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1.
低电荷密度的两性高分子絮凝剂絮凝机理初步探讨   总被引:11,自引:0,他引:11  
详细讨论了两性高分子絮凝剂P(AM-DM-MA)体系中,阴,阳离子基团相对含量以及絮凝剂加量对絮凝性能的影响,结果表明,阳离子基团含量为10mol%,阴离子基团为2mol%-4mol%时絮凝性能最佳。且絮凝剂加量范围很宽。此外通过对悬浮体系和絮凝剂本身的统计分析,认为两性高分子絮凝剂对硅藻土悬浮体系的絮凝是通过若干个高分子链“桥连”而形成粗大的絮体,并非一个高分子链连接几个悬浮颗粒。  相似文献   

2.
王烨  王烁  杨静 《中国科技博览》2013,(16):205-206
采用Fenton高级氧化法深度处理化纤生化出水,考察其氧化作用和絮凝作用对有机物去除的贡献情况。结果表明:在控制初始pH值为3,c(Fe2+)为7.0mmol/L,c(H2O2)为0.15mol/L时,COD总去除率可高达63%,其中氧化作用去除率为40.1%,絮凝作用去除率为22.9%。初始pH、c(Fe2+)以及c(H202)的变化对氧化和絮凝作用影响显著,但在各个反应因素变化范围内氧化作用对COD去除率一直高于絮凝作用对COD去除率。  相似文献   

3.
制备了一种新型聚硅酸铝镁-壳聚糖(PSAM-CTS)复合絮凝剂,并将其用于处理松花江江水。考察了投加量、水样pH值、水温等因素的影响。结果表明:当投加量为1mL,待处理水样为500mL时,PSAM-CTS絮凝剂呈现很好的絮凝脱色效果,适用于处理低温(0~5℃)、偏碱性(pH=7~9)的松花江水。用扫描电镜观察PSAM-CTS絮凝剂的微观形貌,X-射线衍射分析了聚硅酸、壳聚糖、金属离子水解产物三者之间的作用情况。  相似文献   

4.
克雷伯氏杆菌产生的絮凝剂处理垃圾渗滤液的研究   总被引:1,自引:0,他引:1  
本文研究了克雷伯氏杆菌(Klebilla sp.)SLY08所产絮凝剂对垃圾渗滤液的絮凝效果,并对影响絮凝作用的主要因素进行了探讨。絮凝效果表明,在室温、pH7.0及助凝剂Al^3+存在下,该菌株所产生的絮凝剂不仅能有效去除废水中的悬浮固体,而且还能使废水脱色,其脱色率可高达61.8%。与常规絮凝剂相比,具有用量少、絮凝活性高的优点。  相似文献   

5.
以安徽中粮生化燃料酒精有限公司生产废液为例,采用强化混凝沉淀作为前处理,研究了生物絮凝剂与聚合硫酸铁复配时(简称复合微生物絮凝剂)对酒精发酵废液中固体悬浮物(SS)和CODcr的去除效果。结果表明:当酒精发酵废液pH为90,Ca2+添加量为15%,搅拌时间为6min,复合生物絮凝剂投加量为3ppm时,固体悬浮物和CODcr的去除率分别为926%和65.7%,且絮凝沉淀后上清液清透,无悬浮颗粒。絮凝后上清液进行回流调浆发酵,可以降低回配液的浓度、渗透压,减少回配液中酵母代谢产物对酵母的影响,从而提高酒精产量。  相似文献   

6.
建立了固相萃取-高效液相色谱法测定水中5种邻苯二甲酸酯类的方法。通过正交实验确定了固相萃取的最优化条件:洗脱剂组成(乙醚:甲醇)19:1,洗脱速率1.0mL/min,洗脱体积9mL,清洗剂组成(甲醇:水)1:19。液相色谱的最佳条件:检测波长224nm,流速1.0mL/min,采用梯度洗脱,开始时甲醇-水(75:26,V/V),保持6min,第7min甲醇比例上升到100%。结果,5种物质峰面积对浓度进行线性回归的相关系数均大于0.9992,该方法的最低检出限在(0.01~0.07)pg/L之间,加标回收率82.1%~97.4%,相对标准偏差(RSD)1.1%~2.4%。  相似文献   

7.
从花园土壤中筛选到一株有絮凝能力的菌株编号为DF-3,在温度为30℃,通气量(以摇床转速表示)为160r/min时通过实验确定DF-3的最佳培养条件:初始pH为8;20g/L果糖和5g/L葡萄糖为碳源;0.3g/L蛋白胨,0.5g/L酵母膏,0.5g/L尿素和0.2g/L(NH4)2SO4为最佳氮源;无机盐为2g/LKH2PO4,5g/L K2HPO4和0.1g/L NaCl。在这种条件下培养36小时所产微生物絮凝剂对高岭土悬浊液的絮凝率超过90%。  相似文献   

8.
以丙烯酰胺(AM),二甲基二烯丙基氯化铵(DMDAAC),丙烯酸丁酯(BA)为原料,通过自由基胶束共聚法合成了阳离子型疏水缔合共聚物P(AM-DMDAAC-BA)。采用红外光谱,核磁共振谱对聚合物的结构进行了表征。考察了不同合成工艺条件下得到的聚合产物的絮凝性能。研究结果表明,阳离子单体含量和疏水单体含量均对絮凝效果有较大的影响。在阳离子单体含量10mol%,疏水单体含量3mol%,絮凝剂加量25mg/L时,综合絮凝效果较好。  相似文献   

9.
铌掺杂Ba(ZrxTi1-x)O3弛豫铁电陶瓷介电性质的研究   总被引:1,自引:0,他引:1  
马厂杨丽  曹万强 《功能材料》2007,38(A02):788-790
采用传统的固相反应法制备了Ba(Zr0.25Ti0.75)03+xat%Nb2O5(x=0,0.05,0.1,0.15)弛豫铁电陶瓷,研究了Nb2O5加入量对Ba(Zr,Ti)03(BZT)基电容器陶瓷性能的影响,得到了Nb2O5影响其性能的规律。结果表明:当x=0.15时介电常数最大,当x=0.10时介电损耗最小;适量Nb2O5能使材料的介温曲线更加平缓,移峰作用明显。  相似文献   

10.
纤维素/羧甲基壳聚糖共混膜结构与抗菌性能   总被引:13,自引:0,他引:13  
对壳聚糖羰甲基化修饰合成羰甲基壳聚糖,于纤维素的新溶剂6%(质量)NaOH/4%(质量)尿素中制备出纤维/羧甲基壳聚糖共混膜。实验表明,共混膜中羰甲基壳聚糖含量低于50%(质量)时,二者具有良好的相容性,其干,湿态拉伸强度在羧甲基壳聚糖含量20%(质量)时达到最大,分别为94.5MPa和49.4MPa,比纤维素膜分别提高了13.2%和26%。抗菌性能测试显示,共混膜对金黄色葡萄球菌(St.aureus)的抗菌性大于纤维素膜,并且随羰甲基壳糖含量的增加而增强,羧甲基壳聚糖的取代度在0.4左右时,共混膜具有最佳的抗菌效果。  相似文献   

11.
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.  相似文献   

12.
13.
A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.  相似文献   

14.
On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……  相似文献   

15.
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……  相似文献   

16.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

17.
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill.  相似文献   

18.
The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...  相似文献   

19.
Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.  相似文献   

20.
Cubic boron nitride(c-BN) film was deposited on a Si (100) substrate by the RF-magnetron sputtering.The mainly problems for fabrication of c-BN films are the low purity and high intrinsic compressive stress. In order to solve the two problems, the c-BN film with the buffer interlayer was deposited on the substrate which had been implanted with nitrogen and/or boron ions. The results show: the implantation of nitrogen ions can obviously increase c-BN content and reduce the internal stress slightly; while the implantation of boron shows no obvious improvement to the content of c-BN, which can reduce the internal stress in the film obviously. In addition, it is suggested that the implantation of nitrogen and boron shows the best result, which not only can increase the content of c-BN, but also reduce the internal stress in the c-BN film obviously.  相似文献   

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