污染物在弱基混合离子交换树脂上的积累机制
Sarah A Saslow1, Elsa A Cordova1, Nancy M Escobedo1
1Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland 99354, WA, USA.
Journal of hazardous materials
|August 2, 2023
概括
这项研究表明,弱基离子交换树脂有效地从地下水中去除六价 (Cr(VI)) 和,即使有放射性污染物. 硫酸盐的存在影响了去除效率,但共同复杂化增强了的捕获.
科学领域:
- 环境化学环境化学
- 水处理技术水处理技术
- 放射化学 放射化学是指辐射化学.
背景情况:
- 六价 (Cr(VI)) 是地下水中的有毒污染物.
- 放射性同位素如-129,和技术-99对环境构成重大风险.
- 离子交换 (IX) 树脂用于水处理中的污染物去除.
研究的目的:
- 评估使用ResinTech® SIR-700-HP (SIR-700) 离子交换树脂去除CrVI的机制.
- 评估树脂在存在放射性污染物 (-129,,-99) 和常见离子 (硫酸盐,) 的情况下的性能.
- 了解各种氧离子的竞争性相互作用和去除机制.
主要方法:
- 批量测试使用SIR-700树脂的酸硫酸和酸化物形式进行.
- 使用模拟的含有Cr6的地下水,-129,,-99,硫酸盐和.
- 固相特征技术被用来分析去除机制.
主要成果:
- 在模拟地下水中,SIR-700树脂实现了超过97%的Cr (VI) 和U (VI) 去除.
- 高硫酸盐度 (536 mg/L) 将Cr6和U6的去除率降低到80%以上,但与的共同复杂化改善了Cr6的去除.
- 通过与硫酸盐的离子交换和降解到Cr (III) (OH) 3发生了Cr (VI) 的去除; Tc (VII) O4和I (V) O3也经历了降解,去除偏好取决于降解潜力,几何和电荷密度.
结论:
- 弱基离子交换树脂SIR-700-HP在去除受污染的地下水中的Cr (VI) 和U (VI) 方面表现出高效.
- 硫酸盐离子与Cr (VI) 和U (VI) 竞争,但也可以通过复杂化促进U (VI) 的去除.
- 树脂有效地去除多种氧化离子污染物,包括放射性物种,基于它们的电化学和物理特性.
相关概念视频
Ion Exchange
622
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
622
Extraction: Advanced Methods
487
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is...
487
Analyte Adsorption and Distribution
699
In certain chromatographic separations, solutes transfer between the mobile phase and the stationary phase via sorption, which typically refers to the process of adsorption. For many chromatographic systems, the sorption process often depends on the polarity of the compounds—an expression of the overall dipole moment within the molecule. During the separation process, there is competition between the solute and solvent for adsorption to the stationary phase. Highly polar compounds and...
699
Drug Elimination by Renal Route: Tubular Reabsorption
3.5K
During the process of renal excretion, as the glomerular filtrate progresses to the distal convoluted tubule (DCT), drugs that are highly permeable, lipophilic, and nonionized undergo passive reabsorption from the tubular fluid into the surrounding peritubular capillaries. This reabsorption process restricts their elimination through the kidneys. However, the majority of drugs are either weak acids or weak bases, and their ionization level is dependent on pH. By altering the pH of urine, the...
3.5K
Affinity Chromatography
736
Affinity chromatography is a powerful technique extensively utilized for separating and purifying specific biomolecules from complex mixtures. It capitalizes on the highly selective binding between an analyte and its counterpart, such as antibody-antigen interactions. The counterpart is immobilized on the stationary phase, forming an affinity column. The stationary phase typically consists of solid support, such as agarose or porous glass beads, immobilizing the affinity ligand. The mobile...
736
Gravimetry: Inorganic And Organic Precipitating Agents
1.3K
In gravimetry, the precipitant is chosen carefully to obtain a pure solid that can be easily filtered. Common inorganic precipitants can be used to determine several cations and anions. In some cases, the formation of the same precipitate can be used to determine the cation and the anion. For example, the reaction of barium and chromate ions to give barium chromate is used to determine both barium and chromate. However, precipitates such as hydroxides, oxalates, and metal ammonium phosphates...
1.3K


