Removal of steroid hormones and personal care products in wastewater by chemical precipitation

The presence of steroid hormones and endocrine disrupting compounds (EDC) in theenvironment has been connected with the drop in semen quality in men and the number ofhem1aphrodite fish observed downstream wastewater treatment plants. EDC originating fromdown-the-drain chemicals can be reduced by mitigation options but the naturally occurringhormones must be removed though end-of-pipe treatment. In this study, coagulation andflocculation as well as these two techniques combined with sorption were applied to removeestrone, I 7P-estradiol and the synthetic hormone I7a-ethynylestradiol as well as thepreservatives methyl paraben, ethyl paraben, propyl paraben, butyl paraben and isobutylparaben from primary and secondary treated municipal wastewater. It was found thatcoagulation with both iron and aluminium together with an anionic flocculant successfullyremoved organic matter and dissolved phosphorous but not the hormones and only up to 30%of the parabens. This was seen both in the chemical analyses of the individual substances andwell as in an assay of the oestrogenic effects. Applications of powdered activated carbon preand post the chemical coagulation-flocculation significantly increased the oestrogen removal,which is consistent with existing literature. The treatment processes in the studied wastewatertreatment plant removed both the oestrogens and the parabens to below the limit of detection ,though a detectable but small oestrogenicity in the effluent cannot be disregarded.