The research on pursuing of estrogens in the coast urban area and development of its reduction technique.

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The conservation of the coastal environment is a duty for us, so that it is necessary to carry out understanding of the actual impact of estrogens such as 17β-estradiol (E2) and estrone (El) to coastal environment with human activity. On the assumption of the process for coagulation and coprecipitation in the estuary mixing river water contained estrogens, the behavior of E2 was examined by mixing experiments using urban river water and seawater. E2 in river water will diffuse into the coastal area by mixing and diffusion effects of seawater.Since natural estrogens such as E2 and El are excreted daily by humans, E2 and El are always present in sewage wastewater. In this study, the fate of E2 and El as a result of adsorption and decomposition in batch mixing experiments using municipal wastewater and activated sludge collected from an actual municipal sewage treatment plant was investigated. E2 and El in sewage were removed from the liquid phase in contact with activated sludge, and E2 and El adsorbed on the sludge were decomposed in 4 hours. Natural estrogens adsorb onto the activated sludge, and are therefore easy to biodegrade. In addition, the behavior of the highly potential endocrine disrupters E2 and El was investigated in an air-fluidized-bed biofilm reactor system for advanced sewage treatment. The removal of nitrogen as advanced sewage treatment was achieved by the system. However, the removal efficiencies of E2 and El in the biological process were less than 70% and 40%, respectively. Although the system successfully achieved advanced treatment, the removal efficiency of natural estrogens was lower than that for a conventional activated sludge plant. The advanced treatment of municipal sewage must be promoted to improve the aquatic environment, while it is necessary to take into account the fate of estrogens in the process.