Görgényi Miklós, Dewulf Jo, Van Langenhove Herman, Király Zoltán
Institute of Physical Chemistry, University of Szeged, Rerrich B. tér 1, H-6723 Szeged, Hungary.
Chemosphere. 2005 May;59(8):1083-90. doi: 10.1016/j.chemosphere.2004.12.012.
The Ostwald solubility coefficient, L of 17 volatile organic compounds (VOCs) from the gas phase into water and dilute aqueous ammonia solutions was determined by the equilibrium partitioning in closed system-solid phase micro extraction (EPICS-SPME) method at 303 K and at 0-2.5 mol dm(-3) ammonia concentrations. Ammonia increased the solubility of all VOCs nearly linearly, but to a different extent. The difference in the solubility values in aqueous ammonia solutions (Lmix) compared to pure water (L) is explained on the basis of a Linear Solvation Energy Relationship (LSER) equation made applicable for solvent mixtures, logLmix - logL = x((sNH3 - sH2O)pi2H + (aNH3 - aH2O)Sigma2H + (bNH3 - bH2O)Sigmabeta2H + (vNH3 - VH2O)Vx). sNH3 - sH2O, aNH3 - aH2O, bNH3 - bH2O, vNH3 - vH2O are the differences of solvent parameters, x is the mole fraction, pi2H is the solute dipolarity-polarizability, Sigmaalpha2H is the effective hydrogen bond acidity of the solute, Sigmabeta2H is the effective hydrogen bond basicity of the solute and Vx, the McGowan characteristic volume. The most significant term was v, the phase hydrophobicity. The solubility behavior was explained by the change in structure of the aqueous solution: the presence of ammonia reduces the cavity effect. These findings show that the presence of compounds such as ammonia, frequently observed in environmental waters, especially wastewaters, affect the fugacity of VOCs, having consequences for the environmental partitioning of VOCs and having technical consequences towards wastewater treatment technologies.
采用封闭体系-固相微萃取平衡分配法（EPICS-SPME），在303 K以及氨浓度为0 - 2.5 mol dm⁻³的条件下，测定了17种挥发性有机化合物（VOCs）从气相到水和稀氨水溶液中的奥斯特瓦尔德溶解度系数L。氨几乎呈线性增加了所有VOCs的溶解度，但程度不同。根据适用于溶剂混合物的线性溶剂化能关系（LSER）方程，解释了氨水溶液（Lmix）与纯水（L）中溶解度值的差异，即logLmix - logL = x((sNH₃ - sH₂O)π₂H + (aNH₃ - aH₂O)Σα₂H + (bNH₃ - bH₂O)Σβ₂H + (vNH₃ - vH₂O)Vx)。sNH₃ - sH₂O、aNH₃ - aH₂O、bNH₃ - bH₂O、vNH₃ - vH₂O是溶剂参数的差异，x是摩尔分数，π₂H是溶质的偶极矩-极化率，Σα₂H是溶质的有效氢键酸度，Σβ₂H是溶质的有效氢键碱度，Vx是麦高恩特征体积。最显著的项是v，即相疏水性。通过水溶液结构的变化解释了溶解度行为：氨的存在降低了空穴效应。这些发现表明，在环境水体尤其是废水中经常观察到的氨等化合物的存在，会影响VOCs的逸度，对VOCs的环境分配产生影响，并对废水处理技术产生技术影响。
