新型TCAS吸附树脂对水中Cd^2＋的吸附去除研究

通过静态吸附试验，研究一种由超分子受体化合物磺化硫杂杯芳烃（TCAS）与树脂结合的产物——新型TCAS吸附树脂对重金属Cd^2＋的吸附去除性能，并初步探讨了吸附机理。试验研究结果表明，TCAS吸附树脂对Cd^2＋的饱和吸附量为14．45mg/g。当温度为20℃，0．5gTCAS吸附树脂对10mL浓度为5113g／L的Cd^2＋溶液吸附60min时，Cd^2＋的去除率可达到99％以上。pH值是影响TCAS吸附树脂吸附效果的重要因素，在pH=5—9时，Cd^2＋的去除率随着pH值的升高而增大。在试验范围内，TCAS吸附树脂对Cd^2＋吸附符合Freundlich方程。吸附在TCAS吸附树脂上的Cd^2＋可洗脱回收，TCAS吸附树脂也可再生利用。TCAS吸附树脂对重金属Cd^2＋的吸附机理主要归因于TCAS对Cd^2＋的络合作用。     

重金属离子Cd^2＋、Pb^2＋污染对土壤酶活性的影响

通过对土壤中比较重要的两种酶（过氧化氢酶、脲酶）活性的测定，研究了重金属离子（Cd^2＋、Pb^2＋）单因素污染、复合污染对两种酶活性的影响，进而找出重金属污染程度与土壤酶活性的关系，为建立土壤中的酶活性可以表征重金属污染程度的生化指标平台提供试验依据。结果表明，在Cd^2＋、Pb^2＋单因素污染影响中，在一定浓度下的重金属离子对土壤酶活性会有激活效应，但大多表现为抑制效应；Cd^2＋、Pb^2＋复合污染对两种土壤酶活性的影响存在着明显差异，其复合污染对脲酶表现出协同抑制负效应的特征；对过氧化氢酶表现出一定的屏蔽作用。通过重金属离子形态对土壤酶有效性影响的研究，脲酶活性可以作为土壤重金属离子（Cd^2＋、Pb^2＋）单因素和复合污染程度的主要生化指标。     

叉鞭金藻对微量锌、镉的吸附效应研究

研究了叉鞭金藻对微量Zn^2 ,Cd^2 的生物吸附及其机理。结果表明,叉鞭金藻对Zn^2 ,Cd^2 的生物吸附主要经历了快速的吸附和缓慢的吸附两个步骤。pH为6～7时,叉鞭金藻对Zn^2 ,Cd^2 有较好的吸附作用,且死体藻细胞比活体藻细胞能富集更多的Zn^2 ,Cd^2 。吸附符合Freundlich等温吸附模型。     

黄河水中沉积物与锌、镉液-固界面的作用

研究了黄河水中沉积物与重金属污染物Zn^2 、Cd^ 的离子交换吸附作用。结果表明,Zn^2 、Cd^2 在黄河水中主要以M（OH）^ 的形式与沉积物进行－价阳离子交换反应;在天然黄河水pH范围内,Zn^2 、Cd^2 的离子交换率都大于70％;随温度升高,Zn^2 、Cd^2 与沉积物的交换率增加,E-pH曲线向pH值减小的方向位移。     

非固定化和固定化啤酒酵母对Cd^2＋和Cu^2＋的吸附特性研究

对比了不同吸附剂对重金属的吸附效果，同时研究了啤酒酵母的固定化方法、菌体用量对吸附效果的影响、非同定化和固定化啤酒酵母吸附热力学特性。研究结果表明，非固定化死啤酒酵母对Cd^2＋的单位菌体吸附量是常用吸附剂活性炭的3倍；由1：3的海藻酸钠与碱处理啤酒酵母（w／w）制得的固定化颗粒吸附效果最好；菌体用量的增加会降低单位菌体对重金属的吸附量；啤酒酵母对重金属的吸附位点有限，Cd^2＋的实际最大吸附量为13．95mg／g，Cu^2＋为7．67μg／g。非固定化和固定化啤酒酵母对Cu^2＋和Cd^2＋的等温吸附过程均可用Linear方程、Langmuir方程和Freundlich方程来进行拟合，但非同定化啤酒酵母以Langmuir方程最优，其拟合计算的最大吸附量qmzxCd和qmxxCu分别为13．96mg／g和8．01mg／g；固定化啤酒酵母以Freundlich方程最优，实际最大吸附量Cd为75．41mg／g，Cu为66．58mg／g。     

生物吸附重金属的研究进展

从生物吸附的概念、吸附重金属的机理、吸附剂的种类以及生物细胞的固定化、生物吸附工艺过程等方面进行了综述，同时阐述了生物吸附重金属的技术研究进展和应用前景展望。     

浅谈重金属对生物毒性效应的分子机理

初步阐明了重金属对生物产生毒性效应的分子机理以及重金属参与生物过程的生物活性点位；阐述了金属离子对生物活性点位的竞争及其对金属生物毒性的影响；讨论了重金属在生物体内积累的分子机理以及对生物毒性的关系。     

氧化亚铁硫杆菌对电子垃圾焚烧迹地重金属形态的影响

采用生物淋滤法处理电子垃圾焚烧迹地重金属严重污染的土壤。所用氧化亚铁硫杆菌是从矿坑废水中通过一系列培养、分离和纯化得到。实验结果表明，生物淋滤法可以有效地去除土壤中重金属Cu、Ph和Zn，去除率的大小顺序为Zn〉Cu〉Pb；采用五步连续提取法分析处理前后土壤中重金属的存在形态，结果表明，通过氧化亚铁硫杆菌处理受重金属污染的土壤，可以促使易移动的重金属结合态的溶解（可交换态、碳酸盐结合态和Fe—Mn氧化物结合态），并使难移动的重金属结合态向易移动的重金属结合态转变。     

重金属的生物吸附技术研究

利用生物包括发酵工业的菌丝体废渣或海洋微生物对重金属的吸附作用，来治理重金属造成的污染，其具有原料丰富，成本低，处理效率高等优点，是目前国外研究较多的一种处理重金属污染的方法。本文从生物吸附的概念、机理、吸附剂的性能，以及生物吸附剂的固定化等诸方面进行了综述。同时阐述了生物对重金属吸附技术研究的发展趋势和应用前景。     

氧化亚铁硫杆菌对电子垃圾焚烧迹地重金属形态的影响简

采用生物淋滤法处理电子垃圾焚烧迹地重金属严重污染的土壤。所用氧化亚铁硫杆菌是从矿坑废水中通过一系列培养、分离和纯化得到。实验结果表明，生物淋滤法可以有效地去除土壤中重金属Cu、Pb和Zn，去除率的大小顺序为Zn>Cu>Pb；采用五步连续提取法分析处理前后土壤中重金属的存在形态，结果表明，通过氧化亚铁硫杆菌处理受重金属污染的土壤，可以促使易移动的重金属结合态的溶解（可交换态、碳酸盐结合态和Fe-Mn氧化物结合态），并使难移动的重金属结合态向易移动的重金属结合态转变。     

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.