高铁脱硫渣制备高纯度硫酸亚铁及草酸亚铁的研究

以高铁脱硫渣为原料,采取酸浸、除杂和结晶等工艺制备出99%以上硫酸亚铁晶体。研究了酸浸过程中硫酸浓度、浸取温度、时间对铁浸出率的影响,分析了各个影响因素的规律性。结果表明：适宜的浸取条件为硫酸溶液质量分数为25%,在70℃下,不断搅拌浸取6 h。固液分离后调节硫酸亚铁溶液pH=1～2,在70℃下蒸发浓缩结晶,即可得到99%以上硫酸亚铁晶体。     

微生物絮凝剂产生菌的筛选及其絮凝特性

采用常规的微生物学方法,从垃圾渗滤液中筛选到一株高效微生物絮凝剂产生菌LB1,根据其形态学和生理生化特征初步鉴定该菌株属于假单胞菌属,命名为Pseudonomas sp. LB1。LB1所产微生物絮凝剂的絮凝特性的研究结果表明,LB1的最佳产絮凝时间为96 h,所产絮凝活性物质主要是其生长过程中的胞外分泌物和细胞生长后期的次级代谢产物,菌体细胞本身具有一定的助凝作用。LB1所产絮凝剂最佳加样量为3％（体积分数V/V）;对pH的适应范围较宽,在4～10之间具有较高的絮凝活性,均大于75％;温度为25℃时絮凝率为86.3％,在25～60℃之间,絮凝率基本保持稳定;LB1所产絮凝剂对几种废水具有较好的絮凝效果。     

应用贝叶斯理论的河流污染源重建探讨

为深入了解河流中有毒有害物质事故性污染的污染源、污染物质扩散等情况,通过MATLAB实现了河流中污染物质一维扩散模型的差分解法.该扩散模型可用于模拟1个或多个瞬时点源、持续稳定点源和持续变化点源情况下,河流中污染物质浓度随时间的变化,具有一定准确度.根据贝叶斯理论,结合扩散模型和监测数据估计污染源的位置和强度,并采用马尔可夫链蒙特卡罗方法进行后验推断,以解决贝叶斯模型计算复杂的问题.已知污染源情况下,可采用本文给出的扩散模型模拟河流下游污染物质浓度随时间的变化;污染源未知而拥有一定监测数据情况下,则可以采用本文提出的河流污染源重建技术估计污染源的位置、强度等.     

湖北省重大自然灾害数据库的设计与应用

自然灾害,尤其是重大自然灾害是影响生产布局、制约区域经济发展的重要因素,在重大灾害中,气象灾害和地震灾害是对人类威胁最大的灾种。湖北省地处长江中游,是我国重大自然灾害的多发区与重灾区,其减灾、防灾的研究具特别重要的意义。通过对湖北省历代有关气象灾害和地震灾害历史文献的收集、整理、分等分级,并且在计算机软硬件平台的支持下生成数据库,将零散、杂乱的各处有关灾害的史料变成一个有序的信息源,为有关抗灾、防     

山地地形重气扩散模拟中湍流模型的选择

针对类似开县井喷的毒气扩散事故,研究山地地形条件下如何合理选择湍流模型对重气扩散进行大范围数值模拟.在初始条件和边界条件相同条件下,采用密切值法对6个BANS模型(RSM、标准k-ε、RNG k-ε、可实现k-ε、标准k-ω和SST k-ω)的计算结果进行多方案选择,同时参考模拟中所消耗的CPU时间,使选用的模型尽可能在"计算精度"和"计算时间"之间取得平衡.结果表明,对山地条件下的大范围毒气扩散事故的模拟,采用标准k-ε模型时可在"计算精度"和"计算时间"之间取得较好平衡.可见,对山地地形条件下大范围重气扩散的数值模拟宜采用标准k-ε模型.     

风险严重度指数法在毒气泄漏评价中的应用

为评价某区域或某设备潜在的毒气泄漏事故场景的风险水平,以对不同的风险等级进行风险控制和安全规划,详细介绍了工业事故风险评估方法ARAMIS所采用的风险严重度指数法.首先基于事故频率和后果的风险矩阵选取毒气泄漏事故场景;然后运用毒气当量浓度计算任意暴露时间下不同风险严重度等级所对应的特征距离,并根据同一风险等级内风险严重度指数与距离的线性关系计算任意点的风险严重度指数;最后应用1个实例分析了考虑所研究区域的风向概率后对风险严重度指数的真实影响,便于工厂或企业识别不同的风险等级,进行不同场景下风险水平的对比性研究,为其安全设计及风险分析提供了一种新的评估方法.     

Anthropogenic metal cycles in China

The flows and stocks of seven important industrial metals were characterized for mainland China for several years in the dynamically changing decade of 1994–2004. One-year snapshot cycles are provided for chromium, nickel, and silver. For copper, zinc, lead, and iron, multiple-year cycles have been completed; they demonstrate that the flows of these metals into use in China doubled between 2000 and 2004. Although the Chinese per capita flows from production to disposal are mostly shown to be below the global average rate, they are increasing or are expected to increase dramatically. The metal resource efficiency is evaluated for several indicators of material flow analysis; these metrics for China are also below the global average values. The research quantitatively illustrates that China’s metal cycles may pose significant resource and environmental challenges in terms of their magnitudes and potential for growth.     

浅谈资源型城市可持续发展 ──以大庆为例阐述战略规划和环境政策制定的依据和原则

文章分析了资源型城市制定可持续发展战略和环境政策的依据和原则,以大庆开发建设多年来的成功经验和失败教训为例,阐释了资源型城市充分利用资源、资金、文化、人才的重要性和必要性,及对生态环境和人文环境充分保护的紧迫性。进而说明:充分利用好城市的各种资源,充分保护好城市的生态环境和人文环境,及早发展替代产业完成城市转型是资源型城市可持续发展的必由之路。     

Influence of complex reagents on removal of chromium(VI) by zero-valent iron

The removal of Cr(VI) by zero-valent iron (Fe(0)) and the effect of three complex reagents, ethylenediaminetetraacetic acid (EDTA), NaF and 1,10-phenanthroline, on this reaction were investigated using batch reactors at pH values of 4, 5 and 6. The results indicate that the removal of Cr(VI) by Fe(0) is slow at pH 5.0 and that three complex reagents play different roles in the reaction. EDTA and NaF significantly enhance the reaction rate. The zero-order rate constants at pH 5.0 were 5.44 microM min(-1) in the presence of 4mM EDTA and 0.99 micrM min(-1) in the presence of 8 mM NaF, respectively, whereas that of control was only 0.33 micrM min(-1), even at pH=4.0. This enhancement is attributed to the formation of complex compounds between EDTA/NaF and reaction products, such as Cr(III) and Fe(III), which eliminate the precipitates of Cr(III), Fe(III) hydroxides and Cr(x)Fe(1-)(x)(OH)(3) and thus reduce surface passivation of Fe(0). In contrast, 1,10-phenanthroline, a complex reagent for Fe(II), dramatically decreases Cr(VI) reduction by Fe(0). At pH=4.0, the zero-order rate constant in the presence of 1mM of 1,10-phenanthroline was 0.02 micrM min(-1), decreasing by 99.7% and 93.9%, respectively, compared with the results in the presence and absence of EDTA. The results suggest that a pathway of the reduction of Cr(VI) to Cr(III) by Fe(0) may involve dissolution of Fe(0) to produce Fe(II), followed by reduction of Cr(VI) by Fe(II), rather than the direct reaction between Cr(VI) and Fe(0), in which Fe(0) transfers electrons to Cr(VI).     

Numerical Investigation of the Effects of Boundary-Layer Evolution on the Predictions of Ozone and the Efficacy of Emission Control Options in the Northeastern United States

This paper examines the effects of two different planetary boundary-layer (PBL) parameterization schemes – Blackadar and Gayno–Seaman – on the predicted ozone (O₃) concentration fields using the MM5 (Version 3.3) meteorological model and the MODELS-3 photochemical model. The meteorological fields obtained from the two boundary-layer schemes have been used to drive the photochemical model to simulate O₃ concentrations in the northeastern United States for a three-day O₃ episodic period. In addition to large differences in the predicted O₃ levels at individual grid cells, the simulated daily maximum 1-h O₃ concentrations appear at different regions of the modeling domain in these simulations, due to the differences in the vertical exchange formulations in these two PBL schemes. Using process analysis, we compared the differences between the different simulations in terms of the relative importance of chemical and physical processes to O₃ formation and destruction over the diurnal cycle. Finally, examination of the photochemical model's response to reductions in emissions reveals that the choice of equally valid boundary-layer parameterizations can significantly influence the efficacy of emission control strategies.