我国化学工业的“三废”及其资源化

文章在介绍我国化学工业排放三废的严峻现状后,阐述了通过工艺改造和综合回收途径来推进三废资源化的技术对策,以及从宏观和微观上看深化三废资源化的意义和光明前景。     

混合气体爆炸性MFC图形分析

判断混合气体爆炸性常用 3种方法 ,即科瓦德爆炸三角形法、美国矿业局采用的爆炸三角形计算法和最小助燃氧浓度法 ,然而如何准确、快速、形象地得到分析结果在防灾救灾中是十分关键的。笔者的重点是提供一个图形分析方法解决上述问题。VC ++是方法的基本理论依据 ,用一个实例来验证方法的有效性。总之 ,研究表明 :图形分析法可提高安全管理效率。     

Air Pollution Effects on Forest Trees in Balikesir,Turkey

Air pollution has become an actual problem in Balikesir because of rapid urbanisation and increasing of the polluting sources. Air pollutionproblems occur under the unfavorable meteorological conditions which increase in frequency of occurrence in winter due to use of low quality lignite coals for heating. The `Protection of Air Quality' in Turkey dated 1986 is based on the human health criteria. But the critical limit values are lethal for the forest trees as far as SO₂ is concerned. The field observations showed that leaves of the trees have yellow spots indicating acid burns in Balikesir. This study aims at determining the relationships between the SO₂ concentrationsin the air under selected climatic conditions, and the effects of air pollution on forest trees in Balikesir. Samples of leaves were collected from the City Parks in Balikesir, Deirmenboaz forested area located 10 km far fromBalikesiron the Balikesir-Bursa highway, and from the forestation areas near the Balikesir-Edremit highway. Sulfur contents of the leaves were very high especially in the city (2650–5300 g m^-3).Samples from other areas had values lower than this range but above the usual values (850–3612 g m^-3). The diameter increments of the trees were found to be lower and these results clearly showed the adverse impacts. Negative correlations were found between these sulfur concentrations and the daily mean temperatures and wind speeds. Positive correlation was seen between these concentrations and pressures, humidities. Emission sources must be controlled in order to safeguard the forests which protects the soil, facilitate water production, assimilate carbon dioxide in air and produce oxygen. It must be considered that the problems are not only regional but have a global identity.     

Sulfur Metabolism in Polluted Sphagnum Peat Bogs: A Combined 34S–35S–210Pb Study

The size and isotopic behavior of sulfur pools in²¹⁰Pb-dated peat cores were investigated to obtain aninsight into retention mechanisms of pollutant S in twomountain-top peatlands of the Northern Czech Republic, CentralEurope. The bogs were situated 40 km apart in an area whichbetween the years 1985 and 1995 received as much as 130 kg Sha^-1 yr^-1 from the atmosphere. Vertical peataccretion was faster at Pod Jelení horou (JH) than atVelký moál (VM). Organic carbon-bonded S was themost abundant sulfur pool, constituting 77 and 65 wt. % at JHand VM, respectively. At JH both the S concentration maximumand the highest annual S deposition rate were displaceddownward by more than 20 years (from 1987 to the 1960s)indicating that the buried S is vertically mobile. At VM the Sconcentration was the highest in the topmost 2-cm section eventhough atmospheric S deposition peaked in 1987. Differentmechanisms of S isotope redistribution prevailed in thetopmost peat layers at JH, where a negative ³⁴Sshift occurred, and at VM, where a positive ³⁴Sshift occurred. Bacterial sulfate reduction was responsiblefor the negative ³⁴S shift at JH. One possibleexplanation of the positive ³⁴S shift at VM isrelease of ³²S-enriched products of mineralization duringpeat diagenesis. There was a strong positive correlationbetween the abundance of total and pyrite S along the profiles.The presence of pyrite S at VM (526 ± 60 ppm) suggestedthat even at VM bacterial sulfate reduction occurred. Ananaerobic incubation of JH peat indicated sulfate reductionrate of 600 nmol g^-1 day^-1. The turnover times forinorganic S pools were shorter than for the organic S pools.Cumulative S contents in the Czech peat bogs were found to besignificantly lower than in similar sites in the NortheasternU.S., even though the atmospheric S inputs were more thanthree times higher at the Czech sites. Possible causes of suchdiscrepancy are discussed.     

天然气钻井井口安全距离研究分析

分析天然气钻井井场可能发生的事故类型及事故的破坏程度,选择适合的事故后果模型,对天然气井井喷失控后可能发生的蒸气云爆炸及硫化氢扩散的后果进行量化分析,根据超压-冲量准则、热剂量准则和硫化氢扩散行为规律,计算出爆炸波、爆炸火球及硫化氢扩散的危害范围。笔者建立了天然气钻井井口安全距离的计算模型,并提出一种确定安全距离的方法。通过计算给出不同无阻流量、不同硫化氢体积含量的20种条件下的天然气钻井井口安全距离,并应用该模型对某含硫气井井口安全距离进行了计算。实例表明,该方法具备实用性,值得在天然气井选址规划中推广和使用。     

“Vybuchovy trojuhelnik”: A software tool for evaluation of explosibility of coal mine atmosphere

Rescue operations during mine fires or methane explosions are highly dangerous for rescue workers. The knowledge of the composition of the coal mine atmosphere and the calculations of its explosibility may help to increase the safety of the rescuers. In the Czech Republic, a system called “Mine Gas Laboratory” (DPL) has been used for these purposes. The DPL allows measurement of the composition of the mine atmosphere and transmits the data necessary for evaluation to the surface. Up to now the explosibility evaluation of the coal mine atmosphere has depended either on the rescuers’ experience or on software code calculation. The code called “Vybuchovy trojuhelnik” (explosion triangle) is a graphical computing system intended for fast assessment of explosibility of fuel–air mixture. This article introduces the code and describes two simple methods of explosibility evaluation. The first method is “explosion triangle analysis”—a graphical method based on empirical graphs transformed into equations. The second method uses thermodynamic calculation based on chemical balance dynamics and Gibbs and Helmholtz energy. According to the requirements of the Czech Bureau of Mining (CBU) and Central Mine Rescue Service (HBZS), the code solves the problems of explosion triangle for both standard and non-standard coal mine atmosphere compositions. Unfortunately, the atmosphere composition must be introduced manually due to the unknown format of the data transmitted from the old DPL model. On 1 September 2005, a project started to develop a new system for on-line monitoring and atmosphere explosibility evaluation. The system should be able to measure CO₂, O₂, CH₄, H₂ and CO concentrations as well as the wind speed, temperature and humidity. The “Vybuchovy trojuhelnik” code will be used as a basis for explosibility evaluation, and an on-line connection with the new model of DPL will be established.     

高含硫气井分户报警技术研究

设计并介绍分户报警与短信群发结合的报警方式,包括系统采用的布局方法、方案总体设计、整体结构、信息传输网络设计;提出分户报警的新报警策略,并给出分户报警的区域划分方法以及划分的理由和依据。在硬件方面,重点介绍分户警铃的方案,其中包括的两个重要组成部分:无线应急广播发射中心和无线应急广播接收设备;提出采用可寻址智能无线广播的新的技术方法,同时给出建议的设备,总结并分析分户报警系统的功能和特点。通过该警报系统的采用,能大大提高警报通知效率,节省疏散所需的时间。     

苏南地区CO2本底浓度及源汇特征

基于2015~2018年苏州张家港站CO₂在线观测数据，采用时序检查、选取稳定性数据、异常值剔除等质量控制方法获得可靠数据，并通过平均移动过滤（MAF）本底筛分法获得本底数据，讨论苏南地区CO₂变化特征.结果发现：CO₂本底浓度日变化为单峰结构，谷值和峰值分别出现在下午15：00和凌晨5：00前后；季节变化为双峰结构，峰值分别出现在12月和4月；日、季节变化的分布特征均与陆地生态系统、气象条件和人类活动有关.此外，2015~2018年CO₂浓度呈逐年上升趋势，抬升浓度占比逐年增加，吸收浓度占比波动较小，表明人类活动对CO₂浓度的影响正在逐年增加；而陆地生态系统对CO₂吸收汇的作用则相对稳定.源汇分析显示，CO₂抬升浓度随季节小幅波动；吸收浓度则夏半年较低，冬半年较高；抬升浓度日变化为单峰结构，谷值和峰值分别出现在15：00和8：00前后，早晨正值上班高峰，机动车排放可能为早晨峰值的主要因素；吸收浓度日间低、夜间高，这主要与植物光合作用及对流输送有关.分析CO₂浓度与风的关系发现，所有季节静风情况下，CO₂浓度偏高均最为明显，大部分方向CO₂浓度高低与风速大小有明显的负相关，其中S~WNW方向偏高最为明显，这可能是因为SW~NW方向主要为内陆城市群，且测站周边建筑区主要位于W~N方向，弱风有利于本地排放累积的结果.此外，WNW方向风速较大时浓度仍偏高明显，可能与测站W~N方向为建筑区及内陆城市群有关；而测站偏东方向主要为农田和林区，受人类活动影响较小，且海上气流较为洁净，故偏东风较弱时浓度也不高；说明了CO₂浓度除了与风速大小有关外，与周边下垫面类型及较远距离环境特征（城市群或海洋）也有一定的关系.     

生石灰孔结构对高温脱硫性能的影响

喷钙脱硫工艺的炉内脱硫率 ,不仅受工艺参数的影响 ,还与石灰石分解生成的新生CaO或直接喷入的CaO的表面结构有关。本研究用同一石灰石经不同方法 (煅烧、过烧、煅烧 -水合 -脱水等 )制备了四种具有不同比表面积和孔结构的生石灰。高温脱硫研究表明 :这四种不同孔结构的生石灰 ,具有不同的脱硫率。通过对高温脱硫前后吸着剂宏观结构变化的对比 ,发现半径小于 30 的孔易被反应产物堵塞 ,因而脱硫能力有限 ,而半径大于 5 0 的孔对脱硫更有效。本研究将为提高炉内喷钙的脱硫率、研制和开发高效脱硫剂提供新的途径。