Optimizing the design of storage facilities through the application of ISD and QRA

Four strategies can be used to achieve safety in chemical processes: inherent, passive, active and procedural. However, the strategy that offers the best results is the inherent safety approach, especially if it is applied during the initial stages of a project. Inherently Safer Design (ISD) permanently eliminates or reduces hazards, and thus avoids or diminishes the consequences of incidents. ISD can be applied using four strategies: substitution, minimization, moderation and simplification. In this paper, we propose a methodology that combines ISD strategies with Quantitative Risk Assessment (QRA) to optimize the design of storage installations. As 17% of major accidents in the chemical industry occur during the storage process and cause significant losses, it is essential to improve safety in such installations. The proposed method applies QRA to estimate the risk associated with a specific design. The design can then be compared to others to determine which is inherently safer. The risk analysis may incorporate complex phenomena such as the domino effect and possible impacts on vulnerable material and human elements. The methodology was applied to the San Juanico tragedy that occurred in Mexico in 1984.     

人工纳米材料生物效应研究进展

人工纳米材料(MNMs)由于其所具有的独特性质能满足当前工业发展的多样化需求,近年来获得迅速的发展.目前,越来越多的MNMs已被投放市场,给人们生活带来巨大的变化和进步.但是有关MNMs是否对环境和健康产生不利影响的问题,同样引起了人们广泛的关注.通过总结近年来的相关研究资料,一方面探讨了生物对MNMs的暴露途径;另一方面,从MNMs对动物细胞、肺组织和脑组织的毒性效应,MNMs在生物体内的转移、积累以及皮肤对MNMs的吸收等角度,对MNMs的生物效应进行综述.同时,发现MNMs本身独特的物理化学性质和MNMs的表面修饰是影响MNMs生物效应的重要因素.此外,借鉴超细颗粒的研究结果探讨了MNMs生物效应可能的作用机制.最后展望了纳米毒理学的发展.     

地下水的致灾效应及异常地下水流诱发地质灾害

地下水是诱发和触发近地表地质灾害的最主要因素,在地质灾害评价、预测与防治中具有特殊重要的意义。本文对灾害过程中地下水的地质-力学作用一般原理和规律作了较为全面的分析,提出了地质体水敏性和水敏结构的概念,尤其对地下水的化学作用进行了较为深入的分析。结合具体实例,揭示了两类典型的极端情况下地下水触发地质灾害的特殊机理。一类是大型顺层滑坡发生过程中的地下水的“水垫-楔裂”效应;另一类是深埋长隧道中,地下水在高强度水头压力作用下的“劈裂”效应。两类效应在西南地区斜坡地质灾害和深埋长隧道的修建过程中都具有一定的典型意义。     

厚软场地上大跨径桥梁设计反应谱研究

大跨径桥梁塔高、跨径大、自振周期长,深厚、软弱场地的长周期地震动对桥体结构影响较大。我国《公路工程抗震设计规范(JT J004-89)》也只适用主跨不超过150 m的梁桥和拱桥,国内长期以来没有一个适用于大跨径桥梁的抗震设计规范或指南。本文结合大跨径桥梁工程实例,根据场地土层静、动力性能参数的原位测试和动三轴试验结果,进行厚软场地土层地震反应分析,研究厚软场地的地震动效应,讨论了不同地震动强度时厚软场地的设计反应谱特征,分析了现行规范设计反应谱应用的局限性,成果对相关工程有重要指导意义,对大跨径桥梁抗震设计规范的制定也有借鉴作用。     

油田注水泵房噪声治理

调查了油田注水泵房噪声的基本情况.根据噪声来源和特性制定了治理方案,分析了试验应用效果.     

沈阳市环境铅污染对儿童健康的影响

实地调查采样、结合GIS技术进行室内综合分析,系统研究了沈阳市大气、土壤、灰尘中铅污染对儿童健康的影响.结果表明,沈阳市环境中铅暴露普遍,铅污染较严重,铅浓度空间分异大,已形成4个高浓度中心.并且大气铅浓度有明显的日、季和年变化规律沈阳市环境铅污染已经影响了儿童健康,0～10岁儿童(ZPP＞2.3μmol/L)血铅范围是10.98～511.2μg/L,平均值是135.59μg/L,40%的儿童血铅水平超标.儿童血铅与大气铅相关性最大,其次是土壤和灰尘.实行无铅汽油之后,大气铅污染有了很大改善,但是土壤和灰尘中的铅容易以扬尘的方式再次进入大气,存在潜在风险,应引起有关部门足够的重视.     

Co-fermentation of waste activated sludge with food waste for short-chain fatty acids production: effect of pH at ambient temperature

Effect of pH ranging from 4.0 to 11.0 on co-fermentation of waste activated sludge (WAS) with food waste for short-chain fatty acids (SCFAs) production at ambient temperature was investigated in this study. Experimental results showed that the addition of food waste significantly improved the performance of WAS fermentation system, which resulted in the increases of SCFAs production and substrate reduction. The SCFAs production at pH 6.0, 7.0, 8.0, and 9.0 and fermentation time of 4 d was respectively 5022.7, 6540.5, 8236.6, and 7911.7 mg COD·L^-1, whereas in the blank tests (no pH adjustment, pH 8.0 (blank test 1), no food waste addition, pH 8.0 (blank test 2), and no WAS addition (blank test 3)) it was only 1006.9, 971.1, and 1468.5 mg COD·L^-1, respectively. The composition of SCFAs at pH from 6.0 to 9.0 was also different from other conditions and propionic acid was the most prevalent SCFA, which was followed by acetic and n-butyric acids, while acetic acid was the top product under other conditions. At pH 8.0 a higher volatile suspended solids (VSS) reduction of 16.6% for the mixture of WAS and food waste than the sole WAS indicated a synergistic effect existing in fermentation system with WAS and food waste. The influence of pH on the variations of nutrient content was also studied during anaerobic fermentation of the mixture of WAS and food waste at different pH conditions. The release of NH4+-N increased with fermentation time at all pH values investigated except 4.0, 5.0 and in blank test one. The concentrations of soluble phosphorus at acidic pHs and in the blank test one were higher than those obtained at alkaline pHs. Ammonia and phosphorus need to be removed before the SCFAs-enriched fermentation liquid from WAS and food waste was used as the carbon source.     

土地利用变化对生态系统服务的影响研究综述

土地利用/覆被变化是全球环境变化的重要组成部分和主要原因之一,不仅带来了地表结构的巨大变化,而且对生态系统服务也造成重要影响。土地利用变化和生态系统服务研究已成为国际上生态学和地理学等跨学科研究的热点之一。从土地利用变化和生态系统服务的概念及其影响因素分析入手,综述了土地利用面积变化、土地利用方式变化和土地利用空间格局变化等对生态系统服务的影响,归纳了土地利用变化对生态系统服务的影响研究的主要方法和模型,分析了相关研究的不足,并提出了加强生态系统服务动态评估方法和时空动态评估模型的研究、强化土地利用变化对生态系统服务影响的生态学机制研究和注重土地利用变化下生态系统服务评估结果的集成应用研究等建议,以期对我国的土地利用变化与生态系统服务评估研究提供科学参考。     

Estimating the uncertainty of pesticide residue analysis from mango using multi-residue analysis and validation of method

Validation of method was performed for various pesticides on mango matrix involving the processing of sample at ambient and cryogenic conditions. The linearity, limits of detection, repeatability, matrix effect, and recovery were studied as the aspects of method validation. The effect of matrix on recovery was found to be medium (20–50%) and strong (>50%). After correction by matrix-matched calibration curves, the recovery was calculated to be in the range of 80–107% and 80–105% at ambient and cryogenic processing, respectively. The precision estimated for the recovery of pesticides obtained from both solvent- and matrix-matched calibration curves and at both the processing conditions was determined to be >20% except for chlorpyrifos and atrazine. The uncertainty established for the methodology was >20%, which substantiates the efficiency and reliability of methodology used for pesticide residue analysis in mango in this study.     

Removal of methylene blue by coupling black carbon adsorption with TiO2 photodegradation

In this study, the removal of methylene blue (MB) by the coupling of black carbon (BC) and TiO₂ was investigated. The effects of different parameters such as catalyst dose, sorbent, initial concentrations of dye, pH of the solutions, recycles on discoloration, and chemical oxidation demand (COD) reduction of MB were monitored to optimize the reaction conditions. The discoloration and COD conversation rate of MB obtained by the coupling process were 100% after 90?min irradiation. The synergistic effect of MB-adsorption on BC followed by degradation through TiO₂ photocatalysis was proved by FT–IR spectrophotometer. The BC as by-product of natural materials is a promising adsorbent for waste water treatment.