壳聚糖季铵盐用于银杏叶水提液絮凝工艺研究

[目的]研究壳聚糖季铵盐用于银杏叶水提液除杂纯化的效果。[方法]采用壳聚糖改性产物壳聚糖季铵盐对银杏叶水提液进行絮凝处理,以芦丁保留率和药物浊度作为指标,考察了絮凝剂用量、絮凝温度、静置时间对絮凝效果的影响,并通过正交试验确定出最佳工艺条件。[结果]壳聚糖季铵盐对银杏叶水提液絮凝的最佳工艺条件:水提液p H=4.9,水提液温度40℃,壳聚糖季铵盐用量0.4g/L,静置时间3h。[结论]壳聚糖季铵盐絮凝法澄清效果好,经济实用,可用于银杏叶水提液的絮凝纯化。     

微生物絮凝剂B-16在给水处理中的应用研究

采用微生物絮凝剂B-16对低浊度黄河水进行了絮凝净化实验研究.并与聚二甲基二烯丙基氯化胺、聚丙烯酰胺、壳聚糖等絮凝剂的处理效果进行了对比研究.结果表明,B-16具有用量少(常规絮凝剂用量的20%～30%)、适应性广、处理效果好等优点;B-16与聚硅酸氯化铝(PASC)复配使用,浊度去除率最高可以提高28%,高锰酸盐指数去除率最高可以提高19%.动物急毒性试验表明该絮凝剂无急毒性反应.     

城市生活污水剩余污泥深度脱水研究

通过污泥沉降比和泥饼含水率及脱水率的测定,分析絮凝剂和助凝剂对城市生活污水剩余污泥深度脱水性能的影响。对三氯化铝、阳离子聚丙烯酰胺、壳聚糖以及壳聚糖-阳离子聚丙烯酰胺复合絮凝剂的絮凝效果进行比较。结果表明,30 mg/L壳聚糖-阳离子聚丙烯酰胺复合絮凝剂的污泥絮凝效果最好。同时,在壳聚糖-阳离子聚丙烯酰胺条件下,对石灰、粉煤灰、十二烷基苯磺酸钠和硅藻土的脱水效果进行比较研究,结果表明,30 mg/L壳聚糖-阳离子聚丙烯酰胺复合絮凝剂,15%石灰、10%粉煤灰、pH为3,污泥含水率降低至51.36%。     

壳聚糖对银杏叶水提液的絮凝工艺研究

采用天然高分子絮凝剂壳聚糖对银杏叶水提液进行絮凝提取,其目的是优化生产工艺,提高药液的澄清度和药液质量。实验利用光的吸收和散射定律,以絮凝率和总黄酮损失率为衡量指标,判断不同影响因素对絮凝效果的影响,并将其与醇沉工艺的提取方法进行比较。结果通过单因素实验先判断出有利于絮凝的趋势,之后又利用正交实验确定了絮凝的最佳工艺条件:絮凝剂质量浓度1.071 g/L,絮凝温度40℃,体系pH值4.9。并且得出壳聚糖对银杏叶水提液的絮凝工艺效果明显优于醇沉法。     

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.     

两性壳聚糖复合絮凝剂对印染废水的絮凝性能研究

以两性壳聚糖为絮凝剂处理了丝绸印染废水,并与羧甲基壳聚糖、壳聚糖季铵盐、聚合氯化铝和聚丙烯酰胺的絮凝性能进行了比较,研究了废水的pH、絮凝剂的质量浓度、助凝剂的类型及其与两性壳聚糖的复配比对其絮凝性能的影响.结果表明,两性壳聚糖的絮凝性能优于羧甲基壳聚糖、壳聚糖季铵盐、聚合氯化铝和聚丙烯酰胺;在pH为5.0～6.0、絮凝剂两性壳聚糖的质量浓度为90 mg/L时,废水的COD去除率可达76.8%;助凝剂的加入可提高两性壳聚糖对COD的去除率.在m(助凝剂):m(絮凝剂)=40、混凝剂的加入量为2 500～3 000 mg/L时,废水COD的去除率可在80%以上.     

复合型微生物絮凝剂与化学絮凝剂的复配及其应用

通过实验考察F2–F6复合型微生物絮凝剂分别与无机絮凝剂氯化铝、无机高分子絮凝剂聚合氯化铝、有机絮凝剂聚丙烯酰胺复配使用处理泥浆废水絮凝条件和絮凝效果,并对水源水和工业废水中的处理效果进行了测定。实验结果表明：F2–F6微生物絮凝剂与化学絮凝剂配合使用不仅获得了更好的净化效果,而且可大大降低絮凝剂的总投加量。     

壳聚糖絮凝竹叶提取液及机理探讨

以澄清率和黄酮保留率为评价指标,考察了絮凝剂种类与用量、溶液pH值、絮凝时间与温度等因素对竹叶醇提取水溶液絮凝效果的影响。结果表明,壳聚糖絮凝效果明显优于明胶;单因素及正交实验法得到壳聚糖絮凝的较优工艺条件为:溶液pH值5.5,壳聚糖质量浓度为0.1mg/mL,40℃下絮凝10min,静置2h,此时竹叶醇提取水溶液的黄酮保留率为95.8%、澄清率为95.0%。且壳聚糖对竹叶醇提水溶液的絮凝效果优于竹叶水提液和醇提液。Zeta电位和傅里叶红外变换(FT-IR)光谱分析表明,壳聚糖通过电中和反应和吸附架桥作用除去竹叶提取液中的脂类、鞣酸类、蛋白质、多糖和小分子萜类等杂质,提高溶液的澄清度,同时对竹叶黄酮有很好的保留作用。     

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％。     

壳聚糖对桑白皮水提液净化除杂的研究

为了克服传统中药提取工艺醇沉法中有效成分损失率高的缺点,采用絮凝工艺对中药水提液进行除杂。本实验采用天然高分子絮凝剂壳聚糖对桑白皮水提液进行净化除杂,以水提液的澄清度和黄酮损失率为衡量指标,判断不同因素对絮凝效果的影响,确定了絮凝的最佳工艺条件为:壳聚糖浓度为0.747g·L-1,操作温度为40℃,体系pH值为4.9。并将其与醇沉工艺的处理效果进行比较,结果表明絮凝法能够选择性地去除杂质颗粒,提高水提液的澄清度,同时有效成分损失率低。     

Cobalt Schiff base complexes: Synthesis characterization and catalytic application in Suzuki–Miyaura reaction

3-Methoxysalicylaldehyde was condensed with the amines 4-aminoacetophenone and 2-amino-5-bromopyridine to obtain Schiff base ligands, 1 and 2, which were coordinated to cobalt salts as complex 1 and complex 2, respectively. The synthesized ligands and complexes were characterized by spectroscopic (FT-IR, UV-Vis, ¹H-NMR and mass spectrometry), thermal (TGA) and elemental analysis. The structures of the complexes were verified by evaluating their magnetic susceptibility and spectroscopic evidences. Synthesized complexes were studied for their catalytic activity in the Suzuki-Miyaura cross-coupling of aryl halides with phenylboronic acid. Optimized reaction yields 90% of the cyanobiphenyl for complex 1 and 91% for complex 2 with 0.1 mmol of catalyst loading thereby substantiating the C-C coupling efficiency of the synthesized complexes, 1 and 2.     

氧化-混凝工艺处理碱性含砷废水的试验研究

研究了用氧化与混凝组合工艺处理某锑冶炼厂排放的碱性含砷废水。研究结果表明,聚合硫酸铁较三氯化铁、硫酸亚铁对原水中砷的去除效果好;用氧化与混凝组合工艺较单纯用混凝工艺对砷的去除率高：双氧水、次氯酸钠这两种氧化剂中采用次氯酸钠氧化对原水中砷的去除效果及处理成本最佳。     

Coagulation of oil in water using sawdust,bentonite and calcium hydroxide to form floating sheets

The coagulation of oil in water is valuable for the removal of oil from water. The use of a mixture of bentonite and sawdust, with sawdust being the vast majority, is highly effective for the coagulation of oil in water, giving coagulation efficiency 92% or above. A minor amount of calcium hydroxide may be optionally added to the mixture to increase the coagulation efficiency to 94%. The use of organobentonite in place of unmodified bentonite increases the coagulation efficiency further to 95%, but increases cost. Sawdust by itself sinks in water. However, the coagulated aggregates float on water when sawdust is used with the bentonite. These aggregates are sheet-like, with the oil–bentonite–sawdust serving as a continuous matrix and apparently no upper limit to the aggregate sheet size. They contain, for example, 81 vol.% oil, 15 vol.% sawdust, 3 vol.% bentonite (with basal spacing 14.4 Å) and 1 vol.% calcium hydroxide. Upon compression, 73% of the oil in the aggregate is removed. Without sawdust, the aggregates sink in water and the coagulation efficiency is only 37%. The sawdust functions as a fibrous framework for the attachment of the coagulating oil and bentonite, thus facilitating floating aggregate formation and the subsequent removal of the aggregates. In the presence of unmodified bentonite, sawdust enhances the coagulation efficiency significantly, while calcium hydroxide enhances the coagulation efficiency by a much lower degree.     

Facilitation of cascade biocatalysis by artificial multi-enzyme complexes—A review

Multi-enzyme complexes are the results of natural evolution to facilitate cascade biocatalysis. Through enzyme colocalization within a complex, the transfer efficiency of reaction intermediates between adjacent cascade enzymes can be promoted, resulting in enhanced overall reaction efficiency. Inspired by nature, a variety of approaches have been developed for the assembly of artificial multi-enzyme complexes with different spatial organizations, aiming at improving the catalytic efficiency of enzyme cascade. A recent trend of this research area is the creation of enzyme complexes with a controllable spatial organization which helps with the mechanistic studies and bears the potential to further increase metabolic productivity. In this review, we summarize versatile strategies for the assembly of artificial multi-enzyme complexes, followed by an inspection of the mechanistic studies of artificial multi-enzyme complexes for their enhancement of catalytic efficiency. Furthermore, we provide some highlighted in vivo, ex vivo, and in vitro examples that demonstrate the ability of artificial multi-enzyme complexes for enhancing the overall production efficiency of value-added compounds. Recent research progress has revealed the great biotechnological potential of artificial multi-enzyme complexes as a powerful tool for biomanufacturing.     

Coagulation of Concentrated Suspensions of Ultrafine Alumina Powders by pH Shift

Highly concentrated suspensions of ultrafine alumina powders are prepared using 2-phosphonobutane-1,2,4-tricarboxylic acid as dispersant. The coagulation of these suspensions is carried out at around 278 K by adding a blend of acetic anhydride plus ethylene glycol. Coagulation takes place through a pH shift because of a time-delayed hydration of the acetic anhydride. The coagulation kinetics are studied by viscosity measurements with respect to the temperature and composition of the coagulant blend. Finally, the method is used to produce complex 3D parts of large dimensions for bio-applications by direct coagulation casting and the fired bodies are characterized.     

Facilitation of cascade biocatalysis by artificial multi-enzyme complexes — A review

Multi-enzyme complexes are the results of natural evolution to facilitate cascade biocatalysis. Through enzyme colocalization within a complex, the transfer efficiency of reaction intermediates between adjacent cascade enzymes can be promoted, resulting in enhanced overall reaction efficiency. Inspired by nature, a variety of approaches have been developed for the assembly of artificial multi-enzyme complexes with different spatial organizations, aiming at improving the catalytic efficiency of enzyme cascade. A recent trend of this research area is the creation of enzyme complexes with a controllable spatial organization which helps with the mechanistic studies and bears the potential to further increase metabolic productivity. In this review, we summarize versatile strategies for the assembly of artificial multi-enzyme complexes, followed by an inspection of the mechanistic studies of artificial multi-enzyme complexes for their enhancement of catalytic efficiency. Furthermore, we provide some highlighted in vivo, ex vivo, and in vitro examples that demonstrate the ability of artificial multi-enzyme complexes for enhancing the overall production efficiency of value-added compounds. Recent research progress has revealed the great biotechnological potential of artificial multi-enzyme complexes as a powerful tool for biomanufacturing.     

Novel yellow phosphorescent iridium complexes containing a carbazole–oxadiazole unit used in polymeric light-emitting diodes

Yellow iridium complexes Ir(PPOHC)₃ and (PPOHC)₂Ir(acac) (PPOHC: 3-(5-(4-(pyridin-2-yl)phenyl)-1,3,4-oxadiazol-2-yl)-9-hexyl-9H-carbazole) were synthesized and characterized. The Ir(PPOHC)₃ complex has good thermal stability with 5% weight-reduction occurring at 370 °C and a glass-transition temperature of 201 °C. A polymeric light-emitting diode using the Ir(PPOHC)₃ complex as a phosphorescent dopant showed a luminance efficiency of 16.4 cd/A and the maximum external quantum efficiency of 6.6% with CIE coordinates of (0.50, 0.49). A white polymeric light-emitting diode was fabricated using Ir(PPOHC)₃ which showed a luminance efficiency of 15.3 cd/A, with CIE coordinates of (0.39, 0.44). These results indicate that the iridium complexes containing a linked carbazole–oxadiazole unit are promising candidates in high-efficiency electroluminescent devices.     

Novel yellow phosphorescent iridium complexes containing a carbazole-oxadiazole unit used in polymeric light-emitting diodes

Yellow iridium complexes Ir(PPOHC)₃ and (PPOHC)₂Ir(acac) (PPOHC: 3-(5-(4-(pyridin-2-yl)phenyl)-1,3,4-oxadiazol-2-yl)-9-hexyl-9H-carbazole) were synthesized and characterized. The Ir(PPOHC)₃ complex has good thermal stability with 5% weight-reduction occurring at 370 °C and a glass-transition temperature of 201 °C. A polymeric light-emitting diode using the Ir(PPOHC)₃ complex as a phosphorescent dopant showed a luminance efficiency of 16.4 cd/A and the maximum external quantum efficiency of 6.6% with CIE coordinates of (0.50, 0.49). A white polymeric light-emitting diode was fabricated using Ir(PPOHC)₃ which showed a luminance efficiency of 15.3 cd/A, with CIE coordinates of (0.39, 0.44). These results indicate that the iridium complexes containing a linked carbazole-oxadiazole unit are promising candidates in high-efficiency electroluminescent devices.     

Selective adsorption of the gold–cyanide complex from waste rinse water using Dowex 21K XLT resin

The Dowex 21K XLT resin which is a strong basic resin was used to selectively adsorb gold–cyanide complex only, in the actual waste rinse water which coexisted with lead–cyanide complexes. The existence of gold–cyanide complex on the surface of the Dowex 21K XLT resin was proved by SEM and EDX analysis. The maximum removal efficiency value for gold–cyanide complex was about 93% for 10 g/L of resin concentration while adsorption for lead–cyanide complexes did not almost happen at pH 13. The adsorption capacity of Dowex 21K XLT resin for gold and lead–cyanide complexes was about 32 and 0.8 mg/g-dry mass, respectively. Also, most of adsorption process for gold–cyanide complex was completed within 1 h. The exothermic nature of gold–cyanide complex adsorption onto the Dowex 21K XLT resin was revealed because the removal efficiency for gold–cyanide somewhat decreased as temperature increased. It was concluded that the Dowex 21K XLT resin, which has excellent selectivity to gold–cyanide complex, can be applied to the recovery system for gold–cyanide complex in actual waste rinse water.     

Coagulation and Electrocoagulation of Wastes Polluted with Colloids

Abstract

The goal of this work has been to compare for both, continuous and batch processes, the efficiencies of the chemical and the electrochemical coagulation processes with hydrolyzing aluminum salts, and to determine the similarities or differences that exist between both coagulation processes. To meet the objective, experiments of both coagulation technologies have been carried out in the same operation conditions and the results have been interpreted in terms of the mechanisms previously proposed in literature for kaolin coagulation. The charge neutralization by the adsorption of monomeric hydroxocations onto the kaolin surface can be the primary coagulation‐mechanism for low concentration of aluminum and acidic pHs (below 4). In the range of pH 4–7, two primary mechanisms can explain the experimental behavior of the system: sweep flocculation for high concentration of aluminum, and a combination of precipitation‐charge‐neutralization and charge neutralization by adsorption of monomeric or polymeric aluminum, for low concentration of aluminum. In the continuously‐operated processes, the efficiency in the turbidity‐removal seems to be much related to the aluminum species present in the treated waste, and not to the way of adding aluminum to the reaction system. For the same steady‐state pH and aluminum concentration, the same turbidity removal is obtained in both, the chemical and the electrochemical coagulation processes. For high aluminum/kaolin ratios, kaolin suspensions which contain sulfate as electrolyte, achieve better removals of turbidity than those containing chloride ions. The operation mode (continuous or discontinuous) influences greatly on the efficiency of the electrocoagulation processes. Similar efficiencies are obtained for low (below 5 mg dm^?3) and high doses of aluminum (above 20 mg dm^?3). However, at intermediate doses a strong difference is observed, with a more marked decrease in the efficiency in the discontinuous process. This observation has been explained considering that the addition of aluminum in the continuous process is instantaneous (and not progressive as in the discontinuous one), and thus, the sweep coagulation mechanism is more favored in this operation mode.