Gaseous products generated by radiation degradation of N,N-diethylhydroxylamine aqueous solution

In this paper, gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA)in aqueous solution are studied. The results show that by 10～1000 kGy irradiation of the solution in DEHA volume fraction of hydrogen did not change much with different concentrations of DEHA. The volume fraction of methane and ethane decreased, but that of ethene increased, with increasing DEHA concentration. The volume fraction of hydrogen, methane and ethane increased with the dose. The relationship of the volume fraction of ethene with the dose had something to do with the DEHA concentration.     

Gaseous products of aqueous N,N-dimethyl hydroxylamine degraded by radiation

In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.     

Analyses of organics in irradiated aqueous N,N-diethylhydroxylamine solution

The organics in γ-ray irradiated aqueous N, N-diethylhydroxylamine (DEHA) solution, which is used as a reducing agent in reprocessing spent nuclear fuel, were analyzed with gas chromatography equipped with FFAP capil-lary column and flame-ionization detector. It was found that irradiated DEHA solutions contained acetaldehyde, ethanol, and acetic acid. For DEHA of 0.2 mol/L irradiated to 10～1000 kGy, the concents of acetaldehyde, ethanol and acetic acid are (9.7～18.7)×10-3, (0.4～23.4)×10-3 and (6.5～11.7)×10-3 mol/L, respectively. The concentration of DEHA decreases obviously with the dose.     

Analyses of organics in irradiated aqueous N, N-diettiyihydroxylamine solution

The organics in γ-ray irradiated aqueous N, N-diethylhydroxylamine （DEHA） solution, which is used as a reducing agent in reprocessing spent nuclear fuel, were analyzed with gas chromatography equipped with FFAP capii- lary colunm and flame-ionization detector. It was found that irradiated DEHA solutions contained acetaldehyde, ethanol, and acetic acid. For DEHA of 0.2 mol/L irradiated to 10-1000 kGy, the concents of acetaldehyde, ethanol and acetic acid are （9.7-18.7）×10^3, （0.4-23.4）×10^3 and （6.5-11.7）×10^3 mol/L, respectively. The concentration of DEHA decreases obviously with the dose.     

N,N-二甲基羟胺辐解产生的气态烃类的定性和定量分析

报道了用三氧化二铝毛细柱与氢火焰离子化检测器联用的气相色谱法,定性定量分析了N,N-二甲基羟胺水溶液辐解产生的气态烃类。结果表明,辐照剂量为10—1000kGy时,N,N-二甲基羟胺水溶液辐解产生的气态烃类有甲烷、乙烷、乙烯、丙烷、丙烯和正丁烷,当N,N-二甲基羟胺浓度为0.2mol/L时,甲烷的体积分数为9.996×10-6—247.5×10-6,乙烷、丙烷和正丁烷的体积分数较低,而乙烯和丙烯的体积分数则更低。甲烷的体积分数随剂量的增加而增加,而乙烷、乙烯、丙烷、丙烯和正丁烷的体积分数随剂量变化不明显。     

EM>N/EM>，EM>N-/EM>二乙基

研究了N,N-二乙基羟胺(DEHA)水溶液辐解产生的气态烃。当DEHA浓度为0.1~0.5 mol/L,剂量为10~1 000 kGy时,甲烷、乙烷、丙烷和正丁烷的体积分数随剂量的增加而增加,但随DEHA浓度的增加而减少。乙烯和丙烯的体积分数随DEHA浓度的增加而增大,它们与剂量的关系与DEHA浓度有关。     

染料水溶液的辐射降解研究

辐射技术处理环境污染物显示了很大的应用前景,燃煤烟气脱硫脱硝、挥发性有机物净化、废污水处理、污泥消毒和处置等正在逐步走向工业应用。本工作进行印染废水辐照处理研究。     

N,N-二甲基羟胺辐解产生的氢气和一氧化碳的研究

With the development of nuclear power industry, more attentions have been paid on reprocessing power reactor spent fuel. Up to now, PUREX process is the only process available commercially. The process achieves uranium and plutonium separation by means of quick and quantitative reduction of Pu (Ⅳ) to Pu (Ⅲ). Therefore the reductant is very important in PUREX process. Preliminary experiment results[1] show that N, N-dimethyl hydroxylamine not only reduces rapidly Np (Ⅵ) and Pu (Ⅳ) to Np (V) and Pu (Ⅲ), but also stabilizes the Np (V)and Pu (Ⅲ) in acid solution. It may become a salt-free reductant with promising future for applications in the area[2]. However, organics decompose under intense radiation environment, and this affects its reduction efficiency,and products from the degradation may affect separation of the radioactive elements.This paper reports the qualitative and quantitative analysis of hydrogen and carbon monoxide produced by 60Co y-ray degradation of N, N-dimethyl hydroxylamine. The analyses of hydrogen and carbon monoxide were performed by gas chromatography, in which a 2m column packed with 5A molecular sieve and thermal conduc tivity detector[3] were used. The analysis of hydrogen employed argon as carrier gas, the column temperature was 80℃ and the detector temperature was 110℃. The analysis of carbon monoxide used hydrogen as carrier gas, the column temperature was 50℃ and the detector temperature was 80 ℃. The results show that when the concentration of N, N-dimethyl hydroxylamine was between 0.1 mol/L and 0.5 mol/L and the dose delivered by the irradiation was 10-1000 kGy, the volume fraction of hydrogen was (8.0-303.9)× 10-3; and the volume fraction of carbon monoxide is (0-1.7)× 10-3. The volume fraction of hydrogen increased with increasing dose, and it has little relationship with concentration change of N, N-dimethyl hydroxylamine when the irradiation dose was bellow 500 kGy, whereas it increased with the increasing concentration of N, N-dimethyl hydroxylamine when the dose was higher than 500 kGy. The volume fraction of carbon monoxide has little relationship with both the irradiation dose and N, N-dimethyl hydroxylamine concentration.     

聚砜的辐射降解研究进展

回顾了近年来有关各种聚砜材料在电子、γ和重离子辐照下降解机理、气态产物及其辐射化学产额、性能和结构变化的相关研究成果,并对相关研究进展进行了综合分析,有助于理解各类聚砜材料在辐射下的降解行为.     

氯酚类污染物的辐射降解研究进展

以γ射线辐照为基本手段的辐射技术,在环境污染治理中的应用日益广泛。本文着重介绍了辐射技术降解氯酚类污染物(CPs)的辐照分解机理及最新研究进展,并对辐射技术的应用前景和存在的问题进行了评述。同时简要介绍了影响CPs辐照分解效率的各种因素,提出单一辐照工艺对高浓度的CPs的处理都存在一定局限性,而采用臭氧-辐照联用,不仅可降低辐射剂量,而且臭氧在辐射条件下可产生协同效应,既提高了有机物的处理效果,又克服了单用辐射处理时效率随有机物浓度下降而降低的缺点,联合工艺的开发与应用将成为环境污染治理新发展的方向。     

水溶液中环己丁酸的伽玛射线辐射降解研究

采用^60Coγ-射线辐射降解环己丁酸,通过对辐照前后化学需氧量（CODcr）与pH值变化的分析,研究了不同环己丁酸浓度、初始pH值、H202初始浓度和吸收剂量对环己丁酸的辐射降解效果的影响。结果表明：在相同剂量条件下,环己丁酸初始浓度越高,CODcr去除率越低;酸性条件更利于溶液中CODcr的去除;H202与γ-射线辐照之间具有显著的协同效应,H202初始浓度为1mmol·L-1时,其对40mg·L-1环己丁酸的辐射降解的促进效果达到最好。环己丁酸水溶液的CODcr浓度变化服从一级反应动力学方程。     

顶空固相微萃取-气相色谱法测定N,N-二甲基羟胺

建立了顶空固相微萃取-气相色谱测定N,N-二甲基羟胺(DMHAN)的分析方法。采用65μm聚二甲基硅氧烷/二乙烯基苯(PDMS/DVB)进行萃取,考察了萃取时间、萃取温度、溶液pH值、顶空体积及解吸时间等因素的影响,确定了顶空固相微萃取-气相色谱分析DMHAN的最佳实验条件。DMHAN浓度在1.65~49.4mmol/L范围内有良好的线性关系(r=0.997 3),当浓度为8.24 mmol/L时相对标准偏差为2.1%(n=5),检出限为4.67×10~(-2)mmol/L,重加回收率为96.1%~103%。该方法操作简单、稳定,适合后处理料液中DMHAN的测定。     

二甲基羟胺水溶液的脉冲辐解研究

利用脉冲电子束进行二甲基羟胺(DMHAN)水溶液的脉冲辐解研究,对其瞬态光谱中的主要吸收峰作了归属,并初步考察了这些瞬态物种的生长、衰减等行为。研究结果表明,·OH与DMHAN反应生成(CH3)2NO·自由基,测得速率常数为(4.5±0.3)×109mol-1·L·s-1;eaq-与DMHAN反应生成(CH3)2N·自由基,测得速率常数为(1.3±0.04)×109mol-1·L·s-1。     

Extraction of uranyl（VI）ion with N,N—dibutyloctadecanamide from nitric acid solution

The extraction of U(VI) with newly synthesized long chain alkyl amide,N,N-dibutyloctadecanamide(DBODA),has been studied.The dependence of the extraction on nitric acid concentration,DBODA concentration and temperature from nitric acid solution has been investigated and the extracted species has also been investigated using FT-IR spectrometry.The related thermodynamic functions were calculated.The separation factor between U(VI) and Th(IV) is higher and there is no third phase formation under the conditions studied.     

氯代有机污染物辐照脱氯的研究进展

本工作对电离辐射引发的典型氯代有机污染物的脱氯降解机理进行了综述,重点回顾了氯酚、多氯联苯、三氯乙烯和四氯乙烯辐照脱氯降解的研究现状.氯酚在氧化条件下与羟基自由基(·OH)反应首先形成·OH加成物,然后逐步脱氯;在还原条件下水合电子(e-aq)与氯酚直接发生选择性反应脱氯,生成苯酚和氯离子.多氯联苯在有机溶剂中的辐照降...     

Analysis of products of thymine irradiated by ^18O^8＋ ion beam in N2O saturated aqueous solution

Some methods of capillary gas chromatography,such as GC,GC-mS,GC-FT-IR,are used to analyze the products of thymine irradiated by ^18O^8 ion beam in N2O saturated aqueous solution.From the results of GC-MS the molecular weight of products can be determined,and from the results of GC-FT-IR some molecular structure information of products can be obtained.By this way the products,5,6-Dihydrothymine,5-Hydroxyl-5-Methylhydantoin,5-Hydroxyl-6-Hydrothymine,5-Hydro-6-Hydroxylthymine,5-Hydroxymethyluracil,Trans-Thymine glycol,Cis-Thymine glycol and dimers are dtermined without separation of them from sam,ples.Though these products are as same as those products of thymine irraduiated by γ rays in N2O saturated aqueous solution,the mechanism of thymine irradiated by heavy ion beam in aqueous solution is differrent from that by γ rays.The main products of thymine irradiated by ^18O^8 ion beam in N2O saturated aqueous solution are hydroxyl adducts at 5-6 band of thymine,while the main products of thymine irradiated by γ ray in N2O staurated aqueous solution are dimers of thymine.     

辐射技术用于染料废水的脱色与降解

详细阐述了染料废水辐射降解的机理、影响因素和工程应用,为后续研究和工业应用提供参考.经辐照过的染料溶液所产生的·OH、eaq-和H·具有很高的活性,可以和染料分子发生氧化和还原反应,使“-N=N-”和“-C=C-”断裂. OH为强氧化剂,可以直接氧化染料分子并将其降解.eaq-是强还原剂,可迅速脱去染料的颜色,但对脱色...     

微量热法研究硝酸体系中N,N-二甲基羟胺的热稳定性

采用微量热仪研究了硝酸溶液中N,N-二甲基羟胺(DMHAN)的热稳定性,考察了溶液中硝酸浓度、DMHAN浓度和甲基肼(MMH)、空气和氮气气氛、金属元素等对DMHAN热稳定性的影响,并比较了相同条件下DMHAN和羟胺(HAN)的热稳定性。研究结果表明,HNO_3浓度在1.5~3.0mol/L和DMHAN浓度在0.05~0.8mol/L时,DMHAN/HNO_3体系起始反应温度(t0)随硝酸浓度的降低或随DMHAN浓度的升高而增加。当HNO_3/DMHAN摩尔浓度比值分别为2.5~10和12.5~20时,DMHAN/HNO_3体系反应热分别约为865.5kJ/mol和683.4kJ/mol,说明不同的HNO_3/DMHAN摩尔浓度比值,引发DMHAN/HNO_3体系内的各个反应权重不同从而导致体系放热不同。MMH作为支持还原剂,使DMHAN发生分解反应的时间明显滞后;空气、氮气气氛以及后处理流程中的铁和裂片元素锆、钌对DMHAN/HNO_3体系分解反应无明显影响,不锈钢容器对DMHAN/HNO_3分解反应有催化作用。     

吉西他滨-~(13)C,~(15)N_2及其代谢产物的合成

以自制的尿素-~(13)C,~(15)N_2为前体,与3-乙氧基丙烯腈反应制备胞嘧啶-~(13)C,~(15)N_2,用BSA保护后,经与2-脱氧-2,2-二氟-D-赤式-五呋喃糖-3,5-二苯甲酯-1-甲磺酸酯反应生成2′,2′-二氟-2′-脱氧胞嘧啶核苷-3′,5′-二苯甲酸酯-~(13)C,~(15)N_2,分离纯化后经NaOH水解生成吉西他滨-~(13)C,~(15)N_2,再进一步降解脱氨得到吉西他滨-~(13)C,~(15)N_2代谢产物。产品经HPLC,LC-MS和~1H NMR表征确定,化学纯度高于98%,~(13)C同位素丰度为99%,~(15)N同位素丰度为98%。结果表明,合成的吉西他滨-~(13)C,~(15)N可用于药物代谢研究。     

Extraction of lanthanide ions with N,N,N′,N′-tetrabutyl-3-oxadiglycolamide from nitric acid media

Extractability and extraction mechanism of lanthanide ions were investigated by using a new extractant,N,Nn,N′,N′-tetrabutyl-3-oxa-diglycolamide(TBDGA),in toluene from nitric acid media.The effects of HNO_3 and TBDGA concentrations,and temperature,on extraction of lanthanide ions were studied.Stoichiometrics of the main extracted species were HNO_3·TBDGA and M(NO_3)_3-3TBDGA(M = Er,Dy,Tb,Gd,La,Ce,Nd,Sm and Eu).The extracted species for metal ions were established to be ionic complex.In this complex,nitrate anion was not coordinated to the central ion.The extraction pattern increased gradually across the lanthanide ions series,showing enhanced affinity of TBDGA toward heavy lanthanide ions.Thermodynamic parameters were investigated for the exothermic extraction reaction.