西安市兴庆宫公园土壤中重金属含量研究及污染评价

通过对西安市兴庆宫公园表层土壤的取样调查,分析了Cu、Zn、Cd、Cr及Pb等5种重金属的含量及形态分布特征,并对其综合污染状况及潜在生态风险进行分析与评价。结果显示,兴庆宫公园的表层土壤呈碱性,并含有较多有机质;土壤中Cu、Zn、Cd、Cr及Pb平均含量分别为29．89mg／kg、55．28mg／kg、0．169mg／kg、66．71mg／kg和43．59ms／kg;土壤中Cu、Zn、Cd、Cr及Pb化学形态均以残渣态为主;整个公园土壤内梅罗污染指数为2．29,土壤重金属综合污染已经达到中度污染;整个公园潜在生态风险指数平均值为73．89,生态风险等级为轻微。     

生态工业园建设水平的定量评估方法介绍及应用

介绍了工业园内工厂或企业间的关联度以及副产品和废物的循环利用率的计算方法,以扬州生态工业园为例进行了初步计算,并将其与国内外部分工业园进行比较,结果显示有一定差距,指出了进一步提高工业园生态化水平的方向及途径。     

Prevention in the chemical and process industries: Future directions

This paper presents the current trends of future-oriented prevention management in the chemical-using industry. Two concepts leading to the next generation of managing prevention within chemical industrial areas are explained and discussed. The first concept concerns integrated design-based safety and security; the second concerns the collaboration of several chemical plants to increase sustainable development of their activities and their environment.     

苏州工业园区恶臭气体处理新技术

恶臭气体污染已经严重影响了人们的生活。工业区与居民区共建的现象导致恶臭问题投诉较多,如何解决恶臭已成为环境热点问题。主要介绍了几种恶臭处理的新方法,以期能对企业起到参考作用。     

Fenton-活性炭联合处理高浓度工业废水

实验采用Fenton氧化与活性炭吸附相结合的方法处理高浓度工业废水,考察了Fenton反应和活性炭吸附影响COD去除率的的最佳条件。结果表明,Fenton反应的最佳条件为H2O2∶COD=2,Fe2+∶H2O2=1∶4,反应pH=3,反应时间采用60 min。活性炭柱吸附最佳用量采用15 g活性炭吸附50mL Fenton反应后水样,两者结合COD最大去除率达到85.47%。     

乡村产业结构评价--以云南省永胜县为例

乡村产业结构的合理化对农村经济、农民收入、农业生产决策及国民经济发展都有着重要意义,对这种合理化的评价一直是乡村地理学与农业经济学的重要研究内容。在探讨乡村产业结构内涵的基础上,利用产值结构指标、劳动力构成指标和结构变动度指标建立乡村产业结构的评价指标体系,并以此对云南省永胜县近20年来产业结构演化进行个案评价。结果表明,永胜县乡村产业结构正向合理化方向发展,但还存在自然资源尚未得到合理利用、三次产业不协调与农业内部结构不合理、不协调等主要问题,有待进一步完善、合理化。研究同时指出了永胜县乡村产业结构调整的基本对策,即调整农业发展方向,持续稳定的发展农业;以食品加工业为乡镇企业发展突破口,积极发展第三产业。     

Young convict cichlids use visual information to update olfactory homing cues

In this study, we tested the tendency of young cichlids to orient towards their parents using chemical cues. Convict cichlids have biparental defence of their free-swimming young. If young become separated from their family they must rejoin their family within minutes to have any chance of survival. Here, we used a dichotomous Y-maze to test if displaced convict cichlid young can use chemical cues to orient to their family. First, we showed that young preferentially orient toward water taken from their home tank versus blank water taken from a tank that contained no fish. Second, we showed that young prefer home tank water to water from a tank containing another family of convict cichlids. In a third experiment, we placed young convict cichlids in a small aquarium inserted within a larger aquarium. The large aquarium contained either their parents or no fish. The small insert aquarium contained blank water from a tank that had never contained fish. After 20 min in the insert tank, young convict cichlids were placed in the Y-maze and given a choice between either their home tank water or water from the insert tank. Convict cichlids that did not see their parents during the 20-min conditioning period oriented strongly toward chemical cues of their home tank water. Young that saw their parents during the 20-min conditioning period oriented strongly toward the chemical cues of the insert tank. These data indicate that young convict cichlids use visual cues to learn and reset the smell of “home” in less than 20 min.     

Initial phase modelling in numerical explosion applied to process safety

The utilisation of computational fluid dynamics (CFD) in process safety has increased significantly in recent years. The modelling of accidental explosion via CFD has in many cases replaced the classical Multi Energy and Brake Strehlow methods. The benefits obtained with CFD modelling can be diminished if proper modelling of the initial phase of explosion is neglected. In the early stages of an explosion, the flame propagates in a quasi-laminar regime. Proper modelling of the initial laminar phase is a key aspect in order to predict the peak pressure and the time to peak pressure. The present work suggests a modelling approach for the initial laminar phase in explosion scenarios. Findings are compared with experimental data for two classical explosion test cases which resemble the common features in chemical process areas (confinement and congestion). A detailed analysis of the threshold for the transition from laminar to turbulent regime is also carried out. The modelling is implemented in a fully 3D Navier–Stokes compressible formulation. Combustion is treated using a laminar flamelet approach based on the Bray, Moss and Libby (BML) formulation. A novel modified porosity approach developed for the unstructured solver is also considered. Results agree satisfactorily with experiments and the modelling is found to be robust.     

A study of maintenance-related major accident cases in the 21st century

This paper is based on a review of 183 detailed, major accident investigation and analysis reports related to the handling, processing and storage of hydrocarbons and hazardous chemicals over a decade from 2000 to 2011. The reports cover technical, human and organizational factors. In this paper, the Work and Accident Process (WAP) classification scheme is applied to the accident reports with the intention of investigating to what extent maintenance has been a cause of major accidents and what maintenance-related causes have been the most frequent.The main objectives are: (1) to present more current overall statistics of maintenance-related major accidents, (2) to investigate the trend of maintenance-related major accidents over time, and (3) to investigate which maintenance-related major accident causes are the most frequent, requiring the most attention in the drive for improvement.The paper presents statistical analysis and interpretation of maintenance-related major accidents’ moving averages as well as data related to the types of facility, hazardous substances, major accidents and causes. This is based on a thorough review of accident investigation reports.It is found that out of 183 major accidents in the US and Europe, maintenance was linked to 80 (44%) and that the accident trend is decreasing. The results also show that “lack of barrier maintenance” (50%), “deficient design, organization and resource management” (85%) and “deficient planning/scheduling/fault diagnosis” (69%) are the most frequent causes in terms of the active accident process, the latent accident process and the work process respectively.     

化工园区安全规划方法和内容研究

近年来,化工园区在我国得到快速发展,如何进行科学合理的园区安全规划,保护园区周边人员安全,优化内部危险源布局,合理设定园区安全容量,是国内化工园区安全管理工作迫切希望解决的问题。笔者在大量实践工作的基础上,对化工园区安全规划的目的、内容和方法进行了阐述,提出了化工园区外部安全防护距离的概念和计算方法,化工园区内部优化布局的阶梯原则,化工园区安全容量的确定方法,以及化工园区安全规划需要考虑的公用工程和配套设施,安全监管和一体化应急等内容,以期用于指导和推进我国化工园区安全规划的工作。