Rheological Behavior of Wastewater Sludge Following Cationic Polyelectrolyte Flocculation

The rheological characteristics of the wastewater sludge were investigated by using a Haake Rheostress RS 75 rheometer. The shear creep compliance experiments and the dynamic viscosity measurements were conducted. The shear creep compliance experiments indicate the addition of polymer coagulants to the sludge samples will form more rigid structures. The elastic solid-like behaviors were always observed in the samples with polymers. The Voigt model was successfully employed in modeling the viscoelastic retardation behavior of sludge samples in the shear creep compliance tests. Moreover, the dynamic viscosity curves of the sludge samples with/without polymer could be described by the power law model of Ostwald and de Waele at the medium shear rates, ca. 100–300 s^?1. Consequently, addition of polymer to the sludge tends to extend the applicable ranges of the shear rates for the power law model as well as to decrease the power law index.     

Influence of Cationic Starch Adsorption on Fiber Flocculation

The adsorption of cationic starch on hardwood fibers and its influence on flocculation were studied in relation to the dosage of cationic starch, the effect of shear forces and the presence of different concentrations of inorganic salts in the paper stock. Flocculation was monitored by means of a focused beam reflectance measurement (FBRM) probe. It was established that floc size at low shear rates depends on adsorption efficiency. At high shear forces, flocs were irreversibly decomposed despite the presence of a higher amount of adsorbed cationic starch on the fibers. Therefore, flocculation was produced by a bridging mechanism. The results show a significant effect of inorganic salts on the adsorption of cationic starch on fibers. Low concentrations of inorganic salts usually improved the adsorption process while higher concentrations (> 0.01 mol/L) reduced the adsorption and limited the flocculation process.     

污油泥絮凝机理及其研究进展

根据污油泥处理过程,对常见的化学絮凝过程进行了总结,并对主要絮凝机理及优势和局限性进行了分析。得出了结论:吸附架桥、卷扫网捕、电中和、胞外聚合物架桥等机理配合使用,使絮凝剂有优异的絮凝性能,且其经改性、复合、复配等方法使自身有多种絮凝机制,这对于合成高效的污油泥絮凝剂具有重要意义。最后指出污油泥絮凝过程复杂,进一步研究其具体作用方式和机理以及影响絮凝作用的主要因素都将有助于污油泥絮凝剂的广泛应用。     

絮凝法处理稠油污水的试验研究

对处理稠油污水所用的絮凝剂进行了实验研究。选择T-1、P-3处理稠油污水,研究了T-1、P-3的絮凝效果及影响絮凝效果的因素,并通过实验确定了最佳实验条件。对稠油污水中油和悬浮物的去除率分别达到85％和95％以上,处理效果明显。     

二次混凝工艺处理含铜废水的研究

以壳聚糖为絮凝剂,考察了其在不同投加量、pH值及速度梯度下处理含铜废水的效果;在此基础上采取二次混凝法处理高浓度模拟含铜废水.与其它处理工艺相比,二次混凝法在处理效果及处理费用方面均显示出了优越性,为实际含铜废水的处理提供了很好的参考价值.     

Rheological Characterization of Metalized and Non‐Metalized Ethanol Gel Propellants

The gellation of metalized and non‐metalized ethanol with a methylcellulose gelling agent and its effect on the rheological properties (flow and dynamic study) of these gels is reported herein. The rheological study shows that increasing the shear rate reduces the apparent viscosity for a given yield stress (for a shear rate range of 1 to 12 s⁻¹) for both shear rate ranges (1 to 12 and 1 to 1000 s⁻¹) covered in present experiment. The gellant and metal particle concentrations significantly influence the gel apparent viscosity. Distinct changes in thixotropic behavior were observed, while decreasing the concentration of MC gellant and Al metal particles in the ethanol gels. The dynamic study showed that all of the linear viscoelastic regions (LVE) of the gel samples were independent of strain percentage (1 to 10). The G′ values depended on the frequency and exceeded the G′′ values, which indicated a gel‐like highly structured material. The tanδ values showed that all of the ethanol gels were elastic and weak physical gels with a high degree of cross‐linking.     

絮凝法处理含油废水研究进展

絮凝法作为水处理工艺中常见的方法,在废水处理方面具有广阔的发展前景,主要介绍了化学絮凝,联合絮凝,磁絮凝,电絮凝,微絮凝,微生物絮凝的特点,机理,研究和应用情况,并对其在含油废水处理的应用提出了展望。     

油泥清洗废液的絮凝实验研究

采用多级热化学清洗法,对辽河油田石油污泥进行清洗.研究以油泥清洗废液为研究对象,考察了pH值,无机絮凝剂PFS、PAC,有机高分子絮凝剂CPAM、PAM对清洗废液Zeta电位的影响,和对COD去除效率的影响.实验表明:油泥清洗废液适合在偏酸性条件下进行絮凝处理;PFS、PAC和CPAM能使清洗废液Zeta电位正移;在Zeta电位约等于零时,COD去除效率最高,絮凝剂达到最佳投量;当PFS和CPAM组合使用时,可以进一步降低清洗废液的COD.     

污水处理厂污泥于陶粒生产中的综合利用

主要从市场、工艺、经济和社会效益方面，对污水处理厂污泥于陶粒生产中的综合利用问题进行了论述。     

茂金属聚乙烯（mPE）／高压聚乙烯（LDPE）共混熔体的流变学

研究了不同比例共混的茂金属聚乙烯（mPE)和高压聚乙烯（LDPE）熔体的流变行为,讨论了共混物组成、剪切速率和剪切应力以及温度对熔体流变曲线、熔体粘度和膨胀比的影响,mPE的加工提供了理论依据。不同共混比的熔体均为假塑性流体,且熔体假塑性随LDPE含量增大而增强。熔体流动活化能随LDPE组成的增加逐渐增大,粘度对温度的敏感性增强,共混物的非牛顿指数随LDPE的增加而降低,改善了mPE的加工性能。     

The Rheological Behavior of Salt Tolerant Polyacrylamide Solutions

The rheological behavior of viscoelastic fluids was investigated with regard to the specialty of tertiary oil recovery. Aqueous polyacrylamide solutions at different concentrations were selected to simulate viscoelastic polymer systems, and the Haake RS 150 type rheometer was used to measure the rheological behavior. The experimental results showed that the viscoelasticity was positively influenced by polyacrylamide solution concentrations and negatively affected by solution temperatures. The coefficient of first normal stress deference decreased with increasing shear rate. In addition, the relationship between viscosity and the coefficient of first normal stress with shear rate obeyed a power law model. The viscosity decreased with increasing metal ion concentration and time.     

Sludge Ozonation and its Application to a New Advanced Wastewater Treatment Process with Sludge Disintegration

The applicability of sludge ozonation on wastewater treatment processes was investigated to reduce the amount of excess sludge without losing phosphorus removal efficiency. Solubilization degree per ozone consumption for general sludge was in the range from 2.4 to 5.8 gSS/O₃ and from 4.1 to 7.7 gCOD/gO₃. Around 80 to 90% of solubilized organics was biodegradable at a solubilization degree of 0.3. Based on the experimental results, a lab-scale plant with sludge ozonation and phosphorus crystallization was constructed to investigate the treatment performance. Amount of excess sludge was reduced by 93% with almost complete removal of soluble BOD and phosphorus removal efficiency of more than 80%. The percentage of the effluent COD_Cr discharge increased from 10% to 14–17% after installing ozonation and crystallization because of the formation of non-biodegradable organic substances in ozonation process. Energy consumption of the innovative advanced process is comparable or can be even smaller than that of the conventional anaerobic/oxic (A/O) process in spite of the installation of ozonation and crystallization.     

炼油废水生化污泥絮凝处理试验

针对炼油废水生化污泥含水率高、脱水困难等问题,进行了污泥絮凝处理试验研究。试验结果表明阳离子聚丙烯酰胺(CPAM)是炼油废水生化污泥处理的理想絮凝剂。生化污泥经絮凝处理后,污泥具有良好的沉降性能和脱水性能,过滤脱水后,污泥的含水率可从94%~99.8%降低到70%~85%,降低了污泥的含水率和体积,便于运输和最终处置。     

化学絮凝作用对高盐废水Fenton氧化处理过程中产生污泥特性的影响研究

高盐Fenton氧化后产生的氢氧化铁污泥粒度较小,很难通过粗过滤(板框压滤)的方式进行去除。本研究采用聚丙烯酰胺(PAM)对该污泥进行了絮凝和脱水进行中试脱水实验。经过化学絮凝后,污泥的粒径明显增加。PAM絮凝效果显著依赖于溶液的pH,当pH超过10后PAM的絮凝效果变差或失去效用。此外,经过PAM絮凝后,污泥比阻大幅降低,过滤速率明显提高。因此,采用PAM絮凝作为板框粗过滤的预处理技术是可行的。     

First Studies on the Rheological Behavior of Suspensions in Ionic Liquids

The suspension rheology of hematite in the ionic liquid Ecoeng^TM.212 was studied in detail and compared to the pure ionic liquid. This is the first report on the rheological behavior of suspensions in ionic liquids, and it is postulated that colloidal stability and rheology must be considered to understand these results, and to overcome limitations on the production of nanosized particles in industrial applications. Concentrated suspensions of particles in the nanometer range show non‐Newtonian flow behavior including shear thinning and shear thickening. These phenomena are mainly caused by particle‐particle interactions in the suspension, and control of these interactions is critical. The influences of temperature and solid concentration on flow behavior were shown for the pure liquid and the suspensions. It is seen that the ionic liquid follows the Arrhenius equation for non‐associating electrolytes. It is possible to shift all hematite suspension curves to a master curve according to the model of Gleißle and Baloch. Furthermore, the flow behavior of the suspensions can be modeled with the well‐known Herschel‐Bulkley plot. A 10 wt % suspension of Fe₂O₃ follows Newtonian behavior over the entire range, similar to the pure ionic liquid. It is believed that the ionic liquid has an influence on the stability of the particles, leading to a decrease of attractive particle‐particle forces.     

Flocculation Effects of Ozone

There are numerous reports on coagulation/flocculation effects of preozonation, which cannot be interpreted by one single mechanism. About 7 basic processes are presently discussed. This paper presents results from drinking and wastewater treatment, indicating that preozonation effects can be explained with algae flocculation, with the destabilization of particles, and with polymerization of the dissolved organics. In view of the complexity of the systems, it is anticipated that several processes can be responsible, leading to an optimum ozone dosage.     

阳离子型絮凝剂在模拟印染废水中的应用

以直接绿5GLL、活性艳橙K-GN两种模拟印染废水为对象,研究了阳离子絮凝剂PDA的处理效果.研究结果表明,处理效果与絮凝剂的阳离子度、投加量有关,阳离子度为50%的PDA对直接绿5GLL、活性艳橙K-GN较适用,脱色率达65%以上;pH值对处理效果基本没有影响.