使用定量离子特性-活性关系 (QICAR) 模型来预测土壤中金属的固体-液体释放
Wanyang Shi1, Xuedong Wang1, Junxing Yang2
1College of Resource Environment and Tourism, Capital Normal University, Beijing 100048, China.
Journal of hazardous materials
|September 22, 2023
概括
这项研究开发了一种使用元素属性的土壤金属分区 (Kd) 的预测模型,减少了对耗时测量的需求. 该模型有助于评估来自溶解金属的土壤环境风险.
科学领域:
- 环境化学环境化学
- 地质化学 地质化学
- 土壤科学 土壤科学
背景情况:
- 土壤中溶解的金属由于易于被生物组织吸收而带来风险.
- 固体-液体分离系数 (Kd) 对于评估土壤金属环境风险至关重要.
- 传统的Kd测量是耗时且资源密集的.
研究的目的:
- 开发一种定量离子特性-活性关系 (s-QICAR) 模型,用于预测土壤金属Kd.
- 建立基于金属物理化学性质的预测模型,避免直接测量.
- 为土壤环境风险评估和管理提供基础.
主要方法:
- 从现有的文献中收集了102个土壤金属K数据.
- 开发了使用物理化学性质的定量离子特性-活性关系 (s-QICAR) 模型.
- 与十个元素属性相关的Kd (例如,共价键指数,第一个水解常数).
主要成果:
- 确定了10种与K显著相关的物理化学特性 (R2=0.5020.989).
- 建立了39个s-QICAR模型,包括使用共价键指数和第一水解常数的模型.
- 在39个土壤样本中成功预测了Mo,Sb和La的Kd值 (范围:2119978).
结论:
- 开发的s-QICAR模型提供了一种可靠的方法来预测土壤金属Kd.
- 模型性能根据所选择的独立变量 (例如,共价键指数,第一个水解常数) 变化.
- 这种预测方法支持有效的土壤环境风险评估和管理策略.
相关概念视频
Extraction: Advanced Methods
481
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...
481
Precipitation of Ions
28.0K
Predicting Precipitation
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
The equation that describes the equilibrium between solid calcium carbonate and its solvated ions is:
28.0K
Qualitative Analysis
22.4K
For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...
For instance, group IV...
22.4K
Ions as Acids and Bases
23.8K
Salts with Acidic Ions
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
Salts are ionic compounds composed of cations and anions, either of which may be capable of undergoing an acid or base ionization reaction with water. Aqueous salt solutions, therefore, may be acidic, basic, or neutral, depending on the relative acid-base strengths of the salt’s constituent ions. For example, dissolving the ammonium chloride in water results in its dissociation, as described by the equation:
23.8K
Factors Affecting Solubility
33.5K
Compared with pure water, the solubility of an ionic compound is less in aqueous solutions containing a common ion (one also produced by dissolution of the ionic compound). This is an example of a phenomenon known as the common ion effect, which is a consequence of the law of mass action that may be explained using Le Chȃtelier’s principle. Consider the dissolution of silver iodide:
33.5K
Precipitation and Co-precipitation
1.8K
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
1.8K


