水合物法的天然气提氦技术研究

氦气是发展国防军工和高科技产业不可或缺的战略性物资之一.由于氦气在自然界中的富集度很低,目前工业规模化提氦来源主要是含氦天然气.常用的提氦方法有吸附法、吸收法、低温冷凝法、膜分离法等,但它们都不能很好地解决提氦难度大、成本高、规模化工业应用水平较低等缺点.因此,引入水合分离技术,利用含氦天然气各组分生成水合物的条件差异在水合反应过程中对氦气提浓,同时辅以催化脱氢工艺,实现粗氦的精制.     

环境样品中汞形态分析技术的进展

汞的毒性、环境行为、生物有效性不仅跟其浓度有关,还决定于其化学形态,因此汞的形态分析在环境科学中具有重要意义。样品前处理几乎是汞形态分析研究中不可或缺的步骤,而色谱和光谱/质谱联用技术是目前普遍采用的分离检测方法。文章对近十年来这些方面的研究进展进行了综述,主要包括样品的前处理方法如酸/碱溶剂萃取、微波辅助萃取、固相萃取、固相微萃取、单滴微萃取、分散液液微萃取等,以及色谱(液相色谱、气相色谱)和毛细管电泳与光谱/质谱(紫外可见光谱、原子吸收光谱、原子荧光光谱、等离子体质谱等)的联用技术在汞化合物形态分析中的应用情况。最后提出今后应重点研究建立高效、简便的前处理方法,发展高分离度、高灵敏度、高速度的分离检测联用技术,以便更好地对汞的形态进行分析监测。     

Evaluation of a recycling process for printed circuit board by physical separation and heat treatment

Printed circuit boards (PCBs) from discarded personal computer (PC) and hard disk drive were crushed by explosion in water or mechanical comminution in order to disintegrate the attached parts. More parts were stripped from PCB of PC, composed of epoxy resin; than from PCB of household appliance, composed of phenol resin.In an attempt to raise the copper grade of PCB by removing other components, a carbonization treatment was investigated. The crushed PCB without surface-mounted parts was carbonized under a nitrogen atmosphere at 873–1073 K. After screening, the char was classified by size into oversized pieces, undersized pieces and powder. The copper foil and glass fiber pieces were liberated and collected in undersized fraction. The copper foil was liberated easily from glass fiber by stamping treatment.As one of the mounted parts, the multi-layered ceramic capacitors (MLCCs), which contain nickel, were carbonized at 873 K. The magnetic separation is carried out at a lower magnetic field strength of 0.1 T and then at 0.8 T. In the +0.5 mm size fraction the nickel grade in magnetic product was increased from 0.16% to 6.7% and the nickel recovery is 74%.The other useful mounted parts are tantalum capacitors. The tantalum capacitors were collected from mounted parts. The tantalum-sintered bodies were separated from molded resins by heat treatment at 723–773 K in air atmosphere and screening of 0.5 mm. Silica was removed and 70% of tantalum grade was obtained after more than 823 K heating and separation.Next, the evaluation of Cu recycling in PCB is estimated. Energy consumption of new process increased and the treatment cost becomes 3 times higher comparing the conventional process, while the environmental burden of new process decreased comparing conventional process.The nickel recovery process in fine ground particles increased energy and energy cost comparing those of the conventional process. However, the environmental burden decreased than the conventional one.The process for recovering tantalum used more heat for the treatment and therefore the energy consumption increased by 50%, when comparing with conventional process. However, the market price for tantalum is very large; the profit for tantalum recovery is added. Also the environmental burden decreased by the recycling of tantalum recovery. Therefore, the tantalum recovery is very important step in the PCB recycling. If there is no tantalum, the consumed energy and treatment cost increase in the new process, though the environmental burden decreases.     

IMS Method Performance Analyses for Giardia in Water Under Differing Conditions

Immunomagnetic separation (IMS) has been specified as a standard method for the measurement of Giardia under USEPA Method 1623. In this study, IMS was evaluated on the basis of recovery efficiencies for Giardia cysts under various IMS operation conditions. Significant change in recovery was observed by altering the debris ratio of water samples. Notably, cyst recovery efficiencies utilizing IMS dropped with increased turbidity, and results for varying dosages of magnetic beads and cysts indicate that 1 / 100 immunomagnetic beads is sufficient to conjugate large numbers of cysts. Changing vessel volume and replacing the sample buffer had no significant effect on cyst recovery efficiencies.     

高含盐废水脱盐处理技术研究进展

综述了几种常见的高含盐废水脱盐处理技术的发展历程、工艺原理、优缺点及目前的研究进展,分析了热分离、膜分离、电渗析、离子交换、电吸附、微生物脱盐等方法的优缺点,展望了未来废水脱盐工艺的发展方向。指出：脱盐方法将根据各类水体的水质特点更加精细化;多种脱盐技术联合应用也是今后废水脱盐的发展方向。     

再生聚丙烯的洁净化和高质化应用

聚丙烯以其优异的机械性能、高的性价比和多重改性方式成为重要的通用树脂之一,这些产品废弃后产生了种类繁多和数量巨大的再生聚丙烯.通过将再生聚丙烯根据性能和来源进行分类,然后分类阐述各再生聚丙烯物料特点,结合再生聚丙烯改性方式,为高质化应用提出方向.     

膜吸收器吸收CO2的影响因素研究

采用聚丙烯中空纤维膜吸收器,用水、NaOH和K2CO3 水溶液作为吸收剂进行高浓度CO2 吸收试验,考察了气体流率、吸收剂流率、质量分数以及流动方式对吸收率、传质系数和传质速率的影响.结果表明,随着气体流率增大,CO2的吸收率递减,总传质系数和总传质速率增加.在一定的气体流率下,吸收液流率增大,CO2的吸收率、总传质系数和总传质速率增大;吸收液浓度提高,吸收率增大,总传质系数和总传质速率提高.在气体流率较低时,质量分数为5%和8%的NaOH水溶液为吸收剂时的吸收率、总传质系数和总传质速率比较接近.随着气体流率增大,NaOH质量分数为8%时的吸收率、总传质系数和总传质速率增加的值大大超过NaOH质量分数为5%时增加的值.以水为吸收剂时,气体与吸收剂的流动方式为逆流时的吸收率、总传质系数和总传质速率高于并流时的值.     

聚氨酯泡沫材料阴燃发展过程的特性分析

分析对比了相同加热条件下的聚氨酯泡沫材料在有氧和无氧气氛下的升温过程,并对不同加热条件下的聚氨酯泡沫材料的阴燃传播速度进行研究.结果表明:沿着反应进行的方向,分离点的温度越来越低,不同热流条件下的温度分离曲线斜率在实验稳定发展段的变化规律表现得很相似,并在分离点出现后,有氧气氛中的该位置温度在短时间内急剧上升;在阴燃不稳定传播阶段时,热解前锋的速度小于氧化前锋的速度,在稳定传播阶段时,热解前锋速度与氧化前锋速度近乎相等.     

Hydrograph Separation by Incorporating Climatological Factors: Application to Small Experimental Watersheds 1

Abstract: Evaluating the relative amounts of water moving through the different components of the hydrological cycle is required for precise management and planning of water resources. An important aspect of this evaluation is the partitioning of streamflow into surface (quick flow) and base‐flow components. A prior study evaluated 40 different approaches for hydrograph‐partitioning on a field scale watershed in the Coastal Plain of the Southeastern United States and concluded that the Boughton’s method produced the most consistent and accurate results. However, its accuracy depends upon the proper estimation of: (1) the end of surface runoff, and (2) the fraction factor (α) that is function of many physical and hydrologic characteristics of a watershed. Proper identification of the end of surface runoff was accomplished by using a second derivative approach. Applying this approach to 12 years of separately measured surface and subsurface flow data from a field scale watershed (study area) proved to be accurate for 87% of the time. Estimation of the α value was accomplished in this study using two steps: (1) alpha was fitted to individual hydrographs: and, (2) a regression equation that determines these alpha values based on climatological factors (e.g., rainfall, evapotranspiration) was developed. Using these strategies improved the streamflow partitioning method’s performance significantly.     

砷华废渣的综合利用

采用氧化焙烧-软锰矿浆吸收、磁化焙烧-磁选、酸浸工艺处理砷华废渣.氧化焙烧的适宜条件为焙烧温度650 ℃,焙烧时间60 min,废渣粒径97 μm.磁化焙烧的适宜条件为焙烧温度550 ℃,焙烧时间30 min.酸浸的适宜条件为硫酸质量分数20%.经全流程实验,硫以MnSO4*H2O的形式回收,产品质量达到工业级硫酸锰一级标准.铁回收率为84.8%,锌回收率为80.9%,处理后废渣中银含量达246 g/t.处理过程产生的废弃物中砷较为稳定.