Flocculation properties and adsorption kinetics of cationic starches in kaolin suspensions

The flocculation characteristics of cationic starches with degree of substitution (DS 0.32–0.63) have been evaluated in 1.0 wt % kaolin suspension by spectrophotometry and colloid titration. Cationic starch is found to be an effective flocculant for removal of anionic suspension particles. Changes in the electrokinetics of kaolin as a function of pH were investigated in the absence of flocculant. The results show that kaolin in water exhibits a negative surface charge at pH > 2.5. The negative hydrophilic surface sites of kaolin are responsible for the adsorption of cationic starch molecules. The experimental data of the adsorption of cationic starch (DS 0.51) follow a Langmuir isotherm with maximum adsorption capacities of 16.89 mg/g. For the adsorption of cationic starch, chemical reaction seems significant in the rate‐controlling step and the pseudosecond‐order chemical reaction kinetics provides the best correlation for the experimental data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Flocculation behavior of cationic pea starch prepared by the graft copolymerization of acrylamide for wastewater treatment

To improve the flocculation efficiency of coal mine wastewater treatment, we synthesized a cationic flocculant by grafting acrylamide (AM) onto pea starch, and we performed the characterization with elemental analysis, Fourier transform infrared spectrometry, scanning electron microscopy, thermogravimetric analysis, and NMR. The effects of the synthesis conditions were also investigated, and the optimal synthesis parameters of the cationic flocculant were obtained. The mass ratio between pea starch and AM was 0.5 with a reaction temperature of 65 °C. The dosages of ceric ammonium nitrate and 3‐chloro‐2‐hydroxypropyl‐trimethylammonium chloride were 0.02 and 0.11 mol/L, respectively. Application experiments for wastewater treatment were carried out consequently, and the optimal dosage of cationic pea starch was 40 mg/L within the pH range 6–8. Compared with other traditional flocculation products, the cationic pea starch showed the best flocculation behavior for coal mine wastewater. Therefore, the cationic pea‐starch‐grafted AM may be applicable as a novel flocculant in wastewater treatment and has already demonstrated outstanding features. It is bound to replace other traditional flocculants in the future. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43922.     

新型阳离子改性淀粉絮凝剂的结构及其应用性能的研究

采用天然淀粉为原料,合成一种具有高絮凝性能的新型阳离子改性淀粉絮凝剂。实验测定了这种新型絮凝剂的粘度和带电性,并通过红外光谱和扫描电镜确定了产品的组成及结构。测定结果表明：有效含量为10%的阳离子改性淀粉絮凝剂溶液,粘度为9.897 MPa.s,带电56.7 mV。用制得的絮凝剂、PAC和PFS处理用硅藻土配制的原水,絮凝实验结果表明：与PAC和PFS相比,这种新型阳离子改性淀粉絮凝剂具有优良的絮凝性能。     

季铵型阳离子淀粉絮凝剂的微波干法合成、结构表征及应用研究

以3-氯-2-羟丙基三甲基氯化铵为阳离子醚化剂,天然淀粉为原料,微波干法合成具有絮凝、杀菌等功能季铵型阳离子淀粉絮凝剂。研究了各种因素对合成的影响,确定了最佳反应条件。结果表明：在阳离子醚化剂与淀粉摩尔比0．35,NaOn与阳离子醚化剂摩尔比1．2,微波功率184W,辐射时间5min时,产物相对粘度为3．18（0．5％）左右,阳离子取代度为0．31。所得产品与无机絮凝剂PAC复配后具有较好的絮凝及杀菌效果。     

阳离子型改性淀粉对稠油废水絮凝性能考察

合成了三种具有不同阳离子度的阳离子型改性淀粉接枝共聚物絮凝剂ZHYC-n,考察了这三种絮凝剂与PAC复配对稠油废水的絮凝性能,并与市售阳离子型聚丙烯酰胺絮凝剂CPAM进行了对比.絮凝实验结果表明,ZHYC-n与PAC复配具有优良的絮凝脱油脱硫效果,随阳离子度增加絮凝效果显著增加.阳离子型絮凝剂分子链上的阳离子电荷密度不是影响絮凝效果的惟一主要因素,阳离子型改性淀粉接枝共聚物具有的多支链型结构可以明显的提高絮凝剂的絮凝效果.     

高取代度阳离子淀粉处理造纸白水的研究

采用实验室研制的高取代度阳离子淀粉作为絮凝剂对造纸白水进行处理,通过实验探讨了高取代度阳离子淀粉的加入量、废水的pH值及絮凝时间对絮凝效果的影响,确定了高取代度阳离子淀粉处理造纸白水的最佳条件为:阳离子淀粉的投加量为200mg/L,不调pH值,絮凝时间为24h。     

Flocculation of gelatinized starch: Flocculation performance and floc characterization

The removal of single macromolecules impurity is the basis study for the promotion of flocculation technology application in the Chinese herbal medicine solution purification. We applied the flocculation process to remove gelatinized starch in solution. Three types of cationic polyacrylamide (CPAM) with different charge density were used for flocculation of gelatinized starch solution. The flocculation performance was evaluated in terms of the amylose removal ratio (AMRR), the amylopectin removal ratio (APRR), total starch removal ratio (TSRR) and supernatant turbidity (ST). The flocs were characterized by sedimentation performance, Fourier transform infrared (FTIR), scanning electron microscope (SEM) and X-ray photoelectric spectroscopy (XPS) method. The experimental results show that the flocculant CN15 has the best performance for gelatinized starch flocculation among three flocculants. According to the characterization analysis, the flocs exhibited an obvious network structure, and it is concluded that hydrogen bonding between N-H in CPAM and C-O in the starch and bridging flocculation played the essential roles in flocculation of the gelatinized starch.     

微波干法制备阳离子淀粉絮凝剂及其应用

以3—氯—2—羟丙基三甲基氯化铵为阳离子醚化剂，天然物质淀粉为原料，微波干法制得季铵型阳离子淀粉絮凝剂。通过正交试验，研究了各种因素对合成的影响，确定了最佳反应条件。结果表明：阳离子醚化剂与淀粉摩尔比0．35、NaOH与阳离子醚化剂摩尔比1．2、微波功率184W、辐射时间5min时，产物相对黏度为3．18，阳离子取代度为0．31。     

Synthesis,characterization, and flocculation properties of poly(acrylamide‐methacryloxyethyltrimethyl ammonium chloride‐methacryloxypropyltrimethoxy silane)

A novel hydrophobically modified and cationic flocculant poly(acrylamide‐methacryloxyethyltrimethyl ammonium chloride‐methacryloxypropyltrimethoxy silane) (P(AM‐DMC‐MAPMS)) was synthesized by inverse emulsion polymerization. The molecular structure of hydrophobically cationic polyacrylamide (HCPAM) was characterized by FTIR and ¹H‐NMR. The effects of DMC and MAPMS feed ratio on intrinsic viscosity and solubility were measured. The effects of hydrophobically cationic flocculants on reactive brilliant red X‐3B solution and kaolin suspension were studied. It was found that the introduction of MAPMS could increase the intrinsic viscosities of P(AM‐DMC‐MAPMS) and enhance the flocculation properties to anionic dye solution and kaolin suspension, but reduced their water‐solubility. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

P(DMC-AM)对活性染料废水絮凝脱色效果研究

采用混凝烧杯实验,以脱色率为考察指标,研究了系列化阳离子絮凝剂P(DMC-AM)对活性染料废水的絮凝脱色效果和机理。结果表明:P(DMC-AM)阳离子度越大、特征黏度越高、活性染料分子中所含磺酸基数越多,絮凝脱色效果越好,并具有一定耐酸耐盐性。P(DMC-AM)絮凝脱色机理主要为电中和和吸附架桥。实验证明,P(DMC-AM)对活性染料废水具有良好处理效果。     

Cassava starch‐graft‐polymethacrylamide copolymers as flocculants and textile sizing agents

Cassava starch‐graft‐polymethacrylamide (PMAM) copolymers were synthesized by a free‐radical‐initiated polymerization reaction, and the products were tested for their efficiency as flocculants and textile sizing agents. The highest percentages of grafting and monomer conversion were 79.9 and 78.0%, respectively. The grafted starches were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction analysis, scanning electron microscopy, differential scanning calorimetry, and thermogravimetric analysis. The average molecular weight of PMAM chains in the grafted starches ranged from 15.9 to 30.8 × 10⁵ g/mol. The grafted starches exhibited a higher peak viscosity and paste stability in comparison to the native starch (NS). Dynamic mechanical analysis showed that grafting provided fairly shear‐stable hydrogels, and the highest storage modulus obtained was 17,900 Pa compared to 1879 Pa for NS. The flocculation studies demonstrated the superiority of starch‐g‐PMAM over cassava starch and PMAM as an efficient flocculant. The tensile strength of cotton yarns sized with the starch‐grafted copolymer was significantly higher (104 MPa) compared to that sized with NS (34 MPa). © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39810.     

高相对分子质量阳离子型聚丙烯酰胺合成工艺的研究

以丙烯酰胺(AM)和二甲基二烯丙基氯化铵(DMDAAC)为单体,采用溶液聚合法制备DMDAAC-AM共聚物。用正交实验法考察了引发剂用量、温度、单体配比、pH等因素对共聚物阳离子度、特性黏度,以及相对分子质量的影响。结果表明,温度为70℃,pH=8,引发剂量为4 mL,DMDAAC∶AM(质量比)=1∶1时,得到的阳离子型聚丙烯酰胺(CPAM)的相对分子质量最大。用所制得的CPAM对高岭土模拟悬浊水样进行的絮凝实验,发现相对分子量为1.73×106的CPAM的絮凝效果最好,浓度为0.05%的CPAM溶液仅用0.4 mL便可使浊度为22.4的皂土悬浮液的浊度去除率达到85.8%。     

Synthesis,characterization and application of novel polyacrylamide‐grafted barley

Polyacrylamide‐grafted barley (BAR‐g‐PAM) was synthesized by ceric ion‐based conventional method. The grafting of polyacrylamide chains on the polysaccharide backbone was confirmed through various physicochemical techniques such as intrinsic viscosity measurement, ¹³C‐NMR spectra, FTIR spectroscopy, elemental analysis, scanning electron microscopy morphology, thermogravimetric analysis study, number‐average molecular weight, and aqueous solubility. Furthermore, flocculation efficacy of the graft copolymers was studied in coal fine suspension through “jar test” procedure, toward its possible application as a novel flocculant for treatment of coal washery effluent. BAR‐g‐PAM is reported as a novel flocculant that can be used for bulk treatment of coal washery effluents. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41046.     

Synthesis and characterization of grafted carboxymethyl guar gum

Graft copolymers of carboxymethyl guar gum (CMGG) and polyacrylamide (PAM) have been synthesized by grafting polyacrylamide chains onto carboxymethyl guar gum backbone using a ceric‐ion‐induced solution polymerization technique. By varying the amount of initiator, three different grades of graft copolymers are synthesized. The characterization of graft copolymer is carried out by FTIR, NMR, intrinsic viscosity measurement, SEM, SLS, DTG, and rheology. A comparison of flocculation efficiency of CMGG and its graft copolymer shows that the graft copolymer exhibits better flocculation performance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Intrinsic viscosity, surface activity, and flocculation of cationic polyacrylamide modified with fluorinated acrylate

A novel cationic polyacrylamide modified with fluorinated acrylate had been synthesized of acrylamide (AM), methacryloxyethyl trimethylammonium chloride (DMC), and 2-(perfluorooctyl)ethyl acrylate (FEA) by free radical micellar copolymerization in aqueous solution utilizing cetyl trimethylammonium bromide (CTAB) as the surfactant and potassium persulfate (KPS)/sodium bisulfite (SBS) as the redox initiator. Some factors affecting synthesis, such as the amount of FEA, CTAB, and KPS, were described. Surface activity and flocculation of the polymer were studied. The results showed that with the incorporation of FEA, the intrinsic viscosity decreased until the modified polymer was not able to dissolve in water; and with the increase of CTAB and KPS, the intrinsic viscosity decreased firstly then increased slowly. The polymer exhibited good surface activity in both water and salt solution. Its flocculation properties were evaluated with kaolin suspensions using a standard jar test. The results demonstrated the superiority of the copolymer over the no-modified cationic polyacrylamide as a flocculant.     

Flocculation and sedimentation of cane sugar juice particles with cationic homo‐ and copolymers

Rapid flocculation and sedimentation of suspended particles in primary cane sugar juice is achieved using a high molecular weight anionic polymer flocculant. This work reports on efforts to enhance the performance of an anionic flocculant by the addition of cationic polymers. Homopolymers of poly(trimethylammonium ethyl methacrylate chloride) (TMAEMAC) and cationic copolymers of poly(trimethylammonium ethyl acrylate chloride) (TMAEAC) and acrylamide were synthesized and their performance, to enhance the flocculation and sedimentation of cane sugar juice particles, was evaluated by turbidity and settling rate measurements. The charge–patch mechanism best explains the performance of the homopolymers, whereas the action of the copolymers is attributed to the bridging mechanism. The results of this work indicate that the copolymers are more effective than the homopolymers to aid flocculation and sedimentation of the cane sugar juice particles, and that the best‐performing polymers are those that act by the bridging mechanism. Addition of increased amounts of anionic flocculant did not confer an improvement, suggesting that the cationic bridging flocculant targets a different population of particles that is largely responsible for the residual turbidity. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 316–325, 2003     

可生物降解的阳离子淀粉絮凝剂

综述了淀粉大分子上悬挂不同类型胺基如伯，仲，叔以及季铵基基团的阳离子淀粉絮凝剂的制备方法和性能评价。并探讨了各种影响因素如化学结构，絮凝剂剂量，pH值，相对分子质量，胺基基团类型以及氮含量等对絮凝效果的影响。结果表明，在淀粉大分子上悬挂季铵基团的阳离子淀粉絮凝剂效果最好。     

元宝枫水提取液的絮凝研究

研究了阳离子淀粉絮凝剂对元宝枫水提取液的絮凝作用;比较了不同工艺对产品的影响。结果表明:采用阳离子淀粉絮凝剂,澄清时间由醇沉法的48 h缩短为6 h;在阳离子淀粉质量浓度为150 mg/L、絮凝温度为60℃、提取液pH为6.0时,澄清液透光率、总黄酮质量分数分别达90.6%、23.2%。     

Synthesis and application of salt tolerance amphoteric hydrophobic associative flocculants

A series of amphoteric hydrophobic-associative flocculants with outstanding flocculation efficiency and salt tolerance, poly(acrylamide/acrylic acid/dimethyl benzyl aminoethyl acrylate chloride), are successfully prepared (named AAB series) and used to flocculate the montmorillonite suspensions. The solution properties of AAB copolymer are systematically evaluated by viscometer, rheology and steady-state fluorescence analysis. The results suggest that the space network structure forming via hydrophobic-associating interaction can increase solution viscosity and improve the bridging capacity of copolymers. Meanwhile, the apparent viscosity in salt solution increases with increase in the concentration of salt stemming from the anti-polyelectrolyte effect of polyampholyte. Further, the flocculation performances of flocculants in 1 wt% montmorillonite suspensions are evaluated by turbidity, optimal dosage and settlement rate measurement. The results elaborate that the flocculation performances of amphoteric hydrophobic-associating AAB flocculants are better than that of commercial flocculants (cationic and anionic polyacrylamide) and homemade cationic flocculant (AAB-0-5) independent of the type and concentration of salt. The novel ampholyteric hydrophobic-associative flocculants will exhibit intriguing prospective in industry water treatment, in that the anti-polyelectrolyte effect of polyampholyte and hydrophobic-associating interaction can endow excellent flocculation efficiency and salt tolerance.     

天然高分子改性阳离子型絮凝剂的开发与应用

天然高分子改性絮凝剂具有无毒,可生物降解,价廉等优点,近年来得到了国内外学者的广泛重视和开发应用。作者对用于废水处理的改性阳离子淀粉衍生物,本质素省生物,甲壳素衍生物以及兼具有絮凝作用的植物胶改性多功能水处理剂的研究进展进行了简要的评述。