OGO工艺处理城市污水脱氮效果及机理初探

采用改良而成的OGO工艺技术,以试验配水模拟城市生活污水,研究了OGO系统的脱氮效果,通过分析反应器各反应区的脱氮效果,并结合OGO系统脱氮效果观察系统中活性污泥絮体特性,研究分析了OGO系统的脱氮机理.试验结果表明,在进水总氮(TN)和氨氮(NH4 -N)分别为31.15～42.26 mg/L和27.53～38.58 mg/L的条件下,OGO系统对总氮和氨氮的平均去除率分别可达74.31%和83.75%.反应器外环脱氮方式为同时硝化反硝化(SND)脱氮,其脱氮量占反应器脱氮总量的80.48%,OGO工艺对氮素的生物去除绝大部分是通过同时硝化反硝化来实现的;同时硝化反硝化的宏观分区理论和微环境理论均适用于OGO系统.     

DO对膜生物反应器中同步硝化反硝化的影响

采用人工配制的生活污水作为原水,考察了在膜生物反应器(MBR)中不同溶解氧(DO)对于同步硝化反硝化效果的影响.结果表明,将试验条件控制在TN容积负荷为0.35 kgN/(m3*d)、HRT为6 h、SRT为30 d、pH为7～8、温度为25～28 ℃、C/N为9时:在反应器DO的质量浓度为0.6 mg/L条件下,可获得62.5%的NH+4 -N去除率、91.1%的反硝化率和58.3%的SND率;在反应器DO的质量浓度为1.0 mg/L条件下,可获得90.8%的NH+4-N去除率、90.4%的反硝化率和82.5%的SND率;在反应器DO的质量浓度为1.4 mg/L时,可获得93.3%的NH+4-N去除率、77.0%的反硝化率和72.1%的SND率.     

低温下MBBR处理低碳氮质量比生活污水的同步硝化反硝化特性

以缺氧/好氧生物膜系统处理碳氮质量比为3.45±0.77的生活污水,当内回流比(R)为250%~300%时,重点考察低温下好氧移动床生物膜反应器(MBBR)内的同步硝化反硝化(SND)特性。研究结果表明:系统通过延长水力停留时间(HRT)(19.2 h→30.3 h),较好地适应了季节性降温(25.2℃→14.6℃),出水COD((51.1±6.3)mg/L)和NH4+-N((2.76±2.02)mg/L)质量浓度分别达一级B和一级A标准。SND脱氮率受低温影响较小,当水温为(23.0±1.6)℃(R=250%),(19.5±0.9)℃(R=300%),(17.1±0.6)℃(R=300%)和(15.1±0.4)℃(R=300%)时,可去除进水中39.4%~47.3%的总氮TN,出水TN质量浓度分别为(18.44±2.60),(13.92±3.16),(14.93±2.19),(14.11±2.14)mg/L。同步反硝化成为发生SND的关键,平均厚度为323~1 143μm的载体生物膜可形成缺氧"微环境",并在长HRT下有效利用原水中的缓慢降解碳源,发生内源反硝化。在DO质量浓度为(3.5±0.5)mg/L,碳氮质量比为2.5~3.3时,MBBR内的生物膜可实现速率为0.353 mg/(L·h)的同步脱氮。     

DO和HRT对连续流MBBR亚硝酸型SND影响

为探讨亚硝酸型同步硝化反硝化SND过程中的生物脱氮特性,以实际生活污水为对象,通过连续运行移动床生物膜反应器MBBR系统,研究了溶解氧质量浓度DO和水力停留时间HRT对亚硝酸型SND的影响.试验结果表明,化学需氧量COD在200 mg/L左右,HRT为14 h,水温为15~27℃,pH值为6.24~6.98的相对稳定条件下,控制DO在2.9~5.0mg/L的过程中MBBR反应器均能实现亚硝酸型SND,平均亚硝酸盐氮NO2-—N积累率为75.96%;当DO为(4.5±0.3)mg/L时,平均总氮TN去除率达62.89%,取得了最好的TN去除效果,而该条件下NO2-—N的积累率达最小值51.23%,DO过高或过低都会影响系统亚硝酸型SND的进行;当COD在220 mg/L左右,pH值为6.14~7.47,水温为26~31℃,控制溶解氧在(4.5±0.3)mg/L,随HRT的延长,氨氮NH4+—N和TN的去除率明显增大,但NO2-—N的积累率减小,系统的亚硝酸型SND效果逐渐减弱.     

溶解氧对垃圾压缩站废水同时硝化反硝化脱氮的影响

溶解氧（DO）含量是实现同时硝化反硝化生物脱氮的关键因素之一.文中采用同时好氧厌氧生物反应器（SOA）,对反应器内不同DO含量下垃圾压缩站废水中氨氮（NH4＋-N）,CODcr和总氮（TN）含量随时间的变化情况进行了考察.发现DO含量对反应器内CODcr,NH4＋-N和TN的去除效率和效果均有较大的影响.在DO含量（质量浓度,下同）为1.0mg/L时,反应器内的氨氮去除可分为快速和慢速两个阶段.在DO含量为0.5 mg/L时反应器内出现好氧区和厌氧区平衡状态,同时硝化反硝化脱氮效果最佳.反应器内可能存在一定的厌氧氨氧化脱氮过程.     

UASB反应器中高盐含氮废水脱氮过程研究

通过实验研究了在不同盐质量浓度、碳氮比和HRT条件下,高盐含氮废水的反硝化过程中碳源加入、TN、NO3-N和NO2-N的变化规律.分析结果表明:废水反硝化污泥在UASB反应器中经过驯化后可以适应氯离子质量浓度为0～20 g/L的盐质量浓度环境.脱氮性能随着HRT增加和进水C/N增加而提高;而NO2-N积累也随着HRT增加和进水C/N增加而降低.经过优化反应条件,较适宜的条件为进水C/N=3∶1,HRT=7.08 hr.     

丝绸厂汰头废水脱氮试验研究

针对丝绸厂汰头废水高有机物浓度高氮的特点,对SBBR反应器高效脱氮技术进行了系统研究,考察了负荷、DO、温度及碳源投加对反应器脱氮效能的影响,获得了控制反应器高效同步硝化反硝化脱氮的关键工况参数.试验结果表明:SBBR反应器在挂膜密度为35%、DO为6.5mg/L、有机负荷为0.3kgBOD5/m3·d,氮负荷为0.6kgN/m3·d条件下,表现出显著的同时硝化反硝化能力,可使出水NH4 -N浓度降为1.09mg/L,TN降为16.76mg/L,去除率分别为98%和 88.5%.     

侧沟式一体化氧化沟的生物脱氮

一体化氧化沟占地面积小、工艺流程简单,因此已成为环保领域的研究热点.文中采用侧沟式一体化氧化沟技术处理生活污水,进行生物脱氮研究.试验期间,一体化氧化沟进水CODCr为200.00-400.00 mg/L,NH4^＋-N进水从1.24 mg/L迅速提高到39.72mg/L;出水CODCr保持在15.00mg/L以下,氨氮去除效果保持稳定,出水氨氮质量浓度在多数情况下保持在2.00mg/L以下.文中还分析了碱度、CODCr/NH4＋-N质量比对生物硝化作用的影响,并就如何提高反硝化效率提出了建议.     

低温下分段进水多级A/O工艺脱氮规律分析

针对低温污水脱氮效率低的实际问题,研究了利用三级A/O工艺模拟处理低温城市污水的规律.反应器在A,O池容比为1:1、进水温度(10±0.5)℃、水力停留时间(HRT)8 h、污泥停留时间(S R T)40 d、进水流量分配比为5:4:4的条件下连续运行50 d.结果表明:系统对碳源进行了合理分配,促进了反硝化作用从而提高了缺氧段TN的去除效率,出水COD为18～35 mg/L,出水T N低于12 mg/L.污泥浓度呈梯度降低分布,利于富集世代时间不同的微生物.由OUR、镜检和SEM分析结果可见,微生物菌群活性较高且具有稳定性.微生物属水平中具有丰富的反硝化功能细菌.研究证明低温多级A/O系统污水脱氮效率主要受硝化过程限制,硝化作用耗时长、硝化菌活性低是H N4+-N去除不彻底的主要原因.     

不同时期垃圾渗滤液两级UASB-A/O-SBR工艺深度脱氮

应用两级上流式厌氧污泥床(UASB)-缺氧/好氧(A/O)-序批式反应器(SBR)深度处理早期和晚期垃圾渗滤液.首先在一级UASB(UASB1)中实现反硝化,在二级UASB(UASB2)中通过产甲烷降解有机物,在A/O反应器的好氧区进行NH4+-N的硝化,最后在SBR中去除残余NH4+-N及通过反硝化去除NO2--N和NO3--N深度脱氮.试验结果表明:早期渗滤液ρ(COD),ρ(TN)和ρ(NH4+-N)分别为14.8,1.8和1.3 mg/mL,最终出水ρ(TN),ρ(NH4+-N),ρ(NO2--N)和P(NO3--N)分别为28,4,3.4和1.9 mg/L,获得了大于98%的TN和NH4+-N去除率.晚期渗滤液ρ(COD)为2.5 mg/mL;ρ(TN),ρ(NH4+-N)分别为3.0和2.9 mg/mL时,获得99%以上的TN和NH4+-N去除率.最终出水ρ(NH4+-N),ρ(NO2--N)和P(NO3--N)都小于10 mg/L,最终出水ρ(TN)为26～32 mg/L.     

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…     

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).     

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.     

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.