Assessment of the Efficacy of an Advanced Tertiary Treatment Plant to Remove Endocrine Active Chemicals from Sewage Effluent using Bioassays and Chemical Analysis

摘要

With increasing pressure of drought on water resources in Australia, the use of alternative sources such as treated sewage effluents must be evaluated to meet the demand. There are strong public concerns that need to be addressed, particularly the efficacy of sewage treatment plants (STPs) to remove endocrine disrupting chemicals (EDCs). The Gerringong Gerroa STP uses advanced tertiary treatment technologies including biologically activated sludge treatment, sand filtration, ozonation, BAC filtration, microfiltration and finally UV disinfection. The level of treatment provides a final effluent that exceeds agricultural quality guidelines and it is currently being used for this purpose. As an STP that mainly treats domestic effluent, human hormones, Pharmaceuticals and household chemicals are the most likely sources of EDCs. This research investigated the changes in estrogenicity of the effluent after each treatment stage. Effluent samples were taken from eight stages during the treatment process and extracted using solid phase extraction (SPE). The potential of endocrine disruption was evaluated using an Estrogen Receptor Binding Assay (ERBA) and chemical analysis was used to quantify the presence of suspected EDCs. The total estrogenicity of the effluent was successfully decreased to below quantification limits of the ERBA after ozonation and BAC filtration and stayed below detection limits during further treatment, including after storage in an open dam. The chemical composition of the estrogenic agents will also be discussed.