电催化-生化法处理印染废水零排放工艺研究

以河北某印染企业的生产废水为研究对象，采用电催化-生化组合工艺探索了印染废水处理及回用技术。通过实验优化了电催化预处理工艺：槽电压3V，处理时长60min，有效电极工作面积与处理废水体积数值之比为1∶6时，废水的CODCr去除率达44.8%。以该工艺对印染废水预处理，可将BOD5与CODCr之比由0.27提高到0.48，使其生化性显著提高。再配合活性污泥（SBR）生化法进行深度降解后，出水水质可达循环冷却水水质要求，可直接作为循环冷却水回用，实现印染废水零排放。     

组合工艺处理印染废水研究

针对印染废水成分复杂、色度大、浓度高且生物难降解物质多等特点,本文作者采用了混凝沉淀法对印染废水进行预处理,而后以膜生物反应器与反渗透膜分离系统组合工艺处理,研究该工艺对印染废水COD及色度的去除特性.实验结果表明:采用混凝沉淀预处理,膜生物反应器与反渗透膜系统组合工艺处理印染废水具有很好的效果.当原水COD高达2 500 mg/L,色度高达10 000 倍,经该工艺处理后COD降到30 mg/L,NH3-N降到8 mg/L,色度为0,已经达到废水回用标准.     

含酚废水的太阳光/Fenton氧化预处理技术

研究了模拟含酚废水的太阳光/Fenton 氧化预处理技术.结果表明,含酚废水经过适当程度的太阳光/Fenton氧化预处理后,不仅可去除废水的部分COD,还可显著提高废水的混凝性能及可生化性.COD为710.4 mg/L的苯酚废水,直接进行混凝处理时,COD的去除率仅为14.3%,单纯采用太阳光/Fenton氧化处理(氧化剂H2O2的用量为150mg/L)时COD去除率为32%,而采用太阳光/Fenton氧化预处理— 混凝法联合工艺处理后,COD的去除率可达到62.1%,远大于单纯混凝与单纯太阳光/Fenton氧化处理效果之和.实验结果还表明适当程度的太阳光/Fenton 氧化预处理可明显提高苯酚废水的可生化性,使废水的 BOD5/CODCr比值由0.10提高到0.32.     

固定化微生物工艺处理印染废水

采用固定化微生物工艺,对混凝沉淀后退浆工序的印染废水进行了现场中试处理研究.试验结果表明,在水力停留时间(HRT)为20 h的条件下,对于进水化学需氧量(CODCr)为1.0-1.2 g/L的退浆废水,经过两级水解酸化、两级好氧处理后,其出水CODCr<100 mg/L,达到国家一级排放标准.其中,水解酸化阶段的HRT为10 h,CODCr负荷1.7 kg/(d·m3),去除率为44%;好氧阶段HRT为10 h,CODCr负荷1.9 kg/(d·m3),去除率为83%.在此基础上,建立了好氧反应器内大孔载体固定化微生物降解基质的动力学模型.     

壳聚糖絮凝剂对焦化废水生化出水的COD去除研究

采用壳聚糖对经过A/O生物处理后的焦化废水进行深度处理,考察pH值和投药量对混凝作用的影响。焦化废水生化出水的CODCr为367 mg·L-1,浊度为44 NTU,色度为75。通过对不同pH值(4~10)的混凝实验可以看出,当pH值为6时相同投药量下焦化废水生化出水的色度、浊度以及CODCr去除率达到最佳。当絮凝剂的投药量达到10 mg·L-1时各项指标的去除率最高,其色度、浊度和CODCr去除率分别为66.67%、50%和68%。最终出水达到了国家排放标准。     

混凝-氧化法对印染废水的降解、脱色研究

利用混凝法、氧化法对印染废水进行了以达标排放为目的的实验研究。结果表明,对色度为125倍、CODCr为804.4mg/L的印染废水,当絮凝剂用量为3.000g/L,次氯酸用量为10mL/L,在反应时间为1 min,pH为6的反应条件下,可使处理后水的色度达到2倍,CODCr降为118.5mg/L,能够达到国家二级排放标准。     

物理化学法处理活塞环综合废水的试验研究

用隔油、破乳、混凝、沉淀4种物理化学处理方法，对活塞环金属加工、磨削、热处理、电镀清洗的混合废水处理进行试验研究．研究表明：活塞环综合废水经化学破乳一混凝沉淀处理后，CODCr的浓度可较大幅度地降低，平均去除率达62．1％，为后续生化处理创造条件．     

微电解—UV/Fenton法组合预处理印染废水研究

以厦门某印染企业的生产废水为研究对象,采用微电解—UV/Fenton法进行了印染废水预处理的试验研究.通过正交实验得到了微电解反应的最佳条件:pH值为2,铁碳质量比为2,反应时间为90min,曝气量为32L/min.处理后色度去除率可达到90%以上,CODCr去除率在65%左右.向微电解反应的出水中投入双氧水进行UV/Fenton反应,双氧水(质量分数为30%)最佳投入量为20mL/L,处理后色度可降至10倍以内,CODCr可降至600mg/L左右.通过预处理的印染废水可生化性能得到大大提高,B/C由处理前的0.34提高到0.62.     

从蛇毒中提取神经生长因子的废水处理工艺研究

以提取蛇毒中神经生长因子过程中产生的废水为处理对象,经混凝-Fenton试剂催化氧化深度预处理后,改善了可生化性,CODCr降到2230 mg/L,BOD5/CODCr为0.26.随后结合加压SBR法进行生物处理,最佳组合工艺条件为:混凝处理的pH值为8,PAC浓度为150 mg/L;Fenton试剂催化氧化条件为:H2O2的用量为20 ml/L,pH值为4,反应时间为60 min;加压SBR法处理的停留时间为8 h,处理后出水CODCr小于100 mg/L,达到国家规定的一级排放标准.     

垃圾渗滤液生化处理出水混凝实验研究

对垃圾渗滤液生化处理出水混凝沉淀反应的主要影响因素进行了单因素实验研究,在此基础上,采用混交水平正交试验方法综合分析了实验条件对混凝沉淀处理效果的影响.所考察的因素对CODCr去除率影响的次序是:PAC投加量>搅拌时间>PAM投加量;优化后的实验条件:PAC投加量1200 mg/L,PAM投加量5 mg/L,搅拌时间为5 min.在优化后的混凝沉淀条件下,混凝出水CODCr去除率为60.72%,水质接近国家生活垃圾填埋污染控制标准渗滤液排放限值二级要求.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。