微氧强化硫酸盐还原-反硝化脱硫(SR-DSR)工艺因具有同步处理废水中COD、NO3-、SO24-生成S0且运行成本低、流程短的优势而受到关注.但因不同曝气方式而在反应器中形成的不同微氧区的位置对反应器运行效能、S0转化率和群落结构的影响尚不明确.因此,本文以5 mL·min-1·L-1曝气速率、10.4 mmol· L-1硫酸钠、31 mmol· L-1乳酸钠和8 mMol· L-1硝酸钾连续运行膨胀颗粒污泥床(EGSB)反应器,对比研究了回流槽中(底部)曝气(微氧区位于反应器下部)和反应区上部曝气(微氧区分别位于反应器上部和下部但DO更低)运行稳定后,反应器的运行效能、S0转化率和功能微生物的演替规律.结果表明,上部曝气时乳酸盐去除率为100％,出水中乙酸盐浓度为9.1 mmol·L-1,丙酸盐浓度为3.7 mmol· L-1,NO6-去除率为100％,出水中NO2-浓度为0.35 mmol· L-1,SO2-去除率为84％,出水中S2-浓度为2.6 mmol· L-1,S0转化率为59％.与底部曝气相比,上部曝气时出水中乙酸盐和丙酸盐浓度分别升高2.2和1.9 mmol· L-1,NO2-浓度下降0.15 mmol· L-1,S2-浓度降低0.5mMol· L-1,SO42-去除率和S0转化率分别下降6％和1％.上部曝气时,反应器下部和上部均存在相对减弱的微氧环境,使得反应器中硫酸盐还原菌(SRB) Desulfomicrobium和Desulfobulbus的总丰度分别增加9％和5％,硫氧化反硝化菌(soNRB) Halothiobacillaceae和Sulfurovum的丰度均减小3.1％,异养反硝化菌(hNRB)Comamonas的丰度升高0.2％,互营菌Synergistaceae的丰度减少37％.其中,反应器下部的SRB和soNRB总丰度分别升高28％和3％,为So42-还原和S0转化提供了充分条件,而反应器上部的微氧环境又减弱了SO42-还原过程,从而降低了反应器出水中的S2-.因此,在碳源充足的条件下,可以采取反应器上部曝气的方式创造微氧环境,既可以保证较高的S0转化率,又可以减少出水中S2-和NO2-的浓度.

Cornstalks, as a kind of cheap substrates, can effectively reduce the cost of bioflocculant ' s synthesis. With 17%of dilute sulphuric acid hydrolyzing cornstalks, the hydrolysate containing pentose-xylose and hexose-glucose can be produced. Pentose is difficult to be metabolized by microorganism;obtaining strains which metabolize pentose and hexose synchronously from cornstalks are the key to converse of bioflocculant. This study, based on cornstalks hydrolysate as substrate in screening flocculation Strain W4, explored its ability of synchronous metabolism pentose and hexose. The results revealed that Strain W4 was identified as Bacills subtilis via 16S rDNA. The metabolic rate of glucose (027 g·L-1·h-1) by Bacills subtilis exceeded the rate of metabolism of xylose ( 014 g · L-1 · h-1 ) , indicating Strain W4 can produce synchronous metabolism of xylose and glucose. The flocculation rate in synthesizing bioflocculant of Strain W4 from xylose and glucose mediums were 96% and 97% respectively. The main components of bioflocculant W4 were polysaccharide and protein through the analysis of FTIR ( Fourier transform infrared spectroscopy) .

Sludge Management has become an esstntial environmental issue in modern society. This paper overviewed the current status of sludge management research and development. We briefly reviewed the typical characteristics of sludge and its constiuent flocs. Afterward, several important processes in sludge treatment, including conditioning, dewatering, disinfection, hydrolysis, thermal treatment, and resource utilization were addressed. The updated progress in floc structure study was highlighted.

A model to describe the motion of contact line and dynamic contact angle on rough solid surfaces was proposed. It was assumed that a precursor film exists ahead the apparent contact line (ACL) at small velocities of ACL or capillary numbers. The ACL moves on the wetted solid surface, rather than dry solid surface as expected in the conventional hydrodynamic theories. With introduction of the contact line characteristic parameter, λ′, describing the slipping degree of ACL on the precursor film, the relationship between the dynamic contact angle and the velocity of moving contact line were derived. The comparison of the experimental results with the model indicates the dimensionless characteristic parameter, λ, can describe very well the effect of the solid material and surface properties (roughness etc.) on dynamic wetting processes, and is independent of liquid properties. The difference of static contact angles measured by the dynamic measurement technique from static measurement technique was interpreted by this model and the previous hysteresis tension model.

本文采用双阶段模型描述多孔颗粒与气体的传递反应.反应分为两个阶段:气体反应物在扩散进入颗粒内部同时与颗粒发生反应的第一阶段;形成产物层后,扩散和反应用双区域模型来描述的第二阶段.分析发现,蒂勒数是描述过程特性的重要参数,同时反映反应和扩散速度的影响,且与总阻力存在一定关系.利用TGA进行了脱硫反应实验,分析了反应温度、颗粒大小等对反应的影响,实验结果很好地证实了理论分析结论.

高速摄像观察记录细小铂丝上过冷核态沸腾过程, 发现存在汽泡往返扫荡现象. 描述了汽泡往复扫荡现象的一般过程特性和主要特点, 探讨了扫荡引起的沸腾系统内部相互作用以及对换热的影响, 提出了不对称温度场驱动模型并对汽泡扫荡现象进行了初步解释.

应用经典的Moffatt解, 通过引入接触线特征参数λ′, 给出了接触线上的黏性剪切应力, 导出了动态接触角和接触线移动速度的关系, 解释了文献中两种不同测量方法所得静态接触角不一致的现象. 理论所揭示的动态接触角和接触线移动速度的关系曲线和以往文献中的曲线形式基本一致. 通过和Hoffman试验数据的比较发现:λ′与流体性质无关, 是表征壁面性质的特征参数. 初步探讨了λ′的数理意义.

随着社会的发展,人们生活和工业生产所产生的污泥正在急剧增加,成为一个严重的环境问题.本文扼要讨论污泥处理对环境保护的重要意义及其研究现状.首先简单介绍污泥的各种类型与其组成颗粒的特性和结构;而后再对污泥处理中的几步重要程序,包括调理和脱水进行了说明;最后涉及污泥的后处理,如杀菌、水解、热处理和资源化等问题也作了阐述.

随着社会的发展,人们生活和生产所产生的污泥成为一个日益严重的环境问题.本文简要介绍污泥处理对环境保护的重要意义及其现状;讨论活性污泥的分类、工业处理及特性,尤其是结构变化特性及其对污泥处理的重要意义;分析展望污泥特性研究中现有的和潜在的热物理研究方向.

In this paper, a fluidized bed and TGA were employed to perform the flue gas desulfurization; the dynamic characteristics of pores or pore structure were analyzed with the help of mercury porosimeter for different reactant solid samples having porous property under variant conditions. The experimental measurements indicated that the pore structure and its distribution greatly affected or even dominated the dynamic process. The distributed pore model was developed to describe the dynamic characteristic of flue gas desulfurization. The model indicated that the pore structure, especially pore distribution, most\|favored radius, governed the desulfurization process, and the final conversation rate was completely dependent upon the initial porosity of solid desulfurizer. The experiment data were agreed well with the model prediction.

本文建立了干法烟气脱硫反应的实验装置,对以氧化钙为脱硫剂的干法烟气脱硫反应进行了实验研究,并利用压汞仪分析反应过程中参与反应的固体颗粒的孔隙结构的变化情况,对干法烟气脱硫反应过程中的固体颗粒孔隙结构特性进行动态分析,揭示和确定了反应过程中固体颗粒孔隙结构变化规律和脱硫转化率.研究结果表明,孔隙结构,包括孔径分布、最可几孔半径等是决定和影响干法烟气脱硫反应的因素,其中孔隙率决定脱硫反应的最终转化率,孔隙分布则控制着反应的过程特性.

Based on a simplified, transient, one dimensional heat transfer model, this work explored the feasibility of using natural freezing and thawing process for sufficiently conditioning water and wastewater sludge produced in Mainland China. The historical average temperature data (1960~1990) for major cities were first collected. Then, the freezing and thawing times required to condition various thickness of sludge layer were accordingly calculated by the mathematical model. This information was used to estimate the surface area needed and the sludge thickness applicable for the sludge freezing bed. Whilst the feasibility to condition sludge with the assistance of natural climate change in the major cities was evaluated.