聚丙烯酰胺-聚硅酸锌复合絮凝剂的制备和絮凝性能

利用物理复合的方法制备聚丙烯酰胺（PAM）-聚硅酸锌（PSZ）复合絮凝剂。结果表明,聚丙烯酰胺-聚硅酸锌絮凝剂在复配比例为V （PAM）： V （PSZ）=1.0、投加量为0.10 mL、模拟水样pH为8左右时,对高岭土模拟废水絮凝效果最好,脱色率达91.2%,均高于聚丙烯酰胺和聚硅酸锌单独使用的效果（最高脱色率分别达87.66%和89.78%）;而且,在中性和碱性范围内,这种复合絮凝剂受pH影响较小。三种絮凝剂应用于四种工业废水的脱色处理结果表明,聚丙烯酰胺-聚硅酸锌复合絮凝剂的脱色率也均比单一絮凝剂要高。     

聚合氯化铝-聚丙烯酰胺复合絮凝剂的特性及絮凝作用

制备了无机和有机高分子复合絮凝剂聚合氯化铝-聚丙烯酰胺(PAC-PAM),在不调节pH值、投加量为8mg.L-1(以Al3+计)的条件下,絮凝剂净化长江水的效果最佳,余浊达到4.0NTU以下。通过测定絮凝剂的Zeta电位、观察絮凝剂形貌和处理长江水所形成絮体的形貌、分析絮体的粒度分布,对聚合氯化铝和聚合氯化铝-聚丙烯酰胺进行了比较研究,探讨了复合絮凝剂的絮凝机理。结果发现:聚合氯化铝与聚丙烯酰胺复合后,水解产物带有更多正电荷并具分枝状长链结构,增强了电中和及吸附架桥的作用。     

腈纶工艺废水复合絮凝剂的开发及其处理研究

通过选取几种有机、元机絮凝药剂进行单一、复配絮凝实验,研究丁不同絮凝剂处理腈纶工艺废水的絮凝效果,找出一种能够提高腈纶工艺废水预处理效果的复合絮凝剂。实验表明：对腈纶工艺废水来说,无机高分子絮凝剂处理效果较有机高分子絮凝剂要好,其中PFS絮凝效果最好;无机、有机絮凝剂进行复配的絮凝效果明显比使用单一无机、有机絮凝剂要好,最佳组合为PFS与阳离子聚丙烯酰胺（PAM）;若该复合絮凝剂加入一定量的MgSO4后。对CODcr去除效率有较大提高,并且MgSO4用量越多,效果越好;改性聚丙烯酰胺与MgSO4、PFS复配,可使CODCr去除率达到32．5％。     

化学絮凝剂对高岭土微颗粒的絮凝特性研究

以高岭土悬浊液中小于1 μm的高岭土颗粒为对象,研究了无机絮凝荆硫酸铝、聚合氯化铝(PAC)和有机高分子絮凝剂聚丙烯酰胺(PAM)、聚二甲基二烯丙基氯化铵(PDADMAC),以及投加量对悬浊液粒径分布的影响.结果表明,对于粒径在0.200～0.500μm的高岭土颗粒,无机絮凝剂和有机高分子絮凝剂都有较好的絮凝效果;而在0.500～0.700μm粒径的高岭土颗粒,有机高分子絮凝荆的絮凝效果优于无机絮凝剂.不同絮凝剂的投加量对高岭土悬浊液粒径分布有影响,絮凝率也不同.     

有机高分子絮凝剂与蛋白质的相互作用

以溶菌酶为模型蛋白质,系统研究了溶液化学环境（ｐＨ值、盐效应、絮凝剂用量）对部分水解的聚丙烯酰胺（ＰＨＰ）絮凝过程的影响．结果表明：溶液化学环境对絮凝效果及絮体的成长有很大的影响．对体系的（电位进行了测定,进一步揭示出在ＰＨＰ对溶菌酶体系中,絮凝机理以电中和机理为主,同时架桥机理也起一定作用．     

微波法复合絮凝剂的制备及其絮凝性能研究

以聚合氯化铝铁(PAFC)和阳离子聚丙烯酰胺((CPAM)为原料,采用微波法制备了新型复合絮凝剂,并将其用于处理高岭土模拟废水.当CPMA与PAFC的质量比为1:4时,絮凝效果最优.红外光谱分析表明,通过微波作用,无机高分子絮凝剂已接枝到有机高分子絮凝剂上,形成了新型复合絮凝剂.该复合絮凝剂pH适应性宽,投加量少,成本低.当模拟废水pH值为6～9、投加量为1.8mg/L时,去浊率可达到98.5%以上.     

一种新型景观水体絮凝剂的研究

文章研究了用无机絮凝剂硫酸铝、聚丙烯酰胺（PAM）和天然高分子絮凝剂壳聚糖（CTS）进行复配对景观水体的处理效果。实验结果表明：在硫酸铝、聚丙烯酰胺和壳聚糖投加量分别为99.5 mg/L、2.0 mg/L和2.0 mg/L时,絮凝效果最佳,CODCr和浊度的去除率可分别达67.4%与91.0%,与传统的Al2（SO4）3-PAM絮凝剂相比,CODCr和浊度的去除率分别提高了13.8%和4.7%,而且大大减轻了硫酸铝和聚丙烯酰胺对环境的二次污染,具有明显的环境效益。     

复合型絮凝剂PAC-PAM处理含乳化油废水的试验研究

研究了不同条件下的聚合氯化铝和聚丙烯酰胺复合絮凝剂(PAC-PAM)对含乳化油废水的絮凝效果,并与使用单一絮凝剂的效果进行了对比。通过单因素条件试验研究pH值、PAC:PAM配比、溶液温度和沉降时间等操作条件对PAC-PAM复合絮凝剂处理含油废水效果的影响,从而得到PAC-PAM复合絮凝剂处理含油废水的最优条件及絮凝机理。结果表明:PAC-PAM复合絮凝剂处理含乳化油废水的最佳操作条件为:PAC为30mg/L、PAM为6mg/L、溶液温度40℃、溶液pH值为7和沉降时间30min。以COD去除率代表絮凝效果的好坏,最优条件下的COD去除率达到84.57%。复合絮凝剂处理含乳化油废水的絮凝机理主要是:电中和破乳及高分子链的架桥综合作用。与使用单一絮凝剂PAC或PAM相比,PAC-PAM复合絮凝剂对含乳化油废水的絮凝效果更好。     

阳离子聚丙烯酰胺对克雷伯杆菌絮凝效果的研究

采用有机絮凝剂阳离子型聚丙烯酰胺对克雷伯菌菌悬液进行絮凝处理。探讨了浓度、pH值、温度、助滤剂对絮凝剂絮凝及过滤性能的影响,并采用光学显微镜和扫描电子显微镜对菌悬液、絮凝剂和絮体3个方面进行了絮凝形态观察。结果表明,絮凝剂浓度为0.08 g/L,pH=7,温度为37℃时絮凝效果最佳。添加助滤剂Al2(SO4)3.18H2O、CaCl2.2H2O后过滤效果有明显的提高,且絮凝颗粒增大,沉降速度加快。     

聚合氯化铝,聚丙烯酰胺复合絮凝剂处理不同浊度水的研究

本文系统研究了无机高分子铝盐聚合氯化铝（ＰＡＣ）与有机高分子聚丙烯酰胺（ＰＡＭ）复合絮凝剂处理不同浊度水的絮凝效果、性能和机理。测定了最佳投药量、最佳水力条件及余浊度变化、密度变化等，为管式絮凝器用于处理不同浊度水的设计提供了理论依据     

Influence of Zwitterionic CAPB on Flocculation of the Aqueous Cationic Guar Gum/Glauconite Suspensions at Various pH

The influence of the pseudoamphoteric zwitterionic surfactant cocamidopropylbetaine (CAPB) on the stabilizing flocculating properties of the aqueous suspensions of glauconite (GT) with cationic guar gum (CGG) at various pH values was investigated. The following techniques were used: turbidimetry, UV-VIS spectrophotometry, tensiometry, electrophoretic mobility measurements, SEM, CHN, XRD, and FT-IR. It was established that CGG is an effective glauconite flocculant. Moreover, the most probable mechanism that is responsible for flocculation is bridge flocculation resulting from polymer adsorption on the glauconite surface. The adsorption process is caused by electrostatic interactions between the negatively charged glauconite surface and the positively charged polymer. The amount of CGG adsorption increases with the increase of the pH, which was confirmed by the adsorption and zeta potential measurements. The addition of CAPB increases the amount of the polymer adsorption due to the formation of intermolecular polymer–surfactant complexes; however, it reduces flocculation effectiveness.     

壳聚糖混凝效果的实验研究

本文通过对壳聚糖（CH）与聚丙烯酰胺（PAM）在pH值、加入量对混凝效果影响，对难沉降粒子聚沉能力等方面进行了的对比实验，得出结论：壳聚糖的除浊能力大于PAM，最适宜的pH范围为4～7，其优良的混凝性能是由于其独特的聚阳离子结构。     

碱性条件下稻草NH4OH-KOH蒸煮黑液的絮凝处理

利用聚合氯化铝-聚丙烯酰胺处理稻草NH4OH-KOH蒸煮黑液。系统讨论了聚合氯化铝用量、聚丙烯酰胺用量、反应温度和黑液pH值等工艺参数对絮凝效果的影响,继而确定了适宜絮凝工艺条件。结果表明,该絮凝体系对黑液COD去除率为68%,木质素去除率为92%。仪器测试表明絮凝沉淀物中除含有大量木质素外,氮、钾等营养元素的含量分别为23. 73%、6. 24%(均为干基),为絮凝沉淀物制备固体有机肥料创造条件;上层清液pH 为9. 20,呈碱性,杂质含量低,补加NH4OH/KOH后可作为蒸煮液循环使用,使稻草制浆更易于实施清洁生产。     

Polyacrylamides revisited: flocculation of kaolin suspensions and mature fine tailings

A series of acrylamide‐based water‐soluble (co)polymers was synthesized and they were investigated as flocculants of model kaolin suspensions and mature fine tailings of oil sands. The effects of molar mass, charge density, and polymer concentration on flocculation efficiency were studied by monitoring the initial settling rate during sedimentation. Hydrolyzed polyacrylamide (HPAM) with high molar mass and intermediate acrylic acid contents (0.14–0.41 mol/mol (14–41 mol%)) performed better in flocculation tests on kaolin suspensions requiring lower dose for maximum initial settling rate than native polyacrylamide (PAM). Surface force measurements showed that at low polymer concentrations (1 ppm), the partially‐adsorbed polymer induced a bridging attraction between the mica surfaces. Increasing the polymer concentration to 10 and 50 ppm caused purely repulsive forces. The presence of anionic groups in HPAM led to stronger repulsion, which was also demonstrated by the higher viscosity and larger hydrodynamic radius of the charged polymer. The charge‐induced increase in the viscosity of polymer solutions was suppressed by the screening effect of salts in a buffer solution and reducing the viscosity is desirable in the injection of flocculants in the industrial process.     

纳米SiO2表面吸附聚丙烯酰胺及其液相分散稳定性

通过溶胶-凝胶法制备纳米SiO2,讨论聚丙烯酰胺(polyacrylamide,PAM)在其水悬浮体系中的吸附行为。红外光谱分析和吸附实验结果表明。纳米SiO2通过氢键吸附PAM,吸附行为与PAM浓度,PAM分子量和pH值等因素相关。PAM吸附量随着浓度的增加而增大直至达饱和吸附量,并且饱和吸附量随着pH值的减小而增大。相同条件下,PAM分子量越大,表面吸附层的厚度越大,吸附量也越大。吸附PAM后纳米SiO2的表面电荷密度,扩散层电荷密度以及ζ电位发生变化。纳米SiO2吸附PAM后,增加了颗粒间的空间位阻作用,有效阻止纳米SiO2的团聚．若PAM加入量达到过饱和反而会引起纳米SiO2的团聚．     

Optimising the dewatering behaviour of clay tailings through interfacial chemistry, orthokinetic flocculation and controlled shear

The effect of shear on dewatering behaviour and particle interactions of Na-exchanged smectite and kaolinite clay dispersions has been investigated at pH 7.5, using hydrolysable Ca(II) and Mn(II) ions as coagulants and high molecular weight anionic and non-ionic polyacrylamide (PAM A and PAM N, respectively) and polyethylene oxide (PEO) flocculants. Metal ion addition enhanced the flocculation performance by dramatically reducing the magnitude of the particle zeta potential and, in the case of smectite pulp, suppressing osmotic swelling. Under optimum orthokinetic flocculation conditions of controlled agitation rate and duration, PAM A and PEO-based flocs settled faster than those of PAM N whilst kaolinite pulps produced higher sedimentation rates than smectite pulps. The settling rates are nearly an order of magnitude greater than those observed under standard flocculant-pulp mixing/flocculation methods of inversion and plunging. The difference in the flocculant behaviour is attributed to the more expanded conformation of PAM A and PEO polymer chains in contrast to PAM N, whilst the lower yield stresses, reflecting inter-particle bridging and floc network structure strength that are conducive to faster clarification, were displayed by kaolinite pulps. Following shear, similar consolidation enhancement of ≈ 5-7 wt.% solid for both pulps was achieved at an optimum agitation range of 100-200 rpm. This was accompanied by decreased yield stress in the case of PAM A-based pulps, indicating non-reversible disruption of polymer mediated particle and floc network structure. In contrast, the yield stresses of PAM N and PEO flocculated dispersions indicated similar and stronger particle interactions, respectively, upon consolidation following shear. The findings show clear links between effect of shear, interfacial chemistry and polymer structure on pulp particle interactions and dewaterability.     

The flocculation and rheological characteristics of hydrolyzed and unhydrolyzed grafted sodium alginate in aqueous solutions

Sodium alginate is a natural anionic polysaccharide obtained from natural and microbial resources. It is also used as a flocculating agent and thickener. It is grafted with polyacrylamide, in the presence of ceric ammonium nitrate (CAN) as an initiator. The graft copolymer (SAG‐g‐PAM) is again hydrolyzed with some amount of alkali. The flocculation characteristics of hydrolyzed graft copolymer (Hyd SAG‐g‐PAM) are compared with that of the unhydrolyzed ones, in 5 wt % kaolin and 10 wt % iron ore suspensions. The flocculation characteristics of the hydrolyzed graft copolymer are also compared with those of some of the commercial flocculants. The SAG‐g‐PAM and Hyd SAG‐g‐PAM are characterized by IR and intrinsic viscosity measurements. The rheological properties of aqueous solutions of hydrolyzed and unhydrolyzed graft copolymers are measured by Advanced AR‐1000 Rheometer. There is drastic enhancement in flocculation and viscosifying characteristics on hydrolysis of the graft copolymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1480–1488, 2004     

An investigation of the flocculation characteristics of polyacrylamide‐grafted chitosan

To investigate the flocculation characteristics of polyacrylamide (PAM)‐grafted chitosan, a series of PAM‐grafted chitosan copolymer (Chito‐g‐PAM1 to Chito‐g‐PAM4) have been synthesized by ceric ammonium nitrate‐induced solution polymerization technique in nitrogen atmosphere. The flocculation characteristics of the polymer samples (PAM, grafted and ungrafted chitosan) were studied by settling test and jar test methods in the colloidal suspensions of kaolin, iron ore, silica, and bentonite powder. It was found that the settling performance of Chito‐g‐PAM3 is best among the polymer samples. The jar test results indicate that the ungrafted chitosan has better water clarifying performance than both the PAM and grafted chitosan. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Particle separation performance by use of electrical hydro-cyclone

A special electrical hydro-cyclone is developed and tested. In the underflow collection box of the hydro-cyclone, it has a central metal rod electrode and a cylindrical metal wall between which the desired DC electrical potential or no potential is applied. Effect of central rod diameter and length on separation cut size was examined. The aqueous suspensions of silica particles with a median diameter of 754 nm were tested using a 20 mm-diameter hydro-cyclone without underflow.

It was found that the zeta potential of particles increased proportionally with the value of pH. The electrical potential exhibits a stronger effect when the suspension indicates high pH value. The cut size decreases with the increase of initial pH values. This result is due to the increased negative zeta potential under high pH condition and negatively charged particles are easily collected by electrostatic force.

The cut size decreases with the increase of electrode diameter. The cut size becomes smallest under high pH, large electrode diameter and long electrode length conditions. For the negatively charged particles, the center electrode should be negative polarity and outer cylindrical wall should be positive. By use of the electrostatic force, the cut size decreases about 9.2% smaller compared to the standard case without electrostatic force.