O uso da cloração na remoção da atividade estrogênica do estrona

Abstract

Endocrine disrupters (EDs), are substances that even at low concentrations have the ability to imitate or block natural hormones, producing unwelcome responses or stimuli to human health. Among the EDs, the natural estrogen estrone (E1) has the highest daily excretion, about 3,9 μg/d for men and 8 μg/d for women. The outflow of the effluents, containing EDs, causes the contamination of sources of supply and reaching Water Treatment Plant (WTP). Within this context, the study analyzes chlorination (the most used method in the disinfection stage in WTP), with the purpose of removing the estrogenic activity caused by E1. Samples of water doped with 1 μg.L-1 of E1, were concentrated by the solid phase extraction method (SPE). The removal analysis was performed by YES test (Yeast Estrogen Screen), which the modified yeast Saccharomyces cerevisiae is used. When in contact with substances with estrogenic activity, the yeastmetabolizes the chromogenic compound chlorophenol red-β-D-galactopyranosin (CPRG) added in the test, changing the color from yellow to pink. As result, chlorination with 5 mg.L-1 at the contact time of 1 minute resulted in the best removal (98,0%) of the estrogenic activity. Being the strip of removal from 16.5 to 98.0%, for different contact times and doses of chlorine.