부산대학교 도서관

Groundwater is an important resource in Ireland which is under increasing risk from the burgeoning numbers of decentralized houses and their respective on-site treatment systems which discharge effluent to ground via a number of parallel percolation trenches. The three-dimensional performance of separate percolation areas have been intensively monitored to ascertain the attenuation of selected Endocrine Disruption Compounds (EDCs) from freely draining unsaturated subsoils receiving septic tank effluent and secondary treated effluent. The performance of secondary treatment and tertiary treatment horizontal subsurface flow reed beds was also studied with respect to EDC removal. The study showed that the development of a biomat across the percolation areas receiving secondary treated effluent was muted compared to the site receiving septic tank effluent on which the percolating effluent spread naturally by gravity over a much larger area. In general, the results showed the oestrogens (oestrone, oestrdiaol, ethynyloestradiol, and oestriol) percolating though the unsaturated subsoil were significantly degraded with depth down to very low values (