紫外光敏引发合成的P(AM-DAC)污泥脱水絮凝应用研究

采用紫外光敏引发聚合方式合成的较高相对分子质量和阳离子度的阳离子聚丙烯酰胺[P(AM-DAC)]产品作絮凝剂,进行污水处理实验。与紫外光敏引发合成的非离子型PAM和市售阳离子型聚丙烯酰胺对污泥水的絮凝效果进行了比较,探讨了絮凝剂相对分子质量、阳离子度、用量以及种类对污泥水絮凝效果的影响,最终确立了1.1×107相对分子质量、30%阳离子度、4 mg/L絮凝剂、搅拌次数15次为最佳实验条件。     

两性絮凝剂P(AM-co-IA-co-DAC-co-DMC)的合成及絮凝性能

两性聚丙烯酰胺处理污水用量少,毒性低,pH适用范围广,绿色环保。采用水分散聚合方法合成了两性聚丙烯酰胺P(AM-co-IA-co-DAC-co-DMC),以1%的高岭土悬浮液模拟废水,考察絮凝剂用量、特性粘数、体系pH值、温度以及阴阳离子单体配比对絮凝效果的影响。结果表明,当阳、阴离子单体摩尔比为3∶1,特性粘数为3.16 dL/g,用量为3 mg/L时,絮凝效果好,常温下透过率达到98.7%。两性聚丙烯酰胺分子链上的正、负两种电荷基团同时发挥电中和作用和架桥作用,絮凝效果受pH变化的影响较小,明显优于阳、阴离子型聚丙烯酰胺。     

丙烯酰胺-阳离子瓜尔胶接枝共聚物的絮凝性能研究

研究了低温合成的高相对分子质量的天然高分子改性絮凝剂--丙烯酰胺-阳离子瓜尔胶接枝共聚物(CGG-g-PAM)对高浊度烟草废水的絮凝效果,以及PAC投加量、CGG-g-PAM投加量、pH和不同相对分子质量CGG-g-PAM等对浊度(》4 500 NTU)、COD和色度去除率的影响.结果表明,在pH 5,PAC投加质量浓度为120 mg/L,CGG-g-PAM投加质量浓度为3.6 ms/L时,去浊率达98%,COD去除率达24%,色度去除率达20%,且絮凝性能优于阳离子瓜尔胶(CGG)和阳离子聚丙烯酰胺(CPAM).实验研究表明,产品具有良好的絮凝效果,在工业废水处理中具有一定的应用前景.     

壳聚糖-聚阴离子复合絮凝剂的应用

壳聚糖与天然阴离子絮凝剂卡拉胶等进行复配用于红花水提液的絮凝试验,红外光谱分析表明壳聚糖分子上的NH3^＋与卡拉胶分子上的SO3^-通过静电相互作用而联结形成壳聚糖-卡拉胶聚电解质复合物.通过对红花水提液的絮凝试验,研究了不同聚阳离子-聚阴离子间进行复配以及复配方式、复配配比等条件对絮凝效果的影响,结果表明复配的絮凝剂其絮凝效果得到显著提高.     

疏水改性阳离子聚丙烯酰胺絮凝剂的制备及絮凝性能测试

以获得疏水作用力为目标,使用丙烯酸丁酯(BA)对阳离子聚丙烯酰胺(PAM)进行改性,采用自由基胶束聚合法合成P(AM-DAC-BA)三元共聚物,以红外光谱进行结构表征,并考查了制备工艺条件对絮凝性能的影响.结果显示:疏水改性阳离子絮凝剂对高浊度污水具有更好的絮凝效果,疏水单体含量、阳离子含量均对絮凝效果影响较大;疏水单体配比为3 mol％,阳离子单体配比为20～25 mol％,絮凝剂用量为10.0 mg/L;污水pH值为8时,对30 wt％高岭土浊水的絮凝沉降率可达96.5％.     

聚硅酸铝铁絮凝剂处理云南滇池污染水的应用研究

以黄磷炉渣为硅源,采用硝酸浸出黄磷炉渣,通过复合接枝Al3+、Fe3+金属阳离子制备了聚硅酸铝铁絮凝剂,该絮凝剂是一种兼有聚硅酸、聚铝和聚铁絮凝剂综合性能的新型无机高分子吸附剂。对影响其絮凝效果的絮凝剂投入量、滇池污染水pH、沉降温度、沉降时间进行研究,找出了对云南滇池水具有最佳混凝效果的絮凝条件。结果表明,絮凝剂投入量6mg/L、滇池污染水pH为5、沉降温度室温(22℃左右)、沉降时间50min时,对滇池水絮凝效果较好,浊度和COD去除率分别达98.52%和87.05%。     

紫外激发丙酮-乙二醇引发制备离子型聚丙烯酰胺及其絮凝性能

以丙酮-乙二醇(acetone-EG)作为新型引发剂,紫外激发引发单体共聚制备高分子量离子型聚丙烯酰胺,并研究聚合物对原生煤泥水的絮凝效果。将2-丙烯酰胺基-2-甲基丙磺酸(AMPS)阴离子功能单体和二甲基二烯丙基氯化铵(DDAC)阳离子功能单体分别或同时与丙烯酰胺(AM)共聚合成阴离子型聚丙烯酰胺(HPAM)、阳离子型聚丙烯酰胺(CPAM)以及两性型聚丙烯酰胺(APAM)。以离子型聚丙烯酰胺的特性黏数[η]作为指标,获取了该引发体系下每种类型聚丙烯酰胺的最优合成工艺参数,所制备的各类离子型聚丙烯酰胺的特性黏数可分别达到:[η]_(HPAM)=1760m L/g;[η]_(CPAM)=980m L/g;[η]_(APAM)=1120m L/g。用所制备的聚合物对煤泥水进行絮凝,结果表明HPAM用量3~4mg/L时,煤泥水浊度最低降到0.9FTU,絮凝沉降最大速度为61.6cm/min,APAM和CPAM用量4~5mg/L时有较好的絮凝效果,CPAM使煤泥水浊度最低降到1.3FTU,絮凝沉降最大为51.8cm/min,APAM使煤泥水浊度最低降到0.9FTU,絮凝沉降速度最大为58.2cm/min。     

AM/AMPS/DMC聚两性电解质的合成、表征与溶液性能

以丙烯酰胺(AM)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,在0.5 mol/L NaC l溶液中,以2,2-偶氮二[2-(2-咪唑啉-2-代)丙烷]二氢氯化物(VA-044)为引发剂,合成了AM/AMPS/DMC系列聚两性电解质。利用13C NMR对共聚产物结构进行表征,结果表明,在高转化率情况下,共聚物组分与投料比基本一致。考察外加小分子电解质和温度对聚两性电解质溶液性能的影响,结果显示,阴、阳离子数量相近的聚两性电解质溶液的粘度随外加盐浓度增大而增大,在温度升高时,其表观粘度保留率高于聚丙烯酰胺,说明AM/AMPS/DMC系列聚两性电解质具有一定的抗温、耐盐能力。     

阳离子复合混凝剂的制备和应用研究

利用丙烯酰胺、环氧氯丙烷、三乙胺合成了阳离子度为30%的阳离子PAM,再与AS进行复配,制备了一种新型高效的复合絮凝剂PAM-AS.通过对糖纸厂废水的处理实验,探讨了絮凝剂用量对絮凝效果、COD去除效果和透光率的影响.实验表明PAM-AS投药量少,絮凝沉降速度快,COD去除率高,絮凝效果优于聚丙烯酰胺(PAM)和硫酸铝(AS).     

可碱水降解的阳离子聚电解质的合成

以三氧化硫脲(甲脒磺酸)、乙二胺和乙二酸为原料合成了胍羧缩聚阳离子聚电解质。该阳离子聚电解质在酸中稳定,在pH>10水溶液中快速降解;对水体中的微小颗粒和相对分子质量较大的阴离子具有优异的絮凝作用。在酸性介质中收集的絮体可以加碱使其中的阳离子聚电解质破坏,使絮凝回收的有用材料免遭絮凝剂污染而被重新利用。     

Synthesis and viscometric properties of low charge density ampholytic ionomers

The addition of ionic groups onto the molecular structure of a macromolecule produces marked changes in its physical properties. A large volume of literature exists pertaining to the solution and solid phase properties of these charged species spanning a broad range of charge densities. Until recently, however, little work has been published on ionomers containing opposite chargess (i.e., polyampholytes) except with regard to highly charged species. In this study, we focus on the synthesis and solution properties in fresh and high ionic strength solutions of low charge density acrylamide-based polyampholytes not necessarily possessing an equimolar ratio of anionic and cationic units. The results show that the separation of these oppositely-charged monomer units via neutral acrylamide moieties establishes a control over physical properties not readily attainable in the highly-charged polyampholytes (generally insoluble in fresh water) or conventional polyelectrolytes.At low charge densities, typically < 10 mole per cent, the solution properties of these polyampholytes are controlled primarily through intermolecular interactions. That is, gel-like properties are observed above the chain overlap concentration in fresh water due to the anionic-cationic interactions. As a result the viscosity decreases as the ionic strength of the solution is increased. Interestingly, at moderate charge densities, generally 10 mole per cent or higher, intramolecular interactions dominate behaviour in fresh water. As a result, the dilute solution viscosity in fresh water is relatively low, but is markedly enhanced as the ionic strength of the solution is increased. That is, gel-like properties are approached as the chains expand and begin to overlap. Moreover, these results are influenced by the nature of the chain backbone, molecular weight, the chemistry of the dissolved salt, and the level of mobile charge situated on the chain backbone.     

合成型两性水凝胶研究进展

两性水凝胶因其良好的环境响应特性,而成为吸水保水材料领域的研究热点。以阴离子单体与阳离子单体共聚制备两性聚电解质水凝胶和内盐型两性离子单体聚合制备聚甜菜碱型水凝胶为重点,介绍了两性水凝胶的制备、溶胀特性以及性能改进等方面的国内外研究现状及发展趋势。     

Surface modification with acrylic polyampholytes 1, adsorption of acrylic polyampholytes on fiberglass reinforced plastics,and characterization of the polymer adsorbed surfaces

The adsorption of acrylic polyampholytes on fiberglass reinforced plastics (FRP) was investigated using random copolymers derived from (dimethylamino)ethyl methacrylate (DM), methacrylic acid, and t‐butyl methacrylate (t‐BMA). The effect of the copolymer structure changes on the adsorption and the interactions between the copolymers and the surface were assessed using ζ‐potential and contact angle measurements, NMR, and ESCA. The copolymer having the composition of 58 mol % pDM, 38 mol % pMMA, and 4 mol % pt‐BMA was adsorbed on the FRP surface at pH 7, and it formed the highest hydrophilic surface among the tested copolymers. An analysis by use of atomic force microscope revealed that the copolymer afforded a uniform 4–6 nm thick coverage on the FRP. We concluded that the interactions between the copolymer's cationic sites and the anionic FRP surface are important as well as the hydrophobic interaction for adsorption. Furthermore, it is suggested that the hydrophilicity of the copolymer's adsorbed surfaces is related to the density of the copolymer's anionic sites. These results indicate that the ampholytic structure of the polymers would be essential for the surface modification on the FRP. The effect of functional groups of surfaces on the acrylate adsorption was also assessed using surface plasmon resonance. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4454–4461, 2006     

Dye flocculation using polyampholytes and polyelectrolyte‐surfactant nanoparticles

In this article, we report on the dye flocculation performance of polyampholytes containing hydrophobically modified cationic, hydrophilic nonionic, and anionic monomer units, always with an excess of cationic charges. The results are compared with homopolymers and with those obtained using nonstoichiometric polyelectrolyte–surfactant complex (PSC) dispersions with adjustable surface charge density. The polyampholytes as well as the PSC can successfully remove the dye Celliton Fast Blue (Dispers blue 3). The efficiency of dye separation is mainly influenced by the charge of polymers or complexes, demonstrating that charge neutralization is one flocculation mechanism. However, PSC, which are almost neutral, are also able to remove the dye due to their size and structure. In this case, the degree of dye removal is a little bit better and the so‐called flocculation window is broader as in the case of charge neutralization. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1342–1349, 2007     

油田污水处理絮凝剂的研究及发展

概述了油田污水处理过程中所用絮凝剂的分类,对国内外各类絮凝剂：无机高分子絮凝剂（阴离子、阳离子和无机复合絮凝剂）,有机絮凝剂（合成高分子絮凝剂,改性天然高分子絮凝剂和微生物絮凝剂）和复合絮凝剂的研制与开发动态以及取得的较为重要进展进行了综述,对油田污水处理絮凝剂的发展趋势和研究方向做了展望。     

Bitumen–solids attachment induced by cation activation

Interactions between negatively charged bitumen and fine solids under oil sands extraction conditions were simulated using mature fine tailings (MFT) and hydrocarbon oil with dissolved carboxylic acids. Their attachment induced by cation activation was evaluated with different types of cations by simple dynamic attachment tests. The results revealed that solid hydrophobization by adsorbing surfactants was key for oil–solid attachment. Activation by multivalent metal cations was due to surface precipitation of metal hydroxides, followed by chemisorbing anionic surfactants on metal-activated solids to form metal carboxylate complexes/precipitates, thereby hydrophobizing the solids. Activation by cationic surfactants depended on their hydrocarbon chain lengths. For short hydrocarbon chains, where hydrophobic interaction is weaker than electrostatic interaction between the added cationic and anionic surfactants, the added cations promote the adsorption of anionic surfactants by electrostatic interaction to render the solids hydrophobic. For long hydrocarbon chains where hydrophobic interaction is stronger than electrostatic interaction between the added cationic and anionic surfactants, the adsorption of anionic surfactants occurs through the hydrophobic association of the hydrocarbon chains, posing the head group towards water, thereby making the solids less hydrophobic. Activation by cationic flocculants was purely physical (hydrogen bonding and electrostatic): when the solids were turned positive by the added cationic flocculants, the added anionic surfactants then adsorbed onto the solids to render them hydrophobic. It appeared that soluble multivalent metal species (e.g., Ca²⁺ and Mg²⁺) were much less harmful to bitumen extraction than those heavy metals coated on the solids, either in the form of surface precipitates or hydrolyzed ionic species.     

Microelectrophoresis and electron-microscope studies with polymeric flocculants

Mechanisms for the stabilization and flocculation of colloids have been indicated by microelectrophoresis measurements and electron-microscope observations with model colloids and polymeric flocculants. Zeta-potential (ζ) changes and details of floc structure were observed with silica and polystyrene latex colloids. Bridging fibers of polyamine-type flocculants appear to extend radially from the colloidal particles and vary in thickness from 20 to 300 Å. Charge neutralization and bridging may function simultaneously. Incremental additions of cationic flocculants produce gradual reduction in the negative ζ, and maximum flocculation is observed near zero ζ. Subsequent addition of flocculant reverses the potential and finally effects redispersion of the colloid. If incipient charge reversal is produced with a relatively low molecular weight cationic polymer, large flocs may then be formed on the addition of a high molecular weight anionic flocculant. Direct addition of an anionic polymeric flocculant to a negatively charged colloid may raise the negative ζ to a surprisingly high value and may thus effect stabilization instead of flocculation of the colloid.     

The role of surfactants in intensifying and increasing the efficiency of the electroflotation extraction of sparingly soluble lanthanum compounds

Kinetic trends of electroflotation extraction of sparingly soluble lanthanum compounds from solutions containing NaCl, NaNO³, Na²SO⁴, and Na²CO³ were established and studied. The role of surfactants of anionic, cationic and nonionogenic natures, as well as flocculants (first, of anionic and cationic type) that depend on background electrolyte composition (sulfate, chloride, carbonate, nitrate) is determined as positive. The electroflotation extraction of lanthanum hydroxide is shown to proceed with an degree of extraction of up to 96%.     

Interaction mechanism of flocculants with coal waste slurry

Coal tailings are the inevitable by-product of coal mining and preparation plants, and often are problematic in terms of dewatering and solid-liquid separation. The interaction of multi-component fine coal tailings with various coagulants and flocculants are important in dewatering processes. Tunçbilek coal preparation plant wastes are composed of 81% inorganic solids with negative surface charges dominating at all pHs. The highest settling rate and turbidity values without flocculant are obtained at natural pH of 8.3 due to the presence of inorganic ions in the suspension particularly Mg²⁺and Ca²⁺that act as natural coagulants. Additon of medium and low charge density anionic flocculants with high molecular weight at natural pH produced higher settling rates at lower dosages than nonionic and cationic flocculants. It shown that the charge density of anionic flocculants has a significant effect on both settling rate and supernatant turbidity, also the settling rate increases with increasing the degree of anionicity. Anionic flocculants having high molecular weight and high anione charge density produced flocs at sufficient size necessary for settling conditions, yet anionic flocculants having low charge density were more effective in the clarification of suspensions containing clay minerals of high stability. The multivalent ions act as a bridge between negatively charged coal, quartz and clay minerals with anionic groups (-CH₂-(CH-CO)-COO groups) of the polymer. Non-ionic flocculants required higher dosages than other flocculants to achieve equivalent settling rates; though excellent turbidity values were obtained in most common pH values. Cationic flocculants of higher charge densities (%70) achieved good settling rates and low supernatant turbidities (9.9 NTU) at natural pH for a dosage of 119.7 g/t-solids flocculant. An interaction mechanism of each polymer type with different components of the tailings is proposed.     

水质变化对煤泥水絮凝沉降的影响

以高浓度难沉降煤泥水为研究对象,进行了水的pH、硬度对不同类型絮凝剂沉降澄清效果的影响研究。结果表明：非离子型聚丙烯酰胺在煤泥水pH为9,阳离子型聚丙烯酰胺和阴离子型聚丙烯酰胺在pH为5左右时絮凝沉降效果较好;非离子型聚丙烯酰胺、阳离子型聚丙烯酰胺、阴离子型聚丙烯酰胺在水质硬度分别为17.8,53.4,71.2 mmol/L时絮凝沉降效果较好。