Preparation of Fe–Co based MOF-74 and its effective adsorption of arsenic from aqueous solution

To obtain a cost-effective adsorbent for the removal of arsenic in water,a novel nanostructured Fe–Co based metal organic framework(MOF-74)adsorbent was successfully prepared via a simple solvothermal method.The adsorption experiments showed that the optimal molar ratio of Fe/Co in the adsorbent was 2:1.The Fe_2Co_1MOF-74 was characterized by various techniques and the results showed that the nanoparticle diameter ranged from60 to 80 nm and the specific surface area was 147.82 m~2/g.The isotherm and kinetic parameters of arsenic removal on Fe_2Co_1MOF-74 were well-fitted by the Langmuir and pseudo-second-order models.The maximum adsorption capacities toward As(III)and As(V)were 266.52 and 292.29 mg/g,respectively.The presence of sulfate,carbonate and humic acid had no obvious effect on arsenic adsorption.However,coexisting phosphate significantly hindered the removal of arsenic,especially at high concentrations(10 mmol/L).Electrostatic interaction and hydroxyl and metal–oxygen groups played important roles in the adsorption of arsenic.Furthermore,the prepared adsorbent had stable adsorption ability after regeneration and when used in a real-water matrix.The excellent adsorption performance of Fe_2Co_1MOF-74 material makes it a potentially promising adsorbent for the removal of arsenic.     

北京市环境压力及重点调控策略研究

近年来,北京市在控制污染、提高环境质量方面投入了大量人力、物力、财力,取得了较大的成绩,在经济保持较快增长的同时,环境质量得到了持续改善。本文从环境质量、污染防治形势等方面深入分析了北京市的主要环境问题和环境压力,并从强化科学决策、调整能源结构、优化产业结构、深化污染防治等方面提出了具体的调控对策,对于相关管理部门宏观决策具有一定的参考价值。     

上海地区SO2污染现状和趋势分析

根据上海市监测系统长期监测资料，对上海地区大气中ＳＯ２的污染现状进行了综合分析，并总结出ＳＯ２的时空分布规律与特征。应用秩相关系数法，对１９８６￣１９９５年的１０年ＳＯ２浓度均值进行了年际变化趋势检验，同时从最大值、超标率及高浓度日出现天数等不同的侧面，进行了年际变化趋势分析，以充分的证明表明，上海市ＳＯ２年际变化呈显著下降趋势。     

HAZOP风险分析方法在常减压装置中的应用

将风险评价与HAZOP分析结合,对偏差进行风险评价,对辨识出的危险因素进行风险等级划分,确定对装置影响较大的偏差事件,对HAZOP分析中提出的建议措施进行有针对性的实施,以便更准确有效地提高事故预测和控制能力。     

北京奥运会帆船比赛前夕浒苔灾害暴发与青岛市应急行动

北京奥运会开幕前夕,青岛突发历史罕见的浒苔灾害,严重威胁到奥帆赛的举办.本文全面回顾了青岛市在应对这场突发事件的全过程,并运用现代应急管理理论,对其整个事件进行客观评述,总结了青岛市在信息公开、决策指挥、应急准备、科技支撑、综合治理、善后处置等方面的成功经验,并从应急准备、应急处置和应急队伍建设等三个方面对存在的不足和问题进行了深入地查找和分析.     

高速公路建设对低丘陵地区的生态环境影响及保护措施探讨——以安徽省铜南宣高速公路为例

低山丘陵地区高速公路的环境保护是一项综合性的工程,文章针对安徽省低丘陵地区的自然生态特征,以安徽省铜陵-南陵-宣城高速公路为例,从生态系统功能及动植物群落受到的影响两方面对低丘陵地区的高速公路建设产生的生态环境负面影响进行分析,随后从高速公路建设的准备期、施工期、运营期等方面提出了针对性的生态环境保护措施,以维护公路环境,提高公路环境效益,同时为低丘陵地区高速公路建设的生态环境保护工作提供有意义的借鉴。     

医院污水处理的消毒剂及消毒工艺

综合比较目前国内常用的医院污水消毒处理方法，介绍消毒剂的种类和有效氯含量，论述各种消毒工艺的优缺点。     

袋式除尘器在电炉烟尘治理上的应用

结合工程实例，介绍了“低阻、中温、大流量”除尘系统工艺在电炉上的应用，以及除尘系统各组成部分的性能特点和所采用的关键技术，阐述了关键技术的理论依据、设计原则和设计参数。     

Parametric approach of the domino effect for structural fragments

More specific and accurate probabilistic models of the numbers of fragments generated respectively by Boiling Liquid Expanding Vapor Explosions (BLEVEs), Mechanical Explosions (MEs), Confined Explosions (CEs), and Runaway Reactions (RRs) of a horizontal cylindrical vessel were developed using the maximum entropy principle based on historical accident data. The theoretical results from the four probability density functions were compared to the observed data, and the numbers of fragments followed discrete exponential distributions in the interval [1, 9]. Beside the summary of the probabilistic distributions of the other random variables in the process of fragment projection, the effects on the fragment trajectory and target terms were investigated using a parametric approach. The results showed that using the complete model, wind shear, turbulence, and absence of fragment rotation caused the fragments to impact within shorter distances; fragment rotation and lack of wind decreased the probability of impact within a given distance, but the rupture probability of the target was not affected by fragment rotation or wind. The probabilistic confidence intervals of fragment range, impact, and target penetration became narrower with the number of simulation runs, but the accuracy of the results increased. The probability of fragment impact increased with the volume of the target vessel and the degree of filling of the explosion vessel, but did not depend on the kind of explosion. The probability of target rupture increased slowly with the degree of filling of the explosion vessel, but was little influenced by the volume of the target vessel or the kind of explosion.