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1.
以硫酸铝和氯化铁作混凝剂,通过强化混凝对模拟地下水中的氟化物的去除进行了研究,对比了铝铁盐的混凝沉淀除氟效果,考察了硫酸铝混凝剂投加量、水的pH值、浊度、水中共存离子和原水中氟化物初试质量浓度等因素对硫酸铝除氟效果的影响.结果表明,硫酸铝的除氟效果优于氯化铁,混凝剂的投加量和水的pH值是影响硫酸铝混凝沉淀除氟的重要因素,当水的pH≈5.8时,硫酸铝混凝除氟效果最好;高岭土增浊对硫酸铝除氟的效果影响不明显;水中共存离子HCO3-的引入使得除氟效果变差,而SO24-和Cl-的干扰则较小.此外,对硫酸铝混凝沉淀除氟的机理进行了初探.  相似文献   

2.
探讨了混凝法、SBR法以及混凝-SBR法联合工艺对造纸废水的处理效果,分析了混凝剂种类、混凝剂用量、pH值、搅拌速度等因素对造纸废水混凝处理效果的影响.结果表明,聚合硫酸铁(PFS)对造纸废水的混凝处理效果优于硫酸铁和硫酸铝.正交实验结果表明PFS投加量对混凝处理效果有显著影响.直接采用混凝法和SBR法处理造纸废水的效...  相似文献   

3.
在室温条件下,选用氯化铁、明矾、硫酸铝和聚合氯化铝(PAC)4种常见混凝剂,对城市污水处理厂氧化沟出水和二沉池出水进行协同沉淀和后续混凝除磷对比实验;协同沉淀实验的混凝剂投药量为0~40mg/L,pH值为2.36~10.09;后续混凝除磷实验的混凝剂投药量为0~100mg/L,pH值为2.31~10.07.结果表明,协同沉淀除磷时,PAC、明矾、氯化铁以及硫酸铝的适宜投药量分别为15mg/L、20mg/L、30mg/L和25mg/L,pH值适宜范围分别为6.79~8.32、5.82~8.32、6.79~6.92和6.79~6.92;后续混凝除磷时,PAC、明矾、氯化铁以及硫酸铝的适宜投药量分别为30mg/L、70mg/L、50mg/L和40mg/L,pH值适宜范围分别为5.92~10.07、6.92~8.08、6.92~10.07和6.92~8.08.在4种混凝剂中,PAC能够在较小投药量条件下有效地降低出水中的总磷含量,优于其他3种混凝剂的处理效果;在实现相同除磷效果的条件下,后续混凝除磷工艺所需投药量为协同沉淀工艺的1.6~3.5倍,因此建议采用PAC混凝剂和协同沉淀工艺进行总磷去除处理,pH值保持在中性范围内.  相似文献   

4.
焦化废水混凝深度处理研究   总被引:3,自引:0,他引:3  
焦化废水来自于炼焦、煤气净化及焦化产品回收过程中产生的废水,其成分复杂多变,属于难处理的工业废水.经生物处理后的焦化废水很难达到相关标准的要求,因此采用混凝法对焦化废水进一步进行深度处理.实验选择了几种混凝剂如聚合硫酸铁(PFS)、硫酸铝(Al2(SO4)3)及聚丙烯酰胺PAM.通过实验确定各种混凝剂处理焦化废水的最佳pH值、最佳投加量、并确定无机混凝剂、有机絮凝剂配合使用时的最佳实验条件.结果表明:不同混凝剂适用的pH值各不相同,最佳的混凝处理条件是PFS和PAM组合,其能进一步去除色度、CODCr,提高出水水质.  相似文献   

5.
目的研究不同铝盐混凝剂对不同原水水质的混凝效果,并对其结果进行比较。方法取宝鸡渭河原水、清姜河原水为水样,以PAC和PAFC为混凝剂,分别进行最佳投加量和最佳pH的单因素混凝实验,选用混凝效果较好的PAFC进行正交实验,分析混凝后水样浊度与UV254。结果渭河原水中,PAC最佳投加量为4~8mL,PAFC最佳投加量为4~6mL,PAC的最佳pH值为6~8,PAFC的最佳pH值为5~8;在清姜河原水中,PAC的最佳投加量为2~8mL,PAFC的最佳投加量为2~6mL,PAC,PAFC的最佳pH值均为6~8。结论渭河原水浊度与UV254较高,混凝剂投加量比pH值更能影响高浊度原水的混凝效果;清姜河原水浊度与UV254较低,pH值比混凝剂投加量更能影响低浊度原水的混凝效果。PAFC混凝效果的影响因素依次为:搅拌时间、PAFC投加量、pH值;PAFC的混凝最佳操作条件为:PAFC的投加量为6mL,pH值为6,快速搅拌时间为60s。  相似文献   

6.
王婷 《天津科技》2012,(4):27-28
研究模拟超标的含铅废水,考察了混凝工艺对铅的去除效果,研究了混凝剂投加量、pH值和反应过程中搅拌时间对混凝去除铅的效果的影响。结果表明,混凝剂聚合氯化铝(PAC)投加量为85mg/L左右、pH值为10.2左右时可得到对铅较佳的去除效果。  相似文献   

7.
通过单一混凝剂的最佳pH和最佳用量的混凝实验,对四种混凝剂逐级进行复配,并研究了在优选pH和pH不变两种情况下,复配混凝剂对造纸黑液的处理效果.实验表明:四种混凝剂的最佳复配比例为:硫酸铁∶硫酸铝∶聚氯化铝铁∶硫酸铝钾=1∶0.4∶1.4∶1.4(体积比),且优选pH为6.pH=6时,投加用量分别为硫酸铁、硫酸铝、聚氯化铝铁、硫酸铝钾=0.95 g/L、0.4 g/L、1.35 g/L、0.65 g/L的复配混凝剂溶液,CODcr和色度去除率分别为97.78%和97.74%.当黑液pH不变(即pH=7.8)时,CODcr和色度去除率均不大,说明pH对复配混凝剂的处理效果有较大的影响.  相似文献   

8.
透光率脉动检测技术评价混凝剂的混凝效果   总被引:2,自引:0,他引:2  
介绍了一种评价混凝效果的新方法———透光率脉动检测法 ,并以不同浊度的高岭土悬浊液为研究对象 ,投加 3种不同剂量的混凝剂 (硫酸铝、聚合氯化铝、高分子有机絮凝剂HCA) ,通过PDA2 0 0 0检测仪对混凝效果的检测 ,以R指数评价不同混凝剂在多种浊度水样中的混凝效果。结果表明 ,透光率脉动检测技术是一种检测混凝性能的可靠方法  相似文献   

9.
强化混凝去除腐殖酸的试验研究(英文)   总被引:1,自引:0,他引:1  
选用Al2(SO4)3、FeCl3混凝剂对腐殖酸的强化混凝试验表明,强化混凝对腐殖酸有很好的去除效果。pH值和混凝剂投加量是影响腐殖酸处理效率的主要因素,其中调整pH值更有效。Al2(SO4)3混凝的最佳pH值在5左右,FeCl3在4左右。Al2(SO4)3投加量为4mg/L时,DOC、CODMn及UV254去除率可分别达到69.7%、84.8%和96.9%。FeCl3投加量为5mg/L时,DOC、CODMn及UV254去除率可分别达到78.1%、89.3%和97.8%。  相似文献   

10.
染料废水的脱色研究   总被引:9,自引:0,他引:9  
该文研究了在染料废水脱色处理中几种混凝剂及助凝剂混凝处理的最佳PH值、最佳用量、脱色效果以及混凝与其它物化方法联合处理的情形,其中混凝剂-NaClO氧化处理是洒料废水脱色为最佳方案。另外,在新型混凝剂聚合硅酸铝的研制应用方面进行了一定的尝试,实验结果表明,聚合硅酸铝对于染料废水的脱色效果优于其它混凝剂.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
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   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
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   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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