聚丙烯酰胺类絮凝剂在工业废水处理中的应用

一、前言人们早就用天然明矾来处理含固体悬浮物的水,使其加速沉淀。以后又用熟化淀粉、硫酸铝、氯化铝、碱式氯化铝、硫酸亚铁等无机絮凝剂和天然高分子物质对废水进行絮凝处理。随着化学工业的发展,尤其是石油化工的发展,聚电解质开始大量用作絮凝剂。聚电解质的品种较多,但现在作为合成高分子絮凝剂的主要是聚丙烯酰胺类。由于官能团百分比及聚合度大小不一,聚丙烯酰胺有一系列性质不同的产品,通常有以下四种类型:     

腈纶废丝的化学处理及产物的应用(续一)

(接上期) 2.2.2 合成絮凝剂 刘宇、褚庆辉[9]使腈纶废丝与双氰双胺(DCD)在N,N-二甲基甲酰胺(DMF)的溶液中充分混合,在碱性条件下,升温到100 ℃,剧烈搅拌,反应4 h后用盐酸中和,水洗,于50 ℃恒温下干燥过夜,制得絮凝剂PAN-DCD,产品为黄色粉末,产率为89.7%,特性粘数为10.65 ml/g(二甲基亚砜溶液,20 ℃).     

改性淀粉絮凝剂处理印染废水

改性淀粉絮凝剂处理印染废水１前言６０年代初，国外开始使用聚合电解质絮凝剂，尤其是合成有机高分子聚合电解质絮凝剂处理废水的研究。这种絮凝剂不仅使用方便，应用范围广，而且絮凝效果比无机絮凝剂（如铁盐和铝盐）提高几倍至几十倍；此外，它还有絮凝及沉降速度快、...     

阳离子絮凝剂P(AM-DMC)的合成及其对活性染料废水的絮凝脱色

以K2S2O8-脲为引发剂,通过自由基聚合法合成了丙烯酰胺-2-甲基丙烯酰氧乙基三甲基氯化铵P（AM—DMC）絮凝剂,并研究了其对4种活性染料模拟废水的脱色效果,考察了P（AM—DMC）加入量、阳离子度、特性粘数、染料溶液pH等因素对脱色效果的影响。实验结果表明：最佳P（AM—DMC）加入量随染料分子中磺酸基数目的增加而增加,随絮凝剂阳离子度的增大而减少;阳离子度大于52％时,最高脱色率基本相同;特性粘数对脱色效果影响很小;在染料溶液为弱酸性及中性条件下,P（AM—DMC）的脱色效果较好。P（AM—DMC）对活性染料废水的脱色机理是,P（AM—DMC）中的-N^＋（CH3）3与染料分子中的-SO3^-结合,生成-N^＋（CH3）3SO3^-,同时也形成了分子间氢键,通过键合作用使染料分子聚集沉降。     

专利文摘

正一种处理印染废水的复合型絮凝剂及其制备方法该专利公开一种处理印染废水的复合型絮凝剂及其制备方法。该复合型絮凝剂的原料配方按照质量份数计,由20~30份的炉渣、10~15份的硫酸镁和5~10份的聚丙烯酰胺组成。复合型絮凝剂以炉渣搭配硫酸镁和聚丙烯酰胺,其对印染废水的絮     

聚硅酸氯化铝镁的制备及絮凝性能

用聚合硅酸、聚合氯化铝和硫酸镁复合制备复合絮凝剂聚硅酸氯化铝镁。SEM分析结果表明，聚硅酸氯化铝镁为交联的枝杈状聚集态。FTIR仪分析表明，聚铝离子及水解络合离子可与共存的聚硅酸聚合形成配位键。以实际废水为处理对象，比较了自制复合絮凝剂聚硅酸氯化铝镁与市售聚合氯化铝的絮凝效果。实验结果表明:在聚硅酸氯化铝镁加入量为40mg/L、废水pH为3的条件下，以自制聚硅酸氯化铝镁为絮凝剂时废水的COD、BOD5、TP、TN、浊度去除率均较高;自制复合絮凝剂聚硅酸氯化铝镁的废水处理效果均优于市售聚合氯化铝。     

两性聚丙烯酰胺的制备及其絮凝性能

开发了一种对非离子聚丙烯酰胺进行改性制备两性聚丙烯酰胺(APAM)絮凝剂的新方法。以硅藻土悬浮液为絮凝对象,考察了改性反应中影响APAM絮凝效果的因素。结果表明,采用无水乙酸与三甲胺、环氧氯丙烷合成季胺盐型阳离子剂的方法优于采用盐酸的方法;在10mL质量分数为10%、相对分子质量为3×106的非离子型聚丙烯酰胺水溶液中加入8mL浓度为2.6mol/L的阳离子剂,同时控制V(NaOH)∶V(NaClO)为0.44,改性得到的APAM絮凝性能最佳,在pH3～9的较宽范围内对硅藻土悬浮液有较好的絮凝效果。在pH为3、APAM加入量为1.8mg/L时,硅藻土悬浮液的絮凝率可达100%。     

工业固体废物在絮凝剂制备上的应用及问题探讨

介绍了工业固体废物在制备无机高分子絮凝剂上的应用,尤其对它们在制备聚硅酸类絮凝剂上的应用做了较为详细的说明,并对存在的问题进行了探讨.     

阳离子聚丙烯酰胺絮凝剂的制备及其絮凝性能

研究了丙烯酰胺（AM）与丙烯酰氧乙基三甲皋氯化铵共聚反应制备阳离子聚丙烯酰胺絮凝剂的工艺。实验结果表明，最佳聚合条件：pH6．0、（NH4）2S2O8和CH3NaO3S·2H2O总质量分数0．0125％、（NH4）：S2O8与CH3NaO3S·2H2O质量比1．0、偶氮类化合物质量分数0．0125％、单体质量分数（AM和阳离子单体总质量占整个反应体系的质量分数）35％、阳离子度（阳离子单体占AM和阳离子单体之和的质量分数）30％、反应温度25℃。在最佳条件下，所得阳离子聚丙烯酰胺絮凝剂的特性黏数为13．8535dl／g，在其加入量为0．027％的条件下处理污泥，上层清液透光率达99．6％，污泥脱水率达90．5％。并用红外光谱对阳离子聚丙烯酰胺的结构进行了表征。     

聚硅酸铝铁絮凝剂的制备及其在印染废水处理中的应用

以粉煤灰为主要原料制备了聚硅酸铝铁絮凝剂。通过L16(45)正交实验得出粉煤灰中Al3+和Fe3+的最佳浸取实验条件为焙烧温度900℃,m(Na2CO3)∶m(粉煤灰)=0.10,浸取温度为70℃,盐酸质量分数20%,浸取时间为2.0h。通过L9(34)正交实验得出聚硅酸铝铁的最佳制备条件为n(聚硅酸)∶n(Al3+)=1∶0.5,n(聚硅酸)∶n(Fe3+)=1∶0.5,浸出液pH为5.0,熟化温度为60℃。利用制得的聚硅酸铝铁絮凝剂对200mL模拟印染废水进行处理,在絮凝剂加入量为4mL时絮凝效果最好,透光率超过70%。     

炼油废水污泥脱水工艺条件的优化

采用化学除油降黏—污泥调理—离心脱水工艺处理某炼油厂废水处理系统的混合污泥，并对工艺条件进行优化。实验结果表明，最佳的工艺条件为：化学除油降黏阶段处理体系的pH=4，反应温度35 ℃，H₂O₂加入量 2 g/L，m（H₂O₂）∶ m（Fe²⁺）=4，反应时间 60 min；污泥调理反应阶段的CaO加入量7.0 g/L；离心脱水阶段在分离因数为1 558时脱水5 min。在此条件下，得到的泥饼的含水率为70.0%~75.0%（w），含油率小于2%（w），污泥比阻约为3.0×10⁷ s²/g。     

O3氧化法和O3-H2O2氧化法去除水中聚丙烯酰胺

采用O3氧化法和O3-H2O2氧化法去除水中的聚丙烯酰胺（PAM），分别考察了反应时间、O3质量浓度、n（H2O2）∶n（O3）和溶液pH对PAM去除效果的影响。实验结果表明：O3氧化的最佳操作条件为反应时间30 min、O3质量浓度22.6 mg/L、溶液pH 8.5，O3-H2O2氧化的最佳操作条件为反应时间10 min、O3质量浓度22.6 mg/L、n（H2O2）∶n（O3）=0.1、溶液pH 8.5;在最佳操作条件下，O3氧化和O3-H2O2氧化均可有效降低PAM溶液的黏度和PAM质量浓度，但对COD的去除效果不佳，黏度可降至和蒸馏水相近，PAM的去除率可达80%以上，而COD的去除率分别约为15%和28%;O3-H2O2氧化后的PAM比O3氧化后的PAM更容易被微生物利用，两种氧化预处理方法均有利于后续的生化处理。     

Chemical Crosslink Degradable PVA Aqueous Solution by Potassium Persulphate

The aim of this paper is to study the influence of the K₂S₂O₈ content on the properties of poly (vinyl alcohol, (PVA). Firstly, PVA was dissolved in distilled water by heating by heating at 70 °C and then K₂S₂O₈ was added in PVA solution under stirrer. The viscosity of PVA solution in the presence of K₂S₂O₈ was analyzed by Brookfield Viscometers. The effects of K₂S₂O₈ contents, PVA solution, temperature and reaction time on the viscosity of PVA solution were investigated. This was confirmed by Brookfield Viscometers. It is clear that the viscosity of PVA solution in the presence of K₂S₂O₈ increased as function of reaction time and PVA content in solution. Rate of modified PVA was proportional to K₂S₂O₈ contents and temperature and its activation energy was 16 kJ/mol. The structure of PVA in the presence of K₂S₂O₈ changed from original PVA confirmed by ATR-FTIR and solid state NMR. In addition, the thermal properties of PVA containing K₂S₂O₈ were also studied by TGA.     

Polyacetal Polyols for Polyurethanes

The synthesis of telechelic polyacetals with terminal hydroxyl groups (polyacetal polyols), by the reaction of triethylene glycol divinyl ether with dipropylene glycol in the presence of trimethylolpropane or other triols or diols as starters, in acidic catalysis, has been studied. The synthesized liquid polyacetal triols and polyacetal diols were characterized by hydroxyl number, viscosity, acidity, number average molecular weight (M_n), weight average molecular weight (M_w), molecular weight distribution (M_w/M_n), FT-IR spectra. The obtained polyacetals were transformed in cast elastomers by the reaction with the isocyanate Mondur CD (modified diphenyl methane diisocyanate) with properties very close to the elastic polyurethanes obtained by using conventional polyether triols, copolymers propylene oxide–ethylene oxide. The polyacetal polyols are suitable for the synthesis of elastic polyurethanes (polyurethane elastomers, flexible polyurethane foams). Polyacetals are well known biodegradable polymers. Therefore, the polyurethanes based on polyacetal polyols are expected to be biodegradable.     

Converting waste polystyrene into a polymer flocculant for wastewater treatment

We have succeeded in converting waste polystyrene from electrical appliances into a polymer flocculant for treating some kinds of wastewater after chemical modification. Waste polystyrene, such as polystyrene foam and additive-containing TV cabinets, was converted into a water-soluble polymer, polystyrene sulfate (PSS), and PSS of various degrees of aqueous viscosity was obtained by introducing sulfone bridges during sulfonation. We examined the relationship between the degree of flocculation of wastewater and the aqueous viscosity of the PSS, and found that PSS with medium viscosity is most suitable for flocculating inorganic wastewater from a factory, and PSS with high viscosity is most suitable for dewatering organic domestic wastewater. We report how PSS containing sulfone bridges works as a polymer flocculant for treating wastewater. Received: July 19, 2000 / Accepted: September 21, 2000     

Molecular Modification and Compatibilization of Collected Polyethylene

The increasing use of plastics in packaging materials leads to growing amounts of plastic waste. Recycling material is generally regarded as advantageous. But in fact very few products are made from plastic waste, partly this can be explained by that little is known about the recycling process and the properties of collected materials. There is a need for injection moulding grades of recycled polyethylene, while large amounts of extrusion grades are available from packaging waste. A controlled way of de-branching or partly degrading PE would be desirable. Peroxides are commonly used to crosslink polyolefins, but under certain conditions a chain scission reaction occur. Another problem encountered with recycling of polyethylene are the poor miscibility of low amounts contaminations, i. e. polypropylene. A compatibilizer can improve properties of such polymer blends, in this work EPDM is used as compatibilzer. Studies of mechanical properties and viscosity measurements show that it is possible to partly degrade PE with peroxide exposing it to high temperature and oxygen. The properties of PE/PP blends were improved with EPDM as compatibilizer.     

Storage stability of biocrude oils from fast pyrolysis of poultry litter

The unstable nature of biocrude oils produced from conventional pyrolysis of biomass is one of the properties that limits its application. In the disposal of poultry litter via pyrolysis technology, the biocrude oil produced as a value-added product can be used for on farm applications. In this study, we investigated the influence of bedding material (wood shavings) on the storage stability of biocrude oils produced from the fast pyrolysis of poultry litter. The biocrude oils produced from manure, wood (pine and oak), and mixtures of manure and wood in proportions (75:25 50:50, and 25:75 w/w%) were stored under ambient conditions in sealed glass vials for a period of 6 months and their stability were monitored by measuring the changes in viscosity over time. The manure oil had the lowest rate of viscosity change and thus was relatively the most stable and the oils from the 50:50 w/w% litter mixtures were the least stable. The rate of viscosity change of the manure biocrude oil was 1.33 cP/day and that of the 50/50 litter mixture was 7.6 cP/day for pine and 4.17 cP/day for oak.The spectrometric analyses of the biocrude oils showed that the presence of highly reactive oxygenated functionalities in the oil were responsible for the instability characteristic of the litter biocrude oils. The poor stability of the biocrude oil from the 50:50 w/w% litter mixtures was attributed to reactions between nitrogenous compounds (amides) from protein degradation and oxygenated compounds from the decomposition of polysaccharides and lignin. The addition of 10% methanol and 10% ethanol to the oil from 50% manure and 50% pine reduced the initial viscosity of the oil and was also beneficial in slowing down the rate of viscosity change during storage.     

Effect of Bimetallic Soybean Oil Based Polymer on Growth and Plasma Membrane H+-ATPase Activity Among Fungi

In view of bio-inorganic importance, iron and zinc incorporated soybean oil based polymer was prepared by condensation polymerization of oil based fatty amide polyole, sebacic acid, zinc acetate and ferric chloride in a process initiated by sodium ethoxide. Microwave assisted synthesis was used throughout the reaction as it is ecofriendly and requires minimal usage of solvents. Physical techniques such as FT-IR and ¹HNMR have been used to establish the structure of the polymers. Standard laboratory methods like acid value, saponification value, iodine value, specific gravity and viscosity were used to study the chemical diversity of each product. Thermo gravimetry/differential thermal analyzer was used to analyse the thermal behavior of polymer. The synthesized compounds were subjected to biological study. The observed fungicidal characteristics of synthesized compounds indicate that these compounds might be promising antifungal agents defining a new class of antimycotics. The polymers were used in preparation of films which can be used as protective packaging material of edible items.     

Ring-Opening Polymerization of Cyclic Esters onto Liquefied Biomass

Ring-opening polymerization of cyclic esters (-caprolactone, -valerolactone, and l-lactide) onto liquefied biomass (LB) was conducted to obtain the polyester-type polyol and to regulate the characteristics of LB. IR and ¹H-NMR spectra of the obtained polyol showed that the polymerization was successfully conducted in the presence of acid catalyst, which is used in liquefaction. The molecular weight (M_w), hydroxyl value, and viscosity were controllable by changing the reaction conditions. Polyester-type polyurethane foams with a wide range of properties were prepared from the obtained polyol with the appropriate combinations of foaming agents.     

Rheological Studies of Microfibrillar Cellulose Water Dispersions

The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigated. For the first time a detailed study of shear dependent viscosity at low and high shear rate is presented. A peculiar time dependent behaviour measured in the area between 0 and 1000 s⁻¹ was identified. The study shows a hysteresis loop in the shear rate–viscosity relationship at low shear rate. Additional time dependent shear rate measurements were performed, and a hypothesis for a mechanism of interaction and formation of a fibrils network was suggested. Higher temperature caused lower viscosity values, and this difference was increased at higher shear rate values. Oscillatory measurements showed how the closeness of the fibrils helps network creations. Data obtained from high shear measurements showed that 1% MFC water dispersions had a dilatant behaviour at ultra high shear rates with values increasing from 120 to 300 Pa s in the area between 180,000 and 330,000 s⁻¹ .