H2O2对Pu(Ⅴ)的还原动力学研究

在0.1 mol/L NaClO4溶液中研究了Pu(Ⅴ)与H2O2反应的动力学。测定了Pu(Ⅴ)与H2O2的反应速率。探讨了温度以及Fe2+，SO2-4，HCO-3，F-等无机离子的存在对反应的影响。实验结果表明，反应对Pu(Ⅴ)与H2O2呈一级，对溶液中H+呈-1级；速率方程可表示为： -dc(Pu(Ⅴ))/dt=(3.93±1.93)×10-9c(Pu(Ⅴ))c(H2O2)/c(H+)。 随着温度升高，反应速率明显加快，根据Arrhenius规律，计算出了反应的活化能为Ea=84 kJ/mol。地下水中Fe2+，SO2-4，HCO-3，F-等离子的存在，有利于Pu(Ⅴ)的还原。     

硅基季铵化分离材料对Pu(Ⅳ)的吸附性能及机理研究

研究了硅基季铵化分离材料(SiR4N)在硝酸溶液中对Pu(Ⅳ)的吸附性能和机理。结果表明,SiR4N对Pu(Ⅳ)的吸附等温线基本符合Langmuir吸附等温线,吸附为放热反应,ΔH=-7.23 kJ/mol。机理研究结果表明,分配比D与树脂功能基团SiR4N+的关系式为:lgD=3.43+1.74lgn(SiR4N+),其配位比接近于2,由此可推测SiR4N在硝酸溶液体系主要吸附的是[Pu(NO3)6]2-。     

铀的离子交换反应——Ⅱ.硫酸和盐酸介质中铀(Ⅵ)在阳离子交换树脂上的化学状态

本文用红外光谱法和当量计算法研究了在硫酸、盐酸介质中铀(Ⅵ)在阳离子交换树脂上的化学状态及其含量。结果表明,在阳离子交换树脂上,铀(Ⅵ)除了以UO_2~(2 )外,还可以(UO_2HSO_4)~ 和(UO_2Cl)~ 存在,但当酸的浓度低于 0.5N时,其量可忽略不计。即使在酸浓度相当大(2—3N)时,(UO_2HSO_4)~ 和(UO_2Cl)~ 也只占树脂交换容量的很小一部分。因此,在通常用的阳离子交换色层法富集铀同位素的工作中,可以按照阳离子交换树脂上只有 UO_2~(2 )来考虑同位素效应及计算分离因数。     

Re/99Tcm(CO)3-EPBI与Aβ(1～40)结合能力的测定及生物分布

为发展锝-99m标记的阿尔茨海默病(Alzheimer's disease, AD)早期诊断显像药物,在荧光测定法基础上,建立了体外荧光法测定羰基铼配合物与Aβ_(1～40)淀粉样纤维结合的解离常数K_d的方法.同时,合成了配体2-(1-乙基苯并咪唑)吡啶(EPBI)及其铼的配合物Re(CO)_3Cl(EPBI),测定后者与体外缠结Aβ_(1～40)结合的解离常数Kd;采用直接标记法制备EPBI的[~(99)Tc~m(CO)_3]~+配合物,并研究配合物[~(99)Tc~m (CO)_3]~+-EPBI的理化性质及生物分布.结果表明,Re(CO)_3Cl(EPBI)与Aβ_(1～40)结合的解离常数K_d=13.3 μmol/L;正常小鼠体内生物分布研究表明,化合物[~(99)Tc~m (CO)_3]~+-EPBI的脑初始(2 min内)摄取值为(0.63±0.17)%ID/g(n=3),在脑内清除较快,120 min时,摄取值为(0.27±0.03)%ID/g(n=3).     

在Na2CO3溶液中季铵盐萃取Zr机理的研究

用红外光谱分析和季铵盐萃取研究了Zr—DBP界面物在碳酸钠溶液中的溶解机理。结果表明,Zr—DBP界面物在碳酸钠溶液中生成了能溶于水的配合阴离子Zr(CO3)4^4-或ZrO(CO3)3^4-,Zr—DBP界面物溶解前后与纯HDBP的红外谱图相比,溶解液中DBP的P—O键的特征峰与纯HDBP的更为接近。说明界面物在溶解Na2CO3过程中,破坏了原有界面物的配合,DBP不再与Zr配合,而以自由离子形式存在。     

Research on the degradation mechanism of dimethyl phthalate in drinking water by strong ionization discharge

The degradation mechanism of dimethyl phthalate(DMP) in the drinking water was investigated using strong ionization discharge technology in this study. Under the optimized condition, the degradation efficiency of DMP in drinking water was up to 93% in 60 min. A series of analytical techniques including high-performance liquid chromatography, liquid chromatography mass spectrometry, total organic carbon analyzer and ultraviolet–visible spectroscopy were used in the study. It was found that a high concentration of ozone(O_3) produced by dielectric barrier discharge reactor was up to 74.4 mg l~(-1) within 60 min. Tert-butanol, isopropyl alcohol,carbonate ions(CO_3~(2-)) and bicarbonate ions (HCO_3~-) was added to the sample solution to indirectly prove the presence and effect of hydroxyl radicals(·OH). These analytical findings indicate that mono-methyl phthalate, phthalic acid(PA) and methyl ester PA were detected as the major intermediates in the process of DMP degradation. Finally, DMP and all products were mineralized into carbon dioxide(CO_2) and water(H_2O) ultimately. Based on these analysis results, the degradation pathway of DMP by strong ionization discharge technology were proposed.     

Experimental Research on the Sterilization of Escherichia Coli and Bacillus Subtilis in Drinking Water by Dielectric Barrier Discharge

The bactericidal effect on the representative type of Gram-negative Escherichia coli(E.coli) and Gram-positive Bacillus subtilis in drinking water was investigated in this paper by using dielectric barrier discharge(DBD) advanced oxidation technology.The sterilizing rates under different conditions of reaction time t,input voltage V,p H value,and initial concentration of bacteria C_0 were investigated to figure out the optimum sterilization conditions.Our observations and comparisons of cell morphology alteration by scanning electron microscopy and transmission electron microscopy revealed the sterilization mechanisms.The results showed that the sterilizing rate increased obviously with the extension of reaction time t and the rise of input voltage V.The optimal sterilization effect was achieved when the p H value was 7.1.As the initial concentration of bacteria rose,the sterilizing rate decreased.When the input voltage was 2.2 k V and the initial concentration of bacteria was relatively low,the sterilizing rate almost reached 100% after a certain treatment time in neutral aqueous solution.The reasons for the great damage of cell structure and the killing of bacteria are the oxidation of O_3,OH and the accumulation of active species produced by DBD.The article provides a certain theoretical and experimental basis for DBD application in water pollution treatment.     

~(101)Tc半衰期的测量

在微型中子源反应堆中辐照75 mg仲钼酸铵20 min,冷却12 min,然后用α-安息香肟-乙酸乙酯在水相介质为0.8 mol/L HNO3、相比1∶1条件下,连续萃取2次分离出了无载体、放化纯的~(101)Tc样品.用HPGe γ探测器对306.8 keV γ射线采用位置接续法跟踪测量,分别用"平移法"、"迭代法"和"R-值法"进行数据处理,得到~(101)Tc的半衰期为(14.02±0.01) min(n=5),经检验数据可靠.     

铀在特定场址地下水中存在和迁移形态研究及其沉积热力学分析

将化学热力学平衡分析模式与地球化学条件相结合,应用铀元素水文地球化学迁移形式热力学分析方法,计算出某特定场址地下水中铀的化学形态和迁移形态。结果表明：UO2(CO3)2^2-占84．1％,UO2(CO3)^0占8．7％,UO2(CO2)3^-占6．5％。     

萃取液闪法测定生产堆高放废液及其处理工艺中的^99Tc

本文在ＨＮＯ３和Ｈ２ＳＯ２混合介质中，用环己酮从高放废液及其处理 样品中定量萃取＾９９Ｔｃ，分别以Ｋ２ＣＯ３－Ｈ２Ｏ２及ＮａＣＯ２洗涤有机相去除钌，铑，碘等核素。有机相与溶水性的闪烁液混匀，液闪法测量＾９９Ｔｃ的活度。     

预辐射接枝改性无纺布制备铯离子吸附材料

采用预辐射接枝聚合方法制备了4-羟基丁基丙烯酸酯缩水甘油醚(4HBAG)接枝的聚乙烯/聚丙烯(PE/PP)皮芯结构无纺布。用Na_2SO_3对接枝4HBAG的无纺布(PE/PP-g-4HBAG)进行开环反应,改性得到磺酸型吸附材料。在环氧基物质的量转化率52%时获得了磺酸基密度1.4 mmol/g的吸附材料。采用批次吸附和流动吸附对Cs~+的吸附性能进行研究。Cs~+的吸附等温线和吸附动力学表明,吸附过程遵循Langmuir等温线模型和准二级动力学模型。在1 000 SV/h高流速下,Cs~+的最大吸附容量为1.35 mmol/g。在pH=4~10时,吸附率稳定在90%左右,该值随pH值的增加而降低。在Cs~+初始浓度为1 mg/L和10 mg/L的溶液中研究了Na~+对Cs~+吸附率的影响,当Na~+浓度从0增加到20 mmol/L时,Cs~+的吸附率迅速降低。二价和三价金属离子Mg~(2+)、Ca~(2+)和Fe~(3+)对Cs~+吸附更具有阻碍作用。该磺酸型吸附材料在1 000 SV/h的高流速下能快速去除Cs~+。     

U(Ⅵ)在人体组织液中的形态模拟

铀的毒性与其体内形态密切相关,研究铀在人体组织液的形态有助于了解铀的人体毒理。本工作采用热力学平衡模拟方法研究U(Ⅵ)在人体组织液中的形态。建立了含多种金属离子和小分子配体组成的多相组织液热力学平衡模型,模拟研究了H₂OCO₃^2--PO₄^3-体系中UO₂²⁺的形态分布、组织液中UO₂²⁺的形态分布及总CO₃^2-次氮三酯酸（NTA）浓度对组织液中UO₂²⁺形态分布的影响。结果表明,在H₂O-CO₃^2--PO₄^3-体系中,当UO₂²⁺总浓度为1.5 μmol/L、pH>7.0时,UO₂²⁺主要以 [UO₂(CO₃)₃]^4-和[UO₂(CO₃)₂]^2-存在,pH<6.0时,主要以UO₂HPO₄和UO₂(H₂PO₄)₂存在;当UO₂²⁺浓度为0.15 mmol/L、pH>7.0时,UO₂²⁺仍以 [UO₂(CO₃)₃]^4-和[UO₂(CO₃)₂]^2-为主,pH3～6时,主要以固相(UO₂)₃（PO₄)₂出现。在组织液模型中,当UO₂²⁺总浓度为1.5 μmol/L、pH>7.0时,UO₂²⁺主要以 [UO₂(CO₃)₃]^4-、[UO₂(CO₃)₂]^2-和[UO₂Cit₂]^4-存在,pH<6.0时,主要以[UO₂Cit₂]^4-存在;当UO₂²⁺浓度为0.15 mmol/L、pH>7.0时,UO₂²⁺仍以 [UO₂(CO₃)₃]^4-、[UO₂(CO₃)₂]^2-和[UO₂(CO₃)₃]^4-存在,pH 3～6时,以固相(UO₂)₃（PO₄)₂为主。当UO₂²⁺浓度为1.5 μmol/L或0.15 mmol/L时,提高CO₃^2-浓度能改变UO₂²⁺在组织液中的形态分布：[UO₂(CO₃)₃]^4-含量升高,[UO₂(CO₃)₂]^2-和[UO₂Cit₂]^4-含量降低。NTA的加入改变了组织液中UO₂²⁺的形态分布,但并没产生UO₂²⁺的NTA螯合物形态。当UO₂²⁺浓度为1.5 μmol/L时,提高NTA浓度可使UO₂²⁺主要以[UO₂Cit₂]^4-存在;当UO₂²⁺浓度为0.15 mmol/L时,UO₂²⁺主要以[UO₂(CO₃)₂]^4-形式存在。     

pH电位滴定法测定Zr(Ⅳ)-羟基脲配合物表观稳定常数北大核心CSCD

羟基脲(HU)在PUREX流程可作为还原剂和配位剂,其与乏燃料溶解液中重要裂片元素Zr(Ⅳ)的配位作用可提高PUREX流程对Zr的净化水平。本工作对硝酸体系中Zr(Ⅳ)与HU的配位作用进行了初步研究。通过等摩尔连续变化法(又称Job’s法)得到0.3 mol/L HNO_(3)下,Zr(Ⅳ)和HU的配位摩尔比为1∶8,结合半整数法算出Zr(Ⅳ)-HU的表观稳定常数为lg K_(1)≈1.59、lg K_(2)≈1.75、lg K_(3)≈1.88、lg K_(4)≈1.98、lg K_(5)≈2.09、lg K_(6)≈2.27、lg K_(7)≈2.51、lg K_(8)≈3.01。1.0 mol/L HNO_(3)下,Zr(Ⅳ)和HU配位摩尔比为1∶4,表观稳定常数为lg K_(1)≈2.33、lg K_(2)≈2.51、lg K_(3)≈2.78、lg K_(4)≈3.31。3.0 mol/L HNO_(3)下,Zr(Ⅳ)和HU配位摩尔比为1∶2,表观稳定常数为lg K_(1)≈2.69、lg K_(2)≈2.79。     

Removal of NO and SO2 in Corona Discharge Plasma Reactor with Water Film

In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NO~ removal under suitable conditions is obtained in our experiments.     

HEHEHP-煤油溶液淋洗的阴离子交换色层法分离稀土元素的研究

引言 用与水不相混溶的有机萃取剂作淋洗剂的离子交换色层法提出于1975年。1979年杨伯和等人用三脂肪胺硫酸盐的煤油溶液从吸附有铀的阴离子交换树脂上洗脱出高纯度的铀。1980年何寿椿等人用四苯硼钠的甲基异丁基酮等的溶液作淋洗剂在阳离子交换树脂柱上实现了Rb和Cs的分离。与此同时,江林根等人用HDEHP的煤油溶液作淋洗剂,在阳离     

动态连续电解还原制备四价铀的研究

研究了ＵＯ２（ＮＯ３）２－ＨＮＯ３－Ｎ３Ｈ５ＮＯ３－Ｈ２Ｏ体系中，用三级串联电解槽动态连续电解还原制备四价铀的方法，在确定的工艺条件下，当进料液Ｕ（ＶＩ）浓度为１８０ｇ／Ｌ，硝酸浓度为３．１４ｍｏｌ／Ｌ，肼浓度为０．２１０ｍｏｌ／Ｌ，加料速度为２００ｍＬ／ｈ时，可连续制备得到了四价铀浓度大于１５０ｇ／Ｌ的产品溶液。     

Fenton-UV照射法对超高浓度聚乙烯醇有机废液的降解效能

采用Fenton-紫外照射(Fenton-UV)联用工艺对核电厂超高浓度聚乙烯醇(PVA)有机废液进行处理,研究了PVA转化率、平均分子量、溶液黏度等随时间的变化规律。结果表明:对于50 g/L的PVA溶液,H₂O₂投加质量浓度为15 g/L,FeSO₄·7H₂O投加质量浓度为0.050 g/L,初始pH值为3,经过2 h Fenton反应和2 h UV照射(3 mW/cm²)之后,PVA转化率达到100%,溶液平均分子量从60 000～80 000 Da降低到1 000 Da以下,黏度降低到1.1 mPa·s,但总有机碳和化学需氧量(COD)变化不大。Fenton-UV法可作为预处理方法,前期Fenton阶段提高PVA的溶解度,增加反应溶液中的PVA含量,并进行初步降解和氧化;后期UV法进一步降解溶液中的PVA,有效降低其分子量和黏度,为后续处理提供有利条件,最终形成经济可行的超高浓度PVA有机废液处理工艺。     

Degradation of Microcystin-LR by Gas-Liquid Interfacial Discharge Plasma

In this study, we report on the degradation of microcystin-LR （MC-LR） by gas- liquid interracial discharge plasma. The influences of operation parameters such as average input voltage, electrode distance and gas flow rate are investigated. Experimental results indicate that the input voltage and gas flow rate have positive influences on MC-LR degradation, while the electrode distance has a negative one. After 6 min discharge with 25 kV average input voltage and 60 L/h air aerati by discharge both in on, the degradation rate of MC-LR achieves 75.3%. distilled water and MC-LR solution are measured H202 and 03 generated Moreover, an emission spectroscopy is used as an indicator of the processes that take place on the gas-liquid boundary and inside plasma. Varied types of radicals （O, .OH, CO, 03, etc.） are proved to be present in the gas phase during gas-liquid interfacial discharge.     

过氧化氢湿法氧化模拟有机污物的研究

用过氧化氢湿法氧化处理有机污物,研究了过氧化氢的投加量和投加方式,催化剂以及pH值等对反应的影响。结果表明,为提高H2O2的利用率,H2O2应以间歇式投加,选取Fe^2 作催化剂,体系pH值为1～2。为保证反应快速启动和平稳进行,反应时将催化剂总投加量的1／3提前与要分解氧化的物质混合一段时间,剩余2／3在反应进行中连续定量滴加,并于反应结束前半小时投加完毕。正交试验表明,分解2．00g界面污物的最佳实验条件为：pII-1．10mL30％H2O2溶液,10mL 0．1mol／L Fe^2 溶液。反应结束时,反应釜底部的白色残余物经红外分析和元素分析表明主要是磷酸盐。H2O2湿法氧化能够有效分解TBP／OK,HDBP／OK溶液和界面物。     

蛭石和蒙脱石对Sr的吸附性能

研究了蛭石、蒙脱石对Sr的吸附行为及各种实验条件对吸附的影响.结果表明,在室温下,pH=8,初始浓度C_0=20 MBq/L的Sr~(2+)溶液,保持液固比为50∶1(mL∶g)不变时,蛭石和蒙脱石对Sr~(2+)的去除率分别达96.8%和98.5%;在相同条件下,其适宜吸附的pH范围均为3～10,吸附平衡时间分别为2 h和15 min;Ca~(2+)对蛭石和蒙脱石的吸附影响均较大;而2 mol/L HNO_3 能分别将82.7%和98.7%的Sr~(2+) 从蛭石和蒙脱石上解吸下来.蛭石经[Ag(NH_3)_2]~+和1 mol/L HCl改性,吸附率有所提高,[Cu(NH_3)_4]~(2+)的改性能提高蒙脱石的吸附性能;高温改性却使蛭石和蒙脱石的吸附性能变得更差.此外,还用X衍射分析谱(XRD)对改性前后的蛭石和蒙脱石进行了解析,并初步分析了改性后蛭石和蒙脱石吸附性能发生变化的原因.