活性炭负载Fe(Ⅲ)吸附剂去除饮用水中的As(Ⅴ)

利用活性炭负载水合铁氧化物制备了复合吸附剂,并用于饮用水中As(Ⅴ)的去除.研究了活性炭种类、粒度、溶液pH值、Fe(Ⅲ)盐浓度和干扰离子等对As(Ⅴ)去除的影响.结果表明,煤质活性炭作为基质负载水合铁氧化物比椰壳炭和果壳炭具有更好的除砷效果.随着炭粒度降低,除砷效率显著增加.在pH3～9范围内,活性炭负载水合铁氧化物可有效吸附As(Ⅴ).F-,Cl-,SO42-的加入对As(Ⅴ)的去除效率基本无影响,而SiO32-和PO43-则明显抑制As(Ⅴ)的去除.Langmuir模型比Freundlich模型能更好地描述复合吸附剂对As(Ⅴ)的吸附平衡.动力学研究表明,As(Ⅴ)吸附反应可用二级速率方程描述.

Direct decomposition of NO by microwave heating over Fe/NaZSM-5

Catalytic decomposition of NO was studied over Fe/NaZSM-5 catalyst. Novel results were observed with the microwave heating mode. The conversion of NO to N-2 increased remarkably with the increasing of Fe loading. The effects of a series of reaction parameters, including reaction temperature, O-2 concentration, NO concentration, gas flow rate and H2O addition, on the productivity of N-2 have been investigated. It is shown that the catalyst exhibited good endurance to excess O-2 in the microwave heating mode. Under all reaction conditions, NO converted predominantly to N-2. The highest conversion of NO to N-2 was up to 70%. (C) 2002 Elsevier Science B.V. All rights reserved.

三江平原白浆土不同土地利用类型Fe~(2+)分布特征

土壤铁元素由高价态转化为低价态(二价铁),是土壤中铁元素移动的主要途径。为了探讨三江平原不同土地利用类型Fe2+分布情况及影响因素,文章通过在三江平原典型白浆土区采取水田、旱田、草地、林地4种不同土地利用类型样点,对其Fe2+含量及其影响因子进行对比研究分析。结果表明:土壤表层(0～10cm)Fe2+含量高低顺序为水田>草地>旱田>林地,主要影响因子为水分状况和pH值(r=0.851,r=0.909,p<0.01),其中水田Fe2+含量(305.5mg·kg-1)明显高于林地和旱田(30～40mg·kg-1),是其含量的8～10倍;草地除表层(0～20cm)Fe2+含量低于水田外,以下各层含量均高于其它土地利用类型;草地、旱田、林地Fe2+含量垂直分布规律相似:表层(0～10cm)及白浆层(30～40cm)含量略高,40cm以下Fe2+含量持续缓慢递减,相关分析表明旱田、草地主要影响因子为土壤pH值(r=-0.871,r=0.795,p<0.05),林地影响因子相关性均不显著;水田垂直变化趋势与其它3种类型相比有所不同,表层最高达305.5mg·kg-1,至40cm深处急剧递减至35.2mg·kg-1,以下无明显变化,主要影响因子为水分状况和TOC(r=0.962,r=0.991,p<0.01)。

Bluish-white emission from radical carbonyl impurities in amorphous Al2O3 prepared via the Pechini-type sol-gel process

Many efforts have been devoted to exploring novel luminescent materials that do not contain expensive or toxic elements, or do not need mercury vapor plasma as the excitation source. In this paper, amorphous Al2O3 powder samples were prepared via the Pechini-type sol-gel process. The resulting samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), photoluminescence (PL) excitation and emission spectra, kinetic decay, and electron paramagnetic resonance (EPR).

First-principles investigation on the elastic, magnetic and electronic properties of MFe3N (M = Fe, Ru, Os)

The elastic, magnetic and electronic properties of MFe3N (M = Fe, Ru, Os) are investigated via first-principles calculations. The calculated results are in agreement with the experimental and other theoretical data. The high ratios of bulk modulus to shear modulus 2.7, 2.0, and 1.8 for gamma'-Fe4N, RuFe3N, and OsFe3N, respectively, indicate that they have good ductility. gamma'-Fe4N possesses the largest B/C-44 (3.41) ratio, which suggests that it is much prone to shearing. The net magnetic moment per formula unit decreases from 9.90 for gamma'-Fe4N, 7.66 for RuFe3N, to 6.80 mu(B) for OsFe3N.

Hydrothermal synthesis of Fe and Mn doped SnO2 and its magnetic structures

The dilute magnetic semiconductor of Sn1-x-yMnxFeyO2 (0 <= x <= 0.10, 0 <= y <= 0.10) Were syhthesized with the hydrothermal method using SnCl4, Mn(CH3COO)(2) center dot 4H(2)O and FeCl3 center dot 6H(2)O as the raw materials. The structure, morphologies and magnetic properties of the sample were characterized via X-ray powder diffractometer(XRD), transmission electron microscopy(TEM), Raman spectrum and superconducting and quantum interference device(SQUIT), and Mossbeaur spectrum. No secondary phase was found in the XRD spectrum. The morphology of the samples is affected by the kind or the mount of transition metal. The local vibrating model-of Mn Positioned SnO2 sites was found in Raman spectrum. The measured magnetic results indicate that when x = 0.10, y = 0, the sample exhibits strong magnetization in low-temperature (5 K), but the magnetization decrease rapidly at room. temperature; In contrast, when x = 0, y = 0.1, the sample's magnetization and coercivity are both small, but being temperature independent. Mossbeaur spectra indicates that part of the Fe is ferromagnetic coupled, and the simulating results indicate that the ferromagnetic character is intrinsic.

Fe对Pt-Fe/C催化剂电催化氧还原反应活性的影响

制备了用作直接甲醇燃料电池的碳载Pt-Fe(Pt-Fe/C)阴极催化剂,X射线能量色散谱(EDX)、X射线衍射谱和电化学测量的结果表明,在Pt-Fe/C催化剂中,Fe以3种形式存在.质量分数大约为20%的Fe进入Pt的晶格,形成Pt-Fe合金,质量分数大约为80%的Fe没有进入Pt的晶格而以Fe和Fe2O3的形式单独存在.该催化剂经酸处理后,非合金化Fe和Fe2O3被溶解,而使Pt-Fe/C催化剂的电化学活性比表面积要比未经酸处理前的增加约30%左右,导致Pt-Fe/C催化剂对氧还原的电催化活性优于未经酸处理前的Pt-Fe/C催化剂.研究结果表明,Pt-Fe/C催化剂的电化学活性比表面积对氧还原的电催化活性起重要的作用,另外,只有与Pt形成合金的Fe能提高Pt对氧还原的电催化活性,而非合金化的Fe对Pt催化剂对氧还原的电催化活性基本没有影响.

Fe(acac)_3-Al(i-Bu)_3对马来酸酐与茴香脑共聚的催化性能

研究了Fe(acac) 3 Al(i Bu) 3 (acac =乙酰丙酮 )催化体系对马来酸酐 (MA)与茴香脑 (ANE)共聚反应的催化性能 .动力学研究结果表明 ,MA与ANE共聚对单体的浓度呈一级反应 ,其表观活化能为 31 0kJ/mol.用IR和13 CNMR研究了共聚物的结构 ,结果表明聚合物是交替的 ,其中酸酐的含量为 4 5 6 % .用GPC测定了聚合物的分子量及其分布 ,结果表明分子量的分布较窄 ,PDI =1 19～ 1 4 2 .用DTA研究了聚合物的热力学性质 ,其分解温度为 5 0 1 1℃.

Fe(acac)3/phen/O2体系中苯甲醇的选择氧化

研究了Fe(acac)3/phen/O2在碱(K2CO3和NaOH)体系下对苯甲醇的选择氧化反应.循环伏安实验证实,Fe(acac)3通过碱调节其氧化还原电势可直接活化氧.

Separation of thorium(IV) and extracting rare earths from sulfuric and phosphoric acid solutions by solvent extraction method

The bastnasite of Baotou (China) was roasted in concentrated sulfuric acid at 250-300 degreesC and the calcined products were leached by water. Almost all rare earths (RE) were moved into solutions in trivalent along with some radioactive impurity thorium(IV) (Th(IV))which accounts for 0.4% of RE and other impurities such as Fe(III), Ca, F, P, etc. Through fractional extraction (seven stages for extraction and nine for scrubbing), the mass ratio of Th(IV) and RE (ThO2/REO) in solution has decreased to 5 x 10(-6). The purity of ThO2 product recovered from organic phase is above 99%. The iron(III) in solutions can be removed in the form of precipitation by adding some magnesia into the solutions. Then RE can be concentrated by solvent extraction with 2-ethylhexyl phosphinic acid 2-ethylhexylester (P-507). The results of fractional extraction show that the concentration of total RE in aqueous solutions stripped by hydrochloric acid is over 200 g REO/I with the yield of RE above 99%. Individual RE can be attained by solvent extraction with P507 in the following process.

一种结晶硒铁复合物Fe(HSeO3)(Se2O5)的制备方法

本发明提供一种结晶硒铁复合物Ｆｅ（ＨＳｅＯ＃－［３］）（Ｓｅ＃－［２］Ｏ＃－［５］）的制备方法，在较低的反应温度、较短的反应时间下，由Ｆｅ（ＯＨ）＃－［３］溶胶和固体Ｈ＃－［２］ＳｅＯ＃－［３］反应，得到悬浊液，水分蒸干后Ｈ＃－［２］还原，制取Ｆｅ（ＨＳｅＯ＃－［３］）（Ｓｅ＃－［２］Ｏ＃－［５］）。和同类合成方法相比，本方法具有反应条件温和、操作规程简单的优点。