汞污染载金炭间接加热-N2吹扫脱汞研究

采用间接加热-N2吹扫法,对汞污染载金炭中汞的脱除进行试验研究.主要考察了吹扫方式、焙烧温度、N2流量和处理时间对汞脱除效果的影响.结果表明,采用床层内部吹扫方式有利于载金炭中汞的脱除;在550℃、N2 1.6 m3/h·kg、吹扫3 h条件下,能够将载金炭中汞含量由13.833 g/kg降低至0.002 g/kg,汞脱除率达到99.98%以上,而炭烧损率仅1.84%.另外,进行了2种二段法脱汞试验研究:高温蒸汞-N2吹扫法和空气吹扫-N2吹扫法.结果表明,与一段法相比,前者能够大大降低N2的消耗量;而后者没有明显优势,N2用量和能耗均未能明显降低.     

吹扫-捕集法在挥发性有机污染物分析中的应用

吹扫 -捕集法为 2 0世纪 70年代中期推出的痕量挥发性有机化合物的富集方法 ,它具有简便、灵敏度高、富集率高、快速、精密、准确、不使用有机溶剂等特点。 2 0多年以来 ,吹扫 -捕集器和GC、GC/MS等仪器联用测定环境中痕量挥发性有机污染物 ,已获得令人满意的结果 ,因而吹扫 -捕集法将在有机污染分析中得到日益广泛的应用     

吹扫—捕集法在挥发性有机污染物分析中的应用

吹扫－捕集法为20世纪70年代中期推出的痕量挥发性有机化合物的富集方法，它具有简便，灵敏度高，富集率高，快速，精密，准确，不使用有机溶剂等特点，20多年以来，吹扫－捕集器和GC、GC／MS等仪器联用测定环境中痕量挥发性有机污染物，已获得令人满意的结果，因而吹扫－捕集法将在有机污染分析中得到日益广泛的应用。     

饮用水中典型致嗅物质吹扫捕集-气相色谱质谱检测方法及优化

采用吹扫捕集/气相色谱-质谱(GC-MS)法对饮用水中致嗅物质2-甲基异茨醇(2-MIB)和土臭素(GSM)进行测定。通过调整吹扫温度、吹扫时间、吹扫时捕集阱的温度、六通阀温度和传输管线温度,分析吹扫捕集条件对吹扫捕集效率的影响,并确定最佳吹扫捕集条件。2-MIB和GSM的方法检出限(MDL)分别为0.729 ng·L~(-1)和1.037 ng·L~(-1),方法定量限(MQL)分别为2.187 ng·L~(-1)和3.112 ng·L~(-1),平均加标回收率分别在92%~108%和88%~104%范围内,相对标准偏差分别小于6.5%和9.0%.在20~300 ng·L~(-1)的范围内,各异嗅化合物浓度与响应值的线性关系均良好,相关系数均大于0.999。该方法具有操作简便、检出限低,相关性良好、灵敏度高、重复性好等优点。     

大港油田含油污泥热解处理实验研究

采用热解法对含油污泥进行处理.经过筛选,选取活性白土作为催化剂,分别研究反应时间、反应温度、加热速率和氮气吹扫量对热解处理效果的影响.4个影响因素对液相收率的影响顺序为:氮气吹扫量＞反应温度＞反应时间＞加热速率;对反应转化率的影响顺序为:反应温度＞反应时间＞氮气吹扫量＞加热速率.实验理想的反应参数为:反应时间60min,反应温度490℃,加热速率4℃/min,氮气吹扫量90 mL/min.     

吹扫捕集-GC-MS测定废水中的硝基氯苯

建立了吹扫捕集-GC-MS测定水样中硝基氯苯类化合物的方法.考察了吹扫温度、吹扫时间等对吹扫捕集效率和方法检出限的影响.在室温下,当吹扫时间为30 min时,该方法的最低检出限可达0.002 mg/L,工作曲线的线性范围为2×10 -3 ～2 mg/L,相对标准偏差在2%～6%,加标回收率在97.0%～110.0%.与国家标准方法相比,该法具有操作简便、灵敏度高、线性范围宽且无须使用有毒有机溶剂等优点,可满足工业废水和地表水中硝基氯苯的测定要求.     

净水厂生产废水回用对供水水质的影响

通过研究生产废水回用对水质的影响,认为生产废水含固率是影响回用效果的重要评价指标,回用澄清池排泥水和滤池反冲洗水,对水质的影响规律相似.改善混凝条件的最佳含固率范围也是回用对水质影响最小的含固率范围.当含固率小于1%时,回用不会对水质造成影响,当含固率大于1%时,回用较无回用时的水质变差,但不会超过水质标准.回用生产废水可以提高有机物的去除率,主要是因为生产废水中含有的Al(OH)3沉淀物的物理吸附和卷扫絮凝功能.     

报废风机叶片热处理特性及动力学分析

为研究退役风机叶片热处理特性,开展风机叶片的玻璃纤维/环氧树脂风机叶片材料4个不同升温速率(5、10、20、40℃·min^-1)及2种载气氛围(氮气、空气)的热重实验,结合动力学方法对各个反应过程进行研究。热重分析表明玻璃纤维/环氧树脂风机叶片在氮气氛围下存在2个失重阶段,500℃以后质量基本稳定;在空气氛围下存在3个失重阶段,600℃以后质量基本稳定,说明氧气的参与影响了玻璃纤维/环氧树脂的热分解特性。对比不同升温速率下的TG/DTG曲线,随升温速率的提高,TG曲线逐渐向高温方向移动,DTG曲线最大失重率逐渐降低,整个反应过程的质量损失也发生小幅下降。使用Kissinger-Akahira-Sunose(KAS)和Flynn-Wall-Ozawa(FWO)方法研究其动力学过程,结果表明在热解和氧化反应条件下用2种动力学模型求解的活化能取值范围分别为135.14～207.24、137.64～207.58 kJ·mol^-1和117.95～172.19、119.31～173.22 kJ·mol^-1,平均值分别为179.30、...     

吹扫捕集-气相色谱-质谱法测定地表水、废水中丙烯酸酯类

采用吹扫捕集石英毛细管柱DB-624分离、GC/MS测定废水中丙烯酸甲酯、甲基丙烯酸甲酯、丙烯酸乙酯和丙烯酸丁酯。水样吹扫时,通过加硫酸钠盐大幅度降低检出限,最低检出浓度达到0.001 mg/L,加标回收率在83.3%-109%之间,变异系数在3.8%-6.9%之间。     

旋流塔板叶片仰角对湿钙法烟气脱硫过程的影响

实验研究了旋流塔板叶片仰角对钙基湿法烟气脱硫工艺的影响。结果表明 ,一般情况下 ,叶片仰角增大 ,脱硫率有所下降 ,塔的运行稳定性有所下降 ,结垢有所增加。因此 ,在将麻石水膜除尘器改造成旋流板塔脱硫除尘系统的过程中 ,增大叶片仰角的同时一定要考虑脱硫率的下降问题。     

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.     

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.     

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.