Removal of impurities from scandium chloride solution using 732-type resin

The deep removal of Al, Fe(Ⅱ/Ⅲ), Ca, Zr, Ti and Si from scandium chloride solution was carried out by using 732-type strong acid cation exchange resin. The effects of pH value, contact time and complexing agents(EDTA) on the purification process are investigated. The results indicate that the 732-type resin have a good scandium selectivity and the adsorption order is Sc Fe(Ⅲ)Al Ca Zr Ti Si in the pH range of 1-3. The separation of Sc and Zr, Si, Ti can be directly carried out because the resin have a good adsorption effect on Sc, AI and Fe(Ⅲ) but poor adsorption effect on Zr, Si and Ti under the condition of pH = 2.5 and contact time 180 min. The Fe(Ⅱ), Ca and Al are selectively adsorbed on the resin by adding reducing agent ascorbic acid and EDTA into the solution for reducing Fe(Ⅲ) to Fe(Ⅱ) and complexing Sc.By using two-step ion exchange adsorption separation method, the removal rates of Fe(Ⅲ), Ti, Al, Ca, Zr and Si are 95.5%,99.8%,100%,98.2%,98.6% and 100%,respectively.     

Adsorption and desorption properties of D151 resin for Ce(Ⅲ)

The present research is aimed at the development of D151 resin as an adsorbent that it can be used in the adsorption of Ce(Ⅲ) ions.The adsorption and desorption behaviors of Ce(Ⅲ) on D151 resin have been investigated by chemistry analysis.The influence of operational conditions such as contact time,initial concentration of Ce(Ⅲ),initial pH of solution and temperature on the adsorption of Ce(Ⅲ) had also been examined.The results show that the optimal adsorption condition of D151 for Ce(Ⅲ) was achieved at pH=6.50 in HAc-NaAc medium.The maximum uptake capacity of Ce(Ⅲ) was 392 mg/g resin at 298 K.The adsorption of Ce(Ⅲ) followed both the Langmuir isotherm and Freundlich isotherm,and the correlation coefficients had been evaluated.Even kinetics on the adsorption of Ce(Ⅲ) had been studied.The adsorption rate constant k298 K valued was 1.3×10-5 s-1.The calculation data of thermodynamic parameters which ΔS0 value of 91.34 and ΔH0 value of 7.07 kJ/mol indicate the endothermic nature of the adsorption process.While,a decrease of Gibb’s free energy(ΔG0) with increasing temperature indicated the spontaneous nature of the adsorption process.Finally,Ce(Ⅲ) could be eluted by using 0.5 mol/L HCl solution and the elution percentage was as high as 100%.Adsorption mechanism was also proposed for the adsorption of Ce(Ⅲ) ions onto D151 resin using infrared spectroscopy technique.     

钼酸铵溶液化学沉淀法和离子交换法除钒研究

对采用化学沉淀法、运用A,B两种强碱性阴离子树脂交换法,从钼酸铵溶液中分离除钒的工艺条件进行了研究。研究结果表明:控制溶液pH值在8～9时,钒主要以VO 3-状态存在,沉钒效率高,偏钒酸铵沉淀纯度也高,达98.5%以上。A树脂能够深度分离钼酸铵溶液中的钒,最佳工艺条件是:控制料液pH值在7.28左右和降低Cl-浓度。Cl-与A树脂有较强的亲和力,其浓度的增加会显著降低A树脂对钒的吸附容量。在溶液pH值为7.28,几乎不含Cl-的条件下,A树脂饱和吸钒容量达到了21.73 g·L-1,此工艺可控制钼酸铵溶液中钒浓度在0.02 g·L-1以下。A树脂最高解析回收率达到98.68%,确保了钼钒深度分离后钒的回收利用效果。B树脂能够有效回收A树脂解析液中的钒和钼,其吸钒容量达到26.22 g·L-1,吸钼容量达到了71.06 g·L-1。B树脂为A树脂的优化树脂,其饱和吸附容量大于A树脂的饱和吸附容量。     

氢化物发生-原子荧光光谱法测定精碲中微量砷

提出了一种氢化物发生-原子荧光光谱法测定精碲中微量砷的方法。用硝酸溶解样品,氢氧化钾和盐酸调节溶液酸度至pH 5.5~6.5,碲水解沉淀析出。除去了大量基体后,溶液中碲量少于50μg/mL。在盐酸介质中用硫脲-抗坏血酸将砷(预还原为砷(Ⅲ),以标准加入法绘制校准曲线,氢化物发生-原子荧光光谱法测定砷量。方法的检出限为0.02μg/L,砷量在0.02~40μg/L范围内有良好的线性关系。方法操作简便、快速,应用于精碲中痕量砷的测定,测定结果与正戊醇萃取砷钼蓝分光光度法的结果相符,相对标准偏差为4.2%~8.5%,样品的加标回收率在93%~104%之间。     

Modeling Arsenite Adsorption on Rusting Metallic Iron

Experimental data on As(III) adsorption by rusted zero valent iron (ZVI) could be modeled using a simple Langmuir isotherm model. However, the adsorption equilibrium was observed to shift with time, as continued rusting produced additional sites on the rusted ZVI surface for potential arsenic adsorption. A modified Langmuir isotherm model was formulated taking into consideration the temporal variation in the site concentration for potential arsenic adsorption on the rusted ZVI surface. This model simulated the long-term experimental data on As(III) adsorption quite well. The model was further refined by apportioning the arsenic adsorbed on the rusted ZVI surface into labile and irreversibly adsorbed fractions. Finally, the developed model was used to simulate the performance of an adsorption column. The simulation results indicate that an adsorption column of length 0.4 m and diameter 0.056 m, i.e., containing 0.001?m3 of rusted ZVI weighing 4.76 kg, and operated at an empty bed contact time of 12 min, can treat 2,375–2,525 L of water containing 100?μg?L?1 of As(III) such that the effluent As(III) concentration from the column is less than 10?μg?L?1.     

包覆型浸渍树脂在硫酸介质中吸附铟(Ⅲ)的机理

以P507为萃取剂,HZ818大孔吸附树脂为载体,聚乙烯醇为包覆材料,硼酸为交联剂,制备了包覆型P507浸渍树脂。通过饱和法和等摩尔系列法考察了包覆型P507浸渍树脂在硫酸介质中吸附铟(Ⅲ)的机理,并利用红外光谱对包覆前后浸渍树脂及包覆型P507浸渍树脂吸附铟(Ⅲ)后进行了表征分析。结果表明,包覆型P507浸渍树脂在硫酸介质中吸附铟(Ⅲ)的过程是阳离子交换和配位反应共同作用的结果。     

Factors Influencing Arsenite Removal by Zero-Valent Iron

The effects of pH, alkalinity, and mass transfer efficiency on the removal of arsenite [As(III)] by zero-valent iron (ZVI) were evaluated in this study. The optimum pH range for removal of As(III) was found to be between 7 and 8. As(III) removal varied with salinity, pH, alkalinity conditions, and As(III) concentration. Degradation of As(III) removal performance was observed only under conditions of high alkalinity and arsenic concentrations [alkalinity >10?g CaCO3/L and 2.9?mg/L As(III)]. A strong correlation between As(III) removal and increasing Reynolds number in batch testing suggests that mass transfer efficiency plays an important role in the removal of As(III) by ZVI. A diffusion-limited adsorption model was used to describe the removal of As(III) as the result of adsorption to precipitated iron oxides generated from ZVI corrosion. After an initial period of As(III) rapid adsorption to surface rusts formed during manufacturing and exposure to air, As(III) removal rate is most likely controlled by the rate of iron corrosion and the diffusion of As(III) to adsorption sites in ZVI/iron oxides.     

D302-Ⅱ树脂吸附铼的性能研究及应用

针对地浸采铀浸出液低含量铼的回收,研究了D302-Ⅱ弱碱性阴离子交换树脂吸附和解吸铼的性能和机制。通过静态试验考察温度、酸度、时间对树脂吸附的影响;通过动态试验考察了溶液酸度和流速的影响,并进行了解吸剂及其浓度影响试验、抗干扰试验及树脂再生的试验;用地浸采铀浸出液通过D302-Ⅱ树脂,进行模拟回收铼试验。结果表明,D302-Ⅱ树脂对铼的吸附速率快,吸附反应速率常数k=1.6×10-3s-1,半交换期t1/2=433 s。吸附酸度在pH 2.0～5.0范围内,有利于铼的吸附。吸附平衡服从Freundish吸附等温式,吸附反应放热,反应可在常温下进行。动态上柱酸度选择为pH 2.0～5.0,流速1～2 ml.min-1,铼的吸附率可达95%以上;洗脱液选择NH4OH,25倍树脂床体积的3 mol.L-1NH4OH溶液可将铼洗脱完全。地浸采铀浸出液中的共存离子不影响铼的吸附和解吸,0.5 mol.L-1H2SO4溶液可使树脂再生。树脂对铼的静态和动态吸附容量分别为166和162 mg.g-1干树脂,对浓度低至0.03 mg.L-1铼溶液吸附和解吸,回收率可达96%～102%,表明该树脂有较好的应用前景。     

固定化芽孢对铽离子的吸附特性

微生物吸附法作为一种高效、廉价、环境友好的生物技术,已在稀土离子分离回收中逐渐被开发利用。实验通过固定化微生物技术,使用海藻酸钠包埋活性炭与枯草芽孢杆菌芽孢制备成固定化颗粒,处理含稀土离子的废水。对比了固定化芽孢加活性炭、固定化芽孢以及固定化活性炭对铽离子的吸附效果,并探究了不同条件对几种固定化吸附剂吸附铽离子的影响。结果表明:固定化芽孢加活性炭兼具包埋法与吸附法的优点,对铽离子的吸附效果更好; 在包炭量为1:100(活性炭质量:溶液总质量)、芽孢悬液浓度为OD₆₀₀(菌液在600 nm波长处的吸光值)=2、铽离子浓度为100 μmol/L、温度为15~25 ℃、pH=4.5~8.5的条件下吸附60 min,铽去除率可达90%以上。固定化芽孢加活性炭对铽离子的吸附更符合准一级动力学、Langmuir吸附等温线模型。      

某螯合树脂对钒(Ⅳ)离子的吸附行为研究

研究了某螯合树脂A对钒(Ⅳ)离子的吸附行为,考察了pH值、树脂用量、反应时间、反应温度、钒标准溶液浓度对静态吸附效果的影响。实验结果表明,在pH=4、树脂用量1.0g、反应时间4h、温度60℃条件下,螯合树脂A对钒(Ⅳ)的吸附量为184.2mg/g。对螯合树脂A的解吸、共存阳离子的影响等进行了分析。     

粉煤灰处理含钼废水的效果及吸附机理研究

利用粉煤灰对模拟的含钼废水进行除钼吸附实验,分别研究了吸附过程中溶液pH值、吸附剂投加量对吸附效果的影响,并对吸附等温方程及动力学进行了探讨。结果表明,在吸附质钼初始浓度为10mg/L、pH=3.1条件下,粉煤灰对钼的吸附效果最好,除钼率为74.3%;对于50mL的含钼溶液,当吸附剂投加量为2.5g时除钼率达到最高值85.4%。粉煤灰对钼的吸附符合Langmuir吸附等温方程,以表面单分子层吸附为主;吸附过程符合二阶动力学模型,同时具有物理吸附和化学吸附的特征。     

Adsorption of erbium(Ⅲ) on D113-Ⅲ resin from aqueous solutions: batch and column studies

The adsorption and desorption behaviors of Er(Ⅲ) ion on D113-Ⅲ resin were investigated.Batch adsorption studies were carried out with various Er(Ⅲ) ion concentrations,pH,contact time and temperature,indicating that D113-Ⅲ resin could adsorb Er(Ⅲ) ion effectively from aqueous solution.The loading of Er(Ⅲ) ion onto D113-Ⅲ resin increased with increasing the initial concentration.The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.45 to 6.75.In the batch s...     

阴离子交换树脂相分光光度法测定铝合金中痕量铜

建立了以Dowex 1×2型阴离子交换树脂为吸附相,在pH值为8.0、非离子表面活性剂存在下,铜与铜试剂、乳化剂OP三元络合体系测定铜含量的分光光度法。通过试验确定了Dowex 1×2型阴离子树脂用量为0.30 mL、显色剂用量为2.0 mL、乳化剂OP溶液用量为1.0 mL、最佳吸附时间为25 min、最大吸收波长为437 nm。常见共存离子不干扰铜的测定,Fe³⁺、Co²⁺、Ni²⁺对显色体系的干扰,可加入5 mL 50.0 g/L EDTA-200.0 g/L TAC混合掩蔽剂掩蔽。Cu浓度在4.0～50.0 μg/mL范围内符合比尔定律,线性回归方程为A=0.279 0ρ+0.062 7,相关系数r=0.999 3,表观摩尔吸光系数ε为1.79×10⁵ L·mol^-1·cm^-1。方法的检出限为0.063 mg/mL。对铝合金样品中痕量铜进行测定,相对标准偏差(n=6)为3.0%~7.9%,测定结果同原子吸收光谱法的结果一致。     

新型硅基季铵化功能材料对Pu(Ⅳ)的吸附行为研究

研究了硅基季铵化阴离子分离功能材料SiR4N与256×4吡啶型强碱性阴离子交换树脂在硝酸溶液中对Pu(Ⅳ)的吸附性能。结果表明:相同条件下,SiR4N对Pu(Ⅳ)的静态吸附速度比256×4树脂快;在钚、镅分离中,SiR4N的洗涤流出峰和对钚的解吸流出峰的半高宽比256×4树脂的小,表明其具有良好的分离选择性和传质动力性;穿透曲线显示,相同条件下,256×4树脂和SiR4N的交换区高度分别为294mm和165mm,工作交换容量分别为58mg/g和27mg/g;另外,SiR4N的耐辐照性能显著优于256×4树脂。     

Adsorption of erbium(III) on D113-III resin from aqueous solutions: batch and column studies

The adsorption and desorption behaviors of Er(III) ion on D113-III resin were investigated. Batch adsorption studies were carried out with various Er(III) ion concentrations, pH, contact time and temperature, indicating that D113-III resin could adsorb Er(III) ion effectively from aqueous solution. The loading of Er(III) ion onto D113-III resin increased with increasing the initial concentration. The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.45 to 6.75. In the batch system, the D113-III resin exhibited the highest Er(III) ion uptake as 250 mg/g at 298 K, at an initial pH value of 6.04, calculated from the Langmuir isotherm model. The adsorption kinetics was in agreement with Lagergren-first-order kinetics among the Lagergren-first-order model, pseudo-second-order model, liquid film diffusion model and intraparticle diffusion model. The adsorption data gave good fits with Langmuir isotherms. The thermodynamic parameters such as ΔG, which were all negative, indicated that the adsorption of Er(III) ion onto D113-III resin was spontaneous and the positive value of ΔH showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. Er(III) ion could be eluted by using the 4.0 mol/L HCl solution. The characterization of both before and after adsorption of Er(III) ion on D113-III resin was undertaken with IR spectroscopic technique. Moreover, the surface characterization of D113-III resin was described by scanning electron micrographs (SEM).     

钢渣负载纳米零价铁-羟基磷灰石(S-FH)的制备及其对锰的吸附性能

通过液相还原法制备钢渣负载纳米零价铁-羟基磷灰石（S-FH）。分析Fe0-HAP被负载前后的微观形貌,研究了pH、S-FH投加量、反应时间和锰的初始浓度对S-FH吸附锰的影响,并借助吸附动力学模型和吸附等温模型对吸附机理作进一步分析。结果表明,在锰溶液初始浓度5 mg/L、pH=5,S-FH用量0.1 g和反应时间300 min条件下,吸附效果最佳。S-FH对锰的吸附过程更符合Freundlich吸附等温线模型（R2>0.98）和准二级动力学模型（R2>0.99）。吸附机理为离子交换、表面络合和溶解-沉淀。     

Arsenic(III) Adsorption by Mixed-Oxide-Coated Sand: Kinetic Modeling and Desorption Studies

A media developed in the laboratory by applying a coating of iron and manganese to a quartz sand surface, known as mixed-oxide-coated sand (MOCS) is tested in this paper for arsenic(III) adsorption from water. The media has shown alkali resistance. Scanning electron microscope (SEM) images of MOCS have shown uneven and chapped morphology throughout the coated sand surfaces, whereas images of plane quartz sand are flat. The pattern of X-ray diffractograms of plane sand, MOCS, and arsenic-loaded MOCS are similar. The MOCS has an XRD pattern like typical crystalline material. The Langmuir and Freundlich isotherm equations could be used to describe the partitioning behavior of systems at different pH and media doses. Studies on pH effect have shown maximum As(III) removal near neutral pH. The batch kinetic studies data were tested using active available site (AAS) and chemical reaction rate models. The rate constants, equilibrium sorption capacity, and normalized standard deviations were calculated for all models. The tested models almost accurately predict the sorption capacity with respect to time for the whole range of data points. However, sorption kinetic data were better correlated using an AAS equation model based on normalized standard deviation. The results of desorption studies using different regenerants show that 0.2?M NaOH has high desorption efficiency compared with other regenerants for desorption of As(III) from MOCS. The impact of pH on desorption of arsenic(III) was also studied, and results have shown that high pH values show a significant reduction in quantity of arsenic(III) as compared with lower pH values. At pH 11.1, the percentage of arsenic extraction was highest from MOCS media.     

离子交换树脂分离富集-分光光度法测定铜金精矿及尾矿中银

研究了732型阳离子交换树脂柱分离富集银的条件,建立了光度法测定铜精矿、金精矿及其尾矿中银的方法。实验表明,在pH 2~4的条件下,样品溶液中的银与硫脲络合以［Ag(SCN₂H₄ )₃］⁺形式被树脂吸附后,采用10 mL 0.5 mol/L的硫代硫酸钠溶液可定量洗脱,从而消除了绝大部分共存离子的干扰;树脂柱分离-富集后,硫代米蚩酮光度法测定银的检出限为5.0 μg/L。将本方法用于实际样品分析,测得结果与火焰原子吸收光谱法测定值一致,相对标准偏差(RSD,n=5)小于或等于14%,加标回收率为96%～102%。     

Dowex50W-X树脂吸附硫酸溶液中的锶

In this study, strontium adsorption from sulfuric acid solution by different Dowex 50W-X ion exchange resins was investigated. Among these resins, Dowex 50W-X8 resin showed the maximum sorption of strontium from the aqueous solutions. The effect of pH, contact time, mass of resin, temperature, and concentration of interfeting ions on strontium adsorption were evaluated to determine the optimum conditions of strontium sorption process. The kinetic models of sorption were analyzed using pseudo-first and pseudo-second order models. The results indicated that the pseudo-second order kinetic model was more appropriate than the other one. Moreover, the data obtained in this study were fitted into several sorption isotherm models and it was found that the Langmuir sorption isotherm shows the best fitting to the experimental data.     

钢渣负载羟基磷灰石复合材料对水溶液中铀的去除性能

采用溶胶—凝胶法制备出钢渣负载羟基磷灰石复合材料,并通过静态试验方法探讨pH、复合材料投加量、反应时间及铀初始浓度对复合材料吸附水溶液中U(Ⅵ)的影响。结果表明,复合材料对U(Ⅵ)具有较好的去除性能,在pH=4、投加量0.4g、反应时间120min的条件下,对初始浓度5mg/L的水溶液中U(Ⅵ)的去除接近完全,对应吸附量为1.25mg/g。复合材料对U(Ⅵ)的吸附过程为化学吸附,符合准二级动力学模型(R~2=0.996 9);Langmuir吸附等温线模型拟合(R~2=0.999 1)表明,吸附过程为吸附剂表面上的单层吸附;且通过R_L(R_L 0.063)的计算表明,复合材料对U(Ⅵ)的吸附极其接近不可逆吸附。