米根霉细胞壁结构性多糖与丙烯酸接枝共聚反应研究

化学改性天然高分子絮凝剂是利用天然高分子物质进行化学改性而成的。与人工合成的有机高分子絮凝剂相比,它具有选择性大、无毒、价廉、易降解等优点,因此将会有广阔的应用前景,近几年,将乙烯基单体接枝到生物高分子上的工作引起了人们的兴趣,这种天然高分子与合成高分子的结合有可能得到理想的性能,获得新的材料：如生物降解塑料、絮凝剂、离子交换剂等,目前这方面的研究主要中在纤维素、淀粉和壳聚糖的接枝共聚上。     

温度和电极互换频率对电解过程中聚合Al13形成的影响

聚合铝作为一种无机高分子絮凝剂,具有比传统絮凝剂如硫酸铝、氯化铁等效能优异,比有机高分子絮凝剂价格低廉等优点[1￣3]。研究表明,聚合铝絮凝剂实际上是在一定条件下控制铝的水解-聚合-沉淀过程的中间产物,其溶液除存在铝的单体及二聚体外,     

有机阳离子高分子絮凝剂

近年来,有机阳离子高分子絮凝剂得到国内外学者的广泛重视.它的研究、开发、应用都取得了显著进展.本文对此进行评述和介绍,内容涉及阳离子型聚丙烯酰胺接枝共聚物、羟基醚化类、二烷基二烯丙基卤化铵类和环氧氯丙烷与胺反应物,特别是近年来淀粉等天然高分子改性阳离子型絮凝剂和人工合成的无毒有机阳离子高分子絮凝剂.     

高分子重金属絮凝剂在水处理中的研究与应用

概述了高分子重金属絮凝剂在废水处理中的应用进展,包括高分子重金属絮凝剂的种类及废水处理的作用机理,并对除浊效果进行了比较。     

油田作业废水絮凝过程中Zeta电位的研究

以川中矿区典型的压裂酸化废水为研究对象,考察了溶液pH值、无机混凝剂、有机高分子絮凝剂、以及无机混凝剂与有机高分子絮凝剂共同作用对废水Zeta电位的影响,从理论上对油田废水的絮凝特点进行了表征.实验结果证明:油田作业废水适合在酸性条件下进行絮凝处理;聚硅硫酸铁和阳离子有机高分子絮凝剂能使废水颗粒表面Zeta电位明显正移;当联合使用时,先加无机混凝剂,后加有机絮凝剂,能提高污水处理质量.     

阳离子高分子絮凝剂的合成与其表面电性的测定

以三乙烯四胺对聚氯乙烯(PVC)进行改性,合成一系列胺化产物,并经硫酸二甲酯季铵化,得到阳离子高分子絮凝剂.采用元素分析、红外光谱对产物进行结构表征,并通过电荷密度、特性粘度和Zeta电位等测定,研究了该高分子絮凝剂的结构与相关性质间的关系.结果表明:通过控制合成条件,可以改变阳离子高分子絮凝剂的分子量和电荷密度,以适应各种应用条件的需求.     

SPE阴离子交换膜技术电解制备FeO42-及其降解脱色性能的研究

絮凝过程是水的净化与工业废水处理的重要技术单元。在低分子量的无机絮凝剂如铝、铁的氯化物和硫酸盐的基础上，近年来高分子无机絮凝剂的开发研究已成为热点犤１，２犦。其中分子量在１０５以上的聚合氯化铝（PAC）犤３犦，聚合硫酸铁（PFS）犤４犦，铝铁共聚型无机高分子絮凝剂如聚合氯化铝铁（PAFC）犤５犦的研究开发也已取得长足的进步。这些无机絮凝剂在水溶液中，以羟基（－OH）架桥形成多核络离子，通过粘附、交联作用达到使微粒凝聚沉降的目的。本文研究报道的以电化学方法在阳极电解生成的FeO４２－，在微粒粘附、凝聚、沉…     

油田含油废水处理絮凝剂的研究与应用

对国内外石油和石化行业含油废水处理常用絮凝剂进行了综合评述，较详细地介绍了它们的种类，使用性能和近期研究及应用进展情况，与无机、有机絮凝剂相比，复合絮凝剂具有效率高、实用范围广等优点。未来含油废水处理絮凝剂应向无毒，易生物降解的天然高分子改性絮凝剂、微生物絮凝剂和兼具多种功能的水处理剂方向发展。     

可溶性聚硅酸铝铁的制备及其在废水处理中的应用

以赤泥为原料,制备了高效无机高分子絮凝剂——聚硅酸铝铁(PSAF),并将该絮凝剂用于处理工业废水．研究絮凝剂的使用效果与投加量、投加方式、pH值、搅拌条件及水样本身性能间的关系．     

木质素磺酸钙接枝改性及其在染料废水处理中的应用

染料废水具有有机物浓度高、毒性高、COD值高、色度高、可生化性差、脱色困难、排放量大等特点,染料废水的处理是废水处理中的一大难题。目前染料废水的处理一般先通过物理、化学预脱色,破坏其发色基团,去除生物毒性,提高废水的可生化性,然后再进行生物处理。其中所用有机高分子脱色刘有合成有机高分子脱色絮凝剂如RAN—DCD、DC491等,天然有机高分子絮凝剂天     

絮凝处理对聚驱污水中部分水解聚丙烯酰胺浓度的影响

用常见无机和有机絮凝剂处理了聚驱污水,分别考察了絮凝剂单剂和复配处理后聚驱污水中残余部分水解聚丙烯酰胺(HPAM)质量浓度和透光率随絮凝剂剂量的变化.结果表明:采用无机絮凝剂处理聚驱污水时,残余HPAM质量浓度随絮凝剂剂量增加先减小后增大;采用有机絮凝剂处理聚驱污水时,残余HPAM质量浓度随絮凝剂剂量增加而线性增加.将无机絮凝剂与无机絮凝剂复配使用,则残余HPAM质量浓度与透光率成反比;将无机絮凝剂与有机絮凝剂复配使用,则残余HPAM质量浓度取决于复配体系中阳离子聚丙烯酰胺(CPAM)的添加量.     

化学混凝法处理废纸制浆废水的研究

在对瓦楞箱板纸废纸制浆废水的特性作了较系统的分析研究的基础上 ,采用自制的混凝剂LPAS及商品絮凝剂聚合氯化铝PAC ,研究了二者的最佳使用条件与对该废水的处理效果 ,结果表明 :混凝剂LPAS比商品絮凝剂PAC对该废水有更好的处理效果 ,当混凝剂LPAS用量为1 50mg/L时 ,废水CODcr、TSS的去除率分别达 71 .8%和 83.6 % ,添加助凝剂FO4 2 4 0可使絮层的沉降速度加快。     

Color Removal from Aqueous Solutions of Humic Substances in the Presence of Praestol and Aluminum Sulfate

Color removal from aqueous solutions of humic substances by introducing Praestol (cationic coagulant) in combination with aluminum sulfate (flocculant) was studied as a function of the coagulant and flocculant concentrations, chemical composition of flocculant, its molecular weight, macromolecule conformation in solutions, pH, and the order and time of coagulant and flocculant introduction.     

Polyacrylamide Grafted Carboxymethyl Tamarind (CMT-g-PAM): Development and Application of a Novel Polymeric Flocculant

Water is scarce commodity now. Recycling of municipal wastewater, industrial and mineral processing effluents require treatment with the inorganic or organic flocculants. Both synthetic and natural polymers are used as flocculants. Natural polymers are biodegradable and are effective at very large dosages but are very shear stable. The synthetic polymers are highly effective flocculants at very small dosages and have high tailorability, but have poor shear stability. In the authors' laboratory, a novel polymeric flocculant has been developed by grafting polyacrylamide onto the backbone of carboxymethyl tamarind (CMT-g-PAM). Various grades were developed to optimize the best flocculant. The grafted polymers were characterized by various characterization techniques such as intrinsic viscosity measurement, FTIR spectroscopy, ¹³C-NMR spectroscopy, elemental analysis etc. The flocculation studies were carried out using turbidity test as well as settling test. The optimized CMT-g-PAM was then compared with some of the commercial flocculants available in national and international markets in colloidal suspensions and it has been found that our synthesized flocculant surpasses most of the commercial flocculants in performance.     

Treatment of the Wastewater of Finishing-and-Dyeing Production Using Polyelectrolyte Flocculants Based on Nitron Fiber Scrap

The performance of FK-1 and FK-3 cationic polyelectrolytes and of new AMF-2 amphoteric polyelectrolyte in treatment of the wastewater of finishing-and-dyeing production was studied as influenced by the concentrations of flocculant and coagulant.     

PREPARATION AND PROPERTIES OF EXTRACELLULAR BIOPOLYMER FLOCCULANT

The biopolymer flocculant （named PS-2） producing by Pseudomonas fluorescens was investigated. The PS-2 had high efficiency with small dosage, when dealing with kaolin suspension, formed larger floc, with big sedimentation rate, over a wide range of temperatures. Distributing of flocculating activity test showed that the biopolymer flocculant was an extracellular product. The composition analysis of purified biopolymer flocculant showed that it composed mainly of polysaccharide and nucleic acid. The content of polysaccharide was 86. 7%, which determined by using phenol-vitriol method, and the content of nucleic acid was 7.8%, which determined by UV absorption method. The biopolymer flocculant as a powder form showed much better stability than that as a supernatant. The character of biopolymer flocculant was stable even it was heated to 100℃ when it in acidic condition. The optimal conditions to flocculate kaolin suspension were as follows： pH 8-12, flocculant dosage lmL/L, and Ca^2＋ as the optimal cation.     

Sedimentation of Kaolin Suspension in the Presence of Praestol Anionic Flocculant and Aluminum Polyoxychloride and Sulfate Coagulants

The kinetics of sedimentation of kaolin suspension in the presence of coagulants (aluminum polyoxychloride and sulfate) and Praestol anionic flocculant was studied, as influenced by the concentrations of coagulants and flocculant, mode and time of their addition into the suspension, composition of the coagulant mixture, and chemical structure and conformation of flocculant macromolecules.     

Kinetics of adsorption of high molecular weight anionic polyacrylamide onto kaolinite: the flocculation process

The adsorption kinetics of anionic polyacrylamide flocculant onto kaolinite clay are examined as a function of flocculant dosage and pH. Special attention has been given to the flocculation effect during the adsorption process and the resulting inhibition of further adsorption. At pH 8.5 the adsorption capacity of anionic polyacrylamide on kaolinite is low while at pH 4.5, the adsorption capacity increases. Flocculant adsorption has been shown to be related to the amount of available surface area, pH, flocculant dosage, and the resulting floc strength, which controls the rate of new surface area exposure and hence the continuation of further adsorption. At both pH 4.5 and pH 8.5, complete adsorption is achieved at low flocculant dosages and adsorption equilibrium is achieved at high flocculant dosages after 1 day. In contrast, at intermediate flocculant dosages adsorption equilibrium is not reached over a 7-day period, due to a continuously increasing surface area.     

Studies on Characterization of Bioflocculant Exopolysaccharide of <Emphasis Type="Italic">Azotobacter indicus</Emphasis> and Its Potential for Wastewater Treatment

Partially characterized bioflocculant exopolysaccharide (EPS) produced from an Azotobacter indicus ATCC 9540 strain reported in our previous study was further characterized, and its flocculant potential was investigated at different pH, temperature, and cations concentrations. Flocculant activity at different concentrations of EPS in the absence of cations was reanalyzed by slight modified flocculant assay. It revealed that flocculant activity increased in a concentration-dependent manner up to a certain limit, with the maximum flocculation of 72% at 500 mgL⁻¹ EPS concentration, even in the absence of cations. At the concentration of 10 mgL⁻¹, CaCl₂ showed more significant activity (92%) than AlCl₃ and MnSO₄. Differential scanning calorimetry study and flocculant assay revealed high temperature stability of EPS up to 97 °C. Molecular weight of the EPS determined by size exclusion chromatography was found to be approximately 2 × 10⁶ kDa. Investigation on flocculation efficacy of the characterized EPS for wastewater treatment of dairy, woolen, starch, and sugar industry suggested it to be effective and stable at wide pH range of 5–10. Wastewater treatment with biopolymer at 500 mgL⁻¹ showed reduction in biochemical oxygen demand (38–80%), chemical oxygen demand (37–79%), and suspended solids (41–68%). This study suggests that Azotobacter polymer has high potential in wastewater treatment as bioflocculant and can be used as a potential alternative to chemical flocculants.     

Preparation of modified alginate nanoflocculant and adsorbing properties for Pb2+ in wastewater

A novel nano flocculant was prepared through the modification of sodium alginate. In the preparation partially oxidised sodium alginate reacted with triethylenetetramine (TETA) and then reacted with carbon disulfide. The structure of the flocculants was confirmed by elemental analysis, Fourier transform infrared and UV spectrophotometry. The flocculant showed nanoparticle sizes with diameters of 300–350 nm in aqueous solution, and became precipitates after flocculation with Pb²⁺ ions. The flocculant was employed to adsorb Pb²⁺ in wastewater, and the influence of flocculant concentration, flocculation temperature, pH, and time on the adsorption properties were investigated. The results showed that adsorption capacity of the flocculant for Pb²⁺ could reach up to 3.43 mmol g^–1, and the removal rate for Pb²⁺ was over 97%. The adsorption processes corresponded to pseudo second order kinetics and Langmuir isotherm model. The adsorption mechanism involved electrostatic attraction, chemical chelation, netting and sweeping actions.