程序升温条件下铁及其氧化物在CO存在时对N_2O的还原机理

应用热综合分析仪 (TG FTIR)研究了在还原性气氛下Fe及其氧化物对N2 O的催化还原作用 .研究发现铁氧化物对氮氧化物的催化还原能力相当弱 ,而Fe可以高效地降低N2 O分解的初始温度和提高N2 O向N2 的转化率 .在Fe和CO的作用下 ,N2 O的初始分解温度为 92 0K和 10 0 0K .在 112 3K时 ,N2 O的转化率达到 95 %和 80 % .TG/DSC曲线表明了在Fe与N2 O反应过程中CO的作用表现为通过与N2 O在反应表面的竞争吸附使铁氧化物还原为金属铁 ,X射线衍射证明Fe与N2 O反应后的氧化物为Fe2 O3 ;扫描电镜对反应后Fe表面物理形态的研究发现 ,在CO作用下 ,Fe的表面呈松散结构 ,可以保证Fe对氮氧化物反应的连续进行     

Chemical forms and extractability of iron in sediments of three contrasting lakes of China and UK

IntroductionAsanessentialelementforalgalgrowth ,ironplaysanimportantroleintheeutrophicationoflakesandotherwaters .Theroleofironinalgalgrowthmainlyliesinitsphysiologicalfunctionssuchaselectrontransport,oxygentransportorrespirationandfermentation (APHA ,1 975;Trudinger,1 979;Zhou ,1 998a) .Usually,ironispresentinenvironmentinrelativelyhighconcentrations .Incrustalabundance,ironranksfourthinnumber,onlybehindoxygen ,siliconandaluminium(Wedepohl,1 971 ) .However,ironisrelatively“scarce”intheb…     

用萃取剂LIX84I从电子废弃物处理液中选择性萃取铜

考察了相比、水相pH、混合时间等因素对LIX84I萃取铜的影响，结果表明：这些因素对铜的萃取率都有一定的影响，最优化的条件是有机相为30％LIX84I＋70％煤油、室温、相比=2：1、出口水相pH值=2．0、搅拌速度=910r／min、萃取级数为3级，每级的时间为3min。对铜进行三级萃取和一级反萃，可以得到符合电积要求的硫酸铜溶液，萃取率和反萃取率分别可以达到94．6％和97．8％。     

铁限制对铜绿微囊藻光系统活性变化的影响

通过研究铁限制时铜绿微囊藻光系统活性的变化,了解铁限制控制铜绿微囊藻水华过程的机制.结果表明,铁限制使光合效率Fv/Fm明显降低,光系统Ⅱ接受的能量总体上呈减少趋势.超低温荧光发射光谱显示,铁缺乏限制了藻细胞光系统Ⅰ的活性,而相对促进了光系统Ⅱ荧光叶绿素复合物的产生,说明铁限制使铜绿微囊藻细胞的光能分配更趋向于光系统Ⅱ,其中的CP47蛋白荧光几乎完全消失,CP43蛋白荧光则相对增加.     

Emission rate formulae for surface iron ore mining activities

A study was carried out at three surface iron ore mines to determine the total suspended particulate emission rate and to develop the formula for the emission rate of various surface iron ore mining activities. The study covered various mining activities and locations including waste loading and unloading, iron ore loading and unloading, screening plant, exposed waste dump, stock yard, exposed pit surface, transport road and haul road. A set of 10 formulae was developed to calculate the total suspended particulate emission rate of various surface iron ore mining activities. The emission of gaseous pollutants (sulphor dioxide and oxides of nitrogen) was also evaluated but was found negligible for various mining activities, and emission rates were determined for overall mine only. The developed formulae were validated with the measured emission data at another surface iron ore mine. The accuracy of the activity-wise emission rates calculated using the developed formulae was found to vary from 92 to 97% of actual field measurement data. The developed formulae for determination of emission rate from various surface iron ore mining activities will help in predicting air quality status through air quality modelling and designing effective mitigative measures for sensitive areas during the planning stage of a proposed mine.     

An Analysis with the CERT Model of the FSU Market Power in the Carbon Emissions Trading Market

This paper aims to assess the consequences of the amendments made to the Kyoto Protocol during COP 7 in Marrakech. The major issue of hot air and CDM transaction costs is examined using the CERT model to show that primary supply regions, typically those with hot air availability, might control the emissions reduction permit supply market and maximise net export revenues of permit supply by withholding 40 to 60% of available hot air credits. The assumption that primary permit suppliers control permit price via a restriction of hot air supply to the market will inadvertently leave a portion of the market share open to non-Annex B CDM supply, despite potentially extreme variance in CDM transaction costs. A summary table of policy implications on the emissions reduction permit market is also included.     

零价铁激活过硫酸盐降解水中铬黑T特性

采用零价铁/过硫酸盐（Fe⁰/PS）高级氧化工艺降解水中有机染料铬黑T（EBT）,考察了不同体系（PS、Fe⁰、Fe⁰/PS）、PS与Fe⁰物质的量之比、无机阴离子（NO₃^-,CO₃^2-,Cl^-）、溶液初始pH值、温度以及天然有机物对EBT降解的影响.结果表明,Fe⁰/PS工艺降解EBT符合准一级反应动力学模型（R²>0.87）;和Fe⁰以及单独PS处理EBT相比,Fe⁰/PS能够高效降解水中的EBT,20min时EBT的去除率高达96.21%.PS/Fe⁰降解EBT的最佳物质的量之比为1：1.5.溶液中存在的NO₃^-,CO₃^2-以及天然有机物均对EBT降解有不同程度的抑制作用.EBT的降解速率随溶液初始pH值的增加逐渐减小.随着温度的增加,EBT降解速率满足先增加后减小的规律,其反应活化能（Ea）为43.98kJ/mol.EBT在实际水体中的去除率仍能够保持较高的水平.使用GC-MS识别出10种中间产物,并据此提出反应路径.ECOSAR模型分析表明EBT降解产物中小分子有机物的生态毒性高于其大分子有机物.     

生物炭负载零价纳米铁去除土壤中十溴二苯乙烷

作为十溴联苯醚的替代品,新型溴代阻燃剂十溴二苯乙烷（DBDPE）已经在国内外大量使用.随着DBDPE在各种环境介质中被普遍检测到,其造成的环境污染正引起广泛关注.本论文首先制备生物炭（BC）负载零价纳米铁（nZVI）材料（BC/nZVI）,进而研究了BC/nZVI去除土壤中DBDPE的动力学过程,并探究了作用机制.结果表明：BC加入能促进nZVI均匀分散在生物炭的表面,并改善了其分散程度;BC/nZVI去除效率最高（投加量为0.1 g·g^-1,BC：nZVI为2：1,DBDPE初始浓度为10 mg·kg^-1）,24 h内达到了89.74%,去除过程涉及到吸附和降解的共同作用,实验数据符合准一级动力学方程;采用LC-MS-MS探究了DBDPE的降解产物和途径;ECOSAR毒性评价数据显示BC/nZVI能够降低DBDPE的生态毒性.     

氯化剂对铁尾矿焙烧过程中重金属挥发的影响

针对铁尾矿中的重金属,采用氯化焙烧方法进行分离.考察了不同氯化剂（CaCl₂、NaCl和AlCl₃·6H₂O）在不同温度下对铁尾矿中重金属（Cr、Ni、Pb、Zn、Cu）挥发率的影响.结果表明：添加AlCl₃·6H₂O作为氯化剂时,由于其在135℃时过早分解,在1000℃时重金属的最高挥发率均在30%以下.添加NaCl可使重金属Pb、Zn、Cu的挥发率达到90%以上,但Cr和Ni的挥发率分别只有16.2%和30.0%.CaCl₂与NaCl、AlCl₃·6H₂O相比具有最好的去除效果,在900℃的焙烧温度下,能够去除大部分的Pb（97.5%）、Zn（99.0%）和Cu（93.3%）,且Ni、Cr在1000℃时最大挥发率分别为31.9%和49.5%.此外,浸出实验表明,焙烧渣中Cr、Ni、Pb、Zn、Cu浸出浓度均低于GB16889-2008相关限值要求.     

Particulates and carbon monoxide pollution on production floor of steel recycling plant

For this study, particulates or particulate matter (PM) and carbon monoxide (CO) levels were monitored at different sections on the production floor of a scrap metal recycling factory. A Met‐One GT331 dust monitor and A Toxi‐Rae gas monitor were used to measure PM and CO concentrations, respectively. The 24‐hr averaging period concentrations of particulate matter having diameters of 2.5 microns or less in diameter (PM_2.5), particulate matter having diameters of 10 microns or less in diameter (PM₁₀), and total suspended particulates (TSP) within the plant ranged between 8.3 and 50.4 μg/m³, 12.0 and 151.3 μg/m³, and 30.0 and 285.0 μg/m³, respectively, while the maximum 8‐hr concentration of CO within the plant was 20.5 parts per million (ppm). The United States’ Environmental Protection Agency (US EPA) limits for PM_2.5, PM₁₀, and CO were exceeded only in the area around the furnace. Nigeria's Federal Ministry of Environment (FMENV), the World Health Organization (WHO), and the World Bank statutory limit for TSP were also exceeded in the area around the furnace. Toxicity potentials (TP) of the investigated pollutants were greater than 1.0 around the furnace, indicating that work spaces in proximity to the furnace could expose workers to adverse health conditions.