They are partially removed during typical wastewater treatment but the extent of removal varies from plant to plant and among different estrogenic species. This increase may be related to strong sorption of estrogens on biosolids present in a treatment reactor with a potential of a hundred-fold increase in process efficiency. Even if a fraction of this potential could be realized, estrogen removal would be greatly enhanced. Evaluation of biostability of drinking water A method for evaluating drinking water biostability is being developed which is based on measurements of growth rates of attached bacterial cells. The cells originate from tested water and are allowed to attach and grow on the surface of a test coupon under uniform mass transfer conditions.
Current focus is on investigation of bacterial cell detachment due to starvation.
Treatment effects on drinking water biostability Drinking water biostability is assessed by measuring its ability to support bacterial growth. Regrowth of bacteria in water distribution systems was identified as a major source of microbial contamination. Bacterial regrowth is supported by minute quantities of biodegradable matter. Measurements of bacterial growth potential are accomplished with a newly developed method based on growth of attached indigenous bacteria. The method is used to evaluate treatment effects of ozonation, biological filtration, coagulation, and membrane filtration in two large water utilities.