含硼模拟废水处理的研究

对配制2000毫克硼/升的硼酸模拟废水经氧化钙沉淀法处理,硼收率可达90%以上,滤液经阳离子交换树脂(强酸1~#)去钙后,用强碱Ⅱ型阴离子交换树脂(0610)吸附硼,再用氢氧化钠洗脱。阴树脂约可处理100床体积废水。硼酸钙沉淀用硝酸溶解,可结晶回收硼约80%,结晶母液可用于中和含硼的阴树脂洗脱液中的氢氧化钠,回收硼酸。阴、阳树脂流出液的纯水可以循环使用。     

超临界水氧化处理核电站废阴离子交换树脂研究

在间歇式超临界水氧化(SCWO)设备中,对粉碎处理后的阴离子交换树脂水悬浮液在超临界条件下进行了氧化降解处理。实验研究了反应温度、反应压力、反应时间、过氧系数对COD去除率的影响,同时考察了催化剂种类、反应压力和反应温度对氨氮去除率的影响。通过正交试验,得到主要因素对处理效果影响的显著程度排序为:反应温度>反应压力>反应时间>过氧系数。结果表明:在反应温度540 ℃、反应压力26 MPa、反应时间8 min、过氧系数3的条件下,COD去除率为99.65%。针对阴离子树脂中NH₃-N含量高难以去除的问题,选用不同的催化剂CuSO₄、MnO₂、CeO₂添加到反应体系中,结果表明对NH₃-N的氧化效果顺序为CuSO₄>CeO₂>MnO₂,对NH₃-N的最高降解率达到96.53%。     

过氧化氢湿法氧化 IRN78阴离子交换树脂的初步研究

使用过氧化氢湿法氧化技术对核级IRN78阴离子交换树脂进行了氧化降解初步研究。 研究中用硫酸对阴离子交换树脂体系pH值进行了调节,比较了催化剂Fe²⁺、Cu²⁺、Fe²⁺/Cu²⁺混合催化剂对H₂O₂-阴离子交换树脂的催化效果。研究结果表明:使用混合催化剂Fe²⁺/Cu²⁺的摩尔数比为1∶2时湿法氧化IRN78阴离子交换树脂的催化效果优良,氧化降解率达到了99.7%,过氧化氢的利用率达到了 92.7%。实验结果表明过氧化氢湿法氧化技术对于 IRN78阴离子交换树脂有良好的氧化降解效果。     

西安脉冲堆水净化系统混床废树脂的性能变化

测定了西安脉冲堆净化系统混床废阴、阳离子交换树脂的理化性能参数,分析了废阴、阳离子交换树脂发生的性能变化,并考察了不同影响因素对树脂性能变化的贡献。根据废树脂中的杂质分布情况,分析了西安脉冲堆一回路水受到的外来污染情况、反应堆结构材料的腐蚀情况。分析结果显示,混床废阴树脂已基本丧失交换能力,而废阳树脂的剩余交换能力仍较高。反应堆运行产生的辐射效应引起的树脂性能变化较小。废阴树脂交换能力的丧失归因于其交换了大量的杂质离子碳酸根和一定量的有机物。废阴树脂中其它阴离子含量很低,废阳树脂中杂质金属元素含量也很低,说明西安脉冲反应堆堆池水并未受到明显的外来污染。反应堆水池内结构材料存在一定的腐蚀。所得结果为此类反应堆净化系统的安全运行提供了重要的参考数据。     

原子能工业使用的Diaion离子交换树脂

强酸性阳离子交换树脂强碱性阴离子交换树脂DiaionSKNIDiaionSKN3DiaionSANI商品的类型外观OH型金属含量淡褐色透明球状(无龟裂) 铁: 铜: 重金属(如铅):淡黄褐色透明球状(无龟裂)100ppm以下50ppm以下50ppm以下可溶物在温水条件下小于0.1%(每单位干树脂)盐类置换率H型95%以上7Li型99%以上H型1%以下OH型85%以上Cl型5%以下C03型10%以下粒度1,190一420微米(小于420微米的不超过1%)交换容量 H型大于4.7毫克当量/克 7Li型大于4.6毫克当量/克 OH型大于3.7毫克当量/克 混合床用Diaion:以下两种产品是将上述阳离子交换树脂和阴离子交换树…     

碱熔-离子色谱法测定土壤中氟的方法研究

为实现固体废物中氟含量的准确测定,采用氢氧化钠熔融样品,建立了碱熔-自动进样离子色谱法测定土壤中氟的分析方法。对碱熔剂用量、碱熔温度和碱熔时间进行了条件实验,确定了适用于土壤样品的前处理方法,样品于镍坩埚内加入 3.5 g 分析纯 NaOH 于马弗炉中缓慢升温至 370 ℃与样品混合充分,继续升温到 600 ℃熔融 25 min。热水溶解提取、静置澄清 55 h 后取上清液使用 732 型强酸性阳离子交换树脂柱交换 10 min 后待测,将试液使用离子色谱 AS-19 250*4 mm 阴离子分析柱分离,选用 20 mmol·L^-1KOH 淋洗液,流速为 1.0 mL·min^-1,化学抑制电导检测器检测氟含量。用标准物质曲线法进行实验,结果表明：使用土壤和水系沉积物标准物质曲线法进行计算,可以有效提高数据的准确度和校正离子干扰。按照实验方法测定土壤和水系沉积物国家标准物质中氟含量,本方法相关系数 r>0.999,检出限为 1.0 mg·kg^-1,结果的相对标准偏差 RSD<3%、加标回收率介于 91%～105...     

废水组分对离子交换树脂处理含铀废水的影响

采用静态吸附和动态柱式实验相结合的方法,研究含铀废水中其它组分对201×7强碱性阴离子交换树脂处理含铀废水工艺过程除铀性能的影响。实验结果表明：溶液中存在的常量阴离子、三乙醇胺和机油等不同程度影响树脂的交换效率或降低树脂的工作交换容量。当溶液中c(CO^2－₃)≥0.24mol/L、c(HCO^－₃)≥0.28mol/L、c(SO^2－₃)≥0.23mol/L、c(Cl^－)＞0.09mol/L时,出水铀质量浓度大于20μg/L;树脂可允许通过的最大三乙醇胺浓度不应超过250mg/L;树脂中机油含量大于1%时,树脂的工作交换容量下降16%;树脂中机油含量大于11%时,树脂几乎完全失效。     

间歇式超临界水氧化处理核电站废弃阳离子交换树脂研究

采用间歇式超临界水氧化设备,对粉碎后的阳离子交换树脂水悬浮液进行处理。研究了反应温度、压力、停留时间、过氧系数对COD(化学需氧量)去除率的影响,考察了浆料在处理过程中模拟核素的转移,研究了进料pH对反应釜腐蚀的影响。结果表明:主要因素对处理效果的影响排序为:温度过氧系数停留时间压力。最佳处理条件反应温度520℃、压力23MPa、停留时间30min、氧化系数3和进水pH=7下,COD去除率为99.5%,高于99.8%锶离子和钴离子沉积于排盐口。调节进水pH为7,COD的去除率提高了50.6%;树脂的质量减量率达到99.6%。为核废料有效减容提供了新途径。     

铪在离子交换树脂上的吸附行为研究

本工作研究微量铪在阴离子和阳离子交换树脂上不同介质下的吸附行为。实验用阴离子树脂型号为201×7,阳离子树脂型号为2×8,相当于Dowex50×8。离子交换柱柱体积为0.8mL。淋洗介质分别为0.5mol/L HCl-0.001mol/L HF和0.05mol/L HCl-0.001mol/LHF。在阴离子树脂柱中,流速控制为0     

秦山核电站二回路凝结水净化混床树脂再生试验

秦山核电站化学水处理厂房有4台凝结水净化混床。每台装填2125kgD001-TR型阳离子交换树脂、2000kgD201-TR型阴离子交换树脂和375kgS-TR型惰性树脂。树脂层高1.2m,体积约2.7m~3。为了对失效后树脂进行体外再生,采用预定的凝结水净化混床再生工艺条件对首次失效的混床树脂进行了再生试验。树脂经擦洗、分离后,阳树脂和阴树脂     

Estimation of Electrical Resistivity Increase due to Carbon Deficients in Uranium Monocarbides

Pyrolysis of spent ion exchange resins is used to reduce radioactive waste volume and to make the final waste form more stable. The weight loss of cation exchange resin after pyrolysis is only 50w/o, while that of anion exchange resin is 90w/o. Fundamental experiments were performed to investigate the reason for the small weight loss of the former.

The cation resin consists of base polymer and functional sulfonic acid groups. Chemical analyses of the pyrolysis products showed that 65% of the functional groups decomposed at about 300°C and generated SO₂ gas. However, only a small amount of the base polymer was pyrolyzed even at 600°C and the weight loss was only 50w/o. The IR and XPS studies on the residue showed that 35% of the functional sulfonic acid groups was converted to sulfonyl and sulfur bridges between the base polymers during pyrolysis. These bridges made the base polymers thermally stable. Therefore, the small weight loss of the cation resin was attributed to formation of bridges, which originated from the functional groups.     

核电厂离子交换树脂净化能力模拟实验研究

实验选取核电厂废液中典型裂变产物和腐蚀产物离子(Cs+、Sr2+、Co2+)配制水样,针对不同类型树脂、不同树脂层高以及不同床体积流速进行动态交换吸附实验,重点比较了不同条件下核级树脂净化能力(去污因子)的变化。结果表明:树脂层高的增加对去污效果的影响显著,特别是高交联度的树脂,对Cs+、Sr2+、Co2+的去污因子可增加约200%以上;在一定范围内提高床体积流速对树脂的去污效果存在影响,高交联度的树脂流速提高后去污因子有明显上升趋势;在10BV/h(BV=进水流量/树脂装填量)流速下树脂交联度的高低对水样的去污效果影响不明显;在1mg/L水样浓度下,大孔型阳树脂的去污效果较凝胶型阳树脂好;同等条件下,氢/氢氧型混合树脂处理离子态杂质的去污效果较单独的氢型阳树脂好。     

Behaviour of Ion Exchange Resins and Corrosion Inhibitors in Dilute Chemical Decontamination

Ethylene diamine tetra acetic acid (EDTA) is a versatile complexing agent and is being employed in decontamination formulations. The dilute chemical decontamination (DCD) process employs ion exchange resins for regeneration of complexants, collection of metal ions/active isotopes and for removal of the decontaminating chemicals. In this work the interactions of EDTA on cation and anion exchange resins have been studied. The pickup of EDTA on cation exchange resin is by ion exchange mechanism and not possibly by precipitation at the low pH existing in ion exchange resin matrix. A mathematical relationship has been worked out to calculate the amount of EDTA adsorbed per unit volume of the cation exchange resin at a given pH. In addition, the behaviour of DTPA, HEEDTA and NTA on cation exchange resin has been evaluated. The chromatographic behaviour of OH- form of strong base anion exchange resin for a formulation containing EDTA, oxalic acid and citric acid has been reported and its relevance to the decontamination process has been discussed.

Even though the corrosion rate of DCD is very low on most of the materials of construction, influence of time, temperature and the composition of the formulation on carbon steel is studied. Different classes of inhibitors were evaluated for reducing carbon steel corrosion.     

Overall Reaction Rate Analysis of Ion-Exchange Resins Incineration by Fluidized Bed

A kinetic study on the incineration of ion-exchange resins was conducted using fluidized bed. In the experiment, cation or anion exchange resins with known quantities were fed into the fluidized bed maintained at a constant temperature from 550 to 750°C. The apparent reaction rate constants k _ap could be evaluated by the time for completion of combustion derived from the continuous measurement of CO₂ concentration in the off-gas.

It was confirmed that the reaction of the ion-exchange resins proceeded with the shrinking particle model forming no solid product layer and the rate of disappearance of the resins could be expressed by the surface chemical reaction.

Most preferable conditions for incinerating the ion-exchange resins were found to be about 650°C for temperature and more than 4.91 x 10^?2 m-s^?1 for the air velocities at fluidized bed u _B . Also, k _ap for cation and anion exchange resins were found to be 1.25x10^?2 and 1.51x10^?2 s^?1, respectively, at 650°C and u _B of 5.45x10^?2m.s^?1.     

Removal of Fission Products and Their Complexing Agents from Degraded Solvent by Ion Exchange Method

Removal of fission products and their complexing agents from chemically degraded TBP/kerosene and particularly from the kerosene diluent, was studied. With the use of column technique with mixed anion and cation exchange resins, more than 80% of the fission products and their complexing agents were removed. The carboxylic acids, which constitute one of the degradation products bringing about decrease of uranium extractability, were completely removed together with the complexing agents thereof by anion exchange resin. Removal was also obtained of monobutyl and dibutyl phosphoric acids (H₂MBP and HDBP), which can retain fission products and which in actual practice are liable to be formed by hydrolysis of TBP under intensive irradiation with concentrated nitric acid and/or at the elevated temperatures.     

放化分离-液闪测量联合分析核电厂废树脂中的^(55)Fe和^(63)Ni北大核心CSCD

建立了一种核电厂放射性废离子交换树脂中^(55)Fe和^(63)Ni的联合分析方法。将废树脂样品经芬顿氧化消解后,先用氢氧化钠沉淀法沉淀^(55)Fe和^(63)Ni,再用阴离子交换树脂联合丁二酮肟沉淀对杂质离子进行分离纯化,纯化后用液体闪烁计器测量。本方法对废树脂中^(60)Co、^(65)Zn、^(54)Mn等干扰核素的去污因子均大于10^(3)。本方法对^(55)Fe和^(63)Ni的平均化学回收率分别为86%和90%,对废树脂中^(55)Fe和^(63)Ni的检测限分别为5.7 Bq/g、6.8 Bq/g。用加标样品对分析方法进行验证,预期值和测量值的偏差小于±10%。实验测得某核电厂一组一回路实际废树脂样品中^(55)Fe和^(63)Ni的平均活度浓度分别为(76.2±1.4)kBq/g和(120.0±5.1)kBq/g。     

芬顿氧化法预处理放射性废离子交换树脂

为了对放射性废树脂进行预处理,使用芬顿试剂对其进行了氧化降解预处理实验研究。通过正交试验获得了实验操作的合理条件：当过氧化氢的初始浓度为4.0 mol/L、亚铁离子的初始浓度为20 mmol/L、反应时间为4 h、反应温度为95 ℃、溶液的初始pH值为2.5时,该法对3种不同的含铀废湿树脂(50 g)均有理想的降解效果。反应进行2 h后废树脂被完全分解,残液中化学需氧量(COD)的去除率达97%以上,由8.0 ～10.0 g/L降至0.2～0.3 g/L,且吸收液中铀含量无明显增加。实验结果表明,芬顿试剂对放射性废离子交换树脂有较好的氧化降解效果。     

利用数值模拟方法研究树脂裂解反应器的进气结构

利用数值模拟的方法,考察了树脂裂解反应器上部进气方式的效果,发现存在空气利用率低的问题,同时空气还会带走反应器内的大量热量,削弱树脂裂解反应区域的温度,由此证明了试验推论的正确性。同时,利用数值模拟的方法,对设备进气方式进行优化改进:当采用下部进气后,空气的利用率得到明显的提升,空气分布也较为均匀。但此时,空气对反应区域内温度的削弱作用也更为明显。此外,随着设备进气口直径的减小和进气口数量的增加,能够较为明显地提高树脂反应区域的空气分布均匀度,而提升设备的加热功率,对提高反应区域内的温度有显著的作用。     

Uranium (IV)-(VI) Electron Exchange Reactions in Anion Exchange Resin,Tri-n-Octyl Amine and Tri-Butyl Phosphate

A study has been made of the U(IV)-U(VI) electron exchange reactions taking place between natural U(IV) and depleted U(VI) in anion exchange resin, as well as in TnOA/benzene and TBP/benzene systems.

The exchange rate in the anion exchange resin was smaller than the corresponding rates in 8–10 M HCl, which might be explained by considering that the diffusion of the exchangeable species is much slower in the anion exchange resin than in 8–10 M HCl.

The exchange rates in TnOA/benzene and in TBP/benzene were accelerated by decreasing the concentration of TnOA or TBP in benzene. The reason may be that TnOA and TBP, including the exchangeable species, is more easily diffused in dilute than in concentrated solution.

Based on activation energy values, the mechanism of exchange in the anion exchange resin was estimated to be similar to that in 8–10 M HCl solution, and the corresponding mechanism for TBP/benzene similar to that for the cation exchange resin. In the case of TnOA/benzene, the exchange process was presumed to resemble that of the anion exchange resin, judging from the similarity of ionic species extracted thereinto.