Removal of NOx from Flue Gas with Iron Filings Reduction Following Complex Absorption in Ferrous Chelates Aqueous Solutions

Abstract

A novel process for removal of nitrogen oxides (NO_x) from flue gases with iron filings reduction following complex absorption in iron-ethylenediaminetetraacetic acid aqueous solution is proposed. The reaction mechanism involved in the process is discussed briefly. The parameters influencing the process, including the concentration of ferrous chelates, initial pH, amount of iron filings, temperature, flow rate of the flue gas, and inlet nitric oxide concentration and oxygen content of the flue gas, are researched in detail. The optimal NO_x removal conditions are established. The regeneration and circular utilization of the absorption solution also is studied.     

不同纳米修复剂对污染土壤中胡萝卜吸收、转运Cd的影响

通过盆栽实验研究不同纳米修复剂(羟基磷灰石HAP、赤泥RM、Fe3O4、胡敏酸-Fe3O4)对2种不同污染土壤Cd吸收、转运的影响。结果表明,上述纳米修复剂均可显著增加胡萝卜植株生物量,显著提高植株Cd胁迫的耐受指数;不同土壤施用不同纳米修复剂均显著降低胡萝卜植株Cd的含量,并且随着修复剂施加浓度的增加而显著降低;与对照相比,植株茎叶Cd含量最大降低达78.8%,根中Cd的含量最大降低67.8%;添加不同修复剂能不同程度地降低了土壤中Cd的转运系数和富集系数,这可能与施用不同纳米修复剂促进了土壤中非残留态Cd向残留态Cd的转化有关,总体而言,不同纳米型修复剂对降低Cd的有效性顺序为:RM～HAP>胡敏酸-Fe3O4>Fe3O4。     

马兰黄土对Cr(Ⅲ)吸附的试验研究

为获取马兰黄土对水溶液中Cr(Ⅲ)的吸附机制.深入完善马兰黄土除Cr(Ⅲ)的理论研究,设计了等温吸附、土柱吸附、形态提取和去方解石除Cr(Ⅲ)试验.通过对试验结果的对比分析得出,马兰黄土对水溶液中Cr(Ⅲ)的吸附作用主要为方解石水解所引起的Cr(Ⅲ)吸附沉淀反应和铁锰氧化物对Cr(Ⅲ)的表面络合反应,辅以多种矿物对Cr(Ⅲ)的阳离子交换作用;马兰黄土对水溶液中Cr(Ⅲ)的等温吸附方程较符合非线性Langmuir型等温吸附方程,其吸附动力学模型较符合抛物线扩散方程.     

电厂脱硫灰烧成硫铝酸盐水泥的试验研究

电厂脱硫灰由于成分复杂和高硫高钙的特点,为其综合利用造成了很多困难.试验证明,只需添加部分CaO或CaCO2,用脱硫灰作生料即可在1 300℃左右烧成硫铝酸盐水泥.这种方式可以完全利用脱硫灰中的游离CaO,CaCO3,Ca(OH)2和含硫矿物CaSO3与CaSO4,使其转化为水泥熟料矿物,如硫铝酸钙(Ca4Al6O12SO4)、硅酸二钙(Ca2SiO4)等,还能完全利用脱硫灰中的未燃烬碳,因而能达到物尽其用,是一种全新高效的利用方式,具有广阔的应用前景.     

水体中常见无机阴离子对TiO2薄膜光催化降解甲醛的影响

选择了5种水体中常见的阴离子（Cl^-,SO4^2-,HPO4^2-/HPO4^2-,HCO3^-/CO3^2-和NO3^-）,分别考查了其对TiO2薄膜光催化降解模拟甲醛废水的反应速率的影响;从上述离子的光吸收,对.OH的捕获及其生成的相应的无机自由基的氧化作用以及与甲醛的竞争吸附3个方面讨论了上述离子影响TiO2薄膜光催化降解模拟甲醛废水的反应速率的原因。结果表明,HCO3^-/CO3^2-对TiO2薄膜光催化降解甲醛具有抑制作用,Cl^-和SO4^2-的影响不大,H2PO4^-/HPO4^2-和NO3-具有促进作用。造成上述结果的主要原因是HCO3^-/CO2^3-具有很强的.OH捕获作用;Cl^-,SO4^2-对.OH捕获作用以及竞争吸附都较弱;H2PO4^-/HPO4^2-在TiO2表面具有较强的吸附能力,释放出的H＋起到了酸催化剂的作用;NO3^-在紫外光的照射下可以产生.OH,此外NO3^-作为电子受体而降低了TiO2表面光生电子和空穴的复合几率。     

电厂烟气中二氧化碳的捕集技术

通过对传统的MEA法和ECO2技术原理以及费用的分析比较，发现ECO2技术费用低、脱除效率高，ECO2技术比MEA法更适于回收CO2，具有广泛的应用前号。     

支持向量机在城市震后火灾损失预测中的应用

针对地震火灾的复杂性和多变性的特点，在综合分析了各种震后火灾损失预测方法的基础上，提出了基于支持向量机的城市震后火灾损失预测模型。以地震火灾的历史资料为依据，建立学习样本和测试样本，并与BP神经网络预测方法相比较，验证了其可行性，也为其它自然灾害的损失预测提供了简单、有效的方法。     

几种阴阳离子对磷钨酸光催化降解甲基橙的影响

以磷钨酸为光催化剂，在紫外灯照射下，对甲基橙溶液进行光催化降解，考察了几种阴阳离子对磷钨酸光催化降解甲基橙溶液的影响。结果表明：Mg²⁺、Ca²⁺、NO^-₃、SO^2-₄和CO^2-₃均对催化活性有促进作用，其中Mg²⁺和Ca²⁺仅有微弱的促进作用；NO^-₃和SO^2-₄随着浓度的增加促进作用也有所增加；CO^2-₃则随着浓度的增加促进作用呈下降趋势；Mn²⁺、Al³⁺和Cl^-对光解反应存在较强的抑制作用，且Al³⁺和Cl^-随着其浓度的增加，抑制作用增强。     

Statistical analysis of sudden chemical leakage accidents reported in China between 2006 and 2011

According to the data from authoritative sources, 1,400 sudden leakage accidents occurred in China during 2006 to 2011 were investigated, in which, 666 accidents were used for statistical characteristic abstracted with no or little damage. The research results were as follows: (1) Time fluctuation: the yearly number of sudden leakage accidents is shown to be decreasing from 2006 to 2010, and a slightly increase in 2011. Sudden leakage accidents occur mainly in summer, and more than half of the accidents occur from May to September. (2) Regional distribution: the accidents are highly concentrated in the coastal area, in which accidents result from small and medium-sized enterprises more easily than that of the larger ones. (3) Pollutants: hazardous chemicals are up to 95 % of sudden leakage accidents. (4) Steps: transportation represents almost half of the accidents, followed by production, usage, storage, and discard. (5) Pollution and casualties: it is easy to cause environmental pollution and casualties. (6) Causes: more than half of the cases were caused by human factor, followed by management reason, and equipment failure. However, sudden chemical leakage may also be caused by high temperature, rain, wet road, and terrain. (7) The results of principal component analysis: five factors are extracted by the principal component analysis, including pollution, casualties, regional distribution, steps, and month. According to the analysis of the accident, the characteristics, causes, and damages of the sudden leakage accident will be investigated. Therefore, advices for prevention and rescue should be acquired.     

热解吸对污染土壤中不同形态汞的去除作用

选取贵州省万山矿区的汞污染土壤样品进行不同形态汞的热解吸去除行为研究。研究了热解吸过程中∑Hg的去除效果及动力学,以及温度和时间对污染土壤中不同形态汞的去除作用。结果表明,热解吸修复技术可有效去除土壤中的汞,土壤中∑Hg的热解吸过程符合二级动力学方程。固定热解吸时间在10 min时,随着热解吸温度的升高,土壤中水溶态汞、盐酸溶态汞和碱溶态汞含量呈现先下降后上升再下降的趋势,王水溶汞和盐酸溶态汞始终呈现下降趋势,说明不同形态的汞之间发生了转化。热解吸温度为250℃时,随着热解吸时间的增加,环境风险大的水溶态汞、盐酸溶态汞、碱溶态汞和硝酸溶态汞的去除率大幅增加,土壤的有机质损失较少,说明在低温下,延长热解吸时间,对生物毒性强的形态汞有良好的修复效果,且此温度下处理后的土壤更容易恢复农田耕作。