金属改性碳脱除PH3和H2S动力学及反应机理研究

为综合利用黄磷尾气中的CO,通过计算平均活化能和测定XPS、TG／DTA和氮吸附特性的方法,研究了Cu2＋和某金属离子M^n＋改性碳脱除PH,和H2S的动力学和反应机理问题。结果表明：H2S在金属改性碳上反应时平均活化能为134．4J／mol为-0．76级反应,PH,在金属改性碳上反应时平均活化能为1247．6J／mol为-0．8级反应;减小改性碳粒径增加流量可以显著提高其脱除PH,和H。S的速率;XPS、TG／DTA和孔径分布分析证明,改性碳净化H2S和PH3是一个催化吸附过程,H2S和PH3首先与氧在改性碳表面进行催化氧化反应,然后生成S和P2O5沉积吸附在改性碳表面。     

Assessment of the thermal hazards and oxidization mechanism of coloured corn starch dust by TG–FTIR

Starch is widely used in industrial production and in every life, and an increasing number of accidents of starch dust burning and explosions are occurring and have caused serious casualties and economic losses. Previous studies on the oxidative properties and microscopic characterization of coloured corn starch dust have been less systematic than the present study. To prevent coloured corn starch dust explosion accidents more effectively, thermogravimetry and Fourier transform infrared spectroscopy were applied to study the oxidation characteristics of coloured corn starch dust. Seven characteristic temperatures were determined from the thermogravimetric curves and derivative thermogravimetric curves of coloured corn starch dust. The entire oxidation process of coloured corn starch dust was divided into five stages, and a 60% mass loss occurred in the rapid oxidation stage. Three iso-conversion methods were used to calculate the apparent activation energy (E_a) and pre-exponential factor (A) at different oxidation stages. The value of E_a was found to be related to the difficulty of the reaction, and it had a positive correlation with lnA. Six kinds of gases were detected during the oxidation process. The oxidation mechanism was further analysed by the macro and micro characterization of the oxidation process. The findings provide a theoretical basis for preventing and controlling explosion accidents that involve coloured corn starch dust.     

弱粘煤低温氧化活性基团与热效应的研究*

为研究煤氧化过程中活性基团的演变规律及热效应的变化特征,利用原位红外实验装置,实时测量煤升温过程中官能团的动态变化,数据处理得到弱粘煤红外波谱图,利用差减法对特征温度点下的红外光谱图进行处理,得到煤样的差示光谱,计算特征温度点下的红外结构参数;采用差示扫描量热仪,测量煤氧化过程中热流的变化,得到弱粘煤的热流曲线图,并对热流曲线进行阶段划分和氧化动力学计算。结果表明:弱粘煤中芳环数量比较少,环周围侧链较长,内部结构疏松,内部毛细管比较发达,内表面积较大,更容易发生自燃;整个氧化过程中羟基最为活跃,含氧官能团次之,其次是脂肪烃;红外参数计算结果HAL,I2整体呈减小趋势,I1,I3整体呈增大趋势;弱粘煤放热阶段的活化能值为25.12～61.26 kJ/mol,并随着升温速率的增大而减小,与此阶段放热量随升温速率的增大而增大相对应。     

不同污染条件下南京春季CCN活化特征分析

在2018年3~4月对南京北郊地区的气溶胶开展了云凝结核（CCN）特征的外场观测,并结合气象数据、PM_2.5浓度和化学组分信息以及光学特性等数据,对观测期间的污染天和清洁天进行了对比,分析了典型污染过程和新粒子生成天的CCN特征.结果表明,本次观测中气溶胶CCN活性总体较高,各过饱和度（SS）下的平均吸湿性参数（κ）为0.30,在最低过饱和度下（SS=0.17%）κ最低,且最大活化率（B）仅为0.72,表明气溶胶中有较多不易活化的物质.污染天κ高于清洁天,但活化率更低且外混程度更高,主要是受交通和工业排放的吸湿性较差的粒子影响,而颗粒物在夜间可迅速老化,使其吸湿性提升,CCN数浓度增加.新粒子生成天的κ受到粒子成核的影响有明显日变化,对总气溶胶数浓度（N_CN）和CCN数浓度（N_CCN）也有显著贡献.     

机械活化蛇纹石吸附除磷性能及机理研究

为实现废水中磷的绿色高效去除,采用机械活化法制备活性蛇纹石吸附材料,探讨了该材料对废水中30 mg·L^-1正磷酸盐的吸附性能、关键影响因素及吸附去除机理.结果表明,活性蛇纹石对磷的理论最大吸附量(以P计)为126.58 mg·g^-1,当初始pH为7.0、温度为20℃、投加量为0.5 g·L^-1、吸附时间为240 min时,材料对磷的去除率为89.73%.磷的去除率随活化时间、吸附时间和投加量的增加而增大,随pH和温度的增加而降低.利用激光粒度仪、XRD、FTIR和SEM等现代分析测试手段研究了活性蛇纹石对磷的吸附机理.结果表明,机械活化致使蛇纹石颗粒的中值粒径从41.32μm迅速降低到12.00μm,之后粒径不再发生明显变化,进一步的机械力作用使蛇纹石晶体结构受到破坏,导致Mg—OH键能减弱,增强了颗粒表面的Mg吸附位点的活性,并使颗粒表面呈碱性,最终使磷能够以磷酸镁(Mg₃(PO₄)₂·22H₂O)的形式固定在材料表面.等温吸附和吸...     

硫铁化物氧化自燃的动力学分析

为研究含硫油品储油罐中硫铁化物的自燃倾向性,采用STA8000同步热分析仪对10,15,20℃/min等不同升温速率和15,20,25 mL/min等不同空气流量下的硫铁化物进行试验,并通过获得的TG-DSC曲线研究试样的自燃特性;在此基础上,根据Coat模型,利用不同反应机理函数对热重数据进行分析。结果表明:该试验条件下,硫铁化物的氧化进程符合三级反应动力学机制;得出了硫铁化物在不同升温速率和空气流量下的表观活化能;在560～746℃温度区间内,随着升温速率的增加,空气流量的加大,活化能数值明显减小,自燃倾向性增大。研究结果可为预防和控制因硫铁化物自燃引发的火灾、爆炸事故提供理论参考。     

The two faces of high self‐monitors: Chameleonic moderating effects of self‐monitoring on the relationships between personality traits and counterproductive work behaviors

This study examines whether and how self‐monitoring moderates the relationships between two personality traits (agreeableness and conscientiousness) and counterproductive work behavior directed toward the organization (CWB‐O) and toward other employees (CWB‐I). High self‐monitors strive to attain personal goals related to status and prestige enhancement by adjusting their behavior to what the situation requires or allows for. We propose that the status enhancement motive can take on two different yet related forms—impression management (interpersonal potency) and opportunism (win‐at‐all‐costs)—depending on relevant situational cues. We hypothesize that in public, interpersonal settings where their behavior is visible to others, high self‐monitors' desire to enhance their status by looking good to others suppresses the natural expression of low agreeableness via increased engagement in CWB‐I. Conversely, we hypothesize that in private, non‐interpersonal settings where their behavior is rarely visible to others, high self‐monitors' desire to enhance their status by doing whatever it takes to get what they want intensifies the natural expression of low conscientiousness via increased engagement in CWB‐O. On the basis of two independent samples of participants, results of moderated multiple regression analyses provided support for the hypotheses. Copyright © 2013 John Wiley & Sons, Ltd.     

存储于苯酚溶液后的好氧颗粒污泥的活性恢复效果

通过调控SBR的进水COD、曝气量和污泥沉淀时间,对储存于苯酚溶液后的好氧颗粒污泥进行了活性恢复研究,为好氧颗粒污泥活性恢复方法的选择提供参考。结果表明,室温下在60 mg·L⁻¹苯酚溶液中储存150 d的好氧颗粒污泥,经过28 d的培养即可恢复其结构完整性和微生物活性。在活性恢复期间中,好氧颗粒污泥经历了破碎到重塑的演变过程。恢复后的好氧颗粒污泥具有良好的沉降性能,微生物量较大且活性较高,SVI₃₀和SVI₅分别为26.1 mL·g⁻¹和27.6 mL·g⁻¹,MLSS和MLVSS分别为16 903 mg·L⁻¹和12 001 mg·L⁻¹,MLVSS/MLSS为0.71,DHA为71.36 μg·(g·h)⁻¹。好氧颗粒污泥的EPS组分在恢复期间不断发生改变,代表酪氨酸/色氨酸类蛋白和芳香族蛋白类物质的荧光强度随颗粒污泥的活性恢复逐渐增强。恢复后的好氧颗粒污泥对COD、TP和TN的去除率分别为97.34%、89.88%和64.37%。     

纳米零价铁协同Fe(Ⅱ)活化过碳酸钠降解含吐温-80水体中的三氯乙烯

在表面活性剂吐温-80(Tween-80)存在下,采用纳米零价铁(nZVI)协同Fe(Ⅱ)共同活化过碳酸钠(SPC)体系去除污染场地水相中的三氯乙烯(TCE),验证了SPC/Fe(Ⅱ)/nZVI体系降解TCE的有效性,探究了Tween-80浓度、无机阴离子以及溶液初始pH对TCE降解效果的影响,并确定了该体系中活性氧自...     

湿式过氧化氢氧化活性艳蓝KN-R

为了有效地处理印染废水,采用湿式过氧化氢氧化法(wet peroxide oxidation,简称WPO)降解活性艳蓝KN-R。通过筛选反应因子,获得了最佳反应条件。当初始浓度为200 mg/L时,在最优条件下,活性艳蓝KN-R的脱色率和TOC去除率分别为100%和68.54%。在120~150℃考察了该反应的动力学,结果表明,活性艳蓝KN-R的湿式过氧化氢氧化反应符合准一级动力学方程,并且通过计算得到了反应活化能为73.9 kJ/mol。利用气相色谱/质谱联用仪(GC-MS)鉴定活性艳蓝KN-R降解产物主要为几种小分子有机酸,如丁二酸、已二酸、邻苯二甲酸。通过添加自由基捕获剂(叔丁醇)研究了自由基反应机理,结果表明羟基自由基对活性艳蓝KN-R的降解起着主要作用。