Removal of phenol by powdered activated carbon adsorption

In this study, the adsorption performance of powdered activated carbon (PAC) on phenol was investigated in aqueous solutions. Batch adsorption studies were performed to evaluate the effects of various experimental parameters like PAC type, PAC dose, initial solution pH, temperature and pre-oxidation on the adsorption of phenol by PAC and establish the adsorption kinetics, thermodynamics and isothermal models. The results indicated that PAC adsorption is an effective method to remove phenol from water, and the effects of all the five factors on adsorption of phenol were significant. The adsorption rate of phenol by PAC was rapid, and more than 80% phenol could be absorbed by PAC within the initial 10 min. The adsorption process can be well described by pseudo-second-order adsorption kinetic model with rate constant amounted to 0.0313, 0.0305 and 0.0241 mg·μg ^-1·min ^-1 with coal, coconut shell and bamboo charcoal. The equilibrium data of phenol absorbed onto PAC were analyzed by Langmuir, Freundlich and Tempkin adsorption isotherms and Freundlich adsorption isotherm model gave the best correlation with the experimental data. Thermodynamic parameters such as the standard Gibbs free energy (?G^o), enthalpy (?H^o) and entropy (?S^o) obtained in this study indicated that the adsorption of phenol by PAC is spontaneous, exothermic and entropy decreasing.     

多环芳烃活性参数与色谱保留指数相关性分析

为了简化多环芳烃(PAHs)的Koc、Kow和BCF等活性参数的测定和预测工作,通过对PAHs的活性参数与气相色谱保留指数(I)、苯环个数(N)的相关关系分析,分别建立了I与lgKoc、lgKow和lgBCF,N与lgKoc、lgKow和lgBCF间的2类一元线性回归预测方程,以及I、N与lgKoc、lgKow和lgBCF间的二元线性回归预测方程。结果表明,PAHs类化合物的I值或N值分别与lgKoc、lgKow和lgBCF存在明显的线性相关性,均能对上述3种活性参数进行准确预测,其中,用I值建立的一元回归方程的预测精度更好;而利用I值和N值共同建立的二元预测方程经t检验发现,方程中变量N的偏回归系数的统计检验没有显著意义。本研究利用I值建立的一元线性预测模型能较好地预测PAHs类化合物的Koc、Kow和BCF等活性参数,从而为PAHs的活性参数预测提供了一种简便易行的方法。     

甲醛及苯系物混合暴露对小鼠肺脏的氧化损伤作用

为探讨甲醛、苯、甲苯及二甲苯混合气体急性暴露对小鼠肺脏的氧化损伤作用,选用雄性健康昆明种小鼠50只,随机分为对照组和4个染毒组。染毒组1到4中甲醛、苯、甲苯和二甲苯浓度依次为:1.0+1.1+2.0+2.0μg·L-1、3.0+3.3+6.0+6.0μg·L-1、5.0+5.5+10.0+10.0μg·L-1、10.0+11.0+20.0+20.0μg·L-1,各染毒组混合气体的浓度分别是我国室内空气质量标准(GB/T18883-2002)的10、30、50和100倍。用静式吸入染毒方式,每天染毒2h,共染毒10d,实验结束后,测定小鼠肺脏中的氧化损伤指标。结果表明:染毒组小鼠的体重增加幅度均低于对照组,肝脏和脾脏系数显著低于对照组,肺脏ROS、MDA含量随染毒剂量的增加而增加,T-AOC、GSH、CAT、GSH-Px及SOD活力随染毒剂量的增加而降低,并且ROS、MDA含量与混合气体的浓度呈显著的正相关关系,GSH含量与混合气体的浓度呈显著的负相关关系。研究结果显示,甲醛、苯、甲苯及二甲苯混合气体急性暴露对小鼠肺脏具有氧化损伤作用,混合气体的联合毒性效应强于单一组分,ROS、MDA和GSH可以作为评价VOCs急性暴露对机体氧化损伤作用的敏感生物学标志。     

障碍物对火焰传播过程影响数值模拟

采用CFD软件AutoReaGas建立典型的物理模型及数值模型来研究管道内障碍物对可燃气体爆炸火焰传播的影响规律。结果表明,障碍物间距、阻塞率的改变会对爆炸场内的火焰传播速率产生巨大影响。障碍物间距的改变对火焰传播速率的影响是一个先增大后减小的过程;低阻塞率下,火焰传播速度较低。但随着阻塞率的增大可燃气体爆炸火焰传播速度得到明显的增大。为障碍物对可燃气体爆炸传播规律的影响的进一步研究提供了理论依据。     

带乘员及约束系统汽车正面碰撞的有限元法仿真研究

采用计算机模拟的方法,对国产某轿车发生正面碰撞时,乘员在佩带三点式安全带的约束状态下的运动响应进行研究,从乘员的运动响应情况、乘员舱的变形情况、假人的HIC值等几个方面分析了该车型的乘员保护安全性能.模拟结果表明,该车达到了安全法规的要求.并探讨了运用有限元法对带乘员及约束系统的整车正面碰撞的计算机模拟方法.     

淮安市砂土地震液化势的综合评估

建立了BP神经网络模型LM算法的砂土地震液化判别方法,采用LVQ模式分类网络对数据进行分类,选取唐山地震时76个场地、320组现场液化勘察资料为研究对象,训练和检验网络模型的数据各160组,结果表明,该方法的砂土液化预测准确度为96.8%。根据淮安市典型场地土的钻孔资料,采用《建筑抗震设计规范法》液化判别法(规范法)、美国国家地震研究中心建议的液化判别简化方法(NCEER法)和谢君斐-陈国兴液化判别方法(谢-陈法)等3种液化判别方法及本文提出的BP神经网络模型液化判别方法对22个钻孔、120标贯点进行了液化判别,结果表明:14种地震液化判别方法的计算结果基本一致;2NCEER法比谢-陈法的计算结果要保守;3谢-陈法与规范法的计算结果很吻合,预测正确率相差不大;4规范法相对BP神经网络模型法的计算结果要保守;5BP神经网络模型法比其他3种方法的预测结果更符合实际的液化规律。最后,综合4种方法的液化判别结果给出了该地区地震液化势的评估结果,并给出了部分典型地质剖面土层地震液化势分布图。     

Pollution extents of organic substances from a coal gangue dump of Jiulong Coal Mine,China

This paper addresses the distribution and occurrence of harmful organic substances in coal gangue dump from Jiulong Coal Mine and its influence on the environment. The samples were taken from the coal gangue dump and coal waste water stream and analyzed by organic geochemical methods. The results indicate that the coal gangues contain abundant harmful organic substances like polycyclic aromatic hydrocarbons. The TOC and sulfur contents of the samples are much higher than those of the background sample except Sample JL7. The contents of organic bulk parameters are relatively high. Ten carcinogenic PAHs were identified and these harmful organic substances have influenced the surrounding area. Along the waste water stream, organic substances pollute at least 1,800 m far from the coal gangue dump.     

武钢炼铁厂7~#高炉供料系统槽上除尘设计

介绍了武钢7#高炉供料系统槽上除尘设计的考虑因素,针对各种方法的优缺点,采用了槽上侧边抽风加移动式除尘通风口的除尘工艺,取得了很好的除尘效果。并给出了上料过程中产生的粉尘特性及所采用的除尘设备的主要参数,可供参考。     

微波诱导催化剂Fe_2O_3/Al_2O_3对甲基橙废水的处理

采用微波诱导氧化工艺(MIOP)处理模拟甲基橙废水,考察了催化剂用量、微波辐射时间、微波辐射功率及pH值对甲基橙脱色率的影响。结果表明:在微波功率900W、辐射时间5min、催化剂用量2g/L的条件下,处理20mg/L的甲基橙废水脱色率可达93.2%。同时动力学分析表明,该氧化过程符合一级动力学规律。     

Data assimilation in a simple marine ecosystem model based on spatial biological parameterizations

Assuming that a set of constant parameters fits for marine ecosystem modeling and parameter estimation studies on large space scales is questionable since ecosystem types spanning long distances are quite different. In this study, SeaWiFS chlorophyll-a data are assimilated into a simple NPZD model by the adjoint method in a climatological physical environment provided by FOAM. To improve the assimilation results, different spatial parameterization schemes are utilized. The results show that the values of the selected sensitive parameters are spatially variable and the application of spatial parameterizations can improve the assimilation results significantly.