热—碱联合处理改善污泥厌氧消化性能的研究

针对污泥厌氧消化过程中水解速率缓慢的问题,采用热—碱联合的处理方式处理污泥,分别考察热碱处理温度、时间、pH等因素对污泥的破解效果,以污泥上清液中溶解性蛋白质、溶解性多糖、SCOD及COD溶出率来表征对污泥的破解程度,通过生化甲烷势(BMP)试验来评价热碱处理对厌氧消化性能的改善。结果表明,剩余污泥经过热碱处理后COD溶出率、SCOD、溶解性蛋白质及溶解性多糖浓度明显升高,高温及强碱性条件对破解污泥有明显效果,在pH=12、 90℃的条件下处理120 min破解效果最佳,经过预处理的污泥厌氧消化20 d累积甲烷产量1 508 mL,甲烷产率为70.07 mL/g,未处理污泥累积甲烷产量547 mL,甲烷产率为24.14 mL/g,热碱处理后污泥厌氧消化性能得到明显提升。     

剩余污泥低温热水解中试

中国污泥有机物质量比低,厌氧消化速率慢、产气少,60℃左右的热水解是改善措施之一。该文在热水解罐中进行了剩余污泥低温热水解的中试研究,采用热泵供热。对水力停留时间(HRT)、温度(T)、污泥含固率和有机物质量比(CVSS/CSS)等对剩余污泥低温热水解的影响以及重要性进行了分析。试验结果表明:低温热水解的最佳工艺条件为:HRT为1d,温度54~60℃,污泥含固率3%。加碱可以促进水解,当污泥含固率5%时,调节pH到10可使VSS去除率和有机物溶出率分别增加46.8%和100%。正交试验结果表明:温度、污泥含固率和有机物质量比都是热水解的关键影响因素,各因素对VSS去除率和有机物溶出率影响的重要性顺序一致,由大到小的顺序为:污泥含固率、温度、有机物质量比。在最佳工况下,剩余污泥低温热水解后进行中温(35℃)厌氧消化,消化时间10d的情况下,沼气产量比未低温热水解时增加44%。     

处理污泥的"热水解-ASBR"组合工艺研究

近年来污泥"热水解-厌氧消化"处理工艺备受重视,在考察热水解预处理对污泥化学成分及厌氧消化性能影响的基础上,利用厌氧序批式反应器(ASBR)代替传统的连续流搅拌反应器(CSTR),从而建立了"热水解-ASBR"新工艺.研究表明,热水解预处理能改善污泥的厌氧消化性能,最合适的预处理条件是热水解温度170 ℃、热水解时间30 min.热水解污泥厌氧消化时,在水力停留时间(HRT)为20,10,7.5和5 d的条件下ASBR的有机物去除率和甲烷产气率均比CSTR的高,且ASBR合适的HRT为10 d.此时"热水解-ASBR"工艺的TCOD去除率和甲烷产气率比"热水解-CSTR"工艺分别提高27.93%和25.14%.     

热碱解-水解预处理剩余污泥的效果研究

热碱解-水解联合工艺预处理剩余污泥,可以实现污泥快速破胞,释放污泥细胞中的有机物,促进水解过程物质的转化,也有利于回收剩余污泥中的碳源. 基于此优点,本研究考察了温度、pH、反应时间对剩余污泥热碱解破胞效果的影响,以确定适宜的热碱解条件. 比较了不同水力停留时间（HRT=0~120h）下污泥水解过程中SCOD、挥发性脂肪酸（VFAs）、氮磷、蛋白质和糖类浓度的变化,分析了水解过程物质的转化情况. 结果表明,较高的pH（pH11）和较高的温度及延长反应时间均有利于提高污泥破胞效果. 适宜的热碱解条件为:热碱解破胞温度为70℃、初始pH 11,反应时间1 h. 在该条件下,SCOD浓度可超过11500 mg/L,污泥溶胞率为44%. 在水力停留时间为24 h时,VFAs和SCOD浓度分别高于2400 mg/L和5800 mg/L. 研究发现热碱解-水解反应约120h达到平衡,此时蛋白质和糖类稳定在130 mg/L和190 mg/L左右,其中,氮磷主要以氨氮和PO43-形式存在,相应比例分别为89%和94%. 热碱解-水解联合工艺通过加速污泥破胞,释放胞内有机物,能够明显地促进污泥的水解,这为剩余污泥热碱解-水解预处理的应用提供了技术支撑和理论依据.     

碱处理对剩余污泥预处理的研究

污泥固体的水解是厌氧消化的限速步骤,污泥预处理的目的就是破坏污泥的结构及细胞壁,使污泥的絮体结构发生变化,细胞内含物溶出,进入水相,加快厌氧消化速率。本文研究了加碱对污泥性质的影响,全面了解剩余污泥减量化过程中细胞物质的释放规律,还对碱预处理方法对污泥的融胞机理进行了分析。结果表明,碱处理效果最好,释放的SCOD最高（937.984mg/L）,处理后污泥液相中蛋白质、总糖、DNA均增加最多。     

高温预处理对污泥厌氧消化影响的研究

针对抚顺市三宝屯污水处理厂所产生的剩余污泥,在高温条件（70℃）下预处理后在34℃条件下厌氧消化,与无预处理的一步厌氧消化反应进行对比,检验高温预处理对剩余污泥减量化的影响.结果表明,两天预处理后,有机物从污泥中溶出,上清液的COD达到8 980 mg/L,而原污泥上清液的COD只有1 083 mg/L;经过16 d的厌氧消化后,COD、VSS去除率比未预处理的各提高了11.3%、12.3%,总产气量则增加了74 mL,且污泥停留时间可缩短到12d;污泥的沉降性能得到明显改善,pH值明显降低,低至6.1,有机酸浓度明显增大,达到1 058 mg/L（以乙酸计）,但是在厌氧消化过程中产生高浓度的氨氮,使系统保持很好的缓冲能力.而未预处理的污泥在厌氧消化过程中pH值只是在7.1~7.6之间变化,没有明显的产酸阶段.     

温度对CaO2强化剩余污泥厌氧水解，酸化的影响

本文探究了温度对CaO_2强化剩余污泥厌氧水解,酸化的影响。实验结果表明在15~35℃,随着温度的升高,污泥厌氧反应体系中水解和酸化得到加强,且VFA和甲烷的最大积累量分别为3 120 mg/L和196 m L。当温度进一步提高至55℃时,水解反应得到强化,但是过高的温度限制了厌氧微生物对溶解性蛋白质和多糖的利用,进而导致VFA的积累量较少。因此35℃是CaO_2强化剩余污泥水解和酸化的最佳温度。     

超声波促进石化污水厂剩余活性污泥厌氧消化

采用超声波技术分解石化污水厂剩余活性污泥(以下简称“污泥“),考察了超声波对污泥后续厌氧消化的影响.研究表明,超声波可有效分解污泥,提高污泥中溶解性化学需氧量(SCODCr),加速污泥的水解速度,提高污泥厌氧消化效率.在2 000 W/m2超声声强下处理60 min的污泥,厌氧消化25 d累积产生的气体比未处理污泥产生的气体提高了60%以上.厌氧消化10 d,有机物去除率达到40%,比未处理污泥提前约10 d完成厌氧消化.     

不同城市不同类型污泥厌氧消化产气性能比较

在中温（35℃）条件下，对不同城市的浓缩污泥和压滤污泥在60、80和100g/L三种不同负荷率下，进行厌氧消化产气性能比较研究。结果显示，在三种不同的负荷率下，同一污泥的单位总固体（TS）产气量、单位挥发性固体（VS）产气量、消化单位TS产气量、消化单位VS产气量之间没有显著差异。同一城市浓缩污泥和压滤污泥的厌氧消化性能相比有些不同，但差异不显著。取自北京某污水处理厂的两种污泥的厌氧消化性都明显好于河南某污水处理厂的污泥，其浓缩泥和压滤泥的消化单位VS产气量分别为0.7和0.9L/g，具有较佳的厌氧消化性能。     

高温两相厌氧处理高固市政污泥性能

以市政污泥为底物,建立高温两相厌氧消化系统,考察其运行性能,并与单相厌氧消化系统进行对比.运行结果表明两相厌氧消化系统具有更好的处理效果,稳定运行阶段TS、VS去除率和产甲烷比率分别为(41. 6±1. 7)%、(48. 0±4. 4)%和206. 8 m L·g-1VS,均高于单相厌氧消化系统;市政污泥经两相厌氧消化后,其卫生化程度(病原体、重金属及毒性有机物质量浓度)优于单相厌氧消化系统;市政污泥经厌氧消化后脱水性能会下降,但两相厌氧消化系统后的市政污泥具有更好的脱水性能,且最佳PAM投加量为5 g·kg~(-1)TS.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.