The characteristics of estrogens during the recovery of nitrogen and phosphorus from urine by struvite precipitation

Abundant of estrogens is excreted via human urine, bringing the risk of micro-pollution during nutrients recovery from urine. This study investigated the characteristics of estrogens during the ammonification of urine, and then experiments were conducted to study the adsorption of estrogens on struvite, a potential product to recover nutrients from urine. The results showed that no 17a ethinylestradiol could be detected in the urine samples while the concentration of estrone, 17β-estradiol, 17α-estradiol and estriol was 64.2, 2.9, 4.4 and 1.8 ng/L, respectively. Estrone decreased to 1.3 ng/L while 17β-estradiol, 17α-estradiol and estriol decreased to undetected values on the 61
^st
day of ammonification. No obvious adsorption of estrone, 17β-estradiol, 17α-estradiol and estriol was observed through comparing the changes of estrogens before and after struvite precipitation. This supports the nutrients recovery from urine by struvite precipitation.