Effect of electron beam irradiation on estrogens removal from treated wastewater

In order to remove micro pollutants such as estrogens efficiently from wastewater, it is often recommended that conventional wastewater treatment plants (WWTP) be retrofitted with an advanced oxidation process (AOP) for post-treatment purposes. This study examined the effects of electron beam (EB) absorbed dose on the removal of estrogens from biologically treated wastewater. Known concentrations of E1, E2, E3 and EE2 (0.2, 0.5, 5.0 and 10 µg/l) were spiked into samples obtained from a municipal wastewater plant, which were then irradiated with EB doses of 0.2, 2.0, 5.0 and 10.0 kGy. Levels of estrogen after irradiation were analyzed using the liquid-chromatography mass-spectrometry (LC-MS). According to the results obtained, the concentration of estrogens decreased steadily with an increasing absorbed dose up to 2 kGy. However, there was no significant increase in estrogen removal at EB doses above 2 kGy. It is estimated that the removals of the different types of estrogen are ranged from 86 % to 99 %. E2 was found to be the fastest estrogen to be degraded, followed by E3, EE2, and E1.