因素。本文对常见的干细胞种类、特性以及与临床应用相关的内在和外在风险因素进行了综述,旨在以现有的理论和技术条件,探讨治疗性干细胞产品基本的质量控制要求和策略。