Research progress on the occurrence and behaviour of androgens in wastewater treatment plants

If steroid hormones produced from human and animal due to their metabolism and intake of pharmaceuticals are not completely removed in wastewater treatment plants (WWTPs), they are likely to contaminate the receiving water, thus having adverse impacts on the aquatic organisms. Among steroid hormones, the concentration of testosterone is 1~3 orders of magnitude higher than the concentration of estradiol. This paper summarized the studies on the occurrence of androgens in WWTPs. It is shown that primary treatments in municipal WWTPs rarely remove androgens; secondary treatments can remove 80%~100% of androgens, and the Anaerobic-Anoxic-Oxic process is the most effective technology; and the removal rate during tertiary treatments range from -66.7% to 70%. In addition, the new materials development and further research were also involved.