阳离子型聚丙烯酰胺在强酸性环境下的絮凝性能

通过使用阳离子型聚丙烯酰胺(CPAM)对泥沙含固量为50%的强酸性土壤清洗废水进行絮凝沉淀处理,结果表明:在强酸性环境下,阳离子型聚丙烯酰胺依然具有稳定高效的絮凝性能,当相对分子质量为1 400万、离子度为30%、用量在13mg/L时,阳离子型聚丙烯酰胺的絮凝性能非常优异,能在1h内将泥沙含固量降至6%。     

聚丙烯酰胺絮凝处理低放含钚废水技术

以MgCl2作为助剂,采用不同相对分子质量的阳离子聚丙烯酰胺(PAM)对低放含钚废水进行絮凝处理,以钚去除率为评价指标,确定较优絮凝剂及其最佳絮凝条件,对絮凝过程中产生的放射性泥浆体积和沉渣量进行研究,并与传统无机絮凝剂进行比较.实验采用有机絮凝法处理后的废水中钚放射性浓度低于1 Bq/L,钚去除率大于95％.结果表明...     

榕树叶-活性污泥协同曝气处理含

为提高含铀废水的处理效率,改善固液分离效果,采用具有强富集性的榕树叶和具有絮凝作用的城市活性污泥,联合处理含铀废水。探讨了溶液pH值、铀溶液初始浓度、曝气量对含铀废水中铀去除效果的影响及榕树叶-活性污泥相互作用的协同效应,并讨论了榕树叶-活性污泥的等温吸附行为。研究结果表明,榕树叶-活性污泥联合处理含铀废水时产生的协同作用对铀的去除率比单独体系的几何叠加去除率约高70%;当含铀废水的初始pH值为3.5时,去除率达最大,约为100%;pH值增加,去除率明显下降;曝气量在80~100L/h时,铀的最佳去除率达85%以上;榕树叶-活性污泥协同处理不同浓度铀的吸附等温线符合Langmuir和Freundlich等温吸附方程,其相关系数(r)分别为0.992 5和0.999 8。     

聚丙烯酰胺及其衍生物在小口径钻孔护壁堵漏浆液中应用的初步试验

聚丙烯酰胺及其衍生物,目前用于钻孔护壁堵漏浆液中的有:非水解聚丙烯酰胺(PAM)、水解聚丙烯酰胺(HPAM)、磺化聚丙烯酰胺(SPAM)和聚丙烯酸钙(CPA)等。它们与其他处理剂配合,配制的低固相泥浆、无固相冲洗液、速效堵漏浆液和水泥浆等,已在生产和实验室试验中取得了一定的结果,对于小口径钻孔的护壁与堵漏已初步显示出其使用效果和应用前景。一、PAM-水玻璃无固相冲洗液由于高效能处理剂的应用,泥浆从高固相进化到低固相,泥浆的性能得到了很大的改善。那么进而能否这样推断,低固相泥浆的进一步发展,将会出现以新的护壁原理和     

聚丙烯酰胺-咪唑类聚离子液体凝胶的辐射合成及其对铀和碘的吸附

采用γ射线辐射引发技术制备了一类聚丙烯酰胺-咪唑类聚离子液体凝胶(PAm-C_nvim_2Br_2)。当吸收剂量为5kGy时,得到了凝胶分数超过95%的聚离子液体凝胶,其溶胀度可由吸收剂量控制。合成的PAmC_nvim_2Br_2可以从碳酸盐溶液中吸附铀最大吸附量约130mg/g,或从碘化钠溶液中吸附碘离子最大吸附量约160mg/g,吸附过程符合Langmuir模型。红外与XPS分析表明,吸附过程遵循离子交换的反应机理。PAmC_nvim_2Br_2凝胶对铀及碘有很好的吸附、解吸性能,有望用于含有铀和碘的放射性废水处理。     

聚丙烯膜辐射接枝聚丙烯酰胺制备锂离子二次电池隔膜研究

通过共辐射接枝的方法将聚丙烯酰胺(Polyacrylamide,PAAm)接枝到聚丙烯(Polypropylene,PP)膜上,研究了丙烯酰胺单体浓度对接枝率的影响。接枝前后隔膜的红外光谱(Fourier transform infrared spectroscopy,FT-IR)对比表明,聚丙烯酰胺已经成功接枝到PP膜上,对隔膜的热性能、机械性能、电导率等性能进行了表征。将隔膜组装成扣式电池后,充放电循环性能测试结果表明,在相同条件下以PP-g-PAAm作为隔膜的锂离子电池性能优于以原始PP作为隔膜的电池性能。     

明胶/聚丙烯酸/聚N-异丙基丙烯酰胺高强度形状记忆水凝胶的辐射合成及其性能

以明胶、丙烯酸、N-异丙基丙烯酰胺、N,N′-亚甲基双丙烯酰胺为原料,通过两步辐照法制备了具有温度和pH响应的高强度明胶/聚丙烯酸/聚N-异丙基丙烯酰胺形状记忆水凝胶(GAN)。系统研究了GAN的结构、形貌、力学性能和形状记忆行为。结果表明,GAN具有致密的网络结构,其最高拉伸强度及最大断裂伸长率分别可达(5.4±0.3) MPa和745%。GAN在60℃及pH=12.8的形状恢复所需时间分别为10 s及15 min,形状固定率和形状恢复率均在90%以上,显示出优异的环境响应性能。本工作建立了一种制备环境响应型高强度形状记忆水凝胶的新方法。     

聚丙烯酰胺包覆磁性纳米凝胶的光化学法制备及其机理研究

以丙烯酰胺为单体，N，N’-亚甲基双丙烯酰胺为交联剂，采用光化学方法在水溶液体系中制备了聚丙烯酰胺（Polyacrylamide，PAM）包覆的磁性纳米凝胶，用傅立叶变换红外光谱（Fourier transform infrared spectroscopy,FTIR），光子相关光谱（Photo correlation spectroscopy,PCS）和电子自旋共振（Electron spin resonance，ESR）波谱对聚丙烯酰胺磁性纳米凝胶进行了表征。研究了磁性纳米凝胶粒径随反应时间、单体浓度、交联剂浓度的变化规律，并探索了聚丙烯酰胺磁性纳米凝胶的包覆机理。     

絮凝-微滤组合工艺处理含钚废水

为了有效地应用絮凝沉淀与中空纤维膜微滤(CMF)组合工艺处理低放射性的含钚废水，对废水处理工艺中的关键运行条件进行了优化：硫酸亚铁的最佳加入量为ρ（Fe²⁺）=35～60 mg/L，出水pH控制在6.5～9.0，钚去除率大于99.9%。同时还对含U，Am的Pu废水处理实验条件进行了优化，建立了处理含铀、钚、镅的混合废水的实验工艺流程并进行了验证实验。结果表明，采用CMF工艺处理含铀、钚、镅的混合废水，单级处理的总α去除率达到99.87%。     

电子束辐照制备卤胺抗菌棉织物

选用(3-丙烯酰胺丙基)三甲基氯化铵(AAPTAC)为卤胺抗菌单体,采用共辐照工艺制备抗菌棉织物。研究了吸收剂量对织物含氯量和断裂强力的影响。结果表明,织物含氯量随吸收剂量的增加而增多,织物断裂强力随吸收剂量的增加而下降。傅里叶红外光谱证明AAPTAC已成功接枝到棉织物上,扫描电子显微镜分析表明,棉织物的表面具有覆盖物。吸收剂量为43.3 kGy时,氯化后的棉织物可在5 min内杀灭100%的金黄色葡萄球菌和大肠杆菌。     

清洗级联分离同位素的过程中沉积物物质分布的计算方法

在级联分离同位素的过程中,某些分离工质会在级联内发生化学反应,持续产生少量的固体物质沉积在分离设备内。随着沉积物的增加,将逐步影响分离设备的分离性能,进而影响级联的生产运行,因此需要定期对沉积物进行清理。本文针对清理过程,提出一种数值计算方法,用于级联内不同气态物质分布规律的计算。该算法在单机清理参数已知的前提下,以级联级间物质守恒为基础,采用线性迭代算法描述级联内各类气态物质的分布情况,通过总的物质守恒达到计算收敛。算例的数值计算结果表明,本算法在不同级联工况下均能稳定收敛。     

核电厂地坑过滤器附加质量试验研究

采用测量转动惯量的方法对核电厂安全壳地坑过滤器水下附加质量进行测量,分别测量了圆柱、圆筒、双层圆筒、圆筒形地坑过滤器4种结构。将圆柱的附加质量测量值与在理想流体中的理论值进行对比,验证了该方法可以比较准确地测量附加质量。结果分析表明,附加质量不随激振频率变化,圆筒结构附加质量为圆柱结构的1.9倍,双层圆筒附加质量与单层圆筒差异不大;地坑过滤器由于表面开孔附加质量较圆筒结构降低70%;地坑过滤器附加质量与本身质量的值为同一数量级,地坑过滤器设计时不能忽略附加质量。     

超短脉冲激光自生磁场同位素分离实验研究

通过超短脉冲激光与固体氮化硼（BN）靶相互作用过程中产生的自生磁场实现了对同位素硼的分离,采用二次离子质谱法（SIMS）对同位素分离效果进行了测量。研究表明,一级浓缩比达50.8%。     

Principal component analysis in an experimental cold flow model of a fluid catalytic cracking unit by gammametry

The fluid dynamic behavior of riser of a cold flow model of a Fluid Catalytic Cracking Unit (FCCU) was investigated. The experimental data were obtained by the nuclear technique of gamma transmission. A gamma source was placed diametrically opposite to a detector in any straight section of the riser. The gas-solid flow through riser was monitored with a source of Americium-241 what allowed obtaining information of the axial solid concentration without flow disturbance and also identifying the dependence of this concentration profile with several independent variables. The MatLab^® and Statistica^® softwares were used. Statistica tool employed was the Principal Components Analysis (PCA), that consisted of the job of the data organization, through two-dimensional head offices to allow extract relevant information about the importance of the independent variables on axial solid concentration in a cold flow riser. The variables investigated were mass flow rate of solid, mass flow rate of gas, pressure in the riser base and the relative height in the riser. The first two components reached about 98% of accumulated percentage of explained variance.     

Principal component analysis in an experimental cold flow model of a fluid catalytic cracking unit by gammametry

The fluid dynamic behavior of riser of a cold flow model of a Fluid Catalytic Cracking Unit (FCCU) was investigated. The experimental data were obtained by the nuclear technique of gamma transmission. A gamma source was placed diametrically opposite to a detector in any straight section of the riser. The gas-solid flow through riser was monitored with a source of Americium-241 what allowed obtaining information of the axial solid concentration without flow disturbance and also identifying the dependence of this concentration profile with several independent variables. The MatLab^® and Statistica^® softwares were used. Statistica tool employed was the Principal Components Analysis (PCA), that consisted of the job of the data organization, through two-dimensional head offices to allow extract relevant information about the importance of the independent variables on axial solid concentration in a cold flow riser. The variables investigated were mass flow rate of solid, mass flow rate of gas, pressure in the riser base and the relative height in the riser. The first two components reached about 98% of accumulated percentage of explained variance.     

核分析技术研究一种水系沉积物的多元素取样行为

为给研制适用于固体取样微分析质控的天然基体标准物质提供可能的途径，利用3种核分析技术（INAA、PIXE和SRXRF）对自行研制的一种水系沉积物在取样量跨越9个量级（10^-1～10^-10 g）水平进行多元素取样行为研究。实验结果表明，该基体在不同取样量下，一批元素具有满意的取样不确定度。     

分离设备清理的优化方法

分离设备在运行过程中会持续产生少量固体沉积物，需要定期清理。目前常规的清理方法是采用区段单级清理模式，将多个分离设备并联。针对该方法原料用量大、总用时长的缺点，本文提出级联模式清理方法，并通过计算进行单级清理与级联清理方法优化比较。以10级的级联清理为例，优化结果表明，相比常规清理方法，原料使用量节省75.9%，清洗时间节省89.3%。因此，采用级联模式清理可以大幅减少原料使用量，有效缩短清理总时长，显著优于单级模式清理。     

适用于微分析质控的标准物质的探索

本工作选择一种水系沉积物的天然基体进行研究，经研磨、筛选、粒径分布测定后，进行了样品分装和灭菌。结合NAA-PIXE-SRXRF3种核分析技术，在跨越9个量级，即亚g到亚ng的取样量范围内，对这种基体进行了多元素取样行为研究。对准确可称的取样量（几百mg至1mg），利用INAA测定了30余种元素，其中，16种元素的取样不确定度小于1%；利用常规PIXE和微束SRXRF结合的方法，对不可准确称量的更小取样量（<1mg）下的多元素取样行为进行研究。根据入射粒子和待测元素特征X射线在基体中的吸收系数，对实验条件下不同元素的有效取样量进行了估算。初步结果表明：在有效取样量几百μg的条件下，取样不确定度好于1%的有7种元素，在亚ng到几十ng的取样量下，Fe、Cu、Rb的取样不确定度均小于10%，其中，Rb的取样不确定度小于5%。本工作将为研制适用于固体取样的微分析质控天然基体的标准物质提供一个可能的途径。     

Silicate Anion Structural Change in Calcium Silicate Hydrate Gel on Dissolution of Hydrated Cement

High pH conditions of aqueous solutions in a radioactive waste repository can be brought about by dissolution of cementitious materials. In order to clarify the mechanisms involved in maintaining this high pH for long time, we investigated the dissolution phenomena of OPC hydrate.

In the present research, leaching tests on powdered cement hydrates were conducted by changing the ratio of mass of leaching water to mass of OPC hydrate (liquid/solid ratio) from 10∽2, 000 (wt/wt). Ordinary Portland Cement hydrate was contacted with deionized water and placed in a sealed bottle. After a predetermined period, the solid was separated from the solution.

From the results of XRD analysis on the solid phase and the Ca concentration in the aqueous phase, it was confirmed that Ca(OH)₂ was preferentially dissolved when the liquid/solid ratio was 10 or 100 (wt/wt), and that C—S—H gel as well as Ca(OH)₂ were dissolved when the liquid/solid ratio was 500 (wt/wt) or larger. ²⁹Si-NMR results showed that the silicate anion chain of the C-S-H gel became longer when the liquid/solid ratio was 500 (wt/wt) or greater. This indicates that leaching of OPC hydrate results in a structural change of C—S—H gel.     

Development of a Non-conservative Radionuclides Dispersion Model in the Ocean and its Application to Surface Cesium-137 Dispersion in the Irish Sea

A numerical simulation model system that consists of an ocean current model, Princeton Ocean Model (POM), and a particle random-walk model, SEA-GEARN, has been developed to describe the migration behavior of non-conservative radionuclides in a shallow water region. Radionuclides in the ocean are modeled in three phases, i.e., the dissolved phase in seawater, the adsorbed with large particulate matter (LPM) and the adsorbed with active bottom sediment. The adsorption and desorption processes between the dissolved and solid phases are solved by the stochastic method with the kinetic transfer coefficients. Deposition of the LPM and re-suspension from bottom sediment are also considered. The system was applied to simulate the long-term (24-year) dispersion of 137Cs actually released from the BNFL spent nuclear fuel reprocessing plant at Sellafield in United Kingdom. The calculation well reproduced the main characteristics of migration of dissolved ¹³⁷Cs concentration in the Irish Sea.