Predicting the Solubility of Nonelectrolyte Solids Using a Combination of Molecular Simulation with the Solubility Parameter Method MOSCED: Application to the Wastewater Contaminants Monuron, Diuron, Atrazine and Atenolol

Gabriel Gonçalves Nogueira,Jeremy Phifer,Elizabeth O’Loughlin,Ryan Ley,Larissa Ferreira Da Silva,Thomas Nguyen,Spencer Sabatino,Ana Pereira Barbosa,Hrithik Agarwal,Andrew Paluch,Brett Rygelski,Rachel Ollier

doi:10.3390/pr10030538

Abstract

Methods to predict the equilibrium solubility of nonelectrolyte solids are indispensable for early-stage process development, design, and feasibility studies. Conventional analytic methods typically require reference data to regress parameters, which may not be available or limited for novel systems. Molecular simulation is a promising alternative, but is computationally intensive. Here, we demonstrate the ability to use a small number of molecular simulation free energy calculations to generate reference data to regress model parameters for the analytical MOSCED (modified separation of cohesive energy density) model. The result is an efficient analytical method to predict the equilibrium solubility of nonelectrolyte solids. The method is demonstrated for the wastewater contaminants monuron, diuron, atrazine and atenolol. Predictions for monuron, diuron and atrazine are in reasonable agreement with MOSCED parameters regressed using experimental solubility data. Predictions for atenolol are inferior, suggesting a potential limitation in the adopted molecular models, or the solvents selected to generate the necessary reference data.

Highlights

The ability to predict the equilibrium solubility of nonelectrolyte solids is important for a wide range of chemical, biological, and environmental processes
In the present study we are concerned with the ability to predict the equilibrium solubility of nonelectrolyte solids
Given the importance of being able to predict the equilibrium solubility of nonelectrolyte solids, significant work has been done in this area

Summary

Introduction

The ability to predict the equilibrium solubility of nonelectrolyte solids is important for a wide range of chemical, biological, and environmental processes. We consider the environmental contaminants monuron, diuron, atrazine, and atenolol (see Figure 1). The herbicides monuron, diuron and atrazine make their way into surface- and ground-water sources typically as agricultural runoff. Their toxicity is known, their low concentration makes removal and treatment problematic [1–3]. Atenolol is a commonly prescribed cardio-selective beta-blocker which is unable to be metabolized by the human body. Approximately half of the administered dose enters wastewater streams [4–6]. Conventional wastewater treatments plants are not designed to remove these contaminates as their concentration is typically considered low, and below toxic exposure levels.

Methods

Results

Conclusion