Fe（0）/H_2O_2协同降解亚甲基蓝的研究

进行了Fe（0）和H2O2协同催化降解亚甲基蓝的研究,分析了Fe（0）投加量、H2O2投加量、溶液初始pH值和染料初始质量浓度等因素的影响。研究表明：Fe（0）和H2O2协同可有效催化降解亚甲基蓝;在pH为4.5,Fe（0）用量为2.0 g.L-1,H2O2用量为3.0 mmol.L-1时对10 mg.L-1亚甲基蓝的去除率在60 min内达到90%以上。MB的降解去除率随着Fe（0）投加量与H2O2用量的增加而增加,但随着其初始质量浓度的增大而降低。研究结果还表明,Fe（0）和H2O2可在接近中性条件下有效协同催化降解亚甲基蓝。UV-Vis光谱在反应过程的变化说明亚甲基蓝降解生成了一些小分子物质。     

Observer reactions to interpersonal injustice: The roles of perpetrator intent and victim perception

The present research contributes to a growing literature on observer reactions to injustice experienced by others. In particular, we separated two variables that have previously been confounded in prior research, namely perpetrator intent to cause harm and victim perception of harm. We expected that injustice intent and injustice perceptions would have both unique and joint effects on observer reactions. The results of three experiments in which we manipulated perpetrator injustice intent and victim injustice perceptions supported our predictions. First, we found that observers had more negative reactions toward superiors who intended to inflict high versus low levels of interpersonal injustice toward a subordinate. Second, the injustice intent of the superior influenced observers' reactions more than did victim perceptions of injustice. Third, most novel, we found that the mere intent to cause injustice generated negative reactions in observers, even in the absence of a “true” victim—that is, when the subordinate perceptions of injustice were low. Together, our results emphasize the importance of examining observers' reactions to injustice and incorporating perpetrator intentions into the study of organizational justice. Copyright © 2012 John Wiley & Sons, Ltd.     

One-step formation of oligopeptide-like molecules from Glu and Asp in hydrothermal environments

Biopolymer accumulation in the absence of enzymes is an essential step for the chemical evolution of primitive life-like systems, and successful simulation experiments of prebiotic biopolymer formation have suggested that oligopeptides could have formed near submarine hydrothermal vent environments on primitive earth. However, the yield and length of oligopeptides -- typically limited to 6-mers -- seems to be inadequate. One reason is the rapid formation of diketopiperazines (DKPs) from dipeptides. In this study, using a hydrothermal microflow reactor, we show that the one-step synthesis of oligopeptide-like molecules of length up to 20-mers proceeds from Glu and Asp. Yields of up to 0.17-0.57% were obtained in an acidic solution within 183 s at 250-310 degrees C, as evaluated by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analysis and different types of high-performance liquid chromatography (HPLC) analyses. The present study indicates that Glu and Asp may have played important roles in the chemical evolution of oligopeptide-like molecules in hydrothermal vent environments on primitive earth.     

室温Fenton反应过程H2O2有效利用率的影响因素研究

Fenton反应是H2O2在Fe^2＋催化作用下产生氧自由基并氧化污染物的高效方法。但影响Fenton反应过程H2O2分解及其有效利用率的因素是很多的,其中[Fe^2＋]要求控制在3mmol／L以上。酚类体系H2O2的有效利用率不受H2O2浓度变化的影响,但受初始COD的影响,一般表现为随COD的增加,H2O2有效利用率迅速增加。当初始COD一定时,H2O2浓度在600mg／L和1800mg／L时,一元酚与二元酚体系的H2O2有效利用率均出现了两个峰值,前者的峰值分别为11．83gCOD／gH2O2和12．99gCOD／gH2O2,后者的峰值分别为9．01和11．95gCOD／gH2O2。而醇类体系H2O2的有效利用率受H2O2浓度的影响较大,但与初始COD的关系不明显。当H2O2浓度低于300mg／L时,乙醇比对照体系H2O2的分解率高1-3％,而有效利用率仅为0．6gCOD／gH2O2;随H2O2用量的继续增加,其有效利用率趋于0gCOD／gH2O2。而二元醇体系H2O2有效利用率与其浓度间呈“倒U”型规律,H2O2低于300mg／L时,其有效利用率仅为1．25gCOD／gH2O2;H2O2浓度在300mg／L～900mg／L之间时,其有效利用率可达8．96gCOD／gH2O2;其后随着H2O2的增加,有效利用率迅速下降到与乙醇体系相当。在混合体系中,醇羟基和酚羟基所占比例对H2O2有效利用率也有显著的影响,当乙醇比例小于60％时,H2O2有效利用率稳定在13．0gCOD／gH2O2;随乙醇比例的增加,其对H2O2的分解抑制效应表现出剂量依赖关系,H2O2有效利用率也逐渐下降到近于0gCOD／gH2O2,说明这部分H2O2并没有得以有效地分解用于氧化废水中的COD,这在工程实践中应引起高度的重视。     

Biodegradation of trace pharmaceutical substances in wastewater by a membrane bioreactor

The biodegradation of selected pharmaceutical micropollutants, including two pharmaceuticals with argued biodegradation, was studied by a lab-scale membrane bioreactor. The reaction kinetics and affecting factors were also investigated in this paper. Clofibric acid (CA) with contradictive biodegradation reported was degraded almost completely at different hydraulic retention times (HRTs) after adaptation to microorganisms. The biodegradation of CA was disturbed at low pH operation, while the activity of microorganisms recovered again after pH adjustment to neutral condition. Ibuprofen (IBP) degraded under neutral and acidic conditions. Removals of IBP and CA were zero-order and first-order reactions under high and low initial concentrations, respectively. Carbamazepine and diclofenac were not degraded regardless of HRTs and pH.     

水涤脱附条件下活性炭脱硫中有效吸附位的研究

以不同活性炭材料吸附性能测试实验的结果为依据,研究了在水涤脱附条件下活性炭脱硫的机理,指出水在吸附位部分失效过程中起到的几种作用,并从有效吸附位的角度进一步分析了吸附材料特性与吸附性能之间的关系,提出产生有效吸附位的前提是具有一定的反应空间,使之能满足反应分子间距和空间构型的条件.研究表明:吸附材料的孔径分布和外表面积是影响吸附性能的两个关键因素;平均孔径40～50A、颗粒直径为3 mm左右的中孔型颗粒活性炭,是一种理想的吸附材料.     

SO_2体积分数对ZL50活性炭吸附脱硫行为的影响和动力学分析

通过动态吸附烟气脱硫实验,考察了烟气中不同SO2体积分数对ZL50脱硫脱硝活性炭脱硫行为的影响,并进行了动力学分析.随着烟气中SO2体积分数增大,脱硫率和ZL50脱硫脱硝活性炭的活性度下降;SO2吸附量和吸附速率增大.模拟结果表明,Bangham模型模拟效果最优,SO2的催化氧化反应对化学吸附有重要影响;Lagergren准一级吸附速率常数随SO2进口体积分数的增加而增大,表明SO2的催化氧化反应在吸附前期可能为速控步骤.推导和定义了Lagergren模型和Bangham模型的初始吸附速率;推导了文献上的Ho模型和Elovich模型的初始速率式。定义的Bangham初始吸附速率与初始吸附速率实验值吻合最好;建立的Bangham吸附反应动力学模型能较好地描述SO2动态吸附速率.结果表明,SO2的初始反应速率分级数为1或接近1,而O2和水蒸气的初始速率分级数分别为0.15～0.20和0.45～0.50之间的常数.     

分光光度法快速测定水中苯酚

建立了简单、快速的测定水中苯酚的分光光度法。方法基于苯酚与硝普钠在有氨基的试剂盐酸羟胺存在下发生Berthelot颜色反应,生成靛酚染料,从而对苯酚进行光谱测定。考察了测定波长,pH值、Na2HP04-NaOH缓冲溶液用量,硝普钠的用量、盐酸羟胺的用量,反应时间对苯酚检测的影响。在优化的实验条件下,线性范围为0．05—0．5mg·L^-1（r=0．9996）。检出限为0．005mg·L^-1,对浓度为0．3mg·L^-1的苯酚样品溶液平行测定5次,RSD为1．32％。以上结果表明,此方法具有线性范围较宽,灵敏度和精密度较高,操作简便,易实现水质在线监测等特点。     

Laboratory simulation of SO2 heterogeneous reactions on hematite surface under di erent SO2 concentrations

The variations of sulfate formation and optical coe cients during SO2 heterogeneous reactions on hematite surface under di erent SO2 concentrations were examined using in situ di use reflectance infrared Fourier transform spectroscopy (DRIFTS) and ion chromatograph (IC). Laboratory experiments revealed that within ambient SO2 of 0.51–18.6 ppmv, sulfate product, producing velocity, absorption and backward scattering coe cients showed an increasing trend with SO2 concentration. Under given SO2 concentration, the velocity of sulfate producing performed an evolution of initial increasing, midterm decreasing and final stabilizing. The reactive uptake and Brunauer-Emmett-Teller (BET) uptake coe cients of heterogeneous reactions rose with SO2 and exhibited high reactivities. Considering global warming, this result is important for the knowledge of heterogeneous reactions of SO2 on mineral particle surface in the atmosphere and the assessment of their impacts on radiative forcing.     

Model-based zero emission safety concept for reactors with exothermal reactions for chemical plants

To avoid major accidents caused by runaway reactions, a new safety concept called SmartHIP¹ is introduced, with the objective to prevent runaway reactions and avoid emissions. The basic principle is based on an online model-based approach by using safety instrumented systems. Different criteria exist for calculating the hazard potential of a runaway reaction and its early detection. The approaches of the literature from the last years are analysed and divided into three different groups: Divergence, Accumulation and Adiabatic Criterion. Each approach is compared to the other by applying it to an esterification reaction of acetic anhydride with methanol. The approaches are evaluated according to different requirements, like accuracy, wide range of application or reliability.