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1.
采用粉末活性炭(PAC)-超滤(UF)一体化工艺处理微污染水,考察投炭量对浊度、UV254和CODMn去除效果和对膜污染的影响以及有机物去除效果随PAC停留时间的变化。研究结果表明:超滤膜出水浊度保持在0.100 NTU以下,且不受进水浊度以及PAC投加量的影响。在10,20和40 mg/L投加量下,随着PAC投加量增加,有机物去除率逐渐提高,但单位质量PAC有机物去除效果逐渐下降,10 mg/L PAC可以满足试验水质条件下经济性和出水水质的要求。PAC对有机物去除效果随停留时间增加而降低,较高PAC投加量下降幅度较小。PAC-UF工艺可以有效控制膜污染,次氯酸钠与酸、碱形成的复合药剂对跨膜压差恢复效果最佳。  相似文献   

2.
高岭土对铜绿微囊藻的PAC强化絮凝去除技术   总被引:3,自引:0,他引:3  
采用烧杯实验研究了用高岭土作前助凝剂提高PAC去除铜绿微囊藻的有效性.结果表明,经絮凝及30 min的沉淀后,藻细胞去除率都达到92%以上,水体剩余浊度低于1.0 NTU.进一步的正交实验结果表明,pH值是影响用PAC联用高岭土助凝去除铜绿微囊藻的主要因素,且以pH值为7.5~9时效果较好.以聚丙烯酰胺(PAM)为后助凝剂,当投加量达到0.5 mg/L时,可以进一步增加絮凝体体积和密实度,沉淀5 min即可使水体剩余浊度降到1.5 NTU以下,因此,联用投加高岭土、PAM 和PAC是适宜的强化絮凝除藻技术.  相似文献   

3.
目的研究广东省中山市某水厂侧向流斜板填料在新型气浮-沉淀系统中对水库水藻类、浊度的处理效果,提高水库水藻类和浊度的去除率.方法确定PAC投加量、Na OH投加量、进水浊度和进水叶绿素浓度为主要影响因素,采用中心组合设计-响应曲面法建模分析气浮-沉淀后藻类和浊度的去除效果.结果当高藻水(ρ(叶绿素)=4 000 mg/L)PAC投加量为3.84~8.61 mg/L、Na OH投加量为1.88~5.63 mg/L时,叶绿素去除率最高达97.89%;低浊水(浊度=12 NTU)Na OH投加量为1.67~3.25 mg/L、高浊水(浊度=110 NTU)PAC投加量为39.67~25.46 mg/L时,浊度去除率最高分别为97.38%和98.66%.结论含有侧向流斜板填料的新型气浮-沉淀工艺可提高不同季节水库水除藻除浊效果.  相似文献   

4.
利用加载磁絮凝技术对垃圾渗滤液进行预处理试验,考察混凝剂PAC和助凝剂PAM投加量、pH值、磁粉Fe_3O_4投加量、磁场强度、药剂投加顺序等因素对试验的影响.结果表明,在pH为8.0,PAC投加量为600 mg/L,PAM投加量为0.25 mg/L,磁粉投加量为750 mg/L,磁场强度为150m T条件下,先投加PAC再加入磁粉,30 s后投加PAM时,混凝效果最佳,COD的去除率为55.86%,氨氮的去除率为36.13%,浊度的去除率为88.91%.磁絮凝与常规工艺的对比试验表明,投加磁粉对于COD的去除有良好的效果,基本可以取代PAM的作用,但去除氨氮的效果低于PAM.  相似文献   

5.
为提高南方某水厂常规工艺对微污染原水的净化效率,以聚合氯化铝(PAC)为混凝剂,分别采用预氧化(KMnO4、H2O2和O3)、粉末活性炭、助凝剂(PAM)和回流污泥等技术强化微污染原水的混凝过程.结果表明:预氧化强化混凝把原水中有机物氧化分解为分子量较小、疏亲水性较高的有机物,进而提高有机物混凝去除效果,KMnO4、H2O2和O3的适合投加量分别为1.5~2、4~6和4~6 mg/L;粉末活性炭强化混凝是利用粉末活性炭吸附分子量在0.6~3 kD的有机物,从而提高CODMn和色度去除率,粉末活性炭的适合投加量为20~30 mg/L;助凝剂强化混凝是助凝剂PAM能有效提高絮体颗粒尺寸,使得颗粒沉降速度加快,并使CODMn去除率得到提高,PAM投加量为0.2 mg/L;污泥强化混凝沉淀是以回流污泥提供凝聚核心,充分发挥其吸附、卷扫的作用,提高CODMn去除率,污泥适当投加量为15 mg/L.  相似文献   

6.
复合铝混凝剂CPAC强化混凝去除藻类试验研究   总被引:2,自引:0,他引:2  
以三氯化铝和有机高分子PGA为原料,制备了复合混凝剂CPAC,并探讨了该种混凝剂对含藻水的强化混凝去除作用.结果表明:复合混凝剂混凝效果优于单独的无机混凝剂PAC,当混凝剂投加量(以Al质量计)为4.5 mg/L时,PAC的浊度去除率为84.3%,而CPAC的浊度去除率达到93.1%;CPAC对高浊度原水的去除效果好于低浊度原水,当原水浓度从30 NTU提高到1 000 NTU时,混凝剂投加量为4.5 mg/L,其浊度去除率相应的由81%提高到98.2%;混凝剂最挂投加量约为4.5 mg/L,在此浓度下,浊度和叶绿素a 的去除率达到最高,分别为93.1%和82.5%;pH在5.0~9.0范围内,混凝效果均比较稳定.  相似文献   

7.
针对处理低温低浊水时残余铝过高及浊度难去除的问题,采用复合型生物絮凝剂(CBF)处理低温低浊水源水,通过L16(45)正交实验研究了复合型絮凝剂投加量、pH、助凝剂Ca2+投加量、沉降时间和混凝水力条件5个因素对絮凝效果的影响。结果表明,浊度及铝去除率的影响因素均为:pH>水力条件>沉降时间>助凝剂Ca2+投加量>絮凝剂投加量。浊度去除率和铝去除率最佳的絮凝条件:絮凝剂投加量为10 mg/L;助凝剂Ca2+投加量为1.5 mg/L;pH为8.0;水力条件为搅拌速度160 r/min,搅拌时间为40 s;沉降时间为30 min。此时浊度去除率达到88.34%,残余Al去除率为92.43%。研究为应用CBF处理低温低浊水提供了基础数据和技术支持。  相似文献   

8.
为提高絮凝剂的絮凝性能,降低絮凝剂的应用成本,实验研究了两种不同分子量的壳聚糖(CTS)与聚合氯化铝(PAC)复配使用的絮凝性能,并对生活污水进行了处理.结果表明:聚合氯化铝与壳聚糖复合能相互促进其絮凝效能,当壳聚糖分子量为1.05×106,污水pH为6.5,静置30min,总投加量为1.0mg/L,复合絮凝剂组成为PAC : CTS1=0.3 : 0.7时,废水的透光率达到98.9%,优于单独使用PAC和CTS.复合絮凝剂(CTS/PAC)兼有无机和有机絮凝剂的优点,是一种使用范围较广的新型絮凝剂.  相似文献   

9.
采用响应曲面分析研究了聚合氯化铝(PAC)和羧甲基壳聚糖(CMC)复合去除蛋白核小球藻(Chlorella pyrenoidosa)的最优实验条件.在单因素实验的基础上,以PAC的投加量、CMC的投加量以及静置时间为考察因素,以小球藻去除率、残余铝浓度为考察指标,用Box-Behnken实验设计方法设计了共17组实验.结果表明:通过响应曲面预测得到了最优实验条件,在PAC投加量6.56mg(131mg/L)、CMC投加量0.5mg(10mg/L)、静置时间40min时,除藻率达到最大92%,残余铝浓度达到最低0.13mg/L.通过最优预测条件验证,得到的藻类去除率为91%,残余铝浓度为0.16mg/L,说明预测值与实际值差别不大.  相似文献   

10.
将磁粉与聚合氯化铝(PAC)、聚丙烯酰胺(PAM)联用组成复合絮凝剂来处理热轧废水。在改变絮凝剂各组分投加量的条件下进行絮凝试验,分析热轧废水的浊度和含油量变化,研究复合絮凝剂的最优投加方案。试验结果表明,当磁粉、PAC和PAM的投加量分别为5mg/L、15mg/L和1.5mg/L时,热轧废水的净化效果最佳,其浊度由82.6NTU降为10.5NTU,含油量由15.62mg/L降为7.44mg/L。  相似文献   

11.
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.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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。  相似文献   

14.
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  相似文献   

15.
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  相似文献   

16.
17.
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.  相似文献   

18.
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).  相似文献   

19.
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.  相似文献   

20.
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.  相似文献   

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