Degradation of Phthalate Esters in the Environment

Abstract

This chapter reviews the degradation data that are appropriate for modeling the environmental concentration of phthalate diesters. The necessary data are the first-order rates of primary degradation in air, water, and soil. The predominant fate of PDEs is biodegradation in wastewater, aerobic aquatic (water/sediment) environments, and soil. Anaerobic degradation may also play an important role for some phthalates under certain conditions. Of the abiotic processes, the rates of hydrolysis and direct photolysis are too low to have a significant influence on overall phthalate fate. On the other hand, indirect photolysis in air due to hydroxyl radical attack in both vapor phase and particle-sorbed phthalates may have a significant role in the overall environmental degradation of some phthalates. The literature data for these environmental degradation rates are evaluated with regard to their relevance to actual environmental conditions and recommendations are presented for the most likely degradation rates for specific phthalate diesters. The rates of further degradation of phthalate diester degradation products are also briefly discussed.