Growth factors, kinetics and biodegradation mechanism associated with Pseudomonas nitroreducens TX1 grown on octylphenol polyethoxylates

The growth properties and biodegradation mechanism of a Gram-negative bacterium, Pseudomonas nitroreducens TX1 that was able to grow on branched octylphenol polyethoxylates (OPEO(n), average n=9.5) as the sole carbon source over a wide concentration range (1-100,000 mgl(-1)) were studied. Analysis of growth factors indicated the highest specific growth rate (micro) of 0.53 h(-1) was obtained at an initial concentration of 5,000 mgl(-1) OPEO(n). An optimal C/N ratio of 12 was obtained for (NH(4))(2)SO(4) as the nitrogen source in a cultivated medium at pH 7. The kinetic analysis demonstrated that bacterial growth and OPEO(n) degradation followed the Monod equation and were based on a substrate concentration inhibition model and pseudo-first-order reaction, respectively. The substrate inhibition coefficient was over 18,000 mgl(-1) and this indicates that the strain has an ability to sustain growth at high concentrations of OPEO(n) and use it as the sole carbon source under such a stress condition. Furthermore, LC-MS analysis showed that the biodegradation mechanism of dodecyl octaethoxylate (AEO8) by P. nitroreducens TX1 was the sequential cleavage of the ethoxylate chain.     

利用等离子技术治理再生纤维汽车内衬生产过程中的烟气

利用等离子技术,治理树脂聚合法生产再生纤维汽车内饰材料过程中产生的烟气,对等离子净化装置的结构参数、操作参数进行了优化,并对等离子体净化机理进行了分析。利用等离子技术,能够处理常规工艺设备无法治理的极微细可吸入颗粒物和气溶胶烟气;并可同时净化可吸入颗粒物和气态污染物。该设备结构简单、运行费用极低,可在产生烟气的很多行业和领域推广应用。     

污泥中重金属的去除及回收试验

论述了利用离子交换技术循环使用柠檬酸去除污泥中重金属,并置换回收重金属的适宜工艺条件.经柠檬酸处理后,污泥中90%以上的重金属被去除;柠檬酸处理液中的重金属用离子交换法回收,考察了树脂种类、流速、操作方式等因素对离子交换、再生效果的影响;在适宜工艺条件下,重金属的交换率均为100%,而洗脱率均接近90%;柠檬酸及离子交换树脂循环使用,重金属也得到回收,降低了处理成本.     

电动单梁起重机吊具冲顶引发起升电机坠落事故分析

针对一起电动单梁起重机吊具冲顶并引发起升电机坠落的起重作业事故,分析了事故起重机电气控制系统和现场紧急处置中存在的问题,指出了导致事故发生的直接原因和主要原因;并从完善起重机电气控制系统本质安全性和加强起重机械使用安全管理的角度提出了相应建议和意见,对预防类似事故的发生具有借鉴作用.     

高压储氢系统泄漏爆炸事故的动力学演化

为研究燃料氢气泄漏、爆炸的特性和规律,预防高压储氢系统中氢气泄漏爆炸事故发生,以加氢站为背景,数值仿真45 MPa高压储罐氢气泄漏并引发爆炸事故,分析泄漏爆炸动力学性质以及爆炸波在非均匀氢气浓度中的传播机制。同时,基于泄漏爆炸事故演化的力学机理,开展氢气泄漏爆炸动态风险分析,针对氢气不同泄漏量,建立泄漏扩散形成的气云体积、气云爆炸产生的冲击波与空间x,z方向上危害距离之间关系。研究结果表明：氢气泄漏过程中,气云氢气浓度变化与流场雷诺数具有较好一致性;氢气扩散受到高压储氢罐周围装置影响,流场中氢气浓度分布不均匀;当发生燃烧爆炸事故时,冲击波参数和湍动能变化梯度大;得到复杂布局区域冲击波超压峰值与比例距离之间关系式,其相比于理论方法更精细、计算结果更准确。研究结果可为降低高压储氢系统泄漏爆炸事故后果、采取有效防护措施提供一定依据。     

抢救心脏骤停者与黄金4分钟

心脏骤停是人类生命最危险的急症之一。就其紧急程度和危险程度而言, 世界上没有任何一种疾病能够与之相比。心脏骤停是猝死前奏,处理得当,则可逢凶化吉。在北京国际展览中心举办的一次国际车展的开幕式上,有一位70多岁的老者突然心脏病发作,在场的一位小伙子及时有效地给这位老者实施了现场心肺复苏抢救,为挽救患者的生命奠定了良好的基础。后来得知,这位小伙子曾在红十字会接受过正规培训。     

绿色生态城区规划及实践的比较研究

目前,是以提倡低碳环保、绿色生态城市为发展规划的社会,生态化建设正如火如荼地进行中。本文以中新天津生态城、曹妃甸唐山湾生态城、青岛中德生态园这三个地点作比较,以建设绿色生态城市规划协同、共生城市理念、混合开发和生态社区结构这几点进行了分析,总结了城区建设间的问题,并针对这些问题研究解决方案,以达到绿色生态区建设的目的。     

矿井热宽温度环境人体热健康分区热调节模型*

为评价矿井热环境中工人职业健康安全状况,提出矿井热宽温度环境人体热健康状态的基本特征与生理要求,分析热宽温度环境人体分区热调节规律与热健康状态的对应关系。基于生物控制论的观点,提出热宽温度范围内不同热应力作用下人体分区热调节机制,建立人体分区热调节模型。结果表明:模型能实现对环境热应力作用下人体物理热平衡状态与生理状态的参数化描述,揭示多因素作用下人体热健康状态的热应力边界与变化规律。分区热调节模型提供了人体热健康状态定量模拟平台,通过参数调整可使模型适应研究需求,模型为井下热环境工人职业健康安全状况分析与评价提供了可参考的思路与方法。     

Scenario-based assessment and multi-objective optimization of urban development plan with carrying capacity of water system

• Impact of urban development on water system is assessed with carrying capacity. • Impacts on both water resource quantity and environmental quality are involved. • Multi-objective optimization revealing system trade-off facilitate the regulation. • Efficiency, scale and structure of urban development are regulated in two stages. • A roadmap approaching more sustainable development is provided for the case city. Environmental impact assessments and subsequent regulation measures of urban development plans are critical to human progress toward sustainability, since these plans set the scale and structure targets of future socioeconomic development. A three-step methodology for assessing and optimizing an urban development plan focusing on its impacts on the water system was developed. The methodology first predicted the pressure on the water system caused by implementation of the plan under distinct scenarios, then compared the pressure with the carrying capacity threshold to verify the system status; finally, a multi-objective optimization method was used to propose regulation solutions. The methodology enabled evaluation of the water system carrying state, taking socioeconomic development uncertainties into account, and multiple sets of improvement measures under different decisionmaker preferences were generated. The methodology was applied in the case of Zhoushan city in South-east China. The assessment results showed that overloading problems occurred in 11 out of the 13 zones in Zhoushan, with the potential pressure varying from 1.1 to 18.3 times the carrying capacity. As a basic regulation measure, an environmental efficiency upgrade could relieve the overloading in 4 zones and reduce 9%‒63% of the pressure. The optimization of industrial development showed that the pressure could be controlled under the carrying capacity threshold if the planned scale was reduced by 24% and the industrial structure was transformed. Various regulation schemes including a more suitable scale and structure with necessary efficiency standards are provided for decisionmakers that can help the case city approach a more sustainable development pattern.     

Biological conversion pathways of sulfate reduction ammonium oxidation in anammox consortia

• The SRAO phenomena tended to occur only under certain conditions. • High amount of biomass and non-anaerobic condition is requirement for SRAO. • Anammox bacteria cannot oxidize ammonium with sulfate as electron acceptor. • AOB and AnAOB are mainly responsible for ammonium conversion. • Heterotrophic sulfate reduction mainly contributed to sulfate conversion. For over two decades, sulfate reduction with ammonium oxidation (SRAO) had been reported from laboratory experiments. SRAO was considered an autotrophic process mediated by anammox bacteria, in which ammonium as electron donor was oxidized by the electron acceptor sulfate. This process had been attributed to observed transformations of nitrogenous and sulfurous compounds in natural environments. Results obtained differed largely for the conversion mole ratios (ammonium/sulfate), and even the intermediate and final products of sulfate reduction. Thus, the hypothesis of biological conversion pathways of ammonium and sulfate in anammox consortia is implausible. In this study, continuous reactor experiments (with working volume of 3.8L) and batch tests were conducted under normal anaerobic (0.2≤DO<0.5 mg/L) / strict anaerobic (DO<0.2 mg/L) conditions with different biomass proportions to verify the SRAO phenomena and identify possible pathways behind substrate conversion. Key findings were that SRAO occurred only in cases of high amounts of inoculant biomass under normal anaerobic condition, while absent under strict anaerobic conditions for same anammox consortia. Mass balance and stoichiometry were checked based on experimental results and the thermodynamics proposed by previous studies were critically discussed. Thus anammox bacteria do not possess the ability to oxidize ammonium with sulfate as electron acceptor and the assumed SRAO could, in fact, be a combination of aerobic ammonium oxidation, anammox and heterotrophic sulfate reduction processes.