The present invention in one embodiment, is a process that uses a chemical treatment to remove arsenic, organic acids, and heavy metals from antifreeze solutions. In one aspect such a method includes adding an iron salt, to an antifreeze solution containing arsenic and heavy metals with adequate mixing for dispersion throughout the solution. Then, a base is added to increase the pH to a level from about 8 to 10. As the base is added, a precipitate forms and is then removed by standard filtration techniques. The arsenic, organic acids, and heavy metals co-precipitate with the iron and are removed by filtration. The process may either be a batch process or a continuous process.