真空紫外光解α-蒎烯的去除特性和产物分析

采用真空紫外(vacuum ultraviolet,VUV)光解α-蒎烯模拟废气,系统研究了工艺参数、反应介质、活性自由基团对去除率的影响,并对光解产物初步进行分析。结果表明,随着进气流量和进气浓度的增加,去除率相应减少;停留时间为15s,去除负荷达到最大值,为39.003mg.m-3.s-1;进气浓度对反应动力学有较大影响,低浓度转变为高浓度时,一级反应动力学转变为二级反应动力学;反应介质对一级动力学常数影响较大,湿度为35%～45%的标准空气作为反应介质时,一级动力学常数达到最大值,为0.0520s-1;光解体系中存在羟基自由基和臭氧两类主要的强氧化性物质,且羟基自由基最先和α-蒎烯反应,但臭氧氧化占据量的优势;光解产物主要是水溶性较好的小分子醛酮类化合物和羧酸类化合物。     

旋流塔板上气体流场的数值模拟

采用二方程ｋ－ε湍流模型，以实验数据确定入口条件，用ＳＩＭＰＬＥ算法对旋流塔板上气体的速度场及静压场进行了数值计算。其结果与实验值吻合良好，表明数值模拟可用来预测较实验更为详细的气流运动特点。     

声电联合技术氧化降解2-氯酚的研究

在优化电解（EC）条件的基础上，以2-氯酚（2-CP）为模拟污染物，研究了超声（US）-电解（EC）联合技术氧化降解的性能，并初步探讨了其降解过程．结果表明：电解质Na2SO4浓度和pH是影响声电组合技术的重要因素，当pH〉9，电解质Na2SO4浓度大于0．15mol／L时，声电组合降解2-CP的效率最高．US—EC降解2-CP的动力学方程符合拟一级动力学关系，其表观反应速率常数（0．0096min^-1）大于EC（0．0055min^-1）和US（0．0034min^-1）两种单因素作用之和，表明超声与电解组合降解2-CP时，对电解产生显著的协同效应。通过LC／MS检测，2-氯-1，4-对苯醌为2-CP降解中间产物，说明2-CP的降解经历了羟基对位氧化、开环等过程．     

Sludge ozonation and its effect on performance of submerged membrane bio-reactor

To investigate the effects of ozonation on minimizing the excess sludge and enhancing the nitrogen removal in an effluent,batch and continuous experiments in two MBRs with and without sludge ozonation (namely combined and reference run) were carried out. Through ozonation at a dose of 0.16 mg O3/mg MLVSS,53.1% of the treated MLVSS was solubilized,and soluble SCOD/TN ratio of ozonized sludge (OS) was about 8.6 due to the release of cellular nitrogen-contained materials and SCOD loss by ozone mineralization. In addition,the results of batch nitrification and denitrification tests with OS supernatant indicated that solubilized sludge could act as a reducing power for denitrification and a nitrogen source for nitrification. 40-day operation of two MBR systems demonstrated that the recirculation of OS into a bioreactor enabled the combined system have two advantages over the control one. The observed sludge yield (Yobs) was decreased from 0.13 to 0.06g MLSS/g COD,while the nitrogen removal was increased from 64.6% to 72.3%. And sludge ozonation elevated the inorganic fraction of MLSS,but did not impact sludge activities.     

Pd修饰LaNi5贮氢电极的电催化脱氯性能

为提高对氯苯酚(4-CP)脱氯的有效性,采用化学沉积法制备了镧镍合金镀钯电极(Pd/LaNi₅),对其进行了X射线衍射(XRD)、扫描电子显微镜(SEM)和线性扫描伏安(LSV)表征。电催化实验结果表明Pd/LaNi₅电极显示了比LaNi₅电极和Pd/Ni电极更高的4-CP脱氯活性,在初始浓度0.1 mmol·L^-1、表观电流密度10 mA·cm^-2、pH 4.0和钯载量1.8 mg·cm^-2时,4-CP的脱氯率和电流效率分别达到77.3%和0.14%。基于物理化学表征,可以断定电化学脱氯活性的增强主要源于LaNi₅更好的储氢能力。     

旋流塔板上液滴的初始流率分布

在内径３００ｍｍ旋流板试验塔内，以空气－水为介质，采用双探针法液滴粒径分布自动测量系统，测定了不同操作工况下、不同初始位置上液滴流率的相对值；并对影响液滴初始流率的三参数进行了分步回归，拟合出分布函数。     

喷射态筛板上液滴的初始抛射速度

<正> 引言 在喷射状态下的筛板上,存在着大量的以“抛射”方式运动中的液滴,其初始抛射速度v_0是影响该种操作状态下筛板流体力学和传质性能的重要因素.液滴初始抛射速度的研究是深入了解塔板上液滴运动规律和气液接触过程的前提. 目前为止,见诸报道测定v_0的方法只有平板印痕法和摄影法两种,并且由这两种方法所测数据而整理出的结果关联式相差也很大,液滴初始抛射速度的问题尚未能得到     

旋流塔板上的两相流场

在直径300mm塔内,用激光多普勒测速仪对旋流塔板上的流场进行了实验研究,探明其主要特征,进一步证实了过去对不同用途板型的设计思想.采用两方程k-ε湍流模型,应用有限差分法,对塔板上的气流场进行了数值模拟,计算结果与实验值符合良好.     

Aerobic Biodegradation of Chlorinated Hydrocarbons by Bacillus circulans WZ-12 CCTCC M 207006 under Saline Conditions

A novel saline-tolerant bacterium Bacillus circulans WZ-12 was evaluated for its potential to degrade four chlorinated hydrocarbons under saline conditions. CH₂Cl₂ was effectively degraded by Bacillus circulans WZ-12 cells in the medium containing NaCl concentrations ranging from 5 g·L^-1 to 10 g·L^-1, and the maximum degradation efficiency (85%) was achieved at NaCl concentration of 10 g·L^-1. Similarly, Bacillus circulans WZ-12 was able to degrade CH₂BrCl, C₂H₄Cl₂, and C₂H₂Cl₂ in the presence of 10 g NaCl per liter within 24 h. Cells of Bacillus circulans WZ-12 grown in minimal salt medium contained low levels of glycine betaine (GB), but GB levels were 3- to 5-fold higher in cells grown in media with high salt. Kinetic analysis revealed that biodegradation of the four chlorinated hydrocarbons was concentration dependent and a linear inverse correlation (R² 0.85-0.94) was observed between the rate of biodegradation (V) and salt concentration from 5 g·L^-1 to 60 g·L^-1. The growing cells (in minimal salt medium) degraded approximately 50% of the CH₂Cl₂ within 24 h, whereas the resting cells (in physiological saline) degraded only 25% of the CH₂Cl₂ within 24 h and were inactive after 36 h cultivation. Biodegradation could be repeatedly performed for more than 192 h with more than 50% removal efficiency. Bacillus circulans WZ-12 grows well in an aqueous/oil system, hence, it is effective for the treatment of industrial effluents that contain chlorinated hydrocarbons with high salt concentrations.