微波法复合絮凝剂PAFC-PAM的制备及脱色性能

研究了以三氯化铝,三氯化铁和阳离子聚丙烯酰胺为原料,在微波辐照下制备PAFC-PAM复合絮凝剂的工艺条件,探讨了pH值、复合絮凝剂投加量对活性染料模拟废水脱色率的影响,并考察了其对实际印染废水的处理效果。结果表明:在PAM/PAFC质量比为0.25、微波合成功率150W、微波时间3min制得的复合絮凝剂,浊度去除率为98.8%。在pH=8,投加量为42mg/L的最佳絮凝条件下,复合絮凝剂对模拟染料废水脱色率高达97%。与PAFC和PAM相比,PAFC-PAM具有较宽的pH适宜范围和较低的投加量且对实际印染废水的处理效果优于PAFC和PAM。     

A two stage batch adsorber design for methylene blue removal to minimize contact time

The adsorption of methylene blue onto bentonite in a batch adsorber has been studied. Three kinetic models, the intraparticle diffusion equation and the pseudo first and second order equations, were selected to follow the adsorption process. Kinetic parameters, rate constants, equilibrium adsorption capacities and related correlation coefficients for each kinetic model were calculated and discussed. It was shown that the adsorption of methylene blue onto bentonite could be described by the pseudo second order equation. Adsorption of methylene blue onto bentonite followed the Langmuir isotherm. A model has been developed for the design of a two stage batch adsorber based on pseudo second order adsorption kinetics. The model has been optimized with respect to operating time in order to minimize total contact time to achieve a specified amount of methylene blue removal using a fixed mass of adsorbent. The results of two stage batch adsorber design studies showed that the required times for specified amounts of methylene blue removal significantly decreased. This design is particularly suitable for low-cost adsorbents/adsorption systems when minimising contact time is a major operational and design criterion and a significant volume of effluent needs to be treated in the minimum amount of time.     

地铁运行引起的地面振动实测及传播规律分析

对地铁线路某区间段的地面振动进行实测,采集不同测线和不同测点处的水平方向、竖直方向加速度,并转化为傅里叶幅值谱对其进行衰减规律分析。利用公式将加速度记录换算为振级和分频振级,参照相关的国家标准分析不同距离处的振级和频率成分。对比同一加速度记录中的两对开方向列车引起的地面振动,进一步分析振动衰减的规律。所得到的结果可供地面建筑的隔振减振及城市轨道的规划和设计参考。