Removing Steroids from Contaminated Waters Using Radical Reactions

摘要

Among the most important pharmaceutical contaminants in wastewater are the estrogenic steroids steroids. As quantitative removal of steroidal activity can be difficult, radical-based advanced oxidation/reduction processes (AO/RPs) are gaining interest for augmenting traditional water treatments. In support of the application of AO/RPs we have determined rate constants for the reactions of three representative steroids with the oxidizing hydroxyl (OH) and sulfate (SO_4-) radicals. The fast OH rate constants for ethinylestradiol and estradiol suggest a common mechanism of initial radical addition to the common phenol ring, whereas the slower progesterone value is more consistent with hydrogen atom abstraction. The rate constants for SO_4- reaction with estradiol and progesterone are identical, indicating a common initial reaction, but the faster value for ethinylestradiol suggests significant initial oxidative reaction at the triple bond.