不干胶废弃物热解焦燃烧特性

采用非等温热重分析和固定床热解实验研究了不干胶废弃物热解焦生成特性及热解焦燃烧特性,并计算了不同升温速率下热解焦的燃烧动力学参数。结果表明,不干胶废弃物热解焦产率随温度升高而逐渐降低,当热解终温在400~700℃时,热解焦产率在34.64%~22.03%之间;空气气氛下热解焦燃烧过程包括3个阶段:挥发分燃烧阶段(390~600℃)、混合燃烧阶段(390~600℃)和残炭燃烧与矿物分解阶段(650℃);升温速率对热解焦燃烧效果作用明显,升温速率越大,燃烧特性指数越高,燃烧稳定性越好;热解焦燃烧过程可以通过3个一级反应描述,当升温速率为40℃/min时热解焦燃烧各阶段表观活化能明显降低,表明升温速率提高有助于热解焦的燃烧反应活性,更有利于燃烧反应的进行。     

医药类废盐渣的燃烧/热解特性及动力学研究

分析了维生素B6医药类废盐渣成分,采用热重(TG)/差示扫描量热(DSC)对比了废盐渣的燃烧和热解特性,并通过Coats-Redfern积分法确定了不同升温速率下废盐渣的燃烧及热解动力学参数。结果表明:该类废盐渣主要含有氯盐及磷酸盐类物质。燃烧反应比热解反应对废盐渣的热处理效果更好。升温速率对废盐渣燃烧及热解反应的反应温度、活化能和指前因子均具有不同影响。废盐渣的热解过程可用两个一级反应来描述,燃烧过程可用两个一级反应和1个二级反应来描述。     

不同升温速率下城市污水污泥热解特性及动力学研究

利用差热-热重分析法和Coats-Redfern积分法,对杭州某污水处理厂污泥在不同升温速率下的热解特性及反应动力学特征进行研究。实验结果表明,热解温度从室温升至900℃时,污泥热解过程可分为4个失重阶段;升温速率对污泥热解转化率、挥发分析出温度以及最大失重率等热解特性参数都有显著影响。升温速率越高污泥最大失重率越大;而较低的升温速率延迟了污泥热解反应时间,导致污泥失重量相对较大。根据Coats-Redfern积分法计算结果,污泥在氮气氛围下的热解反应为二级反应模式。提高升温速率可显著增加污泥热解的表观活化能和频率因子。     

油田采油污泥的热解动力学及其热解效果研究

以新疆克拉玛依油田采油污泥为对象，分别采用热重分析仪和小型流化床热解反应器研究了含油污泥的热解过程及其热解效果。结果表明，油泥热解主要经历了失水、轻质组分挥发、重组分快速热解失重和缓慢失重4个阶段，热解过程基本符合一级动力学方程，提高热解的升温速率，可使油泥的最大失重速率D_max、失重速率峰值温度θ_max、升温终点的最大失重率都随之增加，表现在动力学上，反映出表观活化能和碰撞频率因子的同时升高，即提高油泥热解转化率的同时也影响了热解效率。失水油泥用流化床热解，在热解温度600℃、反应时间3 min时，油泥回收率可达到87%。     

不干胶废弃物热重分析

为了探索不干胶类包装废弃物的热解特性,采用热重分析手段分析了不同升温速率条件下不干胶类废弃物的失重特点,并且采用Ozawa法和KAS法比较分析不同转化率条件下的表观活化能分布.热重分析结果表明,不干胶类废弃物的热解主要分为3个阶段:第1阶段(室温～ 200℃)为不干胶类废弃物的干燥阶段,第2阶段(200 ～ 590℃)为热解的主要阶段,第3阶段(590 ～800℃)为热解半焦的深度热解阶段.升温速率对热解失重率有重要影响,Ozawa法和KAS法计算结果表明,2种方法计算的热解活化能比较接近,Ozawa法得到的活化能为349.9 kJ/mol,KAS法得到的活化能为336.9kJ/mol;并且不干胶类废弃物的热解表观活化能呈现出阶段性分布.     

TG-FTIR研究生物质成型燃料热解与燃烧特性

利用热重-红外联用分析仪(TG-FTIR)研究了生物质成型燃料(玉米秸杆)的热解和燃烧特性。结果表明,热解和燃烧反应过程均可分为3个阶段:干燥脱气(100~200℃)、挥发分反应(200~400℃)与碳化反应(400~1 000℃)。热解和燃烧主要失重阶段(200~400℃),燃烧反应速率总体上大于热解反应速率。利用Coats-Redfern方法对玉米秸杆的主要失重阶段进行动力学分析发现,热解和燃烧的反应过程符合一级反应模型;在主要失重阶段(200~400℃),热解和燃烧所需的活化能相差不大。FTIR分析表明,热解的气相产物主要分为轻质类气体(H2O、CO2、CO、CH4、HCl、NH3和HCN)和焦油类(酸类和酚类)物质,而燃烧的气相产物主要以CO2和H2O析出为主。     

船舶塑料垃圾热解特性及动力学分析

利用热重分析(TGA)研究船舶塑料垃圾在不同升温速率和不同气氛下的热解特性,并得到了热解动力学参数。结果表明,船舶塑料垃圾的热解过程主要有3个阶段,比一般塑料热解复杂;随着升温速率增大,最大热解速率和最大热解速率温度等热解特性参数也增大,反应变得更剧烈;N2/CO2比为4∶1时,热解反应进行得最完全,固体残留率最少。动力学分析表明,采用3个连续一级反应模型能很好地拟合实验数据;不同的升温速率和气氛比对反应各阶段活化能均有不同程度的影响。     

污泥中抗生素热解特性及动力学分析

通过分析污泥中3种典型抗生素环丙沙星(CIP)、土霉素(OTC)和磺胺二甲嘧啶(SM2)的热解过程与失重特性,研究其热解动力学特征。结果表明:CIP、OTC、SM2主要热解温度区间分别为150~625℃、220~600℃、260~480℃;初始热解温度以及最大失重峰对应温度均为OTCSM2CIP;CIP热解具有2个失重峰,OTC与SM2热解仅有1个失重峰;且SM2热解失重峰最高,反应最剧烈;抗生素热解最终残留物均为残碳,且CIP热解残留率最低,为18.9%。抗生素热解过程可分为3阶段:第1阶段反应级数均为2级,活化能最高,频率因子最大;OTC、SM2与CIP热解平均活化能分别为50.19、72.31、81.85 k J·mol-1,说明OTC热解反应最容易进行,CIP热解则相对较难。上述结果将为污泥热解炭化工艺实现抗生素消减提供良好的理论基础。     

工业废水污泥的热解及升温速率对热解的影响

利用热重分析法对印染、中药和废水处理厂3种典型工业废水污泥进行了热解动力学实验研究。结果表明,工业污泥是一种高挥发分、低固定碳和低热值的劣质燃料。经过消化处理的污泥灰分含量较高,挥发分含量变小。热解过程中有3个失重速率较高的阶段,以挥发分的析出为主。升温速率对热解的最终失重率有重要影响。升温速率增加,热解更剧烈,但最终失重率的变化趋势与污泥种类有关;为使热解效果更好,不同种类的污泥应选择不同的升温速率。不同种类的污泥具有不同的热解特性,印染污泥挥发分析出阶段有2次热解。中药污泥活化能最小,印染污泥挥发分第2次热解的活化能比第1次大幅增加。     

灰色预测模型及分布活化能模型在废电路板热解中的应用

分别在管式炉反应器和热天平上对废电路板的热解行为进行实验研究。在管式炉反应器上考察了在同一升温速率（20 K/min）下不同热解终温 (400、500、600、700和800℃) 对废电路板热解产物产率的影响。在相关实验数据的基础上尝试用灰色理论及方法建立基于热解终温的废电路板热解灰色产率预测模型GM(1,1)，预测结果与实验数据对比表明，该预测模型精度较高，能够较好地对不同热解终温下废电路板热解产物产率进行预测。此外，在热天平上获得的不同升温速率（10、15和20 K/min）下的热失重曲线表明，废电路板的失重速率峰随升温速率的提高逐渐向高温侧移动。采用分布活化能模型对废电路板热失重曲线进行动力学分析，获得废电路板热解活化能的变化曲线。计算结果表明，废电路板热解过程中活化能并不是单一数值，而是随失重率变化的一个函数。所得废电路板热解活化能值在140～250 kJ/mol范围内变化，当失重率在10%～60%之间，活化能值总体呈缓慢上升的趋势，但当失重率＞60%时，活化能值由155.4 kJ/mol迅速增加到244.4 kJ/mol。     

Optimization of Height of Release of Air Pollutants

A number of key projects in the Environmental Protection Agency (EPA) particulate R&;D program having applicability to industry are presented. For electrostatic precipitators (ESP) there is presented the result of work on large diameter discharge electrodes which provide a decrease in penetration of up to a factor of 4 when compared to conventional small diameter electrodes. Also discussed is the multistage ESP which provides a collection efficiency that would require a collecting plate area 4 or 5 times larger with conventional ESP technology. The E-SOX technology makes use of the multistage concept to free up space in the ESP for SO₂ removals of up to 90%. Electrostatically augmented fabric filtration provides a reduction in pressure drop of about 5 0% as compared to conventional fabric filtration. Wind tunnel modeling of windbreaks for material storage piles indicates a potential for providing engineering design data that would allow significant emission reduction caused by wind erosion     

Investigation of the characteristics of the reflectivity of clouds

This paper investigates some of the reflectivity characteristics that clouds (when modelled as solid bodies) must exhibit to be compatible with observations that the reflecting surface of a cloud (i) appears almost equally bright across its face, (ii) is brightest when the cloud is opposite to the Sun but decreases in brightness as the cloud moves to other positions and (iii) increases in brightness with increasing optical thickness of the cloud in the observer's line of sight. These observations, respectively, are shown to imply that the peak value of the bidirectional total reflectivity from a cloud surface (i) increases in inverse proportion to the cosine of the angle between the Sun and the normal to the cloud surface, as the incident angle increases, (ii) appears to be directed back in the direction of the incident radiation, and (iii) increases as optical thickness of the cloud in the observer's line of sight increases. The results could have application in many fields (e.g. modelling diffuse radiance distributions for cloudy skies).     

Estimation of uncertainty of sampling for analysis of pesticide residues

Abstract

A computer model was used to take random samples from primary sample populations obtained from field trials to simulate the uncertainty of sampling for residue analysis of plant commodities and soil. The results indicate about 40%, 30% and 20% relative uncertainty when random samples of size 5, 10 and 25 are taken respectively, from a single lot. Therefore the sample size should be the same for establishing and enforcing legal limits.     

扬中生态环境建设的思考与实践

结合扬中生态环境的基本情况和存在的不足，进行了具体分析，对扬中未来生态建设的发展方向提出了建议及实施措施。     

实验室质量管理体系内部审核的实施

在实施ISO／IEC17025：1999标准《检测和校准实验室能力的通用要求》过程中，通过实验室质量管理体系内部审核的实践与系统分析，识别出内部审核实施阶段的关键环节，提出召开首次会议、收集审核证据、确定审核发现和召开末次会议的技术方法，对提高内部审核的质量和有效性、获得可靠的审核结论具有重要意义。     

次氯酸钠发生器的研制

介绍了电解法生产次氯酸钠的原理 ,并在原有生产工艺的基础上进行了重新设计和对设备的重新选择、改造 ,得出了各个工艺参数的最佳值 ,生产出高品质的次氯酸钠     

An application of the theory of kinematics of mixing to the study of tropospheric dispersion

The most common technique used for numerical simulations of tracer mixing is that of the numerical solution of the advection–diffusion equation with the unresolved fluxes parameterized using the similarity theory. Despite correct predictions of the overall directions of transport, models based on a numerical solution of the advection–diffusion equation lack sufficient accuracy to correctly reproduce the coupling of mixing with small scale processes which are sensitive to the microstructure of the tracer distribution. The objective of this paper is to revisit the basic formalism employed in numerical models used to investigate atmospheric tracers. The main mathematical method proposed here is the theory of kinematics of mixing which could be applied effectively for simulations of atmospheric transport processes. At the beginning of the paper, we introduce simple mathematical transformations in order to demonstrate how complex topological structures are created by mixing processes. These idealistic flow systems are essential to explain transport properties of much more complex three-dimensional geophysical flows. An example of the application of the kinematics of mixing to the analysis of tracer transport on a planetary scale is presented in the following sections. The complex filamentary structures simulated in the numerical experiment are evaluated using some commonly applied statistical measures in order to compare the results with the data published in the literature. The results of the experiment are also analysed with the help of simple conceptual models of fluid filaments. The microstructure of the tracer distribution introduced in the paper is essential to increase our understanding of atmospheric transport and to develop more realistic parameterizations of small-scale mixing. The presented results could also be used to improve calculations of the coupling between microphysical processes and tracer mixing.     

Comparison of methods for evaluation of activity of photocatalytic films

Objective

This work aims to investigate the correlation between the photocatalytic activity determined by methylene blue bleaching (DIN 52980), stearic acid degradation, and degradation of acetone in gas phase.

Method

The photocatalytic TiO₂ coatings included in this investigation ranged from thin commercially available coatings (Activ^TM and BioClean^TM) and ready to use suspensions (Nano-X PK1245) to lab-produced PVD and sol?Cgel coatings. XRD analysis of the photocatalytic coatings showed that all the coatings consisted of nanocrystalline anatase, although the thickness and porosity varied considerably.

Results

The study showed that the reproducibility of the activity measurements was good. However, more importantly, the investigation showed that there is a good correlation between the activities determined by the different methods even though the characteristics of the photocatalytic coatings and the organic probe molecules varied considerably.

Conclusion

The overall findings of this work suggest that there is a good correlation between the investigated methods. These results are promising for the future work concerning standardization of methods for determination of the activity of photocatalytic films.     

Impact of overexploitation of shellfish: northeastern coast of India

India has a very extensive coastline of about 7515 km, rich in diverse living resources. These resources continue to deteriorate with rampant harvesting or are altered for other uses such as aquaculture and fisheries. The present paper deals with degrading coastal habitats in northeastern India, and projects the intensity of the stress arising from the collection of tiger prawn seeds (Penaeus monodon) for aquacultural farms and molluskan shells for poultry feed and edible lime. Indiscriminate exploitation of these resources leads to a heavy reduction of the species concerned and other associated marine communities. The magnitude of such destruction has been quantified. The impacts of biodiversity loss and their after-effects on the ecobalance of this coastal system have become a matter of great concern to ecologists to maintain security and sustainability. The authors propose a public awareness program on themes relating to the importance of biodiversity for human livelihoods.