Removal of 17beta-estradiol and its metabolites from aquaculture wastewater using advanced oxidation processes

The freshwater eel industry is responsible for more than one billion dollars in production globally, and of that production, more than 95% comes from aquaculture. Though a commercially lucrative industry, eel aquaculture does have constraints - male eels mature to an average of 150 g whereas female eels mature to more than 500 g. Additionally, eels do not differentiate their sex until later in life and will generally develop into males in high density aquaculture settings. As a result, these variables constrain the current economic value of freshwater eel culture.

In order to combat these issues, natural estrogen (17beta-estradiol or E2) has been studied as a feed

supplement to increase growth and feminization in freshwater eels. NovaEel Inc., a Nova Scotian aquaculture company, has developed a natural estrogen supplemented feed for American eels. However, this feed regime results in the presence of estrogens such as E2, along with its metabolites: estrone (E1) and estriol (E3) in aquaculture waste streams. Endocrine disrupting compounds (EDCs) such as E2 are becoming emerging concerns for both human and aquatic life. As such, it is crucial to manage these waste streams properly and ensure that sufficient degradation of estrogens is achieved before wastewater is discharged into municipal waste streams and into the environment.

The objective of this research is to determine the most effective, commercially feasible and environmentally friendly option for the removal of estrogens from aquaculture wastewater. Our hypothesis is that UV/TiO2 photoelectrocatalysis will offer an effective and sustainable alternative to more readily available treatment technologies and will result in the formation of minimal estrogenic by-products.